xref: /petsc/src/dm/impls/plex/plexcreate.c (revision 07e0ed13491ea33638e11d68f09133f82a23d344)
1 #define PETSCDM_DLL
2 #include <petsc/private/dmpleximpl.h> /*I   "petscdmplex.h"   I*/
3 #include <petsc/private/hashseti.h>   /*I   "petscdmplex.h"   I*/
4 #include <petscsf.h>
5 #include <petscdmplextransform.h>
6 #include <petscdmlabelephemeral.h>
7 #include <petsc/private/kernels/blockmatmult.h>
8 #include <petsc/private/kernels/blockinvert.h>
9 
10 PetscLogEvent DMPLEX_CreateFromFile, DMPLEX_CreateFromOptions, DMPLEX_BuildFromCellList, DMPLEX_BuildCoordinatesFromCellList;
11 
12 /* External function declarations here */
13 static PetscErrorCode DMInitialize_Plex(DM dm);
14 
15 /* This copies internal things in the Plex structure that we generally want when making a new, related Plex */
16 PetscErrorCode DMPlexCopy_Internal(DM dmin, PetscBool copyPeriodicity, PetscBool copyOverlap, DM dmout)
17 {
18   const PetscReal         *maxCell, *Lstart, *L;
19   VecType                  vecType;
20   MatType                  matType;
21   PetscBool                dist, useCeed;
22   DMPlexReorderDefaultFlag reorder;
23 
24   PetscFunctionBegin;
25   PetscCall(DMGetVecType(dmin, &vecType));
26   PetscCall(DMSetVecType(dmout, vecType));
27   PetscCall(DMGetMatType(dmin, &matType));
28   PetscCall(DMSetMatType(dmout, matType));
29   if (copyPeriodicity) {
30     PetscCall(DMGetPeriodicity(dmin, &maxCell, &Lstart, &L));
31     PetscCall(DMSetPeriodicity(dmout, maxCell, Lstart, L));
32   }
33   PetscCall(DMPlexDistributeGetDefault(dmin, &dist));
34   PetscCall(DMPlexDistributeSetDefault(dmout, dist));
35   PetscCall(DMPlexReorderGetDefault(dmin, &reorder));
36   PetscCall(DMPlexReorderSetDefault(dmout, reorder));
37   PetscCall(DMPlexGetUseCeed(dmin, &useCeed));
38   PetscCall(DMPlexSetUseCeed(dmout, useCeed));
39   ((DM_Plex *)dmout->data)->useHashLocation = ((DM_Plex *)dmin->data)->useHashLocation;
40   ((DM_Plex *)dmout->data)->printSetValues  = ((DM_Plex *)dmin->data)->printSetValues;
41   ((DM_Plex *)dmout->data)->printFEM        = ((DM_Plex *)dmin->data)->printFEM;
42   ((DM_Plex *)dmout->data)->printFVM        = ((DM_Plex *)dmin->data)->printFVM;
43   ((DM_Plex *)dmout->data)->printL2         = ((DM_Plex *)dmin->data)->printL2;
44   ((DM_Plex *)dmout->data)->printLocate     = ((DM_Plex *)dmin->data)->printLocate;
45   ((DM_Plex *)dmout->data)->printTol        = ((DM_Plex *)dmin->data)->printTol;
46   if (copyOverlap) PetscCall(DMPlexSetOverlap_Plex(dmout, dmin, 0));
47   PetscFunctionReturn(PETSC_SUCCESS);
48 }
49 
50 /* Replace dm with the contents of ndm, and then destroy ndm
51    - Share the DM_Plex structure
52    - Share the coordinates
53    - Share the SF
54 */
55 PetscErrorCode DMPlexReplace_Internal(DM dm, DM *ndm)
56 {
57   PetscSF          sf;
58   DM               dmNew = *ndm, coordDM, coarseDM;
59   Vec              coords;
60   const PetscReal *maxCell, *Lstart, *L;
61   PetscInt         dim, cdim;
62 
63   PetscFunctionBegin;
64   if (dm == dmNew) {
65     PetscCall(DMDestroy(ndm));
66     PetscFunctionReturn(PETSC_SUCCESS);
67   }
68   dm->setupcalled = dmNew->setupcalled;
69   PetscCall(DMGetDimension(dmNew, &dim));
70   PetscCall(DMSetDimension(dm, dim));
71   PetscCall(DMGetCoordinateDim(dmNew, &cdim));
72   PetscCall(DMSetCoordinateDim(dm, cdim));
73   PetscCall(DMGetPointSF(dmNew, &sf));
74   PetscCall(DMSetPointSF(dm, sf));
75   PetscCall(DMGetCoordinateDM(dmNew, &coordDM));
76   PetscCall(DMGetCoordinatesLocal(dmNew, &coords));
77   PetscCall(DMSetCoordinateDM(dm, coordDM));
78   PetscCall(DMSetCoordinatesLocal(dm, coords));
79   PetscCall(DMGetCellCoordinateDM(dmNew, &coordDM));
80   PetscCall(DMGetCellCoordinatesLocal(dmNew, &coords));
81   PetscCall(DMSetCellCoordinateDM(dm, coordDM));
82   PetscCall(DMSetCellCoordinatesLocal(dm, coords));
83   /* Do not want to create the coordinate field if it does not already exist, so do not call DMGetCoordinateField() */
84   PetscCall(DMFieldDestroy(&dm->coordinates[0].field));
85   dm->coordinates[0].field            = dmNew->coordinates[0].field;
86   ((DM_Plex *)dmNew->data)->coordFunc = ((DM_Plex *)dm->data)->coordFunc;
87   PetscCall(DMGetPeriodicity(dmNew, &maxCell, &Lstart, &L));
88   PetscCall(DMSetPeriodicity(dm, maxCell, Lstart, L));
89   PetscCall(DMPlexGetGlobalToNaturalSF(dmNew, &sf));
90   PetscCall(DMPlexSetGlobalToNaturalSF(dm, sf));
91   PetscCall(DMDestroy_Plex(dm));
92   PetscCall(DMInitialize_Plex(dm));
93   dm->data = dmNew->data;
94   ((DM_Plex *)dmNew->data)->refct++;
95   PetscCall(DMPlexGetIsoperiodicFaceSF(dm, &sf));
96   PetscCall(DMPlexSetIsoperiodicFaceSF(dm, sf)); // for the compose function effect on dm
97   PetscCall(DMDestroyLabelLinkList_Internal(dm));
98   PetscCall(DMCopyLabels(dmNew, dm, PETSC_OWN_POINTER, PETSC_TRUE, DM_COPY_LABELS_FAIL));
99   PetscCall(DMGetCoarseDM(dmNew, &coarseDM));
100   PetscCall(DMSetCoarseDM(dm, coarseDM));
101   PetscCall(DMDestroy(ndm));
102   PetscFunctionReturn(PETSC_SUCCESS);
103 }
104 
105 /* Swap dm with the contents of dmNew
106    - Swap the DM_Plex structure
107    - Swap the coordinates
108    - Swap the point PetscSF
109 */
110 static PetscErrorCode DMPlexSwap_Static(DM dmA, DM dmB)
111 {
112   DM          coordDMA, coordDMB;
113   Vec         coordsA, coordsB;
114   PetscSF     sfA, sfB;
115   DMField     fieldTmp;
116   void       *tmp;
117   DMLabelLink listTmp;
118   DMLabel     depthTmp;
119   PetscInt    tmpI;
120 
121   PetscFunctionBegin;
122   if (dmA == dmB) PetscFunctionReturn(PETSC_SUCCESS);
123   PetscCall(DMGetPointSF(dmA, &sfA));
124   PetscCall(DMGetPointSF(dmB, &sfB));
125   PetscCall(PetscObjectReference((PetscObject)sfA));
126   PetscCall(DMSetPointSF(dmA, sfB));
127   PetscCall(DMSetPointSF(dmB, sfA));
128   PetscCall(PetscObjectDereference((PetscObject)sfA));
129 
130   PetscCall(DMGetCoordinateDM(dmA, &coordDMA));
131   PetscCall(DMGetCoordinateDM(dmB, &coordDMB));
132   PetscCall(PetscObjectReference((PetscObject)coordDMA));
133   PetscCall(DMSetCoordinateDM(dmA, coordDMB));
134   PetscCall(DMSetCoordinateDM(dmB, coordDMA));
135   PetscCall(PetscObjectDereference((PetscObject)coordDMA));
136 
137   PetscCall(DMGetCoordinatesLocal(dmA, &coordsA));
138   PetscCall(DMGetCoordinatesLocal(dmB, &coordsB));
139   PetscCall(PetscObjectReference((PetscObject)coordsA));
140   PetscCall(DMSetCoordinatesLocal(dmA, coordsB));
141   PetscCall(DMSetCoordinatesLocal(dmB, coordsA));
142   PetscCall(PetscObjectDereference((PetscObject)coordsA));
143 
144   PetscCall(DMGetCellCoordinateDM(dmA, &coordDMA));
145   PetscCall(DMGetCellCoordinateDM(dmB, &coordDMB));
146   PetscCall(PetscObjectReference((PetscObject)coordDMA));
147   PetscCall(DMSetCellCoordinateDM(dmA, coordDMB));
148   PetscCall(DMSetCellCoordinateDM(dmB, coordDMA));
149   PetscCall(PetscObjectDereference((PetscObject)coordDMA));
150 
151   PetscCall(DMGetCellCoordinatesLocal(dmA, &coordsA));
152   PetscCall(DMGetCellCoordinatesLocal(dmB, &coordsB));
153   PetscCall(PetscObjectReference((PetscObject)coordsA));
154   PetscCall(DMSetCellCoordinatesLocal(dmA, coordsB));
155   PetscCall(DMSetCellCoordinatesLocal(dmB, coordsA));
156   PetscCall(PetscObjectDereference((PetscObject)coordsA));
157 
158   fieldTmp                  = dmA->coordinates[0].field;
159   dmA->coordinates[0].field = dmB->coordinates[0].field;
160   dmB->coordinates[0].field = fieldTmp;
161   fieldTmp                  = dmA->coordinates[1].field;
162   dmA->coordinates[1].field = dmB->coordinates[1].field;
163   dmB->coordinates[1].field = fieldTmp;
164   tmp                       = dmA->data;
165   dmA->data                 = dmB->data;
166   dmB->data                 = tmp;
167   listTmp                   = dmA->labels;
168   dmA->labels               = dmB->labels;
169   dmB->labels               = listTmp;
170   depthTmp                  = dmA->depthLabel;
171   dmA->depthLabel           = dmB->depthLabel;
172   dmB->depthLabel           = depthTmp;
173   depthTmp                  = dmA->celltypeLabel;
174   dmA->celltypeLabel        = dmB->celltypeLabel;
175   dmB->celltypeLabel        = depthTmp;
176   tmpI                      = dmA->levelup;
177   dmA->levelup              = dmB->levelup;
178   dmB->levelup              = tmpI;
179   PetscFunctionReturn(PETSC_SUCCESS);
180 }
181 
182 PetscErrorCode DMPlexInterpolateInPlace_Internal(DM dm)
183 {
184   DM idm;
185 
186   PetscFunctionBegin;
187   PetscCall(DMPlexInterpolate(dm, &idm));
188   PetscCall(DMPlexCopyCoordinates(dm, idm));
189   PetscCall(DMPlexReplace_Internal(dm, &idm));
190   PetscFunctionReturn(PETSC_SUCCESS);
191 }
192 
193 /*@C
194   DMPlexCreateCoordinateSpace - Creates a finite element space for the coordinates
195 
196   Collective
197 
198   Input Parameters:
199 + dm        - The `DMPLEX`
200 . degree    - The degree of the finite element or `PETSC_DECIDE`
201 . project   - Flag to project current coordinates into the space
202 - coordFunc - An optional function to map new points from refinement to the surface
203 
204   Level: advanced
205 
206 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `PetscPointFunc`, `PetscFECreateLagrange()`, `DMGetCoordinateDM()`
207 @*/
208 PetscErrorCode DMPlexCreateCoordinateSpace(DM dm, PetscInt degree, PetscBool project, PetscPointFunc coordFunc)
209 {
210   DM_Plex *mesh = (DM_Plex *)dm->data;
211   PetscFE  fe   = NULL;
212   DM       cdm;
213   PetscInt dim, dE, qorder, height;
214 
215   PetscFunctionBegin;
216   PetscCall(DMGetDimension(dm, &dim));
217   PetscCall(DMGetCoordinateDim(dm, &dE));
218   qorder = degree;
219   PetscCall(DMGetCoordinateDM(dm, &cdm));
220   PetscObjectOptionsBegin((PetscObject)cdm);
221   PetscCall(PetscOptionsBoundedInt("-default_quadrature_order", "Quadrature order is one less than quadrature points per edge", "DMPlexCreateCoordinateSpace", qorder, &qorder, NULL, 0));
222   PetscOptionsEnd();
223   PetscCall(DMPlexGetVTKCellHeight(dm, &height));
224   if (degree >= 0) {
225     DMPolytopeType ct = DM_POLYTOPE_UNKNOWN;
226     PetscInt       cStart, cEnd, gct;
227 
228     PetscCall(DMPlexGetHeightStratum(dm, height, &cStart, &cEnd));
229     if (cEnd > cStart) PetscCall(DMPlexGetCellType(dm, cStart, &ct));
230     gct = (PetscInt)ct;
231     PetscCall(MPIU_Allreduce(MPI_IN_PLACE, &gct, 1, MPIU_INT, MPI_MIN, PetscObjectComm((PetscObject)dm)));
232     ct = (DMPolytopeType)gct;
233     // Work around current bug in PetscDualSpaceSetUp_Lagrange()
234     //   Can be seen in plex_tutorials-ex10_1
235     if (ct != DM_POLYTOPE_SEG_PRISM_TENSOR && ct != DM_POLYTOPE_TRI_PRISM_TENSOR && ct != DM_POLYTOPE_QUAD_PRISM_TENSOR) PetscCall(PetscFECreateLagrangeByCell(PETSC_COMM_SELF, dim, dE, ct, degree, qorder, &fe));
236   }
237   PetscCall(DMSetCoordinateDisc(dm, fe, project));
238   PetscCall(PetscFEDestroy(&fe));
239   mesh->coordFunc = coordFunc;
240   PetscFunctionReturn(PETSC_SUCCESS);
241 }
242 
243 /*@
244   DMPlexCreateDoublet - Creates a mesh of two cells of the specified type, optionally with later refinement.
245 
246   Collective
247 
248   Input Parameters:
249 + comm            - The communicator for the `DM` object
250 . dim             - The spatial dimension
251 . simplex         - Flag for simplicial cells, otherwise they are tensor product cells
252 . interpolate     - Flag to create intermediate mesh pieces (edges, faces)
253 - refinementLimit - A nonzero number indicates the largest admissible volume for a refined cell
254 
255   Output Parameter:
256 . newdm - The `DM` object
257 
258   Level: beginner
259 
260 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMSetType()`, `DMCreate()`
261 @*/
262 PetscErrorCode DMPlexCreateDoublet(MPI_Comm comm, PetscInt dim, PetscBool simplex, PetscBool interpolate, PetscReal refinementLimit, DM *newdm)
263 {
264   DM          dm;
265   PetscMPIInt rank;
266 
267   PetscFunctionBegin;
268   PetscCall(DMCreate(comm, &dm));
269   PetscCall(DMSetType(dm, DMPLEX));
270   PetscCall(DMSetDimension(dm, dim));
271   PetscCall(PetscLogEventBegin(DMPLEX_Generate, dm, 0, 0, 0));
272   PetscCallMPI(MPI_Comm_rank(comm, &rank));
273   switch (dim) {
274   case 2:
275     if (simplex) PetscCall(PetscObjectSetName((PetscObject)dm, "triangular"));
276     else PetscCall(PetscObjectSetName((PetscObject)dm, "quadrilateral"));
277     break;
278   case 3:
279     if (simplex) PetscCall(PetscObjectSetName((PetscObject)dm, "tetrahedral"));
280     else PetscCall(PetscObjectSetName((PetscObject)dm, "hexahedral"));
281     break;
282   default:
283     SETERRQ(comm, PETSC_ERR_ARG_OUTOFRANGE, "Cannot make meshes for dimension %" PetscInt_FMT, dim);
284   }
285   if (rank) {
286     PetscInt numPoints[2] = {0, 0};
287     PetscCall(DMPlexCreateFromDAG(dm, 1, numPoints, NULL, NULL, NULL, NULL));
288   } else {
289     switch (dim) {
290     case 2:
291       if (simplex) {
292         PetscInt    numPoints[2]        = {4, 2};
293         PetscInt    coneSize[6]         = {3, 3, 0, 0, 0, 0};
294         PetscInt    cones[6]            = {2, 3, 4, 5, 4, 3};
295         PetscInt    coneOrientations[6] = {0, 0, 0, 0, 0, 0};
296         PetscScalar vertexCoords[8]     = {-0.5, 0.5, 0.0, 0.0, 0.0, 1.0, 0.5, 0.5};
297 
298         PetscCall(DMPlexCreateFromDAG(dm, 1, numPoints, coneSize, cones, coneOrientations, vertexCoords));
299       } else {
300         PetscInt    numPoints[2]        = {6, 2};
301         PetscInt    coneSize[8]         = {4, 4, 0, 0, 0, 0, 0, 0};
302         PetscInt    cones[8]            = {2, 3, 4, 5, 3, 6, 7, 4};
303         PetscInt    coneOrientations[8] = {0, 0, 0, 0, 0, 0, 0, 0};
304         PetscScalar vertexCoords[12]    = {-1.0, -0.5, 0.0, -0.5, 0.0, 0.5, -1.0, 0.5, 1.0, -0.5, 1.0, 0.5};
305 
306         PetscCall(DMPlexCreateFromDAG(dm, 1, numPoints, coneSize, cones, coneOrientations, vertexCoords));
307       }
308       break;
309     case 3:
310       if (simplex) {
311         PetscInt    numPoints[2]        = {5, 2};
312         PetscInt    coneSize[7]         = {4, 4, 0, 0, 0, 0, 0};
313         PetscInt    cones[8]            = {4, 3, 5, 2, 5, 3, 4, 6};
314         PetscInt    coneOrientations[8] = {0, 0, 0, 0, 0, 0, 0, 0};
315         PetscScalar vertexCoords[15]    = {-1.0, 0.0, 0.0, 0.0, -1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 0.0, 0.0};
316 
317         PetscCall(DMPlexCreateFromDAG(dm, 1, numPoints, coneSize, cones, coneOrientations, vertexCoords));
318       } else {
319         PetscInt    numPoints[2]         = {12, 2};
320         PetscInt    coneSize[14]         = {8, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
321         PetscInt    cones[16]            = {2, 3, 4, 5, 6, 7, 8, 9, 5, 4, 10, 11, 7, 12, 13, 8};
322         PetscInt    coneOrientations[16] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
323         PetscScalar vertexCoords[36]     = {-1.0, -0.5, -0.5, -1.0, 0.5, -0.5, 0.0, 0.5, -0.5, 0.0, -0.5, -0.5, -1.0, -0.5, 0.5, 0.0, -0.5, 0.5, 0.0, 0.5, 0.5, -1.0, 0.5, 0.5, 1.0, 0.5, -0.5, 1.0, -0.5, -0.5, 1.0, -0.5, 0.5, 1.0, 0.5, 0.5};
324 
325         PetscCall(DMPlexCreateFromDAG(dm, 1, numPoints, coneSize, cones, coneOrientations, vertexCoords));
326       }
327       break;
328     default:
329       SETERRQ(comm, PETSC_ERR_ARG_OUTOFRANGE, "Cannot make meshes for dimension %" PetscInt_FMT, dim);
330     }
331   }
332   PetscCall(PetscLogEventEnd(DMPLEX_Generate, dm, 0, 0, 0));
333   *newdm = dm;
334   if (refinementLimit > 0.0) {
335     DM          rdm;
336     const char *name;
337 
338     PetscCall(DMPlexSetRefinementUniform(*newdm, PETSC_FALSE));
339     PetscCall(DMPlexSetRefinementLimit(*newdm, refinementLimit));
340     PetscCall(DMRefine(*newdm, comm, &rdm));
341     PetscCall(PetscObjectGetName((PetscObject)*newdm, &name));
342     PetscCall(PetscObjectSetName((PetscObject)rdm, name));
343     PetscCall(DMDestroy(newdm));
344     *newdm = rdm;
345   }
346   if (interpolate) {
347     DM idm;
348 
349     PetscCall(DMPlexInterpolate(*newdm, &idm));
350     PetscCall(DMDestroy(newdm));
351     *newdm = idm;
352   }
353   PetscFunctionReturn(PETSC_SUCCESS);
354 }
355 
356 static PetscErrorCode DMPlexCreateBoxSurfaceMesh_Tensor_1D_Internal(DM dm, const PetscReal lower[], const PetscReal upper[], const PetscInt edges[])
357 {
358   const PetscInt numVertices    = 2;
359   PetscInt       markerRight    = 1;
360   PetscInt       markerLeft     = 1;
361   PetscBool      markerSeparate = PETSC_FALSE;
362   Vec            coordinates;
363   PetscSection   coordSection;
364   PetscScalar   *coords;
365   PetscInt       coordSize;
366   PetscMPIInt    rank;
367   PetscInt       cdim = 1, v;
368 
369   PetscFunctionBegin;
370   PetscCall(PetscOptionsGetBool(((PetscObject)dm)->options, ((PetscObject)dm)->prefix, "-dm_plex_separate_marker", &markerSeparate, NULL));
371   if (markerSeparate) {
372     markerRight = 2;
373     markerLeft  = 1;
374   }
375   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank));
376   if (rank == 0) {
377     PetscCall(DMPlexSetChart(dm, 0, numVertices));
378     PetscCall(DMSetUp(dm)); /* Allocate space for cones */
379     PetscCall(DMSetLabelValue(dm, "marker", 0, markerLeft));
380     PetscCall(DMSetLabelValue(dm, "marker", 1, markerRight));
381   }
382   PetscCall(DMPlexSymmetrize(dm));
383   PetscCall(DMPlexStratify(dm));
384   /* Build coordinates */
385   PetscCall(DMSetCoordinateDim(dm, cdim));
386   PetscCall(DMGetCoordinateSection(dm, &coordSection));
387   PetscCall(PetscSectionSetNumFields(coordSection, 1));
388   PetscCall(PetscSectionSetChart(coordSection, 0, numVertices));
389   PetscCall(PetscSectionSetFieldComponents(coordSection, 0, cdim));
390   for (v = 0; v < numVertices; ++v) {
391     PetscCall(PetscSectionSetDof(coordSection, v, cdim));
392     PetscCall(PetscSectionSetFieldDof(coordSection, v, 0, cdim));
393   }
394   PetscCall(PetscSectionSetUp(coordSection));
395   PetscCall(PetscSectionGetStorageSize(coordSection, &coordSize));
396   PetscCall(VecCreate(PETSC_COMM_SELF, &coordinates));
397   PetscCall(PetscObjectSetName((PetscObject)coordinates, "coordinates"));
398   PetscCall(VecSetSizes(coordinates, coordSize, PETSC_DETERMINE));
399   PetscCall(VecSetBlockSize(coordinates, cdim));
400   PetscCall(VecSetType(coordinates, VECSTANDARD));
401   PetscCall(VecGetArray(coordinates, &coords));
402   coords[0] = lower[0];
403   coords[1] = upper[0];
404   PetscCall(VecRestoreArray(coordinates, &coords));
405   PetscCall(DMSetCoordinatesLocal(dm, coordinates));
406   PetscCall(VecDestroy(&coordinates));
407   PetscFunctionReturn(PETSC_SUCCESS);
408 }
409 
410 static PetscErrorCode DMPlexCreateBoxSurfaceMesh_Tensor_2D_Internal(DM dm, const PetscReal lower[], const PetscReal upper[], const PetscInt edges[])
411 {
412   const PetscInt numVertices    = (edges[0] + 1) * (edges[1] + 1);
413   const PetscInt numEdges       = edges[0] * (edges[1] + 1) + (edges[0] + 1) * edges[1];
414   PetscInt       markerTop      = 1;
415   PetscInt       markerBottom   = 1;
416   PetscInt       markerRight    = 1;
417   PetscInt       markerLeft     = 1;
418   PetscBool      markerSeparate = PETSC_FALSE;
419   Vec            coordinates;
420   PetscSection   coordSection;
421   PetscScalar   *coords;
422   PetscInt       coordSize;
423   PetscMPIInt    rank;
424   PetscInt       v, vx, vy;
425 
426   PetscFunctionBegin;
427   PetscCall(PetscOptionsGetBool(((PetscObject)dm)->options, ((PetscObject)dm)->prefix, "-dm_plex_separate_marker", &markerSeparate, NULL));
428   if (markerSeparate) {
429     markerTop    = 3;
430     markerBottom = 1;
431     markerRight  = 2;
432     markerLeft   = 4;
433   }
434   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank));
435   if (rank == 0) {
436     PetscInt e, ex, ey;
437 
438     PetscCall(DMPlexSetChart(dm, 0, numEdges + numVertices));
439     for (e = 0; e < numEdges; ++e) PetscCall(DMPlexSetConeSize(dm, e, 2));
440     PetscCall(DMSetUp(dm)); /* Allocate space for cones */
441     for (vx = 0; vx <= edges[0]; vx++) {
442       for (ey = 0; ey < edges[1]; ey++) {
443         PetscInt edge   = vx * edges[1] + ey + edges[0] * (edges[1] + 1);
444         PetscInt vertex = ey * (edges[0] + 1) + vx + numEdges;
445         PetscInt cone[2];
446 
447         cone[0] = vertex;
448         cone[1] = vertex + edges[0] + 1;
449         PetscCall(DMPlexSetCone(dm, edge, cone));
450         if (vx == edges[0]) {
451           PetscCall(DMSetLabelValue(dm, "marker", edge, markerRight));
452           PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerRight));
453           if (ey == edges[1] - 1) {
454             PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerRight));
455             PetscCall(DMSetLabelValue(dm, "Face Sets", cone[1], markerRight));
456           }
457         } else if (vx == 0) {
458           PetscCall(DMSetLabelValue(dm, "marker", edge, markerLeft));
459           PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerLeft));
460           if (ey == edges[1] - 1) {
461             PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerLeft));
462             PetscCall(DMSetLabelValue(dm, "Face Sets", cone[1], markerLeft));
463           }
464         }
465       }
466     }
467     for (vy = 0; vy <= edges[1]; vy++) {
468       for (ex = 0; ex < edges[0]; ex++) {
469         PetscInt edge   = vy * edges[0] + ex;
470         PetscInt vertex = vy * (edges[0] + 1) + ex + numEdges;
471         PetscInt cone[2];
472 
473         cone[0] = vertex;
474         cone[1] = vertex + 1;
475         PetscCall(DMPlexSetCone(dm, edge, cone));
476         if (vy == edges[1]) {
477           PetscCall(DMSetLabelValue(dm, "marker", edge, markerTop));
478           PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerTop));
479           if (ex == edges[0] - 1) {
480             PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerTop));
481             PetscCall(DMSetLabelValue(dm, "Face Sets", cone[1], markerTop));
482           }
483         } else if (vy == 0) {
484           PetscCall(DMSetLabelValue(dm, "marker", edge, markerBottom));
485           PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerBottom));
486           if (ex == edges[0] - 1) {
487             PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerBottom));
488             PetscCall(DMSetLabelValue(dm, "Face Sets", cone[1], markerBottom));
489           }
490         }
491       }
492     }
493   }
494   PetscCall(DMPlexSymmetrize(dm));
495   PetscCall(DMPlexStratify(dm));
496   /* Build coordinates */
497   PetscCall(DMSetCoordinateDim(dm, 2));
498   PetscCall(DMGetCoordinateSection(dm, &coordSection));
499   PetscCall(PetscSectionSetNumFields(coordSection, 1));
500   PetscCall(PetscSectionSetChart(coordSection, numEdges, numEdges + numVertices));
501   PetscCall(PetscSectionSetFieldComponents(coordSection, 0, 2));
502   for (v = numEdges; v < numEdges + numVertices; ++v) {
503     PetscCall(PetscSectionSetDof(coordSection, v, 2));
504     PetscCall(PetscSectionSetFieldDof(coordSection, v, 0, 2));
505   }
506   PetscCall(PetscSectionSetUp(coordSection));
507   PetscCall(PetscSectionGetStorageSize(coordSection, &coordSize));
508   PetscCall(VecCreate(PETSC_COMM_SELF, &coordinates));
509   PetscCall(PetscObjectSetName((PetscObject)coordinates, "coordinates"));
510   PetscCall(VecSetSizes(coordinates, coordSize, PETSC_DETERMINE));
511   PetscCall(VecSetBlockSize(coordinates, 2));
512   PetscCall(VecSetType(coordinates, VECSTANDARD));
513   PetscCall(VecGetArray(coordinates, &coords));
514   for (vy = 0; vy <= edges[1]; ++vy) {
515     for (vx = 0; vx <= edges[0]; ++vx) {
516       coords[(vy * (edges[0] + 1) + vx) * 2 + 0] = lower[0] + ((upper[0] - lower[0]) / edges[0]) * vx;
517       coords[(vy * (edges[0] + 1) + vx) * 2 + 1] = lower[1] + ((upper[1] - lower[1]) / edges[1]) * vy;
518     }
519   }
520   PetscCall(VecRestoreArray(coordinates, &coords));
521   PetscCall(DMSetCoordinatesLocal(dm, coordinates));
522   PetscCall(VecDestroy(&coordinates));
523   PetscFunctionReturn(PETSC_SUCCESS);
524 }
525 
526 static PetscErrorCode DMPlexCreateBoxSurfaceMesh_Tensor_3D_Internal(DM dm, const PetscReal lower[], const PetscReal upper[], const PetscInt faces[])
527 {
528   PetscInt     vertices[3], numVertices;
529   PetscInt     numFaces       = 2 * faces[0] * faces[1] + 2 * faces[1] * faces[2] + 2 * faces[0] * faces[2];
530   PetscInt     markerTop      = 1;
531   PetscInt     markerBottom   = 1;
532   PetscInt     markerFront    = 1;
533   PetscInt     markerBack     = 1;
534   PetscInt     markerRight    = 1;
535   PetscInt     markerLeft     = 1;
536   PetscBool    markerSeparate = PETSC_FALSE;
537   Vec          coordinates;
538   PetscSection coordSection;
539   PetscScalar *coords;
540   PetscInt     coordSize;
541   PetscMPIInt  rank;
542   PetscInt     v, vx, vy, vz;
543   PetscInt     voffset, iface = 0, cone[4];
544 
545   PetscFunctionBegin;
546   PetscCheck(faces[0] >= 1 && faces[1] >= 1 && faces[2] >= 1, PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Must have at least 1 face per side");
547   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank));
548   PetscCall(PetscOptionsGetBool(((PetscObject)dm)->options, ((PetscObject)dm)->prefix, "-dm_plex_separate_marker", &markerSeparate, NULL));
549   if (markerSeparate) {
550     markerBottom = 1;
551     markerTop    = 2;
552     markerFront  = 3;
553     markerBack   = 4;
554     markerRight  = 5;
555     markerLeft   = 6;
556   }
557   vertices[0] = faces[0] + 1;
558   vertices[1] = faces[1] + 1;
559   vertices[2] = faces[2] + 1;
560   numVertices = vertices[0] * vertices[1] * vertices[2];
561   if (rank == 0) {
562     PetscInt f;
563 
564     PetscCall(DMPlexSetChart(dm, 0, numFaces + numVertices));
565     for (f = 0; f < numFaces; ++f) PetscCall(DMPlexSetConeSize(dm, f, 4));
566     PetscCall(DMSetUp(dm)); /* Allocate space for cones */
567 
568     /* Side 0 (Top) */
569     for (vy = 0; vy < faces[1]; vy++) {
570       for (vx = 0; vx < faces[0]; vx++) {
571         voffset = numFaces + vertices[0] * vertices[1] * (vertices[2] - 1) + vy * vertices[0] + vx;
572         cone[0] = voffset;
573         cone[1] = voffset + 1;
574         cone[2] = voffset + vertices[0] + 1;
575         cone[3] = voffset + vertices[0];
576         PetscCall(DMPlexSetCone(dm, iface, cone));
577         PetscCall(DMSetLabelValue(dm, "marker", iface, markerTop));
578         PetscCall(DMSetLabelValue(dm, "marker", voffset + 0, markerTop));
579         PetscCall(DMSetLabelValue(dm, "marker", voffset + 1, markerTop));
580         PetscCall(DMSetLabelValue(dm, "marker", voffset + vertices[0] + 0, markerTop));
581         PetscCall(DMSetLabelValue(dm, "marker", voffset + vertices[0] + 1, markerTop));
582         iface++;
583       }
584     }
585 
586     /* Side 1 (Bottom) */
587     for (vy = 0; vy < faces[1]; vy++) {
588       for (vx = 0; vx < faces[0]; vx++) {
589         voffset = numFaces + vy * (faces[0] + 1) + vx;
590         cone[0] = voffset + 1;
591         cone[1] = voffset;
592         cone[2] = voffset + vertices[0];
593         cone[3] = voffset + vertices[0] + 1;
594         PetscCall(DMPlexSetCone(dm, iface, cone));
595         PetscCall(DMSetLabelValue(dm, "marker", iface, markerBottom));
596         PetscCall(DMSetLabelValue(dm, "marker", voffset + 0, markerBottom));
597         PetscCall(DMSetLabelValue(dm, "marker", voffset + 1, markerBottom));
598         PetscCall(DMSetLabelValue(dm, "marker", voffset + vertices[0] + 0, markerBottom));
599         PetscCall(DMSetLabelValue(dm, "marker", voffset + vertices[0] + 1, markerBottom));
600         iface++;
601       }
602     }
603 
604     /* Side 2 (Front) */
605     for (vz = 0; vz < faces[2]; vz++) {
606       for (vx = 0; vx < faces[0]; vx++) {
607         voffset = numFaces + vz * vertices[0] * vertices[1] + vx;
608         cone[0] = voffset;
609         cone[1] = voffset + 1;
610         cone[2] = voffset + vertices[0] * vertices[1] + 1;
611         cone[3] = voffset + vertices[0] * vertices[1];
612         PetscCall(DMPlexSetCone(dm, iface, cone));
613         PetscCall(DMSetLabelValue(dm, "marker", iface, markerFront));
614         PetscCall(DMSetLabelValue(dm, "marker", voffset + 0, markerFront));
615         PetscCall(DMSetLabelValue(dm, "marker", voffset + 1, markerFront));
616         PetscCall(DMSetLabelValue(dm, "marker", voffset + vertices[0] * vertices[1] + 0, markerFront));
617         PetscCall(DMSetLabelValue(dm, "marker", voffset + vertices[0] * vertices[1] + 1, markerFront));
618         iface++;
619       }
620     }
621 
622     /* Side 3 (Back) */
623     for (vz = 0; vz < faces[2]; vz++) {
624       for (vx = 0; vx < faces[0]; vx++) {
625         voffset = numFaces + vz * vertices[0] * vertices[1] + vertices[0] * (vertices[1] - 1) + vx;
626         cone[0] = voffset + vertices[0] * vertices[1];
627         cone[1] = voffset + vertices[0] * vertices[1] + 1;
628         cone[2] = voffset + 1;
629         cone[3] = voffset;
630         PetscCall(DMPlexSetCone(dm, iface, cone));
631         PetscCall(DMSetLabelValue(dm, "marker", iface, markerBack));
632         PetscCall(DMSetLabelValue(dm, "marker", voffset + 0, markerBack));
633         PetscCall(DMSetLabelValue(dm, "marker", voffset + 1, markerBack));
634         PetscCall(DMSetLabelValue(dm, "marker", voffset + vertices[0] * vertices[1] + 0, markerBack));
635         PetscCall(DMSetLabelValue(dm, "marker", voffset + vertices[0] * vertices[1] + 1, markerBack));
636         iface++;
637       }
638     }
639 
640     /* Side 4 (Left) */
641     for (vz = 0; vz < faces[2]; vz++) {
642       for (vy = 0; vy < faces[1]; vy++) {
643         voffset = numFaces + vz * vertices[0] * vertices[1] + vy * vertices[0];
644         cone[0] = voffset;
645         cone[1] = voffset + vertices[0] * vertices[1];
646         cone[2] = voffset + vertices[0] * vertices[1] + vertices[0];
647         cone[3] = voffset + vertices[0];
648         PetscCall(DMPlexSetCone(dm, iface, cone));
649         PetscCall(DMSetLabelValue(dm, "marker", iface, markerLeft));
650         PetscCall(DMSetLabelValue(dm, "marker", voffset + 0, markerLeft));
651         PetscCall(DMSetLabelValue(dm, "marker", voffset + vertices[0] + 0, markerLeft));
652         PetscCall(DMSetLabelValue(dm, "marker", voffset + vertices[1] + 0, markerLeft));
653         PetscCall(DMSetLabelValue(dm, "marker", voffset + vertices[0] * vertices[1] + vertices[0], markerLeft));
654         iface++;
655       }
656     }
657 
658     /* Side 5 (Right) */
659     for (vz = 0; vz < faces[2]; vz++) {
660       for (vy = 0; vy < faces[1]; vy++) {
661         voffset = numFaces + vz * vertices[0] * vertices[1] + vy * vertices[0] + faces[0];
662         cone[0] = voffset + vertices[0] * vertices[1];
663         cone[1] = voffset;
664         cone[2] = voffset + vertices[0];
665         cone[3] = voffset + vertices[0] * vertices[1] + vertices[0];
666         PetscCall(DMPlexSetCone(dm, iface, cone));
667         PetscCall(DMSetLabelValue(dm, "marker", iface, markerRight));
668         PetscCall(DMSetLabelValue(dm, "marker", voffset + 0, markerRight));
669         PetscCall(DMSetLabelValue(dm, "marker", voffset + vertices[0] + 0, markerRight));
670         PetscCall(DMSetLabelValue(dm, "marker", voffset + vertices[0] * vertices[1] + 0, markerRight));
671         PetscCall(DMSetLabelValue(dm, "marker", voffset + vertices[0] * vertices[1] + vertices[0], markerRight));
672         iface++;
673       }
674     }
675   }
676   PetscCall(DMPlexSymmetrize(dm));
677   PetscCall(DMPlexStratify(dm));
678   /* Build coordinates */
679   PetscCall(DMSetCoordinateDim(dm, 3));
680   PetscCall(DMGetCoordinateSection(dm, &coordSection));
681   PetscCall(PetscSectionSetNumFields(coordSection, 1));
682   PetscCall(PetscSectionSetChart(coordSection, numFaces, numFaces + numVertices));
683   PetscCall(PetscSectionSetFieldComponents(coordSection, 0, 3));
684   for (v = numFaces; v < numFaces + numVertices; ++v) {
685     PetscCall(PetscSectionSetDof(coordSection, v, 3));
686     PetscCall(PetscSectionSetFieldDof(coordSection, v, 0, 3));
687   }
688   PetscCall(PetscSectionSetUp(coordSection));
689   PetscCall(PetscSectionGetStorageSize(coordSection, &coordSize));
690   PetscCall(VecCreate(PETSC_COMM_SELF, &coordinates));
691   PetscCall(PetscObjectSetName((PetscObject)coordinates, "coordinates"));
692   PetscCall(VecSetSizes(coordinates, coordSize, PETSC_DETERMINE));
693   PetscCall(VecSetBlockSize(coordinates, 3));
694   PetscCall(VecSetType(coordinates, VECSTANDARD));
695   PetscCall(VecGetArray(coordinates, &coords));
696   for (vz = 0; vz <= faces[2]; ++vz) {
697     for (vy = 0; vy <= faces[1]; ++vy) {
698       for (vx = 0; vx <= faces[0]; ++vx) {
699         coords[((vz * (faces[1] + 1) + vy) * (faces[0] + 1) + vx) * 3 + 0] = lower[0] + ((upper[0] - lower[0]) / faces[0]) * vx;
700         coords[((vz * (faces[1] + 1) + vy) * (faces[0] + 1) + vx) * 3 + 1] = lower[1] + ((upper[1] - lower[1]) / faces[1]) * vy;
701         coords[((vz * (faces[1] + 1) + vy) * (faces[0] + 1) + vx) * 3 + 2] = lower[2] + ((upper[2] - lower[2]) / faces[2]) * vz;
702       }
703     }
704   }
705   PetscCall(VecRestoreArray(coordinates, &coords));
706   PetscCall(DMSetCoordinatesLocal(dm, coordinates));
707   PetscCall(VecDestroy(&coordinates));
708   PetscFunctionReturn(PETSC_SUCCESS);
709 }
710 
711 static PetscErrorCode DMPlexCreateBoxSurfaceMesh_Internal(DM dm, PetscInt dim, const PetscInt faces[], const PetscReal lower[], const PetscReal upper[], PetscBool interpolate)
712 {
713   PetscFunctionBegin;
714   PetscValidLogicalCollectiveInt(dm, dim, 2);
715   PetscCall(PetscLogEventBegin(DMPLEX_Generate, dm, 0, 0, 0));
716   PetscCall(DMSetDimension(dm, dim - 1));
717   PetscCall(DMSetCoordinateDim(dm, dim));
718   switch (dim) {
719   case 1:
720     PetscCall(DMPlexCreateBoxSurfaceMesh_Tensor_1D_Internal(dm, lower, upper, faces));
721     break;
722   case 2:
723     PetscCall(DMPlexCreateBoxSurfaceMesh_Tensor_2D_Internal(dm, lower, upper, faces));
724     break;
725   case 3:
726     PetscCall(DMPlexCreateBoxSurfaceMesh_Tensor_3D_Internal(dm, lower, upper, faces));
727     break;
728   default:
729     SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Dimension not supported: %" PetscInt_FMT, dim);
730   }
731   PetscCall(PetscLogEventEnd(DMPLEX_Generate, dm, 0, 0, 0));
732   if (interpolate) PetscCall(DMPlexInterpolateInPlace_Internal(dm));
733   PetscFunctionReturn(PETSC_SUCCESS);
734 }
735 
736 /*@C
737   DMPlexCreateBoxSurfaceMesh - Creates a mesh on the surface of the tensor product of unit intervals (box) using tensor cells (hexahedra).
738 
739   Collective
740 
741   Input Parameters:
742 + comm        - The communicator for the `DM` object
743 . dim         - The spatial dimension of the box, so the resulting mesh is has dimension `dim`-1
744 . faces       - Number of faces per dimension, or `NULL` for (1,) in 1D and (2, 2) in 2D and (1, 1, 1) in 3D
745 . lower       - The lower left corner, or `NULL` for (0, 0, 0)
746 . upper       - The upper right corner, or `NULL` for (1, 1, 1)
747 - interpolate - Flag to create intermediate mesh pieces (edges, faces)
748 
749   Output Parameter:
750 . dm - The `DM` object
751 
752   Level: beginner
753 
754 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMSetFromOptions()`, `DMPlexCreateBoxMesh()`, `DMPlexCreateFromFile()`, `DMSetType()`, `DMCreate()`
755 @*/
756 PetscErrorCode DMPlexCreateBoxSurfaceMesh(MPI_Comm comm, PetscInt dim, const PetscInt faces[], const PetscReal lower[], const PetscReal upper[], PetscBool interpolate, DM *dm)
757 {
758   PetscInt  fac[3] = {1, 1, 1};
759   PetscReal low[3] = {0, 0, 0};
760   PetscReal upp[3] = {1, 1, 1};
761 
762   PetscFunctionBegin;
763   PetscCall(DMCreate(comm, dm));
764   PetscCall(DMSetType(*dm, DMPLEX));
765   PetscCall(DMPlexCreateBoxSurfaceMesh_Internal(*dm, dim, faces ? faces : fac, lower ? lower : low, upper ? upper : upp, interpolate));
766   PetscFunctionReturn(PETSC_SUCCESS);
767 }
768 
769 static PetscErrorCode DMPlexCreateLineMesh_Internal(DM dm, PetscInt segments, PetscReal lower, PetscReal upper, DMBoundaryType bd)
770 {
771   PetscInt     i, fStart, fEnd, numCells = 0, numVerts = 0;
772   PetscInt     numPoints[2], *coneSize, *cones, *coneOrientations;
773   PetscScalar *vertexCoords;
774   PetscReal    L, maxCell;
775   PetscBool    markerSeparate = PETSC_FALSE;
776   PetscInt     markerLeft = 1, faceMarkerLeft = 1;
777   PetscInt     markerRight = 1, faceMarkerRight = 2;
778   PetscBool    wrap = (bd == DM_BOUNDARY_PERIODIC || bd == DM_BOUNDARY_TWIST) ? PETSC_TRUE : PETSC_FALSE;
779   PetscMPIInt  rank;
780 
781   PetscFunctionBegin;
782   PetscAssertPointer(dm, 1);
783 
784   PetscCall(DMSetDimension(dm, 1));
785   PetscCall(DMCreateLabel(dm, "marker"));
786   PetscCall(DMCreateLabel(dm, "Face Sets"));
787 
788   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank));
789   if (rank == 0) numCells = segments;
790   if (rank == 0) numVerts = segments + (wrap ? 0 : 1);
791 
792   numPoints[0] = numVerts;
793   numPoints[1] = numCells;
794   PetscCall(PetscMalloc4(numCells + numVerts, &coneSize, numCells * 2, &cones, numCells + numVerts, &coneOrientations, numVerts, &vertexCoords));
795   PetscCall(PetscArrayzero(coneOrientations, numCells + numVerts));
796   for (i = 0; i < numCells; ++i) coneSize[i] = 2;
797   for (i = 0; i < numVerts; ++i) coneSize[numCells + i] = 0;
798   for (i = 0; i < numCells; ++i) {
799     cones[2 * i]     = numCells + i % numVerts;
800     cones[2 * i + 1] = numCells + (i + 1) % numVerts;
801   }
802   for (i = 0; i < numVerts; ++i) vertexCoords[i] = lower + (upper - lower) * ((PetscReal)i / (PetscReal)numCells);
803   PetscCall(DMPlexCreateFromDAG(dm, 1, numPoints, coneSize, cones, coneOrientations, vertexCoords));
804   PetscCall(PetscFree4(coneSize, cones, coneOrientations, vertexCoords));
805 
806   PetscCall(PetscOptionsGetBool(((PetscObject)dm)->options, ((PetscObject)dm)->prefix, "-dm_plex_separate_marker", &markerSeparate, NULL));
807   if (markerSeparate) {
808     markerLeft  = faceMarkerLeft;
809     markerRight = faceMarkerRight;
810   }
811   if (!wrap && rank == 0) {
812     PetscCall(DMPlexGetHeightStratum(dm, 1, &fStart, &fEnd));
813     PetscCall(DMSetLabelValue(dm, "marker", fStart, markerLeft));
814     PetscCall(DMSetLabelValue(dm, "marker", fEnd - 1, markerRight));
815     PetscCall(DMSetLabelValue(dm, "Face Sets", fStart, faceMarkerLeft));
816     PetscCall(DMSetLabelValue(dm, "Face Sets", fEnd - 1, faceMarkerRight));
817   }
818   if (wrap) {
819     L       = upper - lower;
820     maxCell = (PetscReal)1.1 * (L / (PetscReal)PetscMax(1, segments));
821     PetscCall(DMSetPeriodicity(dm, &maxCell, &lower, &L));
822   }
823   PetscCall(DMPlexSetRefinementUniform(dm, PETSC_TRUE));
824   PetscFunctionReturn(PETSC_SUCCESS);
825 }
826 
827 static PetscErrorCode DMPlexCreateBoxMesh_Simplex_Internal(DM dm, PetscInt dim, const PetscInt faces[], const PetscReal lower[], const PetscReal upper[], const DMBoundaryType periodicity[], PetscBool interpolate)
828 {
829   DM      boundary, vol;
830   DMLabel bdlabel;
831 
832   PetscFunctionBegin;
833   PetscAssertPointer(dm, 1);
834   for (PetscInt i = 0; i < dim; ++i) PetscCheck(periodicity[i] == DM_BOUNDARY_NONE, PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Periodicity is not supported for simplex meshes");
835   PetscCall(DMCreate(PetscObjectComm((PetscObject)dm), &boundary));
836   PetscCall(DMSetType(boundary, DMPLEX));
837   PetscCall(DMPlexCreateBoxSurfaceMesh_Internal(boundary, dim, faces, lower, upper, PETSC_FALSE));
838   PetscCall(DMPlexGenerate(boundary, NULL, interpolate, &vol));
839   PetscCall(DMGetLabel(vol, "marker", &bdlabel));
840   if (bdlabel) PetscCall(DMPlexLabelComplete(vol, bdlabel));
841   PetscCall(DMPlexCopy_Internal(dm, PETSC_TRUE, PETSC_FALSE, vol));
842   PetscCall(DMPlexReplace_Internal(dm, &vol));
843   PetscCall(DMDestroy(&boundary));
844   PetscFunctionReturn(PETSC_SUCCESS);
845 }
846 
847 static PetscErrorCode DMPlexCreateCubeMesh_Internal(DM dm, const PetscReal lower[], const PetscReal upper[], const PetscInt edges[], DMBoundaryType bdX, DMBoundaryType bdY, DMBoundaryType bdZ)
848 {
849   DMLabel     cutLabel  = NULL;
850   PetscInt    markerTop = 1, faceMarkerTop = 1;
851   PetscInt    markerBottom = 1, faceMarkerBottom = 1;
852   PetscInt    markerFront = 1, faceMarkerFront = 1;
853   PetscInt    markerBack = 1, faceMarkerBack = 1;
854   PetscInt    markerRight = 1, faceMarkerRight = 1;
855   PetscInt    markerLeft = 1, faceMarkerLeft = 1;
856   PetscInt    dim;
857   PetscBool   markerSeparate = PETSC_FALSE, cutMarker = PETSC_FALSE;
858   PetscMPIInt rank;
859 
860   PetscFunctionBegin;
861   PetscCall(DMGetDimension(dm, &dim));
862   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank));
863   PetscCall(DMCreateLabel(dm, "marker"));
864   PetscCall(DMCreateLabel(dm, "Face Sets"));
865   PetscCall(PetscOptionsGetBool(((PetscObject)dm)->options, ((PetscObject)dm)->prefix, "-dm_plex_periodic_cut", &cutMarker, NULL));
866   if (bdX == DM_BOUNDARY_PERIODIC || bdX == DM_BOUNDARY_TWIST || bdY == DM_BOUNDARY_PERIODIC || bdY == DM_BOUNDARY_TWIST || bdZ == DM_BOUNDARY_PERIODIC || bdZ == DM_BOUNDARY_TWIST) {
867     if (cutMarker) {
868       PetscCall(DMCreateLabel(dm, "periodic_cut"));
869       PetscCall(DMGetLabel(dm, "periodic_cut", &cutLabel));
870     }
871   }
872   switch (dim) {
873   case 2:
874     faceMarkerTop    = 3;
875     faceMarkerBottom = 1;
876     faceMarkerRight  = 2;
877     faceMarkerLeft   = 4;
878     break;
879   case 3:
880     faceMarkerBottom = 1;
881     faceMarkerTop    = 2;
882     faceMarkerFront  = 3;
883     faceMarkerBack   = 4;
884     faceMarkerRight  = 5;
885     faceMarkerLeft   = 6;
886     break;
887   default:
888     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Dimension %" PetscInt_FMT " not supported", dim);
889   }
890   PetscCall(PetscOptionsGetBool(((PetscObject)dm)->options, ((PetscObject)dm)->prefix, "-dm_plex_separate_marker", &markerSeparate, NULL));
891   if (markerSeparate) {
892     markerBottom = faceMarkerBottom;
893     markerTop    = faceMarkerTop;
894     markerFront  = faceMarkerFront;
895     markerBack   = faceMarkerBack;
896     markerRight  = faceMarkerRight;
897     markerLeft   = faceMarkerLeft;
898   }
899   {
900     const PetscInt numXEdges    = rank == 0 ? edges[0] : 0;
901     const PetscInt numYEdges    = rank == 0 ? edges[1] : 0;
902     const PetscInt numZEdges    = rank == 0 ? edges[2] : 0;
903     const PetscInt numXVertices = rank == 0 ? (bdX == DM_BOUNDARY_PERIODIC || bdX == DM_BOUNDARY_TWIST ? edges[0] : edges[0] + 1) : 0;
904     const PetscInt numYVertices = rank == 0 ? (bdY == DM_BOUNDARY_PERIODIC || bdY == DM_BOUNDARY_TWIST ? edges[1] : edges[1] + 1) : 0;
905     const PetscInt numZVertices = rank == 0 ? (bdZ == DM_BOUNDARY_PERIODIC || bdZ == DM_BOUNDARY_TWIST ? edges[2] : edges[2] + 1) : 0;
906     const PetscInt numCells     = numXEdges * numYEdges * numZEdges;
907     const PetscInt numXFaces    = numYEdges * numZEdges;
908     const PetscInt numYFaces    = numXEdges * numZEdges;
909     const PetscInt numZFaces    = numXEdges * numYEdges;
910     const PetscInt numTotXFaces = numXVertices * numXFaces;
911     const PetscInt numTotYFaces = numYVertices * numYFaces;
912     const PetscInt numTotZFaces = numZVertices * numZFaces;
913     const PetscInt numFaces     = numTotXFaces + numTotYFaces + numTotZFaces;
914     const PetscInt numTotXEdges = numXEdges * numYVertices * numZVertices;
915     const PetscInt numTotYEdges = numYEdges * numXVertices * numZVertices;
916     const PetscInt numTotZEdges = numZEdges * numXVertices * numYVertices;
917     const PetscInt numVertices  = numXVertices * numYVertices * numZVertices;
918     const PetscInt numEdges     = numTotXEdges + numTotYEdges + numTotZEdges;
919     const PetscInt firstVertex  = (dim == 2) ? numFaces : numCells;
920     const PetscInt firstXFace   = (dim == 2) ? 0 : numCells + numVertices;
921     const PetscInt firstYFace   = firstXFace + numTotXFaces;
922     const PetscInt firstZFace   = firstYFace + numTotYFaces;
923     const PetscInt firstXEdge   = numCells + numFaces + numVertices;
924     const PetscInt firstYEdge   = firstXEdge + numTotXEdges;
925     const PetscInt firstZEdge   = firstYEdge + numTotYEdges;
926     Vec            coordinates;
927     PetscSection   coordSection;
928     PetscScalar   *coords;
929     PetscInt       coordSize;
930     PetscInt       v, vx, vy, vz;
931     PetscInt       c, f, fx, fy, fz, e, ex, ey, ez;
932 
933     PetscCall(DMPlexSetChart(dm, 0, numCells + numFaces + numEdges + numVertices));
934     for (c = 0; c < numCells; c++) PetscCall(DMPlexSetConeSize(dm, c, 6));
935     for (f = firstXFace; f < firstXFace + numFaces; ++f) PetscCall(DMPlexSetConeSize(dm, f, 4));
936     for (e = firstXEdge; e < firstXEdge + numEdges; ++e) PetscCall(DMPlexSetConeSize(dm, e, 2));
937     PetscCall(DMSetUp(dm)); /* Allocate space for cones */
938     /* Build cells */
939     for (fz = 0; fz < numZEdges; ++fz) {
940       for (fy = 0; fy < numYEdges; ++fy) {
941         for (fx = 0; fx < numXEdges; ++fx) {
942           PetscInt cell  = (fz * numYEdges + fy) * numXEdges + fx;
943           PetscInt faceB = firstZFace + (fy * numXEdges + fx) * numZVertices + fz;
944           PetscInt faceT = firstZFace + (fy * numXEdges + fx) * numZVertices + ((fz + 1) % numZVertices);
945           PetscInt faceF = firstYFace + (fz * numXEdges + fx) * numYVertices + fy;
946           PetscInt faceK = firstYFace + (fz * numXEdges + fx) * numYVertices + ((fy + 1) % numYVertices);
947           PetscInt faceL = firstXFace + (fz * numYEdges + fy) * numXVertices + fx;
948           PetscInt faceR = firstXFace + (fz * numYEdges + fy) * numXVertices + ((fx + 1) % numXVertices);
949           /* B,  T,  F,  K,  R,  L */
950           PetscInt ornt[6] = {-2, 0, 0, -3, 0, -2}; /* ??? */
951           PetscInt cone[6];
952 
953           /* no boundary twisting in 3D */
954           cone[0] = faceB;
955           cone[1] = faceT;
956           cone[2] = faceF;
957           cone[3] = faceK;
958           cone[4] = faceR;
959           cone[5] = faceL;
960           PetscCall(DMPlexSetCone(dm, cell, cone));
961           PetscCall(DMPlexSetConeOrientation(dm, cell, ornt));
962           if (bdX != DM_BOUNDARY_NONE && fx == numXEdges - 1 && cutLabel) PetscCall(DMLabelSetValue(cutLabel, cell, 2));
963           if (bdY != DM_BOUNDARY_NONE && fy == numYEdges - 1 && cutLabel) PetscCall(DMLabelSetValue(cutLabel, cell, 2));
964           if (bdZ != DM_BOUNDARY_NONE && fz == numZEdges - 1 && cutLabel) PetscCall(DMLabelSetValue(cutLabel, cell, 2));
965         }
966       }
967     }
968     /* Build x faces */
969     for (fz = 0; fz < numZEdges; ++fz) {
970       for (fy = 0; fy < numYEdges; ++fy) {
971         for (fx = 0; fx < numXVertices; ++fx) {
972           PetscInt face    = firstXFace + (fz * numYEdges + fy) * numXVertices + fx;
973           PetscInt edgeL   = firstZEdge + (fy * numXVertices + fx) * numZEdges + fz;
974           PetscInt edgeR   = firstZEdge + (((fy + 1) % numYVertices) * numXVertices + fx) * numZEdges + fz;
975           PetscInt edgeB   = firstYEdge + (fz * numXVertices + fx) * numYEdges + fy;
976           PetscInt edgeT   = firstYEdge + (((fz + 1) % numZVertices) * numXVertices + fx) * numYEdges + fy;
977           PetscInt ornt[4] = {0, 0, -1, -1};
978           PetscInt cone[4];
979 
980           if (dim == 3) {
981             /* markers */
982             if (bdX != DM_BOUNDARY_PERIODIC) {
983               if (fx == numXVertices - 1) {
984                 PetscCall(DMSetLabelValue(dm, "Face Sets", face, faceMarkerRight));
985                 PetscCall(DMSetLabelValue(dm, "marker", face, markerRight));
986               } else if (fx == 0) {
987                 PetscCall(DMSetLabelValue(dm, "Face Sets", face, faceMarkerLeft));
988                 PetscCall(DMSetLabelValue(dm, "marker", face, markerLeft));
989               }
990             }
991           }
992           cone[0] = edgeB;
993           cone[1] = edgeR;
994           cone[2] = edgeT;
995           cone[3] = edgeL;
996           PetscCall(DMPlexSetCone(dm, face, cone));
997           PetscCall(DMPlexSetConeOrientation(dm, face, ornt));
998         }
999       }
1000     }
1001     /* Build y faces */
1002     for (fz = 0; fz < numZEdges; ++fz) {
1003       for (fx = 0; fx < numXEdges; ++fx) {
1004         for (fy = 0; fy < numYVertices; ++fy) {
1005           PetscInt face    = firstYFace + (fz * numXEdges + fx) * numYVertices + fy;
1006           PetscInt edgeL   = firstZEdge + (fy * numXVertices + fx) * numZEdges + fz;
1007           PetscInt edgeR   = firstZEdge + (fy * numXVertices + ((fx + 1) % numXVertices)) * numZEdges + fz;
1008           PetscInt edgeB   = firstXEdge + (fz * numYVertices + fy) * numXEdges + fx;
1009           PetscInt edgeT   = firstXEdge + (((fz + 1) % numZVertices) * numYVertices + fy) * numXEdges + fx;
1010           PetscInt ornt[4] = {0, 0, -1, -1};
1011           PetscInt cone[4];
1012 
1013           if (dim == 3) {
1014             /* markers */
1015             if (bdY != DM_BOUNDARY_PERIODIC) {
1016               if (fy == numYVertices - 1) {
1017                 PetscCall(DMSetLabelValue(dm, "Face Sets", face, faceMarkerBack));
1018                 PetscCall(DMSetLabelValue(dm, "marker", face, markerBack));
1019               } else if (fy == 0) {
1020                 PetscCall(DMSetLabelValue(dm, "Face Sets", face, faceMarkerFront));
1021                 PetscCall(DMSetLabelValue(dm, "marker", face, markerFront));
1022               }
1023             }
1024           }
1025           cone[0] = edgeB;
1026           cone[1] = edgeR;
1027           cone[2] = edgeT;
1028           cone[3] = edgeL;
1029           PetscCall(DMPlexSetCone(dm, face, cone));
1030           PetscCall(DMPlexSetConeOrientation(dm, face, ornt));
1031         }
1032       }
1033     }
1034     /* Build z faces */
1035     for (fy = 0; fy < numYEdges; ++fy) {
1036       for (fx = 0; fx < numXEdges; ++fx) {
1037         for (fz = 0; fz < numZVertices; fz++) {
1038           PetscInt face    = firstZFace + (fy * numXEdges + fx) * numZVertices + fz;
1039           PetscInt edgeL   = firstYEdge + (fz * numXVertices + fx) * numYEdges + fy;
1040           PetscInt edgeR   = firstYEdge + (fz * numXVertices + ((fx + 1) % numXVertices)) * numYEdges + fy;
1041           PetscInt edgeB   = firstXEdge + (fz * numYVertices + fy) * numXEdges + fx;
1042           PetscInt edgeT   = firstXEdge + (fz * numYVertices + ((fy + 1) % numYVertices)) * numXEdges + fx;
1043           PetscInt ornt[4] = {0, 0, -1, -1};
1044           PetscInt cone[4];
1045 
1046           if (dim == 2) {
1047             if (bdX == DM_BOUNDARY_TWIST && fx == numXEdges - 1) {
1048               edgeR += numYEdges - 1 - 2 * fy;
1049               ornt[1] = -1;
1050             }
1051             if (bdY == DM_BOUNDARY_TWIST && fy == numYEdges - 1) {
1052               edgeT += numXEdges - 1 - 2 * fx;
1053               ornt[2] = 0;
1054             }
1055             if (bdX != DM_BOUNDARY_NONE && fx == numXEdges - 1 && cutLabel) PetscCall(DMLabelSetValue(cutLabel, face, 2));
1056             if (bdY != DM_BOUNDARY_NONE && fy == numYEdges - 1 && cutLabel) PetscCall(DMLabelSetValue(cutLabel, face, 2));
1057           } else {
1058             /* markers */
1059             if (bdZ != DM_BOUNDARY_PERIODIC) {
1060               if (fz == numZVertices - 1) {
1061                 PetscCall(DMSetLabelValue(dm, "Face Sets", face, faceMarkerTop));
1062                 PetscCall(DMSetLabelValue(dm, "marker", face, markerTop));
1063               } else if (fz == 0) {
1064                 PetscCall(DMSetLabelValue(dm, "Face Sets", face, faceMarkerBottom));
1065                 PetscCall(DMSetLabelValue(dm, "marker", face, markerBottom));
1066               }
1067             }
1068           }
1069           cone[0] = edgeB;
1070           cone[1] = edgeR;
1071           cone[2] = edgeT;
1072           cone[3] = edgeL;
1073           PetscCall(DMPlexSetCone(dm, face, cone));
1074           PetscCall(DMPlexSetConeOrientation(dm, face, ornt));
1075         }
1076       }
1077     }
1078     /* Build Z edges*/
1079     for (vy = 0; vy < numYVertices; vy++) {
1080       for (vx = 0; vx < numXVertices; vx++) {
1081         for (ez = 0; ez < numZEdges; ez++) {
1082           const PetscInt edge    = firstZEdge + (vy * numXVertices + vx) * numZEdges + ez;
1083           const PetscInt vertexB = firstVertex + (ez * numYVertices + vy) * numXVertices + vx;
1084           const PetscInt vertexT = firstVertex + (((ez + 1) % numZVertices) * numYVertices + vy) * numXVertices + vx;
1085           PetscInt       cone[2];
1086 
1087           cone[0] = vertexB;
1088           cone[1] = vertexT;
1089           PetscCall(DMPlexSetCone(dm, edge, cone));
1090           if (dim == 3) {
1091             if (bdX != DM_BOUNDARY_PERIODIC) {
1092               if (vx == numXVertices - 1) {
1093                 PetscCall(DMSetLabelValue(dm, "marker", edge, markerRight));
1094                 PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerRight));
1095                 if (ez == numZEdges - 1) PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerRight));
1096               } else if (vx == 0) {
1097                 PetscCall(DMSetLabelValue(dm, "marker", edge, markerLeft));
1098                 PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerLeft));
1099                 if (ez == numZEdges - 1) PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerLeft));
1100               }
1101             }
1102             if (bdY != DM_BOUNDARY_PERIODIC) {
1103               if (vy == numYVertices - 1) {
1104                 PetscCall(DMSetLabelValue(dm, "marker", edge, markerBack));
1105                 PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerBack));
1106                 if (ez == numZEdges - 1) PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerBack));
1107               } else if (vy == 0) {
1108                 PetscCall(DMSetLabelValue(dm, "marker", edge, markerFront));
1109                 PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerFront));
1110                 if (ez == numZEdges - 1) PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerFront));
1111               }
1112             }
1113           }
1114         }
1115       }
1116     }
1117     /* Build Y edges*/
1118     for (vz = 0; vz < numZVertices; vz++) {
1119       for (vx = 0; vx < numXVertices; vx++) {
1120         for (ey = 0; ey < numYEdges; ey++) {
1121           const PetscInt nextv   = (dim == 2 && bdY == DM_BOUNDARY_TWIST && ey == numYEdges - 1) ? (numXVertices - vx - 1) : (vz * numYVertices + ((ey + 1) % numYVertices)) * numXVertices + vx;
1122           const PetscInt edge    = firstYEdge + (vz * numXVertices + vx) * numYEdges + ey;
1123           const PetscInt vertexF = firstVertex + (vz * numYVertices + ey) * numXVertices + vx;
1124           const PetscInt vertexK = firstVertex + nextv;
1125           PetscInt       cone[2];
1126 
1127           cone[0] = vertexF;
1128           cone[1] = vertexK;
1129           PetscCall(DMPlexSetCone(dm, edge, cone));
1130           if (dim == 2) {
1131             if ((bdX != DM_BOUNDARY_PERIODIC) && (bdX != DM_BOUNDARY_TWIST)) {
1132               if (vx == numXVertices - 1) {
1133                 PetscCall(DMSetLabelValue(dm, "Face Sets", edge, faceMarkerRight));
1134                 PetscCall(DMSetLabelValue(dm, "marker", edge, markerRight));
1135                 PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerRight));
1136                 if (ey == numYEdges - 1) PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerRight));
1137               } else if (vx == 0) {
1138                 PetscCall(DMSetLabelValue(dm, "Face Sets", edge, faceMarkerLeft));
1139                 PetscCall(DMSetLabelValue(dm, "marker", edge, markerLeft));
1140                 PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerLeft));
1141                 if (ey == numYEdges - 1) PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerLeft));
1142               }
1143             } else {
1144               if (vx == 0 && cutLabel) {
1145                 PetscCall(DMLabelSetValue(cutLabel, edge, 1));
1146                 PetscCall(DMLabelSetValue(cutLabel, cone[0], 1));
1147                 if (ey == numYEdges - 1) PetscCall(DMLabelSetValue(cutLabel, cone[1], 1));
1148               }
1149             }
1150           } else {
1151             if (bdX != DM_BOUNDARY_PERIODIC) {
1152               if (vx == numXVertices - 1) {
1153                 PetscCall(DMSetLabelValue(dm, "marker", edge, markerRight));
1154                 PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerRight));
1155                 if (ey == numYEdges - 1) PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerRight));
1156               } else if (vx == 0) {
1157                 PetscCall(DMSetLabelValue(dm, "marker", edge, markerLeft));
1158                 PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerLeft));
1159                 if (ey == numYEdges - 1) PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerLeft));
1160               }
1161             }
1162             if (bdZ != DM_BOUNDARY_PERIODIC) {
1163               if (vz == numZVertices - 1) {
1164                 PetscCall(DMSetLabelValue(dm, "marker", edge, markerTop));
1165                 PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerTop));
1166                 if (ey == numYEdges - 1) PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerTop));
1167               } else if (vz == 0) {
1168                 PetscCall(DMSetLabelValue(dm, "marker", edge, markerBottom));
1169                 PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerBottom));
1170                 if (ey == numYEdges - 1) PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerBottom));
1171               }
1172             }
1173           }
1174         }
1175       }
1176     }
1177     /* Build X edges*/
1178     for (vz = 0; vz < numZVertices; vz++) {
1179       for (vy = 0; vy < numYVertices; vy++) {
1180         for (ex = 0; ex < numXEdges; ex++) {
1181           const PetscInt nextv   = (dim == 2 && bdX == DM_BOUNDARY_TWIST && ex == numXEdges - 1) ? (numYVertices - vy - 1) * numXVertices : (vz * numYVertices + vy) * numXVertices + (ex + 1) % numXVertices;
1182           const PetscInt edge    = firstXEdge + (vz * numYVertices + vy) * numXEdges + ex;
1183           const PetscInt vertexL = firstVertex + (vz * numYVertices + vy) * numXVertices + ex;
1184           const PetscInt vertexR = firstVertex + nextv;
1185           PetscInt       cone[2];
1186 
1187           cone[0] = vertexL;
1188           cone[1] = vertexR;
1189           PetscCall(DMPlexSetCone(dm, edge, cone));
1190           if (dim == 2) {
1191             if ((bdY != DM_BOUNDARY_PERIODIC) && (bdY != DM_BOUNDARY_TWIST)) {
1192               if (vy == numYVertices - 1) {
1193                 PetscCall(DMSetLabelValue(dm, "Face Sets", edge, faceMarkerTop));
1194                 PetscCall(DMSetLabelValue(dm, "marker", edge, markerTop));
1195                 PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerTop));
1196                 if (ex == numXEdges - 1) PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerTop));
1197               } else if (vy == 0) {
1198                 PetscCall(DMSetLabelValue(dm, "Face Sets", edge, faceMarkerBottom));
1199                 PetscCall(DMSetLabelValue(dm, "marker", edge, markerBottom));
1200                 PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerBottom));
1201                 if (ex == numXEdges - 1) PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerBottom));
1202               }
1203             } else {
1204               if (vy == 0 && cutLabel) {
1205                 PetscCall(DMLabelSetValue(cutLabel, edge, 1));
1206                 PetscCall(DMLabelSetValue(cutLabel, cone[0], 1));
1207                 if (ex == numXEdges - 1) PetscCall(DMLabelSetValue(cutLabel, cone[1], 1));
1208               }
1209             }
1210           } else {
1211             if (bdY != DM_BOUNDARY_PERIODIC) {
1212               if (vy == numYVertices - 1) {
1213                 PetscCall(DMSetLabelValue(dm, "marker", edge, markerBack));
1214                 PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerBack));
1215                 if (ex == numXEdges - 1) PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerBack));
1216               } else if (vy == 0) {
1217                 PetscCall(DMSetLabelValue(dm, "marker", edge, markerFront));
1218                 PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerFront));
1219                 if (ex == numXEdges - 1) PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerFront));
1220               }
1221             }
1222             if (bdZ != DM_BOUNDARY_PERIODIC) {
1223               if (vz == numZVertices - 1) {
1224                 PetscCall(DMSetLabelValue(dm, "marker", edge, markerTop));
1225                 PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerTop));
1226                 if (ex == numXEdges - 1) PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerTop));
1227               } else if (vz == 0) {
1228                 PetscCall(DMSetLabelValue(dm, "marker", edge, markerBottom));
1229                 PetscCall(DMSetLabelValue(dm, "marker", cone[0], markerBottom));
1230                 if (ex == numXEdges - 1) PetscCall(DMSetLabelValue(dm, "marker", cone[1], markerBottom));
1231               }
1232             }
1233           }
1234         }
1235       }
1236     }
1237     PetscCall(DMPlexSymmetrize(dm));
1238     PetscCall(DMPlexStratify(dm));
1239     /* Build coordinates */
1240     PetscCall(DMGetCoordinateSection(dm, &coordSection));
1241     PetscCall(PetscSectionSetNumFields(coordSection, 1));
1242     PetscCall(PetscSectionSetFieldComponents(coordSection, 0, dim));
1243     PetscCall(PetscSectionSetChart(coordSection, firstVertex, firstVertex + numVertices));
1244     for (v = firstVertex; v < firstVertex + numVertices; ++v) {
1245       PetscCall(PetscSectionSetDof(coordSection, v, dim));
1246       PetscCall(PetscSectionSetFieldDof(coordSection, v, 0, dim));
1247     }
1248     PetscCall(PetscSectionSetUp(coordSection));
1249     PetscCall(PetscSectionGetStorageSize(coordSection, &coordSize));
1250     PetscCall(VecCreate(PETSC_COMM_SELF, &coordinates));
1251     PetscCall(PetscObjectSetName((PetscObject)coordinates, "coordinates"));
1252     PetscCall(VecSetSizes(coordinates, coordSize, PETSC_DETERMINE));
1253     PetscCall(VecSetBlockSize(coordinates, dim));
1254     PetscCall(VecSetType(coordinates, VECSTANDARD));
1255     PetscCall(VecGetArray(coordinates, &coords));
1256     for (vz = 0; vz < numZVertices; ++vz) {
1257       for (vy = 0; vy < numYVertices; ++vy) {
1258         for (vx = 0; vx < numXVertices; ++vx) {
1259           coords[((vz * numYVertices + vy) * numXVertices + vx) * dim + 0] = lower[0] + ((upper[0] - lower[0]) / numXEdges) * vx;
1260           coords[((vz * numYVertices + vy) * numXVertices + vx) * dim + 1] = lower[1] + ((upper[1] - lower[1]) / numYEdges) * vy;
1261           if (dim == 3) coords[((vz * numYVertices + vy) * numXVertices + vx) * dim + 2] = lower[2] + ((upper[2] - lower[2]) / numZEdges) * vz;
1262         }
1263       }
1264     }
1265     PetscCall(VecRestoreArray(coordinates, &coords));
1266     PetscCall(DMSetCoordinatesLocal(dm, coordinates));
1267     PetscCall(VecDestroy(&coordinates));
1268   }
1269   PetscFunctionReturn(PETSC_SUCCESS);
1270 }
1271 
1272 static PetscErrorCode DMPlexCreateBoxMesh_Tensor_Internal(DM dm, PetscInt dim, const PetscInt faces[], const PetscReal lower[], const PetscReal upper[], const DMBoundaryType periodicity[])
1273 {
1274   DMBoundaryType bdt[3] = {DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE};
1275   PetscInt       fac[3] = {0, 0, 0}, d;
1276 
1277   PetscFunctionBegin;
1278   PetscAssertPointer(dm, 1);
1279   PetscValidLogicalCollectiveInt(dm, dim, 2);
1280   PetscCall(DMSetDimension(dm, dim));
1281   for (d = 0; d < dim; ++d) {
1282     fac[d] = faces[d];
1283     bdt[d] = periodicity[d];
1284   }
1285   PetscCall(DMPlexCreateCubeMesh_Internal(dm, lower, upper, fac, bdt[0], bdt[1], bdt[2]));
1286   if (periodicity[0] == DM_BOUNDARY_PERIODIC || periodicity[0] == DM_BOUNDARY_TWIST || periodicity[1] == DM_BOUNDARY_PERIODIC || periodicity[1] == DM_BOUNDARY_TWIST || (dim > 2 && (periodicity[2] == DM_BOUNDARY_PERIODIC || periodicity[2] == DM_BOUNDARY_TWIST))) {
1287     PetscReal L[3]       = {-1., -1., 0.};
1288     PetscReal maxCell[3] = {-1., -1., 0.};
1289 
1290     for (d = 0; d < dim; ++d) {
1291       if (periodicity[d] != DM_BOUNDARY_NONE) {
1292         L[d]       = upper[d] - lower[d];
1293         maxCell[d] = 1.1 * (L[d] / PetscMax(1, faces[d]));
1294       }
1295     }
1296     PetscCall(DMSetPeriodicity(dm, maxCell, lower, L));
1297   }
1298   PetscCall(DMPlexSetRefinementUniform(dm, PETSC_TRUE));
1299   PetscFunctionReturn(PETSC_SUCCESS);
1300 }
1301 
1302 static PetscErrorCode DMPlexCreateBoxMesh_Internal(DM dm, DMPlexShape shape, PetscInt dim, PetscBool simplex, const PetscInt faces[], const PetscReal lower[], const PetscReal upper[], const DMBoundaryType periodicity[], PetscBool interpolate)
1303 {
1304   PetscFunctionBegin;
1305   PetscCall(PetscLogEventBegin(DMPLEX_Generate, dm, 0, 0, 0));
1306   if (shape == DM_SHAPE_ZBOX) PetscCall(DMPlexCreateBoxMesh_Tensor_SFC_Internal(dm, dim, faces, lower, upper, periodicity, interpolate));
1307   else if (dim == 1) PetscCall(DMPlexCreateLineMesh_Internal(dm, faces[0], lower[0], upper[0], periodicity[0]));
1308   else if (simplex) PetscCall(DMPlexCreateBoxMesh_Simplex_Internal(dm, dim, faces, lower, upper, periodicity, interpolate));
1309   else PetscCall(DMPlexCreateBoxMesh_Tensor_Internal(dm, dim, faces, lower, upper, periodicity));
1310   if (!interpolate && dim > 1 && !simplex) {
1311     DM udm;
1312 
1313     PetscCall(DMPlexUninterpolate(dm, &udm));
1314     PetscCall(DMPlexCopyCoordinates(dm, udm));
1315     PetscCall(DMPlexReplace_Internal(dm, &udm));
1316   }
1317   PetscCall(PetscLogEventEnd(DMPLEX_Generate, dm, 0, 0, 0));
1318   PetscFunctionReturn(PETSC_SUCCESS);
1319 }
1320 
1321 /*@C
1322   DMPlexCreateBoxMesh - Creates a mesh on the tensor product of unit intervals (box) using simplices or tensor cells (hexahedra).
1323 
1324   Collective
1325 
1326   Input Parameters:
1327 + comm        - The communicator for the `DM` object
1328 . dim         - The spatial dimension
1329 . simplex     - `PETSC_TRUE` for simplices, `PETSC_FALSE` for tensor cells
1330 . faces       - Number of faces per dimension, or `NULL` for (1,) in 1D and (2, 2) in 2D and (1, 1, 1) in 3D
1331 . lower       - The lower left corner, or `NULL` for (0, 0, 0)
1332 . upper       - The upper right corner, or `NULL` for (1, 1, 1)
1333 . periodicity - The boundary type for the X,Y,Z direction, or `NULL` for `DM_BOUNDARY_NONE`
1334 - interpolate - Flag to create intermediate mesh pieces (edges, faces)
1335 
1336   Output Parameter:
1337 . dm - The `DM` object
1338 
1339   Level: beginner
1340 
1341   Note:
1342   To customize this mesh using options, use
1343 .vb
1344   DMCreate(comm, &dm);
1345   DMSetType(dm, DMPLEX);
1346   DMSetFromOptions(dm);
1347 .ve
1348   and use the options in `DMSetFromOptions()`.
1349 
1350   Here is the numbering returned for 2 faces in each direction for tensor cells\:
1351 .vb
1352  10---17---11---18----12
1353   |         |         |
1354   |         |         |
1355  20    2   22    3    24
1356   |         |         |
1357   |         |         |
1358   7---15----8---16----9
1359   |         |         |
1360   |         |         |
1361  19    0   21    1   23
1362   |         |         |
1363   |         |         |
1364   4---13----5---14----6
1365 .ve
1366   and for simplicial cells
1367 .vb
1368  14----8---15----9----16
1369   |\     5  |\      7 |
1370   | \       | \       |
1371  13   2    14    3    15
1372   | 4   \   | 6   \   |
1373   |       \ |       \ |
1374  11----6---12----7----13
1375   |\        |\        |
1376   | \    1  | \     3 |
1377  10   0    11    1    12
1378   | 0   \   | 2   \   |
1379   |       \ |       \ |
1380   8----4----9----5----10
1381 .ve
1382 
1383 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMSetFromOptions()`, `DMPlexCreateFromFile()`, `DMPlexCreateHexCylinderMesh()`, `DMSetType()`, `DMCreate()`
1384 @*/
1385 PetscErrorCode DMPlexCreateBoxMesh(MPI_Comm comm, PetscInt dim, PetscBool simplex, const PetscInt faces[], const PetscReal lower[], const PetscReal upper[], const DMBoundaryType periodicity[], PetscBool interpolate, DM *dm)
1386 {
1387   PetscInt       fac[3] = {1, 1, 1};
1388   PetscReal      low[3] = {0, 0, 0};
1389   PetscReal      upp[3] = {1, 1, 1};
1390   DMBoundaryType bdt[3] = {DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE};
1391 
1392   PetscFunctionBegin;
1393   PetscCall(DMCreate(comm, dm));
1394   PetscCall(DMSetType(*dm, DMPLEX));
1395   PetscCall(DMPlexCreateBoxMesh_Internal(*dm, DM_SHAPE_BOX, dim, simplex, faces ? faces : fac, lower ? lower : low, upper ? upper : upp, periodicity ? periodicity : bdt, interpolate));
1396   if (periodicity) PetscCall(DMLocalizeCoordinates(*dm));
1397   PetscFunctionReturn(PETSC_SUCCESS);
1398 }
1399 
1400 static PetscErrorCode DMPlexCreateWedgeBoxMesh_Internal(DM dm, const PetscInt faces[], const PetscReal lower[], const PetscReal upper[], const DMBoundaryType periodicity[])
1401 {
1402   DM       bdm, vol;
1403   PetscInt i;
1404 
1405   PetscFunctionBegin;
1406   // TODO Now we can support periodicity
1407   for (i = 0; i < 3; ++i) PetscCheck(periodicity[i] == DM_BOUNDARY_NONE, PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Periodicity not yet supported");
1408   PetscCall(DMCreate(PetscObjectComm((PetscObject)dm), &bdm));
1409   PetscCall(DMSetType(bdm, DMPLEX));
1410   PetscCall(DMSetDimension(bdm, 2));
1411   PetscCall(PetscLogEventBegin(DMPLEX_Generate, bdm, 0, 0, 0));
1412   PetscCall(DMPlexCreateBoxMesh_Simplex_Internal(bdm, 2, faces, lower, upper, periodicity, PETSC_TRUE));
1413   PetscCall(DMPlexExtrude(bdm, faces[2], upper[2] - lower[2], PETSC_TRUE, PETSC_FALSE, PETSC_FALSE, NULL, NULL, &vol));
1414   PetscCall(PetscLogEventEnd(DMPLEX_Generate, bdm, 0, 0, 0));
1415   PetscCall(DMDestroy(&bdm));
1416   PetscCall(DMPlexReplace_Internal(dm, &vol));
1417   if (lower[2] != 0.0) {
1418     Vec          v;
1419     PetscScalar *x;
1420     PetscInt     cDim, n;
1421 
1422     PetscCall(DMGetCoordinatesLocal(dm, &v));
1423     PetscCall(VecGetBlockSize(v, &cDim));
1424     PetscCall(VecGetLocalSize(v, &n));
1425     PetscCall(VecGetArray(v, &x));
1426     x += cDim;
1427     for (i = 0; i < n; i += cDim) x[i] += lower[2];
1428     PetscCall(VecRestoreArray(v, &x));
1429     PetscCall(DMSetCoordinatesLocal(dm, v));
1430   }
1431   PetscFunctionReturn(PETSC_SUCCESS);
1432 }
1433 
1434 /*@
1435   DMPlexCreateWedgeBoxMesh - Creates a 3-D mesh tesselating the (x,y) plane and extruding in the third direction using wedge cells.
1436 
1437   Collective
1438 
1439   Input Parameters:
1440 + comm        - The communicator for the `DM` object
1441 . faces       - Number of faces per dimension, or `NULL` for (1, 1, 1)
1442 . lower       - The lower left corner, or `NULL` for (0, 0, 0)
1443 . upper       - The upper right corner, or `NULL` for (1, 1, 1)
1444 . periodicity - The boundary type for the X,Y,Z direction, or `NULL` for `DM_BOUNDARY_NONE`
1445 . orderHeight - If `PETSC_TRUE`, orders the extruded cells in the height first. Otherwise, orders the cell on the layers first
1446 - interpolate - Flag to create intermediate mesh pieces (edges, faces)
1447 
1448   Output Parameter:
1449 . dm - The `DM` object
1450 
1451   Level: beginner
1452 
1453 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexCreateHexCylinderMesh()`, `DMPlexCreateWedgeCylinderMesh()`, `DMExtrude()`, `DMPlexCreateBoxMesh()`, `DMSetType()`, `DMCreate()`
1454 @*/
1455 PetscErrorCode DMPlexCreateWedgeBoxMesh(MPI_Comm comm, const PetscInt faces[], const PetscReal lower[], const PetscReal upper[], const DMBoundaryType periodicity[], PetscBool orderHeight, PetscBool interpolate, DM *dm)
1456 {
1457   PetscInt       fac[3] = {1, 1, 1};
1458   PetscReal      low[3] = {0, 0, 0};
1459   PetscReal      upp[3] = {1, 1, 1};
1460   DMBoundaryType bdt[3] = {DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE};
1461 
1462   PetscFunctionBegin;
1463   PetscCall(DMCreate(comm, dm));
1464   PetscCall(DMSetType(*dm, DMPLEX));
1465   PetscCall(DMPlexCreateWedgeBoxMesh_Internal(*dm, faces ? faces : fac, lower ? lower : low, upper ? upper : upp, periodicity ? periodicity : bdt));
1466   if (!interpolate) {
1467     DM udm;
1468 
1469     PetscCall(DMPlexUninterpolate(*dm, &udm));
1470     PetscCall(DMPlexReplace_Internal(*dm, &udm));
1471   }
1472   if (periodicity) PetscCall(DMLocalizeCoordinates(*dm));
1473   PetscFunctionReturn(PETSC_SUCCESS);
1474 }
1475 
1476 /*
1477   DMPlexTensorPointLexicographic_Private - Returns all tuples of size 'len' with nonnegative integers that are all less than or equal to 'max' for that dimension.
1478 
1479   Input Parameters:
1480 + len - The length of the tuple
1481 . max - The maximum for each dimension, so values are in [0, max)
1482 - tup - A tuple of length len+1: tup[len] > 0 indicates a stopping condition
1483 
1484   Output Parameter:
1485 . tup - A tuple of `len` integers whose entries are at most `max`
1486 
1487   Level: developer
1488 
1489   Note:
1490   Ordering is lexicographic with lowest index as least significant in ordering.
1491   e.g. for len == 2 and max == 2, this will return, in order, {0,0}, {1,0}, {2,0}, {0,1}, {1,1}, {2,1}, {0,2}, {1,2}, {2,2}.
1492 
1493 .seealso: PetscDualSpaceTensorPointLexicographic_Internal(), PetscDualSpaceLatticePointLexicographic_Internal()
1494 */
1495 static PetscErrorCode DMPlexTensorPointLexicographic_Private(PetscInt len, const PetscInt max[], PetscInt tup[])
1496 {
1497   PetscInt i;
1498 
1499   PetscFunctionBegin;
1500   for (i = 0; i < len; ++i) {
1501     if (tup[i] < max[i] - 1) {
1502       break;
1503     } else {
1504       tup[i] = 0;
1505     }
1506   }
1507   if (i == len) tup[i - 1] = max[i - 1];
1508   else ++tup[i];
1509   PetscFunctionReturn(PETSC_SUCCESS);
1510 }
1511 
1512 static PetscInt TupleToIndex_Private(PetscInt len, const PetscInt max[], const PetscInt tup[])
1513 {
1514   PetscInt i, idx = tup[len - 1];
1515 
1516   for (i = len - 2; i >= 0; --i) {
1517     idx *= max[i];
1518     idx += tup[i];
1519   }
1520   return idx;
1521 }
1522 
1523 static PetscErrorCode DestroyExtent_Private(void *extent)
1524 {
1525   return PetscFree(extent);
1526 }
1527 
1528 static PetscErrorCode DMPlexCreateHypercubicMesh_Internal(DM dm, PetscInt dim, const PetscReal lower[], const PetscReal upper[], const PetscInt edges[], const DMBoundaryType bd[])
1529 {
1530   Vec          coordinates;
1531   PetscSection coordSection;
1532   DMLabel      cutLabel    = NULL;
1533   PetscBool    cutMarker   = PETSC_FALSE;
1534   PetscBool    periodic    = PETSC_FALSE;
1535   PetscInt     numCells    = 1, c;
1536   PetscInt     numVertices = 1, v;
1537   PetscScalar *coords;
1538   PetscInt    *vertices, *vert, *vtmp, *supp, cone[2];
1539   PetscInt     d, e, cell = 0, coordSize;
1540   PetscMPIInt  rank;
1541 
1542   PetscFunctionBegin;
1543   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank));
1544   PetscCall(DMSetDimension(dm, dim));
1545   PetscCall(PetscCalloc4(dim, &vertices, dim, &vert, dim, &vtmp, 2 * dim, &supp));
1546   PetscCall(DMCreateLabel(dm, "marker"));
1547   PetscCall(PetscOptionsGetBool(((PetscObject)dm)->options, ((PetscObject)dm)->prefix, "-dm_plex_periodic_cut", &cutMarker, NULL));
1548   for (d = 0; d < dim; ++d) periodic = (periodic || bd[d] == DM_BOUNDARY_PERIODIC) ? PETSC_TRUE : PETSC_FALSE;
1549   if (periodic && cutMarker) {
1550     PetscCall(DMCreateLabel(dm, "periodic_cut"));
1551     PetscCall(DMGetLabel(dm, "periodic_cut", &cutLabel));
1552   }
1553   for (d = 0; d < dim; ++d) PetscCheck(bd[d] == DM_BOUNDARY_PERIODIC, PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Hypercubic mesh must be periodic now");
1554   for (d = 0; d < dim; ++d) {
1555     vertices[d] = edges[d];
1556     numVertices *= vertices[d];
1557   }
1558   numCells = numVertices * dim;
1559   PetscCall(DMPlexSetChart(dm, 0, numCells + numVertices));
1560   for (c = 0; c < numCells; ++c) PetscCall(DMPlexSetConeSize(dm, c, 2));
1561   for (v = numCells; v < numCells + numVertices; ++v) PetscCall(DMPlexSetSupportSize(dm, v, 2 * dim));
1562   /* TODO Loop over boundary and reset support sizes */
1563   PetscCall(DMSetUp(dm)); /* Allocate space for cones and supports */
1564   /* Build cell cones and vertex supports */
1565   PetscCall(DMCreateLabel(dm, "celltype"));
1566   while (vert[dim - 1] < vertices[dim - 1]) {
1567     const PetscInt vertex = TupleToIndex_Private(dim, vertices, vert) + numCells;
1568     PetscInt       s      = 0;
1569 
1570     PetscCall(PetscPrintf(PETSC_COMM_SELF, "Vertex %" PetscInt_FMT ":", vertex));
1571     for (d = 0; d < dim; ++d) PetscCall(PetscPrintf(PETSC_COMM_SELF, " %" PetscInt_FMT, vert[d]));
1572     PetscCall(PetscPrintf(PETSC_COMM_SELF, "\n"));
1573     PetscCall(DMPlexSetCellType(dm, vertex, DM_POLYTOPE_POINT));
1574     for (d = 0; d < dim; ++d) {
1575       for (e = 0; e < dim; ++e) vtmp[e] = vert[e];
1576       vtmp[d] = (vert[d] + 1) % vertices[d];
1577       cone[0] = vertex;
1578       cone[1] = TupleToIndex_Private(dim, vertices, vtmp) + numCells;
1579       PetscCall(PetscPrintf(PETSC_COMM_SELF, "  Vertex %" PetscInt_FMT ":", cone[1]));
1580       for (e = 0; e < dim; ++e) PetscCall(PetscPrintf(PETSC_COMM_SELF, " %" PetscInt_FMT, vtmp[e]));
1581       PetscCall(PetscPrintf(PETSC_COMM_SELF, "\n"));
1582       PetscCall(DMPlexSetCone(dm, cell, cone));
1583       PetscCall(DMPlexSetCellType(dm, cell, DM_POLYTOPE_SEGMENT));
1584       PetscCall(PetscPrintf(PETSC_COMM_SELF, "  Edge %" PetscInt_FMT " (%" PetscInt_FMT " %" PetscInt_FMT ")\n", cell, cone[0], cone[1]));
1585       ++cell;
1586     }
1587     for (d = 0; d < dim; ++d) {
1588       for (e = 0; e < dim; ++e) vtmp[e] = vert[e];
1589       vtmp[d]   = (vert[d] + vertices[d] - 1) % vertices[d];
1590       supp[s++] = TupleToIndex_Private(dim, vertices, vtmp) * dim + d;
1591       supp[s++] = (vertex - numCells) * dim + d;
1592       PetscCall(DMPlexSetSupport(dm, vertex, supp));
1593     }
1594     PetscCall(DMPlexTensorPointLexicographic_Private(dim, vertices, vert));
1595   }
1596   PetscCall(DMPlexStratify(dm));
1597   /* Build coordinates */
1598   PetscCall(DMGetCoordinateSection(dm, &coordSection));
1599   PetscCall(PetscSectionSetNumFields(coordSection, 1));
1600   PetscCall(PetscSectionSetFieldComponents(coordSection, 0, dim));
1601   PetscCall(PetscSectionSetChart(coordSection, numCells, numCells + numVertices));
1602   for (v = numCells; v < numCells + numVertices; ++v) {
1603     PetscCall(PetscSectionSetDof(coordSection, v, dim));
1604     PetscCall(PetscSectionSetFieldDof(coordSection, v, 0, dim));
1605   }
1606   PetscCall(PetscSectionSetUp(coordSection));
1607   PetscCall(PetscSectionGetStorageSize(coordSection, &coordSize));
1608   PetscCall(VecCreate(PETSC_COMM_SELF, &coordinates));
1609   PetscCall(PetscObjectSetName((PetscObject)coordinates, "coordinates"));
1610   PetscCall(VecSetSizes(coordinates, coordSize, PETSC_DETERMINE));
1611   PetscCall(VecSetBlockSize(coordinates, dim));
1612   PetscCall(VecSetType(coordinates, VECSTANDARD));
1613   PetscCall(VecGetArray(coordinates, &coords));
1614   for (d = 0; d < dim; ++d) vert[d] = 0;
1615   while (vert[dim - 1] < vertices[dim - 1]) {
1616     const PetscInt vertex = TupleToIndex_Private(dim, vertices, vert);
1617 
1618     for (d = 0; d < dim; ++d) coords[vertex * dim + d] = lower[d] + ((upper[d] - lower[d]) / vertices[d]) * vert[d];
1619     PetscCall(PetscPrintf(PETSC_COMM_SELF, "Vertex %" PetscInt_FMT ":", vertex));
1620     for (d = 0; d < dim; ++d) PetscCall(PetscPrintf(PETSC_COMM_SELF, " %" PetscInt_FMT, vert[d]));
1621     for (d = 0; d < dim; ++d) PetscCall(PetscPrintf(PETSC_COMM_SELF, " %g", (double)PetscRealPart(coords[vertex * dim + d])));
1622     PetscCall(PetscPrintf(PETSC_COMM_SELF, "\n"));
1623     PetscCall(DMPlexTensorPointLexicographic_Private(dim, vertices, vert));
1624   }
1625   PetscCall(VecRestoreArray(coordinates, &coords));
1626   PetscCall(DMSetCoordinatesLocal(dm, coordinates));
1627   PetscCall(VecDestroy(&coordinates));
1628   PetscCall(PetscFree4(vertices, vert, vtmp, supp));
1629   //PetscCall(DMSetPeriodicity(dm, NULL, lower, upper));
1630   // Attach the extent
1631   {
1632     PetscContainer c;
1633     PetscInt      *extent;
1634 
1635     PetscCall(PetscMalloc1(dim, &extent));
1636     for (PetscInt d = 0; d < dim; ++d) extent[d] = edges[d];
1637     PetscCall(PetscContainerCreate(PETSC_COMM_SELF, &c));
1638     PetscCall(PetscContainerSetUserDestroy(c, DestroyExtent_Private));
1639     PetscCall(PetscContainerSetPointer(c, extent));
1640     PetscCall(PetscObjectCompose((PetscObject)dm, "_extent", (PetscObject)c));
1641     PetscCall(PetscContainerDestroy(&c));
1642   }
1643   PetscFunctionReturn(PETSC_SUCCESS);
1644 }
1645 
1646 /*@C
1647   DMPlexCreateHypercubicMesh - Creates a periodic mesh on the tensor product of unit intervals using only vertices and edges.
1648 
1649   Collective
1650 
1651   Input Parameters:
1652 + comm  - The communicator for the DM object
1653 . dim   - The spatial dimension
1654 . edges - Number of edges per dimension, or `NULL` for (1,) in 1D and (2, 2) in 2D and (1, 1, 1) in 3D
1655 . lower - The lower left corner, or `NULL` for (0, 0, 0)
1656 - upper - The upper right corner, or `NULL` for (1, 1, 1)
1657 
1658   Output Parameter:
1659 . dm - The DM object
1660 
1661   Level: beginner
1662 
1663   Note:
1664   If you want to customize this mesh using options, you just need to
1665 .vb
1666   DMCreate(comm, &dm);
1667   DMSetType(dm, DMPLEX);
1668   DMSetFromOptions(dm);
1669 .ve
1670   and use the options on the `DMSetFromOptions()` page.
1671 
1672   The vertices are numbered is lexicographic order, and the dim edges exiting a vertex in the positive orthant are number consecutively,
1673 .vb
1674  18--0-19--2-20--4-18
1675   |     |     |     |
1676  13    15    17    13
1677   |     |     |     |
1678  24-12-25-14-26-16-24
1679   |     |     |     |
1680   7     9    11     7
1681   |     |     |     |
1682  21--6-22--8-23-10-21
1683   |     |     |     |
1684   1     3     5     1
1685   |     |     |     |
1686  18--0-19--2-20--4-18
1687 .ve
1688 
1689 .seealso: `DMSetFromOptions()`, `DMPlexCreateFromFile()`, `DMPlexCreateHexCylinderMesh()`, `DMSetType()`, `DMCreate()`
1690 @*/
1691 PetscErrorCode DMPlexCreateHypercubicMesh(MPI_Comm comm, PetscInt dim, const PetscInt edges[], const PetscReal lower[], const PetscReal upper[], DM *dm)
1692 {
1693   PetscInt       *edg;
1694   PetscReal      *low, *upp;
1695   DMBoundaryType *bdt;
1696   PetscInt        d;
1697 
1698   PetscFunctionBegin;
1699   PetscCall(DMCreate(comm, dm));
1700   PetscCall(DMSetType(*dm, DMPLEX));
1701   PetscCall(PetscMalloc4(dim, &edg, dim, &low, dim, &upp, dim, &bdt));
1702   for (d = 0; d < dim; ++d) {
1703     edg[d] = edges ? edges[d] : 1;
1704     low[d] = lower ? lower[d] : 0.;
1705     upp[d] = upper ? upper[d] : 1.;
1706     bdt[d] = DM_BOUNDARY_PERIODIC;
1707   }
1708   PetscCall(DMPlexCreateHypercubicMesh_Internal(*dm, dim, low, upp, edg, bdt));
1709   PetscCall(PetscFree4(edg, low, upp, bdt));
1710   PetscFunctionReturn(PETSC_SUCCESS);
1711 }
1712 
1713 /*@C
1714   DMPlexSetOptionsPrefix - Sets the prefix used for searching for all `DM` options in the database.
1715 
1716   Logically Collective
1717 
1718   Input Parameters:
1719 + dm     - the `DM` context
1720 - prefix - the prefix to prepend to all option names
1721 
1722   Level: advanced
1723 
1724   Note:
1725   A hyphen (-) must NOT be given at the beginning of the prefix name.
1726   The first character of all runtime options is AUTOMATICALLY the hyphen.
1727 
1728 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `SNESSetFromOptions()`
1729 @*/
1730 PetscErrorCode DMPlexSetOptionsPrefix(DM dm, const char prefix[])
1731 {
1732   DM_Plex *mesh = (DM_Plex *)dm->data;
1733 
1734   PetscFunctionBegin;
1735   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
1736   PetscCall(PetscObjectSetOptionsPrefix((PetscObject)dm, prefix));
1737   PetscCall(PetscObjectSetOptionsPrefix((PetscObject)mesh->partitioner, prefix));
1738   PetscFunctionReturn(PETSC_SUCCESS);
1739 }
1740 
1741 /* Remap geometry to cylinder
1742    TODO: This only works for a single refinement, then it is broken
1743 
1744      Interior square: Linear interpolation is correct
1745      The other cells all have vertices on rays from the origin. We want to uniformly expand the spacing
1746      such that the last vertex is on the unit circle. So the closest and farthest vertices are at distance
1747 
1748        phi     = arctan(y/x)
1749        d_close = sqrt(1/8 + 1/4 sin^2(phi))
1750        d_far   = sqrt(1/2 + sin^2(phi))
1751 
1752      so we remap them using
1753 
1754        x_new = x_close + (x - x_close) (1 - d_close) / (d_far - d_close)
1755        y_new = y_close + (y - y_close) (1 - d_close) / (d_far - d_close)
1756 
1757      If pi/4 < phi < 3pi/4 or -3pi/4 < phi < -pi/4, then we switch x and y.
1758 */
1759 static void snapToCylinder(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f0[])
1760 {
1761   const PetscReal dis = 1.0 / PetscSqrtReal(2.0);
1762   const PetscReal ds2 = 0.5 * dis;
1763 
1764   if ((PetscAbsScalar(u[0]) <= ds2) && (PetscAbsScalar(u[1]) <= ds2)) {
1765     f0[0] = u[0];
1766     f0[1] = u[1];
1767   } else {
1768     PetscReal phi, sinp, cosp, dc, df, x, y, xc, yc;
1769 
1770     x    = PetscRealPart(u[0]);
1771     y    = PetscRealPart(u[1]);
1772     phi  = PetscAtan2Real(y, x);
1773     sinp = PetscSinReal(phi);
1774     cosp = PetscCosReal(phi);
1775     if ((PetscAbsReal(phi) > PETSC_PI / 4.0) && (PetscAbsReal(phi) < 3.0 * PETSC_PI / 4.0)) {
1776       dc = PetscAbsReal(ds2 / sinp);
1777       df = PetscAbsReal(dis / sinp);
1778       xc = ds2 * x / PetscAbsReal(y);
1779       yc = ds2 * PetscSignReal(y);
1780     } else {
1781       dc = PetscAbsReal(ds2 / cosp);
1782       df = PetscAbsReal(dis / cosp);
1783       xc = ds2 * PetscSignReal(x);
1784       yc = ds2 * y / PetscAbsReal(x);
1785     }
1786     f0[0] = xc + (u[0] - xc) * (1.0 - dc) / (df - dc);
1787     f0[1] = yc + (u[1] - yc) * (1.0 - dc) / (df - dc);
1788   }
1789   f0[2] = u[2];
1790 }
1791 
1792 static PetscErrorCode DMPlexCreateHexCylinderMesh_Internal(DM dm, DMBoundaryType periodicZ)
1793 {
1794   const PetscInt dim = 3;
1795   PetscInt       numCells, numVertices;
1796   PetscMPIInt    rank;
1797 
1798   PetscFunctionBegin;
1799   PetscCall(PetscLogEventBegin(DMPLEX_Generate, dm, 0, 0, 0));
1800   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank));
1801   PetscCall(DMSetDimension(dm, dim));
1802   /* Create topology */
1803   {
1804     PetscInt cone[8], c;
1805 
1806     numCells    = rank == 0 ? 5 : 0;
1807     numVertices = rank == 0 ? 16 : 0;
1808     if (periodicZ == DM_BOUNDARY_PERIODIC) {
1809       numCells *= 3;
1810       numVertices = rank == 0 ? 24 : 0;
1811     }
1812     PetscCall(DMPlexSetChart(dm, 0, numCells + numVertices));
1813     for (c = 0; c < numCells; c++) PetscCall(DMPlexSetConeSize(dm, c, 8));
1814     PetscCall(DMSetUp(dm));
1815     if (rank == 0) {
1816       if (periodicZ == DM_BOUNDARY_PERIODIC) {
1817         cone[0] = 15;
1818         cone[1] = 18;
1819         cone[2] = 17;
1820         cone[3] = 16;
1821         cone[4] = 31;
1822         cone[5] = 32;
1823         cone[6] = 33;
1824         cone[7] = 34;
1825         PetscCall(DMPlexSetCone(dm, 0, cone));
1826         cone[0] = 16;
1827         cone[1] = 17;
1828         cone[2] = 24;
1829         cone[3] = 23;
1830         cone[4] = 32;
1831         cone[5] = 36;
1832         cone[6] = 37;
1833         cone[7] = 33; /* 22 25 26 21 */
1834         PetscCall(DMPlexSetCone(dm, 1, cone));
1835         cone[0] = 18;
1836         cone[1] = 27;
1837         cone[2] = 24;
1838         cone[3] = 17;
1839         cone[4] = 34;
1840         cone[5] = 33;
1841         cone[6] = 37;
1842         cone[7] = 38;
1843         PetscCall(DMPlexSetCone(dm, 2, cone));
1844         cone[0] = 29;
1845         cone[1] = 27;
1846         cone[2] = 18;
1847         cone[3] = 15;
1848         cone[4] = 35;
1849         cone[5] = 31;
1850         cone[6] = 34;
1851         cone[7] = 38;
1852         PetscCall(DMPlexSetCone(dm, 3, cone));
1853         cone[0] = 29;
1854         cone[1] = 15;
1855         cone[2] = 16;
1856         cone[3] = 23;
1857         cone[4] = 35;
1858         cone[5] = 36;
1859         cone[6] = 32;
1860         cone[7] = 31;
1861         PetscCall(DMPlexSetCone(dm, 4, cone));
1862 
1863         cone[0] = 31;
1864         cone[1] = 34;
1865         cone[2] = 33;
1866         cone[3] = 32;
1867         cone[4] = 19;
1868         cone[5] = 22;
1869         cone[6] = 21;
1870         cone[7] = 20;
1871         PetscCall(DMPlexSetCone(dm, 5, cone));
1872         cone[0] = 32;
1873         cone[1] = 33;
1874         cone[2] = 37;
1875         cone[3] = 36;
1876         cone[4] = 22;
1877         cone[5] = 25;
1878         cone[6] = 26;
1879         cone[7] = 21;
1880         PetscCall(DMPlexSetCone(dm, 6, cone));
1881         cone[0] = 34;
1882         cone[1] = 38;
1883         cone[2] = 37;
1884         cone[3] = 33;
1885         cone[4] = 20;
1886         cone[5] = 21;
1887         cone[6] = 26;
1888         cone[7] = 28;
1889         PetscCall(DMPlexSetCone(dm, 7, cone));
1890         cone[0] = 35;
1891         cone[1] = 38;
1892         cone[2] = 34;
1893         cone[3] = 31;
1894         cone[4] = 30;
1895         cone[5] = 19;
1896         cone[6] = 20;
1897         cone[7] = 28;
1898         PetscCall(DMPlexSetCone(dm, 8, cone));
1899         cone[0] = 35;
1900         cone[1] = 31;
1901         cone[2] = 32;
1902         cone[3] = 36;
1903         cone[4] = 30;
1904         cone[5] = 25;
1905         cone[6] = 22;
1906         cone[7] = 19;
1907         PetscCall(DMPlexSetCone(dm, 9, cone));
1908 
1909         cone[0] = 19;
1910         cone[1] = 20;
1911         cone[2] = 21;
1912         cone[3] = 22;
1913         cone[4] = 15;
1914         cone[5] = 16;
1915         cone[6] = 17;
1916         cone[7] = 18;
1917         PetscCall(DMPlexSetCone(dm, 10, cone));
1918         cone[0] = 22;
1919         cone[1] = 21;
1920         cone[2] = 26;
1921         cone[3] = 25;
1922         cone[4] = 16;
1923         cone[5] = 23;
1924         cone[6] = 24;
1925         cone[7] = 17;
1926         PetscCall(DMPlexSetCone(dm, 11, cone));
1927         cone[0] = 20;
1928         cone[1] = 28;
1929         cone[2] = 26;
1930         cone[3] = 21;
1931         cone[4] = 18;
1932         cone[5] = 17;
1933         cone[6] = 24;
1934         cone[7] = 27;
1935         PetscCall(DMPlexSetCone(dm, 12, cone));
1936         cone[0] = 30;
1937         cone[1] = 28;
1938         cone[2] = 20;
1939         cone[3] = 19;
1940         cone[4] = 29;
1941         cone[5] = 15;
1942         cone[6] = 18;
1943         cone[7] = 27;
1944         PetscCall(DMPlexSetCone(dm, 13, cone));
1945         cone[0] = 30;
1946         cone[1] = 19;
1947         cone[2] = 22;
1948         cone[3] = 25;
1949         cone[4] = 29;
1950         cone[5] = 23;
1951         cone[6] = 16;
1952         cone[7] = 15;
1953         PetscCall(DMPlexSetCone(dm, 14, cone));
1954       } else {
1955         cone[0] = 5;
1956         cone[1] = 8;
1957         cone[2] = 7;
1958         cone[3] = 6;
1959         cone[4] = 9;
1960         cone[5] = 12;
1961         cone[6] = 11;
1962         cone[7] = 10;
1963         PetscCall(DMPlexSetCone(dm, 0, cone));
1964         cone[0] = 6;
1965         cone[1] = 7;
1966         cone[2] = 14;
1967         cone[3] = 13;
1968         cone[4] = 12;
1969         cone[5] = 15;
1970         cone[6] = 16;
1971         cone[7] = 11;
1972         PetscCall(DMPlexSetCone(dm, 1, cone));
1973         cone[0] = 8;
1974         cone[1] = 17;
1975         cone[2] = 14;
1976         cone[3] = 7;
1977         cone[4] = 10;
1978         cone[5] = 11;
1979         cone[6] = 16;
1980         cone[7] = 18;
1981         PetscCall(DMPlexSetCone(dm, 2, cone));
1982         cone[0] = 19;
1983         cone[1] = 17;
1984         cone[2] = 8;
1985         cone[3] = 5;
1986         cone[4] = 20;
1987         cone[5] = 9;
1988         cone[6] = 10;
1989         cone[7] = 18;
1990         PetscCall(DMPlexSetCone(dm, 3, cone));
1991         cone[0] = 19;
1992         cone[1] = 5;
1993         cone[2] = 6;
1994         cone[3] = 13;
1995         cone[4] = 20;
1996         cone[5] = 15;
1997         cone[6] = 12;
1998         cone[7] = 9;
1999         PetscCall(DMPlexSetCone(dm, 4, cone));
2000       }
2001     }
2002     PetscCall(DMPlexSymmetrize(dm));
2003     PetscCall(DMPlexStratify(dm));
2004   }
2005   /* Create cube geometry */
2006   {
2007     Vec             coordinates;
2008     PetscSection    coordSection;
2009     PetscScalar    *coords;
2010     PetscInt        coordSize, v;
2011     const PetscReal dis = 1.0 / PetscSqrtReal(2.0);
2012     const PetscReal ds2 = dis / 2.0;
2013 
2014     /* Build coordinates */
2015     PetscCall(DMGetCoordinateSection(dm, &coordSection));
2016     PetscCall(PetscSectionSetNumFields(coordSection, 1));
2017     PetscCall(PetscSectionSetFieldComponents(coordSection, 0, dim));
2018     PetscCall(PetscSectionSetChart(coordSection, numCells, numCells + numVertices));
2019     for (v = numCells; v < numCells + numVertices; ++v) {
2020       PetscCall(PetscSectionSetDof(coordSection, v, dim));
2021       PetscCall(PetscSectionSetFieldDof(coordSection, v, 0, dim));
2022     }
2023     PetscCall(PetscSectionSetUp(coordSection));
2024     PetscCall(PetscSectionGetStorageSize(coordSection, &coordSize));
2025     PetscCall(VecCreate(PETSC_COMM_SELF, &coordinates));
2026     PetscCall(PetscObjectSetName((PetscObject)coordinates, "coordinates"));
2027     PetscCall(VecSetSizes(coordinates, coordSize, PETSC_DETERMINE));
2028     PetscCall(VecSetBlockSize(coordinates, dim));
2029     PetscCall(VecSetType(coordinates, VECSTANDARD));
2030     PetscCall(VecGetArray(coordinates, &coords));
2031     if (rank == 0) {
2032       coords[0 * dim + 0]  = -ds2;
2033       coords[0 * dim + 1]  = -ds2;
2034       coords[0 * dim + 2]  = 0.0;
2035       coords[1 * dim + 0]  = ds2;
2036       coords[1 * dim + 1]  = -ds2;
2037       coords[1 * dim + 2]  = 0.0;
2038       coords[2 * dim + 0]  = ds2;
2039       coords[2 * dim + 1]  = ds2;
2040       coords[2 * dim + 2]  = 0.0;
2041       coords[3 * dim + 0]  = -ds2;
2042       coords[3 * dim + 1]  = ds2;
2043       coords[3 * dim + 2]  = 0.0;
2044       coords[4 * dim + 0]  = -ds2;
2045       coords[4 * dim + 1]  = -ds2;
2046       coords[4 * dim + 2]  = 1.0;
2047       coords[5 * dim + 0]  = -ds2;
2048       coords[5 * dim + 1]  = ds2;
2049       coords[5 * dim + 2]  = 1.0;
2050       coords[6 * dim + 0]  = ds2;
2051       coords[6 * dim + 1]  = ds2;
2052       coords[6 * dim + 2]  = 1.0;
2053       coords[7 * dim + 0]  = ds2;
2054       coords[7 * dim + 1]  = -ds2;
2055       coords[7 * dim + 2]  = 1.0;
2056       coords[8 * dim + 0]  = dis;
2057       coords[8 * dim + 1]  = -dis;
2058       coords[8 * dim + 2]  = 0.0;
2059       coords[9 * dim + 0]  = dis;
2060       coords[9 * dim + 1]  = dis;
2061       coords[9 * dim + 2]  = 0.0;
2062       coords[10 * dim + 0] = dis;
2063       coords[10 * dim + 1] = -dis;
2064       coords[10 * dim + 2] = 1.0;
2065       coords[11 * dim + 0] = dis;
2066       coords[11 * dim + 1] = dis;
2067       coords[11 * dim + 2] = 1.0;
2068       coords[12 * dim + 0] = -dis;
2069       coords[12 * dim + 1] = dis;
2070       coords[12 * dim + 2] = 0.0;
2071       coords[13 * dim + 0] = -dis;
2072       coords[13 * dim + 1] = dis;
2073       coords[13 * dim + 2] = 1.0;
2074       coords[14 * dim + 0] = -dis;
2075       coords[14 * dim + 1] = -dis;
2076       coords[14 * dim + 2] = 0.0;
2077       coords[15 * dim + 0] = -dis;
2078       coords[15 * dim + 1] = -dis;
2079       coords[15 * dim + 2] = 1.0;
2080       if (periodicZ == DM_BOUNDARY_PERIODIC) {
2081         /* 15 31 19 */ coords[16 * dim + 0] = -ds2;
2082         coords[16 * dim + 1]                = -ds2;
2083         coords[16 * dim + 2]                = 0.5;
2084         /* 16 32 22 */ coords[17 * dim + 0] = ds2;
2085         coords[17 * dim + 1]                = -ds2;
2086         coords[17 * dim + 2]                = 0.5;
2087         /* 17 33 21 */ coords[18 * dim + 0] = ds2;
2088         coords[18 * dim + 1]                = ds2;
2089         coords[18 * dim + 2]                = 0.5;
2090         /* 18 34 20 */ coords[19 * dim + 0] = -ds2;
2091         coords[19 * dim + 1]                = ds2;
2092         coords[19 * dim + 2]                = 0.5;
2093         /* 29 35 30 */ coords[20 * dim + 0] = -dis;
2094         coords[20 * dim + 1]                = -dis;
2095         coords[20 * dim + 2]                = 0.5;
2096         /* 23 36 25 */ coords[21 * dim + 0] = dis;
2097         coords[21 * dim + 1]                = -dis;
2098         coords[21 * dim + 2]                = 0.5;
2099         /* 24 37 26 */ coords[22 * dim + 0] = dis;
2100         coords[22 * dim + 1]                = dis;
2101         coords[22 * dim + 2]                = 0.5;
2102         /* 27 38 28 */ coords[23 * dim + 0] = -dis;
2103         coords[23 * dim + 1]                = dis;
2104         coords[23 * dim + 2]                = 0.5;
2105       }
2106     }
2107     PetscCall(VecRestoreArray(coordinates, &coords));
2108     PetscCall(DMSetCoordinatesLocal(dm, coordinates));
2109     PetscCall(VecDestroy(&coordinates));
2110   }
2111   /* Create periodicity */
2112   if (periodicZ == DM_BOUNDARY_PERIODIC || periodicZ == DM_BOUNDARY_TWIST) {
2113     PetscReal L[3]       = {-1., -1., 0.};
2114     PetscReal maxCell[3] = {-1., -1., 0.};
2115     PetscReal lower[3]   = {0.0, 0.0, 0.0};
2116     PetscReal upper[3]   = {1.0, 1.0, 1.5};
2117     PetscInt  numZCells  = 3;
2118 
2119     L[2]       = upper[2] - lower[2];
2120     maxCell[2] = 1.1 * (L[2] / numZCells);
2121     PetscCall(DMSetPeriodicity(dm, maxCell, lower, L));
2122   }
2123   {
2124     DM          cdm;
2125     PetscDS     cds;
2126     PetscScalar c[2] = {1.0, 1.0};
2127 
2128     PetscCall(DMPlexCreateCoordinateSpace(dm, 1, PETSC_TRUE, snapToCylinder));
2129     PetscCall(DMGetCoordinateDM(dm, &cdm));
2130     PetscCall(DMGetDS(cdm, &cds));
2131     PetscCall(PetscDSSetConstants(cds, 2, c));
2132   }
2133   PetscCall(PetscLogEventEnd(DMPLEX_Generate, dm, 0, 0, 0));
2134 
2135   /* Wait for coordinate creation before doing in-place modification */
2136   PetscCall(DMPlexInterpolateInPlace_Internal(dm));
2137   PetscFunctionReturn(PETSC_SUCCESS);
2138 }
2139 
2140 /*@
2141   DMPlexCreateHexCylinderMesh - Creates a mesh on the tensor product of the unit interval with the circle (cylinder) using hexahedra.
2142 
2143   Collective
2144 
2145   Input Parameters:
2146 + comm      - The communicator for the `DM` object
2147 - periodicZ - The boundary type for the Z direction
2148 
2149   Output Parameter:
2150 . dm - The `DM` object
2151 
2152   Level: beginner
2153 
2154   Note:
2155   Here is the output numbering looking from the bottom of the cylinder\:
2156 .vb
2157        17-----14
2158         |     |
2159         |  2  |
2160         |     |
2161  17-----8-----7-----14
2162   |     |     |     |
2163   |  3  |  0  |  1  |
2164   |     |     |     |
2165  19-----5-----6-----13
2166         |     |
2167         |  4  |
2168         |     |
2169        19-----13
2170 
2171  and up through the top
2172 
2173        18-----16
2174         |     |
2175         |  2  |
2176         |     |
2177  18----10----11-----16
2178   |     |     |     |
2179   |  3  |  0  |  1  |
2180   |     |     |     |
2181  20-----9----12-----15
2182         |     |
2183         |  4  |
2184         |     |
2185        20-----15
2186 .ve
2187 
2188 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexCreateBoxMesh()`, `DMSetType()`, `DMCreate()`
2189 @*/
2190 PetscErrorCode DMPlexCreateHexCylinderMesh(MPI_Comm comm, DMBoundaryType periodicZ, DM *dm)
2191 {
2192   PetscFunctionBegin;
2193   PetscAssertPointer(dm, 3);
2194   PetscCall(DMCreate(comm, dm));
2195   PetscCall(DMSetType(*dm, DMPLEX));
2196   PetscCall(DMPlexCreateHexCylinderMesh_Internal(*dm, periodicZ));
2197   PetscFunctionReturn(PETSC_SUCCESS);
2198 }
2199 
2200 static PetscErrorCode DMPlexCreateWedgeCylinderMesh_Internal(DM dm, PetscInt n, PetscBool interpolate)
2201 {
2202   const PetscInt dim = 3;
2203   PetscInt       numCells, numVertices, v;
2204   PetscMPIInt    rank;
2205 
2206   PetscFunctionBegin;
2207   PetscCheck(n >= 0, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Number of wedges %" PetscInt_FMT " cannot be negative", n);
2208   PetscCall(PetscLogEventBegin(DMPLEX_Generate, dm, 0, 0, 0));
2209   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank));
2210   PetscCall(DMSetDimension(dm, dim));
2211   /* Must create the celltype label here so that we do not automatically try to compute the types */
2212   PetscCall(DMCreateLabel(dm, "celltype"));
2213   /* Create topology */
2214   {
2215     PetscInt cone[6], c;
2216 
2217     numCells    = rank == 0 ? n : 0;
2218     numVertices = rank == 0 ? 2 * (n + 1) : 0;
2219     PetscCall(DMPlexSetChart(dm, 0, numCells + numVertices));
2220     for (c = 0; c < numCells; c++) PetscCall(DMPlexSetConeSize(dm, c, 6));
2221     PetscCall(DMSetUp(dm));
2222     for (c = 0; c < numCells; c++) {
2223       cone[0] = c + n * 1;
2224       cone[1] = (c + 1) % n + n * 1;
2225       cone[2] = 0 + 3 * n;
2226       cone[3] = c + n * 2;
2227       cone[4] = (c + 1) % n + n * 2;
2228       cone[5] = 1 + 3 * n;
2229       PetscCall(DMPlexSetCone(dm, c, cone));
2230       PetscCall(DMPlexSetCellType(dm, c, DM_POLYTOPE_TRI_PRISM_TENSOR));
2231     }
2232     PetscCall(DMPlexSymmetrize(dm));
2233     PetscCall(DMPlexStratify(dm));
2234   }
2235   for (v = numCells; v < numCells + numVertices; ++v) PetscCall(DMPlexSetCellType(dm, v, DM_POLYTOPE_POINT));
2236   /* Create cylinder geometry */
2237   {
2238     Vec          coordinates;
2239     PetscSection coordSection;
2240     PetscScalar *coords;
2241     PetscInt     coordSize, c;
2242 
2243     /* Build coordinates */
2244     PetscCall(DMGetCoordinateSection(dm, &coordSection));
2245     PetscCall(PetscSectionSetNumFields(coordSection, 1));
2246     PetscCall(PetscSectionSetFieldComponents(coordSection, 0, dim));
2247     PetscCall(PetscSectionSetChart(coordSection, numCells, numCells + numVertices));
2248     for (v = numCells; v < numCells + numVertices; ++v) {
2249       PetscCall(PetscSectionSetDof(coordSection, v, dim));
2250       PetscCall(PetscSectionSetFieldDof(coordSection, v, 0, dim));
2251     }
2252     PetscCall(PetscSectionSetUp(coordSection));
2253     PetscCall(PetscSectionGetStorageSize(coordSection, &coordSize));
2254     PetscCall(VecCreate(PETSC_COMM_SELF, &coordinates));
2255     PetscCall(PetscObjectSetName((PetscObject)coordinates, "coordinates"));
2256     PetscCall(VecSetSizes(coordinates, coordSize, PETSC_DETERMINE));
2257     PetscCall(VecSetBlockSize(coordinates, dim));
2258     PetscCall(VecSetType(coordinates, VECSTANDARD));
2259     PetscCall(VecGetArray(coordinates, &coords));
2260     for (c = 0; c < numCells; c++) {
2261       coords[(c + 0 * n) * dim + 0] = PetscCosReal(2.0 * c * PETSC_PI / n);
2262       coords[(c + 0 * n) * dim + 1] = PetscSinReal(2.0 * c * PETSC_PI / n);
2263       coords[(c + 0 * n) * dim + 2] = 1.0;
2264       coords[(c + 1 * n) * dim + 0] = PetscCosReal(2.0 * c * PETSC_PI / n);
2265       coords[(c + 1 * n) * dim + 1] = PetscSinReal(2.0 * c * PETSC_PI / n);
2266       coords[(c + 1 * n) * dim + 2] = 0.0;
2267     }
2268     if (rank == 0) {
2269       coords[(2 * n + 0) * dim + 0] = 0.0;
2270       coords[(2 * n + 0) * dim + 1] = 0.0;
2271       coords[(2 * n + 0) * dim + 2] = 1.0;
2272       coords[(2 * n + 1) * dim + 0] = 0.0;
2273       coords[(2 * n + 1) * dim + 1] = 0.0;
2274       coords[(2 * n + 1) * dim + 2] = 0.0;
2275     }
2276     PetscCall(VecRestoreArray(coordinates, &coords));
2277     PetscCall(DMSetCoordinatesLocal(dm, coordinates));
2278     PetscCall(VecDestroy(&coordinates));
2279   }
2280   PetscCall(PetscLogEventEnd(DMPLEX_Generate, dm, 0, 0, 0));
2281   /* Interpolate */
2282   if (interpolate) PetscCall(DMPlexInterpolateInPlace_Internal(dm));
2283   PetscFunctionReturn(PETSC_SUCCESS);
2284 }
2285 
2286 /*@
2287   DMPlexCreateWedgeCylinderMesh - Creates a mesh on the tensor product of the unit interval with the circle (cylinder) using wedges.
2288 
2289   Collective
2290 
2291   Input Parameters:
2292 + comm        - The communicator for the `DM` object
2293 . n           - The number of wedges around the origin
2294 - interpolate - Create edges and faces
2295 
2296   Output Parameter:
2297 . dm - The `DM` object
2298 
2299   Level: beginner
2300 
2301 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexCreateHexCylinderMesh()`, `DMPlexCreateBoxMesh()`, `DMSetType()`, `DMCreate()`
2302 @*/
2303 PetscErrorCode DMPlexCreateWedgeCylinderMesh(MPI_Comm comm, PetscInt n, PetscBool interpolate, DM *dm)
2304 {
2305   PetscFunctionBegin;
2306   PetscAssertPointer(dm, 4);
2307   PetscCall(DMCreate(comm, dm));
2308   PetscCall(DMSetType(*dm, DMPLEX));
2309   PetscCall(DMPlexCreateWedgeCylinderMesh_Internal(*dm, n, interpolate));
2310   PetscFunctionReturn(PETSC_SUCCESS);
2311 }
2312 
2313 static inline PetscReal DiffNormReal(PetscInt dim, const PetscReal x[], const PetscReal y[])
2314 {
2315   PetscReal prod = 0.0;
2316   PetscInt  i;
2317   for (i = 0; i < dim; ++i) prod += PetscSqr(x[i] - y[i]);
2318   return PetscSqrtReal(prod);
2319 }
2320 
2321 static inline PetscReal DotReal(PetscInt dim, const PetscReal x[], const PetscReal y[])
2322 {
2323   PetscReal prod = 0.0;
2324   PetscInt  i;
2325   for (i = 0; i < dim; ++i) prod += x[i] * y[i];
2326   return prod;
2327 }
2328 
2329 /* The first constant is the sphere radius */
2330 static void snapToSphere(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f0[])
2331 {
2332   PetscReal r     = PetscRealPart(constants[0]);
2333   PetscReal norm2 = 0.0, fac;
2334   PetscInt  n     = uOff[1] - uOff[0], d;
2335 
2336   for (d = 0; d < n; ++d) norm2 += PetscSqr(PetscRealPart(u[d]));
2337   fac = r / PetscSqrtReal(norm2);
2338   for (d = 0; d < n; ++d) f0[d] = u[d] * fac;
2339 }
2340 
2341 static PetscErrorCode DMPlexCreateSphereMesh_Internal(DM dm, PetscInt dim, PetscBool simplex, PetscReal R)
2342 {
2343   const PetscInt embedDim = dim + 1;
2344   PetscSection   coordSection;
2345   Vec            coordinates;
2346   PetscScalar   *coords;
2347   PetscReal     *coordsIn;
2348   PetscInt       numCells, numEdges, numVerts = 0, firstVertex = 0, v, firstEdge, coordSize, d, e;
2349   PetscMPIInt    rank;
2350 
2351   PetscFunctionBegin;
2352   PetscValidLogicalCollectiveBool(dm, simplex, 3);
2353   PetscCall(PetscLogEventBegin(DMPLEX_Generate, dm, 0, 0, 0));
2354   PetscCall(DMSetDimension(dm, dim));
2355   PetscCall(DMSetCoordinateDim(dm, dim + 1));
2356   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank));
2357   switch (dim) {
2358   case 1:
2359     numCells = 16;
2360     numVerts = numCells;
2361 
2362     // Build Topology
2363     PetscCall(DMPlexSetChart(dm, 0, numCells + numVerts));
2364     for (PetscInt c = 0; c < numCells; c++) PetscCall(DMPlexSetConeSize(dm, c, embedDim));
2365     PetscCall(DMSetUp(dm));
2366     for (PetscInt c = 0; c < numCells; ++c) {
2367       PetscInt cone[2];
2368 
2369       cone[0] = c + numCells;
2370       cone[1] = (c + 1) % numVerts + numCells;
2371       PetscCall(DMPlexSetCone(dm, c, cone));
2372     }
2373     PetscCall(DMPlexSymmetrize(dm));
2374     PetscCall(DMPlexStratify(dm));
2375     PetscCall(PetscMalloc1(numVerts * embedDim, &coordsIn));
2376     for (PetscInt v = 0; v < numVerts; ++v) {
2377       const PetscReal rad = 2. * PETSC_PI * v / numVerts;
2378 
2379       coordsIn[v * embedDim + 0] = PetscCosReal(rad);
2380       coordsIn[v * embedDim + 1] = PetscSinReal(rad);
2381     }
2382     break;
2383   case 2:
2384     if (simplex) {
2385       const PetscReal radius    = PetscSqrtReal(1 + PETSC_PHI * PETSC_PHI) / (1.0 + PETSC_PHI);
2386       const PetscReal edgeLen   = 2.0 / (1.0 + PETSC_PHI) * (R / radius);
2387       const PetscInt  degree    = 5;
2388       PetscReal       vertex[3] = {0.0, 1.0 / (1.0 + PETSC_PHI), PETSC_PHI / (1.0 + PETSC_PHI)};
2389       PetscInt        s[3]      = {1, 1, 1};
2390       PetscInt        cone[3];
2391       PetscInt       *graph;
2392 
2393       vertex[0] *= R / radius;
2394       vertex[1] *= R / radius;
2395       vertex[2] *= R / radius;
2396       numCells    = rank == 0 ? 20 : 0;
2397       numVerts    = rank == 0 ? 12 : 0;
2398       firstVertex = numCells;
2399       /* Use icosahedron, which for a R-sphere has coordinates which are all cyclic permutations of
2400 
2401            (0, \pm 1/\phi+1, \pm \phi/\phi+1)
2402 
2403          where \phi^2 - \phi - 1 = 0, meaning \phi is the golden ratio \frac{1 + \sqrt{5}}{2}. The edge
2404          length is then given by 2/(1+\phi) = 2 * 0.38197 = 0.76393.
2405       */
2406       /* Construct vertices */
2407       PetscCall(PetscCalloc1(numVerts * embedDim, &coordsIn));
2408       if (rank == 0) {
2409         for (PetscInt p = 0, i = 0; p < embedDim; ++p) {
2410           for (s[1] = -1; s[1] < 2; s[1] += 2) {
2411             for (s[2] = -1; s[2] < 2; s[2] += 2) {
2412               for (d = 0; d < embedDim; ++d) coordsIn[i * embedDim + d] = s[(d + p) % embedDim] * vertex[(d + p) % embedDim];
2413               ++i;
2414             }
2415           }
2416         }
2417       }
2418       /* Construct graph */
2419       PetscCall(PetscCalloc1(numVerts * numVerts, &graph));
2420       for (PetscInt i = 0; i < numVerts; ++i) {
2421         PetscInt k = 0;
2422         for (PetscInt j = 0; j < numVerts; ++j) {
2423           if (PetscAbsReal(DiffNormReal(embedDim, &coordsIn[i * embedDim], &coordsIn[j * embedDim]) - edgeLen) < PETSC_SMALL) {
2424             graph[i * numVerts + j] = 1;
2425             ++k;
2426           }
2427         }
2428         PetscCheck(k == degree, PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Invalid icosahedron, vertex %" PetscInt_FMT " degree %" PetscInt_FMT " != %" PetscInt_FMT, i, k, degree);
2429       }
2430       /* Build Topology */
2431       PetscCall(DMPlexSetChart(dm, 0, numCells + numVerts));
2432       for (PetscInt c = 0; c < numCells; c++) PetscCall(DMPlexSetConeSize(dm, c, embedDim));
2433       PetscCall(DMSetUp(dm)); /* Allocate space for cones */
2434       /* Cells */
2435       for (PetscInt i = 0, c = 0; i < numVerts; ++i) {
2436         for (PetscInt j = 0; j < i; ++j) {
2437           for (PetscInt k = 0; k < j; ++k) {
2438             if (graph[i * numVerts + j] && graph[j * numVerts + k] && graph[k * numVerts + i]) {
2439               cone[0] = firstVertex + i;
2440               cone[1] = firstVertex + j;
2441               cone[2] = firstVertex + k;
2442               /* Check orientation */
2443               {
2444                 const PetscInt epsilon[3][3][3] = {
2445                   {{0, 0, 0},  {0, 0, 1},  {0, -1, 0}},
2446                   {{0, 0, -1}, {0, 0, 0},  {1, 0, 0} },
2447                   {{0, 1, 0},  {-1, 0, 0}, {0, 0, 0} }
2448                 };
2449                 PetscReal normal[3];
2450                 PetscInt  e, f;
2451 
2452                 for (d = 0; d < embedDim; ++d) {
2453                   normal[d] = 0.0;
2454                   for (e = 0; e < embedDim; ++e) {
2455                     for (f = 0; f < embedDim; ++f) normal[d] += epsilon[d][e][f] * (coordsIn[j * embedDim + e] - coordsIn[i * embedDim + e]) * (coordsIn[k * embedDim + f] - coordsIn[i * embedDim + f]);
2456                   }
2457                 }
2458                 if (DotReal(embedDim, normal, &coordsIn[i * embedDim]) < 0) {
2459                   PetscInt tmp = cone[1];
2460                   cone[1]      = cone[2];
2461                   cone[2]      = tmp;
2462                 }
2463               }
2464               PetscCall(DMPlexSetCone(dm, c++, cone));
2465             }
2466           }
2467         }
2468       }
2469       PetscCall(DMPlexSymmetrize(dm));
2470       PetscCall(DMPlexStratify(dm));
2471       PetscCall(PetscFree(graph));
2472     } else {
2473       /*
2474         12-21--13
2475          |     |
2476         25  4  24
2477          |     |
2478   12-25--9-16--8-24--13
2479    |     |     |     |
2480   23  5 17  0 15  3  22
2481    |     |     |     |
2482   10-20--6-14--7-19--11
2483          |     |
2484         20  1  19
2485          |     |
2486         10-18--11
2487          |     |
2488         23  2  22
2489          |     |
2490         12-21--13
2491        */
2492       PetscInt cone[4], ornt[4];
2493 
2494       numCells    = rank == 0 ? 6 : 0;
2495       numEdges    = rank == 0 ? 12 : 0;
2496       numVerts    = rank == 0 ? 8 : 0;
2497       firstVertex = numCells;
2498       firstEdge   = numCells + numVerts;
2499       /* Build Topology */
2500       PetscCall(DMPlexSetChart(dm, 0, numCells + numEdges + numVerts));
2501       for (PetscInt c = 0; c < numCells; c++) PetscCall(DMPlexSetConeSize(dm, c, 4));
2502       for (e = firstEdge; e < firstEdge + numEdges; ++e) PetscCall(DMPlexSetConeSize(dm, e, 2));
2503       PetscCall(DMSetUp(dm)); /* Allocate space for cones */
2504       if (rank == 0) {
2505         /* Cell 0 */
2506         cone[0] = 14;
2507         cone[1] = 15;
2508         cone[2] = 16;
2509         cone[3] = 17;
2510         PetscCall(DMPlexSetCone(dm, 0, cone));
2511         ornt[0] = 0;
2512         ornt[1] = 0;
2513         ornt[2] = 0;
2514         ornt[3] = 0;
2515         PetscCall(DMPlexSetConeOrientation(dm, 0, ornt));
2516         /* Cell 1 */
2517         cone[0] = 18;
2518         cone[1] = 19;
2519         cone[2] = 14;
2520         cone[3] = 20;
2521         PetscCall(DMPlexSetCone(dm, 1, cone));
2522         ornt[0] = 0;
2523         ornt[1] = 0;
2524         ornt[2] = -1;
2525         ornt[3] = 0;
2526         PetscCall(DMPlexSetConeOrientation(dm, 1, ornt));
2527         /* Cell 2 */
2528         cone[0] = 21;
2529         cone[1] = 22;
2530         cone[2] = 18;
2531         cone[3] = 23;
2532         PetscCall(DMPlexSetCone(dm, 2, cone));
2533         ornt[0] = 0;
2534         ornt[1] = 0;
2535         ornt[2] = -1;
2536         ornt[3] = 0;
2537         PetscCall(DMPlexSetConeOrientation(dm, 2, ornt));
2538         /* Cell 3 */
2539         cone[0] = 19;
2540         cone[1] = 22;
2541         cone[2] = 24;
2542         cone[3] = 15;
2543         PetscCall(DMPlexSetCone(dm, 3, cone));
2544         ornt[0] = -1;
2545         ornt[1] = -1;
2546         ornt[2] = 0;
2547         ornt[3] = -1;
2548         PetscCall(DMPlexSetConeOrientation(dm, 3, ornt));
2549         /* Cell 4 */
2550         cone[0] = 16;
2551         cone[1] = 24;
2552         cone[2] = 21;
2553         cone[3] = 25;
2554         PetscCall(DMPlexSetCone(dm, 4, cone));
2555         ornt[0] = -1;
2556         ornt[1] = -1;
2557         ornt[2] = -1;
2558         ornt[3] = 0;
2559         PetscCall(DMPlexSetConeOrientation(dm, 4, ornt));
2560         /* Cell 5 */
2561         cone[0] = 20;
2562         cone[1] = 17;
2563         cone[2] = 25;
2564         cone[3] = 23;
2565         PetscCall(DMPlexSetCone(dm, 5, cone));
2566         ornt[0] = -1;
2567         ornt[1] = -1;
2568         ornt[2] = -1;
2569         ornt[3] = -1;
2570         PetscCall(DMPlexSetConeOrientation(dm, 5, ornt));
2571         /* Edges */
2572         cone[0] = 6;
2573         cone[1] = 7;
2574         PetscCall(DMPlexSetCone(dm, 14, cone));
2575         cone[0] = 7;
2576         cone[1] = 8;
2577         PetscCall(DMPlexSetCone(dm, 15, cone));
2578         cone[0] = 8;
2579         cone[1] = 9;
2580         PetscCall(DMPlexSetCone(dm, 16, cone));
2581         cone[0] = 9;
2582         cone[1] = 6;
2583         PetscCall(DMPlexSetCone(dm, 17, cone));
2584         cone[0] = 10;
2585         cone[1] = 11;
2586         PetscCall(DMPlexSetCone(dm, 18, cone));
2587         cone[0] = 11;
2588         cone[1] = 7;
2589         PetscCall(DMPlexSetCone(dm, 19, cone));
2590         cone[0] = 6;
2591         cone[1] = 10;
2592         PetscCall(DMPlexSetCone(dm, 20, cone));
2593         cone[0] = 12;
2594         cone[1] = 13;
2595         PetscCall(DMPlexSetCone(dm, 21, cone));
2596         cone[0] = 13;
2597         cone[1] = 11;
2598         PetscCall(DMPlexSetCone(dm, 22, cone));
2599         cone[0] = 10;
2600         cone[1] = 12;
2601         PetscCall(DMPlexSetCone(dm, 23, cone));
2602         cone[0] = 13;
2603         cone[1] = 8;
2604         PetscCall(DMPlexSetCone(dm, 24, cone));
2605         cone[0] = 12;
2606         cone[1] = 9;
2607         PetscCall(DMPlexSetCone(dm, 25, cone));
2608       }
2609       PetscCall(DMPlexSymmetrize(dm));
2610       PetscCall(DMPlexStratify(dm));
2611       /* Build coordinates */
2612       PetscCall(PetscCalloc1(numVerts * embedDim, &coordsIn));
2613       if (rank == 0) {
2614         coordsIn[0 * embedDim + 0] = -R;
2615         coordsIn[0 * embedDim + 1] = R;
2616         coordsIn[0 * embedDim + 2] = -R;
2617         coordsIn[1 * embedDim + 0] = R;
2618         coordsIn[1 * embedDim + 1] = R;
2619         coordsIn[1 * embedDim + 2] = -R;
2620         coordsIn[2 * embedDim + 0] = R;
2621         coordsIn[2 * embedDim + 1] = -R;
2622         coordsIn[2 * embedDim + 2] = -R;
2623         coordsIn[3 * embedDim + 0] = -R;
2624         coordsIn[3 * embedDim + 1] = -R;
2625         coordsIn[3 * embedDim + 2] = -R;
2626         coordsIn[4 * embedDim + 0] = -R;
2627         coordsIn[4 * embedDim + 1] = R;
2628         coordsIn[4 * embedDim + 2] = R;
2629         coordsIn[5 * embedDim + 0] = R;
2630         coordsIn[5 * embedDim + 1] = R;
2631         coordsIn[5 * embedDim + 2] = R;
2632         coordsIn[6 * embedDim + 0] = -R;
2633         coordsIn[6 * embedDim + 1] = -R;
2634         coordsIn[6 * embedDim + 2] = R;
2635         coordsIn[7 * embedDim + 0] = R;
2636         coordsIn[7 * embedDim + 1] = -R;
2637         coordsIn[7 * embedDim + 2] = R;
2638       }
2639     }
2640     break;
2641   case 3:
2642     if (simplex) {
2643       const PetscReal edgeLen         = 1.0 / PETSC_PHI;
2644       PetscReal       vertexA[4]      = {0.5, 0.5, 0.5, 0.5};
2645       PetscReal       vertexB[4]      = {1.0, 0.0, 0.0, 0.0};
2646       PetscReal       vertexC[4]      = {0.5, 0.5 * PETSC_PHI, 0.5 / PETSC_PHI, 0.0};
2647       const PetscInt  degree          = 12;
2648       PetscInt        s[4]            = {1, 1, 1};
2649       PetscInt        evenPerm[12][4] = {
2650         {0, 1, 2, 3},
2651         {0, 2, 3, 1},
2652         {0, 3, 1, 2},
2653         {1, 0, 3, 2},
2654         {1, 2, 0, 3},
2655         {1, 3, 2, 0},
2656         {2, 0, 1, 3},
2657         {2, 1, 3, 0},
2658         {2, 3, 0, 1},
2659         {3, 0, 2, 1},
2660         {3, 1, 0, 2},
2661         {3, 2, 1, 0}
2662       };
2663       PetscInt  cone[4];
2664       PetscInt *graph, p, i, j, k, l;
2665 
2666       vertexA[0] *= R;
2667       vertexA[1] *= R;
2668       vertexA[2] *= R;
2669       vertexA[3] *= R;
2670       vertexB[0] *= R;
2671       vertexB[1] *= R;
2672       vertexB[2] *= R;
2673       vertexB[3] *= R;
2674       vertexC[0] *= R;
2675       vertexC[1] *= R;
2676       vertexC[2] *= R;
2677       vertexC[3] *= R;
2678       numCells    = rank == 0 ? 600 : 0;
2679       numVerts    = rank == 0 ? 120 : 0;
2680       firstVertex = numCells;
2681       /* Use the 600-cell, which for a unit sphere has coordinates which are
2682 
2683            1/2 (\pm 1, \pm 1,    \pm 1, \pm 1)                          16
2684                (\pm 1,    0,       0,      0)  all cyclic permutations   8
2685            1/2 (\pm 1, \pm phi, \pm 1/phi, 0)  all even permutations    96
2686 
2687          where \phi^2 - \phi - 1 = 0, meaning \phi is the golden ratio \frac{1 + \sqrt{5}}{2}. The edge
2688          length is then given by 1/\phi = 0.61803.
2689 
2690          http://buzzard.pugetsound.edu/sage-practice/ch03s03.html
2691          http://mathworld.wolfram.com/600-Cell.html
2692       */
2693       /* Construct vertices */
2694       PetscCall(PetscCalloc1(numVerts * embedDim, &coordsIn));
2695       i = 0;
2696       if (rank == 0) {
2697         for (s[0] = -1; s[0] < 2; s[0] += 2) {
2698           for (s[1] = -1; s[1] < 2; s[1] += 2) {
2699             for (s[2] = -1; s[2] < 2; s[2] += 2) {
2700               for (s[3] = -1; s[3] < 2; s[3] += 2) {
2701                 for (d = 0; d < embedDim; ++d) coordsIn[i * embedDim + d] = s[d] * vertexA[d];
2702                 ++i;
2703               }
2704             }
2705           }
2706         }
2707         for (p = 0; p < embedDim; ++p) {
2708           s[1] = s[2] = s[3] = 1;
2709           for (s[0] = -1; s[0] < 2; s[0] += 2) {
2710             for (d = 0; d < embedDim; ++d) coordsIn[i * embedDim + d] = s[(d + p) % embedDim] * vertexB[(d + p) % embedDim];
2711             ++i;
2712           }
2713         }
2714         for (p = 0; p < 12; ++p) {
2715           s[3] = 1;
2716           for (s[0] = -1; s[0] < 2; s[0] += 2) {
2717             for (s[1] = -1; s[1] < 2; s[1] += 2) {
2718               for (s[2] = -1; s[2] < 2; s[2] += 2) {
2719                 for (d = 0; d < embedDim; ++d) coordsIn[i * embedDim + d] = s[evenPerm[p][d]] * vertexC[evenPerm[p][d]];
2720                 ++i;
2721               }
2722             }
2723           }
2724         }
2725       }
2726       PetscCheck(i == numVerts, PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Invalid 600-cell, vertices %" PetscInt_FMT " != %" PetscInt_FMT, i, numVerts);
2727       /* Construct graph */
2728       PetscCall(PetscCalloc1(numVerts * numVerts, &graph));
2729       for (i = 0; i < numVerts; ++i) {
2730         for (j = 0, k = 0; j < numVerts; ++j) {
2731           if (PetscAbsReal(DiffNormReal(embedDim, &coordsIn[i * embedDim], &coordsIn[j * embedDim]) - edgeLen) < PETSC_SMALL) {
2732             graph[i * numVerts + j] = 1;
2733             ++k;
2734           }
2735         }
2736         PetscCheck(k == degree, PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Invalid 600-cell, vertex %" PetscInt_FMT " degree %" PetscInt_FMT " != %" PetscInt_FMT, i, k, degree);
2737       }
2738       /* Build Topology */
2739       PetscCall(DMPlexSetChart(dm, 0, numCells + numVerts));
2740       for (PetscInt c = 0; c < numCells; c++) PetscCall(DMPlexSetConeSize(dm, c, embedDim));
2741       PetscCall(DMSetUp(dm)); /* Allocate space for cones */
2742       /* Cells */
2743       if (rank == 0) {
2744         for (PetscInt i = 0, c = 0; i < numVerts; ++i) {
2745           for (j = 0; j < i; ++j) {
2746             for (k = 0; k < j; ++k) {
2747               for (l = 0; l < k; ++l) {
2748                 if (graph[i * numVerts + j] && graph[j * numVerts + k] && graph[k * numVerts + i] && graph[l * numVerts + i] && graph[l * numVerts + j] && graph[l * numVerts + k]) {
2749                   cone[0] = firstVertex + i;
2750                   cone[1] = firstVertex + j;
2751                   cone[2] = firstVertex + k;
2752                   cone[3] = firstVertex + l;
2753                   /* Check orientation: https://ef.gy/linear-algebra:normal-vectors-in-higher-dimensional-spaces */
2754                   {
2755                     const PetscInt epsilon[4][4][4][4] = {
2756                       {{{0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}},  {{0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 1}, {0, 0, -1, 0}}, {{0, 0, 0, 0}, {0, 0, 0, -1}, {0, 0, 0, 0}, {0, 1, 0, 0}}, {{0, 0, 0, 0}, {0, 0, 1, 0}, {0, -1, 0, 0}, {0, 0, 0, 0}}},
2757 
2758                       {{{0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, -1}, {0, 0, 1, 0}}, {{0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}},  {{0, 0, 0, 1}, {0, 0, 0, 0}, {0, 0, 0, 0}, {-1, 0, 0, 0}}, {{0, 0, -1, 0}, {0, 0, 0, 0}, {1, 0, 0, 0}, {0, 0, 0, 0}}},
2759 
2760                       {{{0, 0, 0, 0}, {0, 0, 0, 1}, {0, 0, 0, 0}, {0, -1, 0, 0}}, {{0, 0, 0, -1}, {0, 0, 0, 0}, {0, 0, 0, 0}, {1, 0, 0, 0}}, {{0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}},  {{0, 1, 0, 0}, {-1, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}}},
2761 
2762                       {{{0, 0, 0, 0}, {0, 0, -1, 0}, {0, 1, 0, 0}, {0, 0, 0, 0}}, {{0, 0, 1, 0}, {0, 0, 0, 0}, {-1, 0, 0, 0}, {0, 0, 0, 0}}, {{0, -1, 0, 0}, {1, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}}, {{0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}} }
2763                     };
2764                     PetscReal normal[4];
2765                     PetscInt  e, f, g;
2766 
2767                     for (d = 0; d < embedDim; ++d) {
2768                       normal[d] = 0.0;
2769                       for (e = 0; e < embedDim; ++e) {
2770                         for (f = 0; f < embedDim; ++f) {
2771                           for (g = 0; g < embedDim; ++g) {
2772                             normal[d] += epsilon[d][e][f][g] * (coordsIn[j * embedDim + e] - coordsIn[i * embedDim + e]) * (coordsIn[k * embedDim + f] - coordsIn[i * embedDim + f]) * (coordsIn[l * embedDim + f] - coordsIn[i * embedDim + f]);
2773                           }
2774                         }
2775                       }
2776                     }
2777                     if (DotReal(embedDim, normal, &coordsIn[i * embedDim]) < 0) {
2778                       PetscInt tmp = cone[1];
2779                       cone[1]      = cone[2];
2780                       cone[2]      = tmp;
2781                     }
2782                   }
2783                   PetscCall(DMPlexSetCone(dm, c++, cone));
2784                 }
2785               }
2786             }
2787           }
2788         }
2789       }
2790       PetscCall(DMPlexSymmetrize(dm));
2791       PetscCall(DMPlexStratify(dm));
2792       PetscCall(PetscFree(graph));
2793     }
2794     break;
2795   default:
2796     SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Unsupported dimension for sphere: %" PetscInt_FMT, dim);
2797   }
2798   /* Create coordinates */
2799   PetscCall(DMGetCoordinateSection(dm, &coordSection));
2800   PetscCall(PetscSectionSetNumFields(coordSection, 1));
2801   PetscCall(PetscSectionSetFieldComponents(coordSection, 0, embedDim));
2802   PetscCall(PetscSectionSetChart(coordSection, firstVertex, firstVertex + numVerts));
2803   for (v = firstVertex; v < firstVertex + numVerts; ++v) {
2804     PetscCall(PetscSectionSetDof(coordSection, v, embedDim));
2805     PetscCall(PetscSectionSetFieldDof(coordSection, v, 0, embedDim));
2806   }
2807   PetscCall(PetscSectionSetUp(coordSection));
2808   PetscCall(PetscSectionGetStorageSize(coordSection, &coordSize));
2809   PetscCall(VecCreate(PETSC_COMM_SELF, &coordinates));
2810   PetscCall(VecSetBlockSize(coordinates, embedDim));
2811   PetscCall(PetscObjectSetName((PetscObject)coordinates, "coordinates"));
2812   PetscCall(VecSetSizes(coordinates, coordSize, PETSC_DETERMINE));
2813   PetscCall(VecSetType(coordinates, VECSTANDARD));
2814   PetscCall(VecGetArray(coordinates, &coords));
2815   for (v = 0; v < numVerts; ++v)
2816     for (d = 0; d < embedDim; ++d) coords[v * embedDim + d] = coordsIn[v * embedDim + d];
2817   PetscCall(VecRestoreArray(coordinates, &coords));
2818   PetscCall(DMSetCoordinatesLocal(dm, coordinates));
2819   PetscCall(VecDestroy(&coordinates));
2820   PetscCall(PetscFree(coordsIn));
2821   {
2822     DM          cdm;
2823     PetscDS     cds;
2824     PetscScalar c = R;
2825 
2826     PetscCall(DMPlexCreateCoordinateSpace(dm, 1, PETSC_TRUE, snapToSphere));
2827     PetscCall(DMGetCoordinateDM(dm, &cdm));
2828     PetscCall(DMGetDS(cdm, &cds));
2829     PetscCall(PetscDSSetConstants(cds, 1, &c));
2830   }
2831   PetscCall(PetscLogEventEnd(DMPLEX_Generate, dm, 0, 0, 0));
2832   /* Wait for coordinate creation before doing in-place modification */
2833   if (simplex) PetscCall(DMPlexInterpolateInPlace_Internal(dm));
2834   PetscFunctionReturn(PETSC_SUCCESS);
2835 }
2836 
2837 typedef void (*TPSEvaluateFunc)(const PetscReal[], PetscReal *, PetscReal[], PetscReal (*)[3]);
2838 
2839 /*
2840  The Schwarz P implicit surface is
2841 
2842      f(x) = cos(x0) + cos(x1) + cos(x2) = 0
2843 */
2844 static void TPSEvaluate_SchwarzP(const PetscReal y[3], PetscReal *f, PetscReal grad[], PetscReal (*hess)[3])
2845 {
2846   PetscReal c[3] = {PetscCosReal(y[0] * PETSC_PI), PetscCosReal(y[1] * PETSC_PI), PetscCosReal(y[2] * PETSC_PI)};
2847   PetscReal g[3] = {-PetscSinReal(y[0] * PETSC_PI), -PetscSinReal(y[1] * PETSC_PI), -PetscSinReal(y[2] * PETSC_PI)};
2848   f[0]           = c[0] + c[1] + c[2];
2849   for (PetscInt i = 0; i < 3; i++) {
2850     grad[i] = PETSC_PI * g[i];
2851     for (PetscInt j = 0; j < 3; j++) hess[i][j] = (i == j) ? -PetscSqr(PETSC_PI) * c[i] : 0.;
2852   }
2853 }
2854 
2855 // u[] is a tentative normal on input. Replace with the implicit function gradient in the same direction
2856 static PetscErrorCode TPSExtrudeNormalFunc_SchwarzP(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt r, PetscScalar u[], void *ctx)
2857 {
2858   for (PetscInt i = 0; i < 3; i++) u[i] = -PETSC_PI * PetscSinReal(x[i] * PETSC_PI);
2859   return PETSC_SUCCESS;
2860 }
2861 
2862 /*
2863  The Gyroid implicit surface is
2864 
2865  f(x,y,z) = sin(pi * x) * cos (pi * (y + 1/2))  + sin(pi * (y + 1/2)) * cos(pi * (z + 1/4)) + sin(pi * (z + 1/4)) * cos(pi * x)
2866 
2867 */
2868 static void TPSEvaluate_Gyroid(const PetscReal y[3], PetscReal *f, PetscReal grad[], PetscReal (*hess)[3])
2869 {
2870   PetscReal s[3] = {PetscSinReal(PETSC_PI * y[0]), PetscSinReal(PETSC_PI * (y[1] + .5)), PetscSinReal(PETSC_PI * (y[2] + .25))};
2871   PetscReal c[3] = {PetscCosReal(PETSC_PI * y[0]), PetscCosReal(PETSC_PI * (y[1] + .5)), PetscCosReal(PETSC_PI * (y[2] + .25))};
2872   f[0]           = s[0] * c[1] + s[1] * c[2] + s[2] * c[0];
2873   grad[0]        = PETSC_PI * (c[0] * c[1] - s[2] * s[0]);
2874   grad[1]        = PETSC_PI * (c[1] * c[2] - s[0] * s[1]);
2875   grad[2]        = PETSC_PI * (c[2] * c[0] - s[1] * s[2]);
2876   hess[0][0]     = -PetscSqr(PETSC_PI) * (s[0] * c[1] + s[2] * c[0]);
2877   hess[0][1]     = -PetscSqr(PETSC_PI) * (c[0] * s[1]);
2878   hess[0][2]     = -PetscSqr(PETSC_PI) * (c[2] * s[0]);
2879   hess[1][0]     = -PetscSqr(PETSC_PI) * (s[1] * c[2] + s[0] * c[1]);
2880   hess[1][1]     = -PetscSqr(PETSC_PI) * (c[1] * s[2]);
2881   hess[2][2]     = -PetscSqr(PETSC_PI) * (c[0] * s[1]);
2882   hess[2][0]     = -PetscSqr(PETSC_PI) * (s[2] * c[0] + s[1] * c[2]);
2883   hess[2][1]     = -PetscSqr(PETSC_PI) * (c[2] * s[0]);
2884   hess[2][2]     = -PetscSqr(PETSC_PI) * (c[1] * s[2]);
2885 }
2886 
2887 // u[] is a tentative normal on input. Replace with the implicit function gradient in the same direction
2888 static PetscErrorCode TPSExtrudeNormalFunc_Gyroid(PetscInt dim, PetscReal time, const PetscReal x[], PetscInt r, PetscScalar u[], void *ctx)
2889 {
2890   PetscReal s[3] = {PetscSinReal(PETSC_PI * x[0]), PetscSinReal(PETSC_PI * (x[1] + .5)), PetscSinReal(PETSC_PI * (x[2] + .25))};
2891   PetscReal c[3] = {PetscCosReal(PETSC_PI * x[0]), PetscCosReal(PETSC_PI * (x[1] + .5)), PetscCosReal(PETSC_PI * (x[2] + .25))};
2892   u[0]           = PETSC_PI * (c[0] * c[1] - s[2] * s[0]);
2893   u[1]           = PETSC_PI * (c[1] * c[2] - s[0] * s[1]);
2894   u[2]           = PETSC_PI * (c[2] * c[0] - s[1] * s[2]);
2895   return PETSC_SUCCESS;
2896 }
2897 
2898 /*
2899    We wish to solve
2900 
2901          min_y || y - x ||^2  subject to f(y) = 0
2902 
2903    Let g(y) = grad(f).  The minimization problem is equivalent to asking to satisfy
2904    f(y) = 0 and (y-x) is parallel to g(y).  We do this by using Householder QR to obtain a basis for the
2905    tangent space and ask for both components in the tangent space to be zero.
2906 
2907    Take g to be a column vector and compute the "full QR" factorization Q R = g,
2908    where Q = I - 2 n n^T is a symmetric orthogonal matrix.
2909    The first column of Q is parallel to g so the remaining two columns span the null space.
2910    Let Qn = Q[:,1:] be those remaining columns.  Then Qn Qn^T is an orthogonal projector into the tangent space.
2911    Since Q is symmetric, this is equivalent to multiplying by Q and taking the last two entries.
2912    In total, we have a system of 3 equations in 3 unknowns:
2913 
2914      f(y) = 0                       1 equation
2915      Qn^T (y - x) = 0               2 equations
2916 
2917    Here, we compute the residual and Jacobian of this system.
2918 */
2919 static void TPSNearestPointResJac(TPSEvaluateFunc feval, const PetscScalar x[], const PetscScalar y[], PetscScalar res[], PetscScalar J[])
2920 {
2921   PetscReal yreal[3] = {PetscRealPart(y[0]), PetscRealPart(y[1]), PetscRealPart(y[2])};
2922   PetscReal d[3]     = {PetscRealPart(y[0] - x[0]), PetscRealPart(y[1] - x[1]), PetscRealPart(y[2] - x[2])};
2923   PetscReal f, grad[3], n[3], norm, norm_y[3], nd, nd_y[3], sign;
2924   PetscReal n_y[3][3] = {
2925     {0, 0, 0},
2926     {0, 0, 0},
2927     {0, 0, 0}
2928   };
2929 
2930   feval(yreal, &f, grad, n_y);
2931 
2932   for (PetscInt i = 0; i < 3; i++) n[i] = grad[i];
2933   norm = PetscSqrtReal(PetscSqr(n[0]) + PetscSqr(n[1]) + PetscSqr(n[2]));
2934   for (PetscInt i = 0; i < 3; i++) norm_y[i] = 1. / norm * n[i] * n_y[i][i];
2935 
2936   // Define the Householder reflector
2937   sign = n[0] >= 0 ? 1. : -1.;
2938   n[0] += norm * sign;
2939   for (PetscInt i = 0; i < 3; i++) n_y[0][i] += norm_y[i] * sign;
2940 
2941   norm      = PetscSqrtReal(PetscSqr(n[0]) + PetscSqr(n[1]) + PetscSqr(n[2]));
2942   norm_y[0] = 1. / norm * (n[0] * n_y[0][0]);
2943   norm_y[1] = 1. / norm * (n[0] * n_y[0][1] + n[1] * n_y[1][1]);
2944   norm_y[2] = 1. / norm * (n[0] * n_y[0][2] + n[2] * n_y[2][2]);
2945 
2946   for (PetscInt i = 0; i < 3; i++) {
2947     n[i] /= norm;
2948     for (PetscInt j = 0; j < 3; j++) {
2949       // note that n[i] is n_old[i]/norm when executing the code below
2950       n_y[i][j] = n_y[i][j] / norm - n[i] / norm * norm_y[j];
2951     }
2952   }
2953 
2954   nd = n[0] * d[0] + n[1] * d[1] + n[2] * d[2];
2955   for (PetscInt i = 0; i < 3; i++) nd_y[i] = n[i] + n_y[0][i] * d[0] + n_y[1][i] * d[1] + n_y[2][i] * d[2];
2956 
2957   res[0] = f;
2958   res[1] = d[1] - 2 * n[1] * nd;
2959   res[2] = d[2] - 2 * n[2] * nd;
2960   // J[j][i] is J_{ij} (column major)
2961   for (PetscInt j = 0; j < 3; j++) {
2962     J[0 + j * 3] = grad[j];
2963     J[1 + j * 3] = (j == 1) * 1. - 2 * (n_y[1][j] * nd + n[1] * nd_y[j]);
2964     J[2 + j * 3] = (j == 2) * 1. - 2 * (n_y[2][j] * nd + n[2] * nd_y[j]);
2965   }
2966 }
2967 
2968 /*
2969    Project x to the nearest point on the implicit surface using Newton's method.
2970 */
2971 static PetscErrorCode TPSNearestPoint(TPSEvaluateFunc feval, PetscScalar x[])
2972 {
2973   PetscScalar y[3] = {x[0], x[1], x[2]}; // Initial guess
2974 
2975   PetscFunctionBegin;
2976   for (PetscInt iter = 0; iter < 10; iter++) {
2977     PetscScalar res[3], J[9];
2978     PetscReal   resnorm;
2979     TPSNearestPointResJac(feval, x, y, res, J);
2980     resnorm = PetscSqrtReal(PetscSqr(PetscRealPart(res[0])) + PetscSqr(PetscRealPart(res[1])) + PetscSqr(PetscRealPart(res[2])));
2981     if (0) { // Turn on this monitor if you need to confirm quadratic convergence
2982       PetscCall(PetscPrintf(PETSC_COMM_SELF, "[%" PetscInt_FMT "] res [%g %g %g]\n", iter, (double)PetscRealPart(res[0]), (double)PetscRealPart(res[1]), (double)PetscRealPart(res[2])));
2983     }
2984     if (resnorm < PETSC_SMALL) break;
2985 
2986     // Take the Newton step
2987     PetscCall(PetscKernel_A_gets_inverse_A_3(J, 0., PETSC_FALSE, NULL));
2988     PetscKernel_v_gets_v_minus_A_times_w_3(y, J, res);
2989   }
2990   for (PetscInt i = 0; i < 3; i++) x[i] = y[i];
2991   PetscFunctionReturn(PETSC_SUCCESS);
2992 }
2993 
2994 const char *const DMPlexTPSTypes[] = {"SCHWARZ_P", "GYROID", "DMPlexTPSType", "DMPLEX_TPS_", NULL};
2995 
2996 static PetscErrorCode DMPlexCreateTPSMesh_Internal(DM dm, DMPlexTPSType tpstype, const PetscInt extent[], const DMBoundaryType periodic[], PetscBool tps_distribute, PetscInt refinements, PetscInt layers, PetscReal thickness)
2997 {
2998   PetscMPIInt rank;
2999   PetscInt    topoDim = 2, spaceDim = 3, numFaces = 0, numVertices = 0, numEdges = 0;
3000   PetscInt(*edges)[2] = NULL, *edgeSets = NULL;
3001   PetscInt            *cells_flat = NULL;
3002   PetscReal           *vtxCoords  = NULL;
3003   TPSEvaluateFunc      evalFunc   = NULL;
3004   PetscSimplePoint_Fn *normalFunc = NULL;
3005   DMLabel              label;
3006 
3007   PetscFunctionBegin;
3008   PetscCall(PetscLogEventBegin(DMPLEX_Generate, dm, 0, 0, 0));
3009   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank));
3010   PetscCheck((layers != 0) ^ (thickness == 0.), PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_INCOMP, "Layers %" PetscInt_FMT " must be nonzero iff thickness %g is nonzero", layers, (double)thickness);
3011   switch (tpstype) {
3012   case DMPLEX_TPS_SCHWARZ_P:
3013     PetscCheck(!periodic || (periodic[0] == DM_BOUNDARY_NONE && periodic[1] == DM_BOUNDARY_NONE && periodic[2] == DM_BOUNDARY_NONE), PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Schwarz P does not support periodic meshes");
3014     if (rank == 0) {
3015       PetscInt(*cells)[6][4][4] = NULL; // [junction, junction-face, cell, conn]
3016       PetscInt  Njunctions = 0, Ncuts = 0, Npipes[3], vcount;
3017       PetscReal L = 1;
3018 
3019       Npipes[0]   = (extent[0] + 1) * extent[1] * extent[2];
3020       Npipes[1]   = extent[0] * (extent[1] + 1) * extent[2];
3021       Npipes[2]   = extent[0] * extent[1] * (extent[2] + 1);
3022       Njunctions  = extent[0] * extent[1] * extent[2];
3023       Ncuts       = 2 * (extent[0] * extent[1] + extent[1] * extent[2] + extent[2] * extent[0]);
3024       numVertices = 4 * (Npipes[0] + Npipes[1] + Npipes[2]) + 8 * Njunctions;
3025       PetscCall(PetscMalloc1(3 * numVertices, &vtxCoords));
3026       PetscCall(PetscMalloc1(Njunctions, &cells));
3027       PetscCall(PetscMalloc1(Ncuts * 4, &edges));
3028       PetscCall(PetscMalloc1(Ncuts * 4, &edgeSets));
3029       // x-normal pipes
3030       vcount = 0;
3031       for (PetscInt i = 0; i < extent[0] + 1; i++) {
3032         for (PetscInt j = 0; j < extent[1]; j++) {
3033           for (PetscInt k = 0; k < extent[2]; k++) {
3034             for (PetscInt l = 0; l < 4; l++) {
3035               vtxCoords[vcount++] = (2 * i - 1) * L;
3036               vtxCoords[vcount++] = 2 * j * L + PetscCosReal((2 * l + 1) * PETSC_PI / 4) * L / 2;
3037               vtxCoords[vcount++] = 2 * k * L + PetscSinReal((2 * l + 1) * PETSC_PI / 4) * L / 2;
3038             }
3039           }
3040         }
3041       }
3042       // y-normal pipes
3043       for (PetscInt i = 0; i < extent[0]; i++) {
3044         for (PetscInt j = 0; j < extent[1] + 1; j++) {
3045           for (PetscInt k = 0; k < extent[2]; k++) {
3046             for (PetscInt l = 0; l < 4; l++) {
3047               vtxCoords[vcount++] = 2 * i * L + PetscSinReal((2 * l + 1) * PETSC_PI / 4) * L / 2;
3048               vtxCoords[vcount++] = (2 * j - 1) * L;
3049               vtxCoords[vcount++] = 2 * k * L + PetscCosReal((2 * l + 1) * PETSC_PI / 4) * L / 2;
3050             }
3051           }
3052         }
3053       }
3054       // z-normal pipes
3055       for (PetscInt i = 0; i < extent[0]; i++) {
3056         for (PetscInt j = 0; j < extent[1]; j++) {
3057           for (PetscInt k = 0; k < extent[2] + 1; k++) {
3058             for (PetscInt l = 0; l < 4; l++) {
3059               vtxCoords[vcount++] = 2 * i * L + PetscCosReal((2 * l + 1) * PETSC_PI / 4) * L / 2;
3060               vtxCoords[vcount++] = 2 * j * L + PetscSinReal((2 * l + 1) * PETSC_PI / 4) * L / 2;
3061               vtxCoords[vcount++] = (2 * k - 1) * L;
3062             }
3063           }
3064         }
3065       }
3066       // junctions
3067       for (PetscInt i = 0; i < extent[0]; i++) {
3068         for (PetscInt j = 0; j < extent[1]; j++) {
3069           for (PetscInt k = 0; k < extent[2]; k++) {
3070             const PetscInt J = (i * extent[1] + j) * extent[2] + k, Jvoff = (Npipes[0] + Npipes[1] + Npipes[2]) * 4 + J * 8;
3071             PetscCheck(vcount / 3 == Jvoff, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Unexpected vertex count");
3072             for (PetscInt ii = 0; ii < 2; ii++) {
3073               for (PetscInt jj = 0; jj < 2; jj++) {
3074                 for (PetscInt kk = 0; kk < 2; kk++) {
3075                   double Ls           = (1 - sqrt(2) / 4) * L;
3076                   vtxCoords[vcount++] = 2 * i * L + (2 * ii - 1) * Ls;
3077                   vtxCoords[vcount++] = 2 * j * L + (2 * jj - 1) * Ls;
3078                   vtxCoords[vcount++] = 2 * k * L + (2 * kk - 1) * Ls;
3079                 }
3080               }
3081             }
3082             const PetscInt jfaces[3][2][4] = {
3083               {{3, 1, 0, 2}, {7, 5, 4, 6}}, // x-aligned
3084               {{5, 4, 0, 1}, {7, 6, 2, 3}}, // y-aligned
3085               {{6, 2, 0, 4}, {7, 3, 1, 5}}  // z-aligned
3086             };
3087             const PetscInt pipe_lo[3] = {// vertex numbers of pipes
3088                                          ((i * extent[1] + j) * extent[2] + k) * 4, ((i * (extent[1] + 1) + j) * extent[2] + k + Npipes[0]) * 4, ((i * extent[1] + j) * (extent[2] + 1) + k + Npipes[0] + Npipes[1]) * 4};
3089             const PetscInt pipe_hi[3] = {// vertex numbers of pipes
3090                                          (((i + 1) * extent[1] + j) * extent[2] + k) * 4, ((i * (extent[1] + 1) + j + 1) * extent[2] + k + Npipes[0]) * 4, ((i * extent[1] + j) * (extent[2] + 1) + k + 1 + Npipes[0] + Npipes[1]) * 4};
3091             for (PetscInt dir = 0; dir < 3; dir++) { // x,y,z
3092               const PetscInt ijk[3] = {i, j, k};
3093               for (PetscInt l = 0; l < 4; l++) { // rotations
3094                 cells[J][dir * 2 + 0][l][0] = pipe_lo[dir] + l;
3095                 cells[J][dir * 2 + 0][l][1] = Jvoff + jfaces[dir][0][l];
3096                 cells[J][dir * 2 + 0][l][2] = Jvoff + jfaces[dir][0][(l - 1 + 4) % 4];
3097                 cells[J][dir * 2 + 0][l][3] = pipe_lo[dir] + (l - 1 + 4) % 4;
3098                 cells[J][dir * 2 + 1][l][0] = Jvoff + jfaces[dir][1][l];
3099                 cells[J][dir * 2 + 1][l][1] = pipe_hi[dir] + l;
3100                 cells[J][dir * 2 + 1][l][2] = pipe_hi[dir] + (l - 1 + 4) % 4;
3101                 cells[J][dir * 2 + 1][l][3] = Jvoff + jfaces[dir][1][(l - 1 + 4) % 4];
3102                 if (ijk[dir] == 0) {
3103                   edges[numEdges][0] = pipe_lo[dir] + l;
3104                   edges[numEdges][1] = pipe_lo[dir] + (l + 1) % 4;
3105                   edgeSets[numEdges] = dir * 2 + 1;
3106                   numEdges++;
3107                 }
3108                 if (ijk[dir] + 1 == extent[dir]) {
3109                   edges[numEdges][0] = pipe_hi[dir] + l;
3110                   edges[numEdges][1] = pipe_hi[dir] + (l + 1) % 4;
3111                   edgeSets[numEdges] = dir * 2 + 2;
3112                   numEdges++;
3113                 }
3114               }
3115             }
3116           }
3117         }
3118       }
3119       PetscCheck(numEdges == Ncuts * 4, PetscObjectComm((PetscObject)dm), PETSC_ERR_PLIB, "Edge count %" PetscInt_FMT " incompatible with number of cuts %" PetscInt_FMT, numEdges, Ncuts);
3120       numFaces   = 24 * Njunctions;
3121       cells_flat = cells[0][0][0];
3122     }
3123     evalFunc   = TPSEvaluate_SchwarzP;
3124     normalFunc = TPSExtrudeNormalFunc_SchwarzP;
3125     break;
3126   case DMPLEX_TPS_GYROID:
3127     if (rank == 0) {
3128       // This is a coarse mesh approximation of the gyroid shifted to being the zero of the level set
3129       //
3130       //     sin(pi*x)*cos(pi*(y+1/2)) + sin(pi*(y+1/2))*cos(pi*(z+1/4)) + sin(pi*(z+1/4))*cos(x)
3131       //
3132       // on the cell [0,2]^3.
3133       //
3134       // Think about dividing that cell into four columns, and focus on the column [0,1]x[0,1]x[0,2].
3135       // If you looked at the gyroid in that column at different slices of z you would see that it kind of spins
3136       // like a boomerang:
3137       //
3138       //     z = 0          z = 1/4        z = 1/2        z = 3/4     //
3139       //     -----          -------        -------        -------     //
3140       //                                                              //
3141       //     +       +      +       +      +       +      +   \   +   //
3142       //      \                                   /            \      //
3143       //       \            `-_   _-'            /              }     //
3144       //        *-_            `-'            _-'              /      //
3145       //     +     `-+      +       +      +-'     +      +   /   +   //
3146       //                                                              //
3147       //                                                              //
3148       //     z = 1          z = 5/4        z = 3/2        z = 7/4     //
3149       //     -----          -------        -------        -------     //
3150       //                                                              //
3151       //     +-_     +      +       +      +     _-+      +   /   +   //
3152       //        `-_            _-_            _-`            /        //
3153       //           \        _-'   `-_        /              {         //
3154       //            \                       /                \        //
3155       //     +       +      +       +      +       +      +   \   +   //
3156       //
3157       //
3158       // This course mesh approximates each of these slices by two line segments,
3159       // and then connects the segments in consecutive layers with quadrilateral faces.
3160       // All of the end points of the segments are multiples of 1/4 except for the
3161       // point * in the picture for z = 0 above and the similar points in other layers.
3162       // That point is at (gamma, gamma, 0), where gamma is calculated below.
3163       //
3164       // The column  [1,2]x[1,2]x[0,2] looks the same as this column;
3165       // The columns [1,2]x[0,1]x[0,2] and [0,1]x[1,2]x[0,2] are mirror images.
3166       //
3167       // As for how this method turned into the names given to the vertices:
3168       // that was not systematic, it was just the way it worked out in my handwritten notes.
3169 
3170       PetscInt facesPerBlock = 64;
3171       PetscInt vertsPerBlock = 56;
3172       PetscInt extentPlus[3];
3173       PetscInt numBlocks, numBlocksPlus;
3174       const PetscInt A = 0, B = 1, C = 2, D = 3, E = 4, F = 5, G = 6, H = 7, II = 8, J = 9, K = 10, L = 11, M = 12, N = 13, O = 14, P = 15, Q = 16, R = 17, S = 18, T = 19, U = 20, V = 21, W = 22, X = 23, Y = 24, Z = 25, Ap = 26, Bp = 27, Cp = 28, Dp = 29, Ep = 30, Fp = 31, Gp = 32, Hp = 33, Ip = 34, Jp = 35, Kp = 36, Lp = 37, Mp = 38, Np = 39, Op = 40, Pp = 41, Qp = 42, Rp = 43, Sp = 44, Tp = 45, Up = 46, Vp = 47, Wp = 48, Xp = 49, Yp = 50, Zp = 51, Aq = 52, Bq = 53, Cq = 54, Dq = 55;
3175       const PetscInt pattern[64][4] = {
3176   /* face to vertex within the coarse discretization of a single gyroid block */
3177   /* layer 0 */
3178         {A,           C,           K,           G          },
3179         {C,           B,           II,          K          },
3180         {D,           A,           H,           L          },
3181         {B + 56 * 1,  D,           L,           J          },
3182         {E,           B + 56 * 1,  J,           N          },
3183         {A + 56 * 2,  E,           N,           H + 56 * 2 },
3184         {F,           A + 56 * 2,  G + 56 * 2,  M          },
3185         {B,           F,           M,           II         },
3186  /* layer 1 */
3187         {G,           K,           Q,           O          },
3188         {K,           II,          P,           Q          },
3189         {L,           H,           O + 56 * 1,  R          },
3190         {J,           L,           R,           P          },
3191         {N,           J,           P,           S          },
3192         {H + 56 * 2,  N,           S,           O + 56 * 3 },
3193         {M,           G + 56 * 2,  O + 56 * 2,  T          },
3194         {II,          M,           T,           P          },
3195  /* layer 2 */
3196         {O,           Q,           Y,           U          },
3197         {Q,           P,           W,           Y          },
3198         {R,           O + 56 * 1,  U + 56 * 1,  Ap         },
3199         {P,           R,           Ap,          W          },
3200         {S,           P,           X,           Bp         },
3201         {O + 56 * 3,  S,           Bp,          V + 56 * 1 },
3202         {T,           O + 56 * 2,  V,           Z          },
3203         {P,           T,           Z,           X          },
3204  /* layer 3 */
3205         {U,           Y,           Ep,          Dp         },
3206         {Y,           W,           Cp,          Ep         },
3207         {Ap,          U + 56 * 1,  Dp + 56 * 1, Gp         },
3208         {W,           Ap,          Gp,          Cp         },
3209         {Bp,          X,           Cp + 56 * 2, Fp         },
3210         {V + 56 * 1,  Bp,          Fp,          Dp + 56 * 1},
3211         {Z,           V,           Dp,          Hp         },
3212         {X,           Z,           Hp,          Cp + 56 * 2},
3213  /* layer 4 */
3214         {Dp,          Ep,          Mp,          Kp         },
3215         {Ep,          Cp,          Ip,          Mp         },
3216         {Gp,          Dp + 56 * 1, Lp,          Np         },
3217         {Cp,          Gp,          Np,          Jp         },
3218         {Fp,          Cp + 56 * 2, Jp + 56 * 2, Pp         },
3219         {Dp + 56 * 1, Fp,          Pp,          Lp         },
3220         {Hp,          Dp,          Kp,          Op         },
3221         {Cp + 56 * 2, Hp,          Op,          Ip + 56 * 2},
3222  /* layer 5 */
3223         {Kp,          Mp,          Sp,          Rp         },
3224         {Mp,          Ip,          Qp,          Sp         },
3225         {Np,          Lp,          Rp,          Tp         },
3226         {Jp,          Np,          Tp,          Qp + 56 * 1},
3227         {Pp,          Jp + 56 * 2, Qp + 56 * 3, Up         },
3228         {Lp,          Pp,          Up,          Rp         },
3229         {Op,          Kp,          Rp,          Vp         },
3230         {Ip + 56 * 2, Op,          Vp,          Qp + 56 * 2},
3231  /* layer 6 */
3232         {Rp,          Sp,          Aq,          Yp         },
3233         {Sp,          Qp,          Wp,          Aq         },
3234         {Tp,          Rp,          Yp,          Cq         },
3235         {Qp + 56 * 1, Tp,          Cq,          Wp + 56 * 1},
3236         {Up,          Qp + 56 * 3, Xp + 56 * 1, Dq         },
3237         {Rp,          Up,          Dq,          Zp         },
3238         {Vp,          Rp,          Zp,          Bq         },
3239         {Qp + 56 * 2, Vp,          Bq,          Xp         },
3240  /* layer 7 (the top is the periodic image of the bottom of layer 0) */
3241         {Yp,          Aq,          C + 56 * 4,  A + 56 * 4 },
3242         {Aq,          Wp,          B + 56 * 4,  C + 56 * 4 },
3243         {Cq,          Yp,          A + 56 * 4,  D + 56 * 4 },
3244         {Wp + 56 * 1, Cq,          D + 56 * 4,  B + 56 * 5 },
3245         {Dq,          Xp + 56 * 1, B + 56 * 5,  E + 56 * 4 },
3246         {Zp,          Dq,          E + 56 * 4,  A + 56 * 6 },
3247         {Bq,          Zp,          A + 56 * 6,  F + 56 * 4 },
3248         {Xp,          Bq,          F + 56 * 4,  B + 56 * 4 }
3249       };
3250       const PetscReal gamma                = PetscAcosReal((PetscSqrtReal(3.) - 1.) / PetscSqrtReal(2.)) / PETSC_PI;
3251       const PetscReal patternCoords[56][3] = {
3252         {1.,        0.,        0.  }, /* A  */
3253         {0.,        1.,        0.  }, /* B  */
3254         {gamma,     gamma,     0.  }, /* C  */
3255         {1 + gamma, 1 - gamma, 0.  }, /* D  */
3256         {2 - gamma, 2 - gamma, 0.  }, /* E  */
3257         {1 - gamma, 1 + gamma, 0.  }, /* F  */
3258 
3259         {.5,        0,         .25 }, /* G  */
3260         {1.5,       0.,        .25 }, /* H  */
3261         {.5,        1.,        .25 }, /* II */
3262         {1.5,       1.,        .25 }, /* J  */
3263         {.25,       .5,        .25 }, /* K  */
3264         {1.25,      .5,        .25 }, /* L  */
3265         {.75,       1.5,       .25 }, /* M  */
3266         {1.75,      1.5,       .25 }, /* N  */
3267 
3268         {0.,        0.,        .5  }, /* O  */
3269         {1.,        1.,        .5  }, /* P  */
3270         {gamma,     1 - gamma, .5  }, /* Q  */
3271         {1 + gamma, gamma,     .5  }, /* R  */
3272         {2 - gamma, 1 + gamma, .5  }, /* S  */
3273         {1 - gamma, 2 - gamma, .5  }, /* T  */
3274 
3275         {0.,        .5,        .75 }, /* U  */
3276         {0.,        1.5,       .75 }, /* V  */
3277         {1.,        .5,        .75 }, /* W  */
3278         {1.,        1.5,       .75 }, /* X  */
3279         {.5,        .75,       .75 }, /* Y  */
3280         {.5,        1.75,      .75 }, /* Z  */
3281         {1.5,       .25,       .75 }, /* Ap */
3282         {1.5,       1.25,      .75 }, /* Bp */
3283 
3284         {1.,        0.,        1.  }, /* Cp */
3285         {0.,        1.,        1.  }, /* Dp */
3286         {1 - gamma, 1 - gamma, 1.  }, /* Ep */
3287         {1 + gamma, 1 + gamma, 1.  }, /* Fp */
3288         {2 - gamma, gamma,     1.  }, /* Gp */
3289         {gamma,     2 - gamma, 1.  }, /* Hp */
3290 
3291         {.5,        0.,        1.25}, /* Ip */
3292         {1.5,       0.,        1.25}, /* Jp */
3293         {.5,        1.,        1.25}, /* Kp */
3294         {1.5,       1.,        1.25}, /* Lp */
3295         {.75,       .5,        1.25}, /* Mp */
3296         {1.75,      .5,        1.25}, /* Np */
3297         {.25,       1.5,       1.25}, /* Op */
3298         {1.25,      1.5,       1.25}, /* Pp */
3299 
3300         {0.,        0.,        1.5 }, /* Qp */
3301         {1.,        1.,        1.5 }, /* Rp */
3302         {1 - gamma, gamma,     1.5 }, /* Sp */
3303         {2 - gamma, 1 - gamma, 1.5 }, /* Tp */
3304         {1 + gamma, 2 - gamma, 1.5 }, /* Up */
3305         {gamma,     1 + gamma, 1.5 }, /* Vp */
3306 
3307         {0.,        .5,        1.75}, /* Wp */
3308         {0.,        1.5,       1.75}, /* Xp */
3309         {1.,        .5,        1.75}, /* Yp */
3310         {1.,        1.5,       1.75}, /* Zp */
3311         {.5,        .25,       1.75}, /* Aq */
3312         {.5,        1.25,      1.75}, /* Bq */
3313         {1.5,       .75,       1.75}, /* Cq */
3314         {1.5,       1.75,      1.75}, /* Dq */
3315       };
3316       PetscInt(*cells)[64][4] = NULL;
3317       PetscBool *seen;
3318       PetscInt  *vertToTrueVert;
3319       PetscInt   count;
3320 
3321       for (PetscInt i = 0; i < 3; i++) extentPlus[i] = extent[i] + 1;
3322       numBlocks = 1;
3323       for (PetscInt i = 0; i < 3; i++) numBlocks *= extent[i];
3324       numBlocksPlus = 1;
3325       for (PetscInt i = 0; i < 3; i++) numBlocksPlus *= extentPlus[i];
3326       numFaces = numBlocks * facesPerBlock;
3327       PetscCall(PetscMalloc1(numBlocks, &cells));
3328       PetscCall(PetscCalloc1(numBlocksPlus * vertsPerBlock, &seen));
3329       for (PetscInt k = 0; k < extent[2]; k++) {
3330         for (PetscInt j = 0; j < extent[1]; j++) {
3331           for (PetscInt i = 0; i < extent[0]; i++) {
3332             for (PetscInt f = 0; f < facesPerBlock; f++) {
3333               for (PetscInt v = 0; v < 4; v++) {
3334                 PetscInt vertRaw     = pattern[f][v];
3335                 PetscInt blockidx    = vertRaw / 56;
3336                 PetscInt patternvert = vertRaw % 56;
3337                 PetscInt xplus       = (blockidx & 1);
3338                 PetscInt yplus       = (blockidx & 2) >> 1;
3339                 PetscInt zplus       = (blockidx & 4) >> 2;
3340                 PetscInt zcoord      = (periodic && periodic[2] == DM_BOUNDARY_PERIODIC) ? ((k + zplus) % extent[2]) : (k + zplus);
3341                 PetscInt ycoord      = (periodic && periodic[1] == DM_BOUNDARY_PERIODIC) ? ((j + yplus) % extent[1]) : (j + yplus);
3342                 PetscInt xcoord      = (periodic && periodic[0] == DM_BOUNDARY_PERIODIC) ? ((i + xplus) % extent[0]) : (i + xplus);
3343                 PetscInt vert        = ((zcoord * extentPlus[1] + ycoord) * extentPlus[0] + xcoord) * 56 + patternvert;
3344 
3345                 cells[(k * extent[1] + j) * extent[0] + i][f][v] = vert;
3346                 seen[vert]                                       = PETSC_TRUE;
3347               }
3348             }
3349           }
3350         }
3351       }
3352       for (PetscInt i = 0; i < numBlocksPlus * vertsPerBlock; i++)
3353         if (seen[i]) numVertices++;
3354       count = 0;
3355       PetscCall(PetscMalloc1(numBlocksPlus * vertsPerBlock, &vertToTrueVert));
3356       PetscCall(PetscMalloc1(numVertices * 3, &vtxCoords));
3357       for (PetscInt i = 0; i < numBlocksPlus * vertsPerBlock; i++) vertToTrueVert[i] = -1;
3358       for (PetscInt k = 0; k < extentPlus[2]; k++) {
3359         for (PetscInt j = 0; j < extentPlus[1]; j++) {
3360           for (PetscInt i = 0; i < extentPlus[0]; i++) {
3361             for (PetscInt v = 0; v < vertsPerBlock; v++) {
3362               PetscInt vIdx = ((k * extentPlus[1] + j) * extentPlus[0] + i) * vertsPerBlock + v;
3363 
3364               if (seen[vIdx]) {
3365                 PetscInt thisVert;
3366 
3367                 vertToTrueVert[vIdx] = thisVert = count++;
3368 
3369                 for (PetscInt d = 0; d < 3; d++) vtxCoords[3 * thisVert + d] = patternCoords[v][d];
3370                 vtxCoords[3 * thisVert + 0] += i * 2;
3371                 vtxCoords[3 * thisVert + 1] += j * 2;
3372                 vtxCoords[3 * thisVert + 2] += k * 2;
3373               }
3374             }
3375           }
3376         }
3377       }
3378       for (PetscInt i = 0; i < numBlocks; i++) {
3379         for (PetscInt f = 0; f < facesPerBlock; f++) {
3380           for (PetscInt v = 0; v < 4; v++) cells[i][f][v] = vertToTrueVert[cells[i][f][v]];
3381         }
3382       }
3383       PetscCall(PetscFree(vertToTrueVert));
3384       PetscCall(PetscFree(seen));
3385       cells_flat = cells[0][0];
3386       numEdges   = 0;
3387       for (PetscInt i = 0; i < numFaces; i++) {
3388         for (PetscInt e = 0; e < 4; e++) {
3389           PetscInt         ev[]       = {cells_flat[i * 4 + e], cells_flat[i * 4 + ((e + 1) % 4)]};
3390           const PetscReal *evCoords[] = {&vtxCoords[3 * ev[0]], &vtxCoords[3 * ev[1]]};
3391 
3392           for (PetscInt d = 0; d < 3; d++) {
3393             if (!periodic || periodic[0] != DM_BOUNDARY_PERIODIC) {
3394               if (evCoords[0][d] == 0. && evCoords[1][d] == 0.) numEdges++;
3395               if (evCoords[0][d] == 2. * extent[d] && evCoords[1][d] == 2. * extent[d]) numEdges++;
3396             }
3397           }
3398         }
3399       }
3400       PetscCall(PetscMalloc1(numEdges, &edges));
3401       PetscCall(PetscMalloc1(numEdges, &edgeSets));
3402       for (PetscInt edge = 0, i = 0; i < numFaces; i++) {
3403         for (PetscInt e = 0; e < 4; e++) {
3404           PetscInt         ev[]       = {cells_flat[i * 4 + e], cells_flat[i * 4 + ((e + 1) % 4)]};
3405           const PetscReal *evCoords[] = {&vtxCoords[3 * ev[0]], &vtxCoords[3 * ev[1]]};
3406 
3407           for (PetscInt d = 0; d < 3; d++) {
3408             if (!periodic || periodic[d] != DM_BOUNDARY_PERIODIC) {
3409               if (evCoords[0][d] == 0. && evCoords[1][d] == 0.) {
3410                 edges[edge][0]   = ev[0];
3411                 edges[edge][1]   = ev[1];
3412                 edgeSets[edge++] = 2 * d;
3413               }
3414               if (evCoords[0][d] == 2. * extent[d] && evCoords[1][d] == 2. * extent[d]) {
3415                 edges[edge][0]   = ev[0];
3416                 edges[edge][1]   = ev[1];
3417                 edgeSets[edge++] = 2 * d + 1;
3418               }
3419             }
3420           }
3421         }
3422       }
3423     }
3424     evalFunc   = TPSEvaluate_Gyroid;
3425     normalFunc = TPSExtrudeNormalFunc_Gyroid;
3426     break;
3427   }
3428 
3429   PetscCall(DMSetDimension(dm, topoDim));
3430   if (rank == 0) PetscCall(DMPlexBuildFromCellList(dm, numFaces, numVertices, 4, cells_flat));
3431   else PetscCall(DMPlexBuildFromCellList(dm, 0, 0, 0, NULL));
3432   PetscCall(PetscFree(cells_flat));
3433   {
3434     DM idm;
3435     PetscCall(DMPlexInterpolate(dm, &idm));
3436     PetscCall(DMPlexReplace_Internal(dm, &idm));
3437   }
3438   if (rank == 0) PetscCall(DMPlexBuildCoordinatesFromCellList(dm, spaceDim, vtxCoords));
3439   else PetscCall(DMPlexBuildCoordinatesFromCellList(dm, spaceDim, NULL));
3440   PetscCall(PetscFree(vtxCoords));
3441 
3442   PetscCall(DMCreateLabel(dm, "Face Sets"));
3443   PetscCall(DMGetLabel(dm, "Face Sets", &label));
3444   for (PetscInt e = 0; e < numEdges; e++) {
3445     PetscInt        njoin;
3446     const PetscInt *join, verts[] = {numFaces + edges[e][0], numFaces + edges[e][1]};
3447     PetscCall(DMPlexGetJoin(dm, 2, verts, &njoin, &join));
3448     PetscCheck(njoin == 1, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Expected unique join of vertices %" PetscInt_FMT " and %" PetscInt_FMT, edges[e][0], edges[e][1]);
3449     PetscCall(DMLabelSetValue(label, join[0], edgeSets[e]));
3450     PetscCall(DMPlexRestoreJoin(dm, 2, verts, &njoin, &join));
3451   }
3452   PetscCall(PetscFree(edges));
3453   PetscCall(PetscFree(edgeSets));
3454   if (tps_distribute) {
3455     DM               pdm = NULL;
3456     PetscPartitioner part;
3457 
3458     PetscCall(DMPlexGetPartitioner(dm, &part));
3459     PetscCall(PetscPartitionerSetFromOptions(part));
3460     PetscCall(DMPlexDistribute(dm, 0, NULL, &pdm));
3461     if (pdm) PetscCall(DMPlexReplace_Internal(dm, &pdm));
3462     // Do not auto-distribute again
3463     PetscCall(DMPlexDistributeSetDefault(dm, PETSC_FALSE));
3464   }
3465 
3466   PetscCall(DMPlexSetRefinementUniform(dm, PETSC_TRUE));
3467   for (PetscInt refine = 0; refine < refinements; refine++) {
3468     PetscInt     m;
3469     DM           dmf;
3470     Vec          X;
3471     PetscScalar *x;
3472     PetscCall(DMRefine(dm, MPI_COMM_NULL, &dmf));
3473     PetscCall(DMPlexReplace_Internal(dm, &dmf));
3474 
3475     PetscCall(DMGetCoordinatesLocal(dm, &X));
3476     PetscCall(VecGetLocalSize(X, &m));
3477     PetscCall(VecGetArray(X, &x));
3478     for (PetscInt i = 0; i < m; i += 3) PetscCall(TPSNearestPoint(evalFunc, &x[i]));
3479     PetscCall(VecRestoreArray(X, &x));
3480   }
3481 
3482   // Face Sets has already been propagated to new vertices during refinement; this propagates to the initial vertices.
3483   PetscCall(DMGetLabel(dm, "Face Sets", &label));
3484   PetscCall(DMPlexLabelComplete(dm, label));
3485 
3486   PetscCall(PetscLogEventEnd(DMPLEX_Generate, dm, 0, 0, 0));
3487 
3488   if (thickness > 0) {
3489     DM              edm, cdm, ecdm;
3490     DMPlexTransform tr;
3491     const char     *prefix;
3492     PetscOptions    options;
3493     // Code from DMPlexExtrude
3494     PetscCall(DMPlexTransformCreate(PetscObjectComm((PetscObject)dm), &tr));
3495     PetscCall(DMPlexTransformSetDM(tr, dm));
3496     PetscCall(DMPlexTransformSetType(tr, DMPLEXEXTRUDE));
3497     PetscCall(PetscObjectGetOptionsPrefix((PetscObject)dm, &prefix));
3498     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)tr, prefix));
3499     PetscCall(PetscObjectGetOptions((PetscObject)dm, &options));
3500     PetscCall(PetscObjectSetOptions((PetscObject)tr, options));
3501     PetscCall(DMPlexTransformExtrudeSetLayers(tr, layers));
3502     PetscCall(DMPlexTransformExtrudeSetThickness(tr, thickness));
3503     PetscCall(DMPlexTransformExtrudeSetTensor(tr, PETSC_FALSE));
3504     PetscCall(DMPlexTransformExtrudeSetSymmetric(tr, PETSC_TRUE));
3505     PetscCall(DMPlexTransformExtrudeSetNormalFunction(tr, normalFunc));
3506     PetscCall(DMPlexTransformSetFromOptions(tr));
3507     PetscCall(PetscObjectSetOptions((PetscObject)tr, NULL));
3508     PetscCall(DMPlexTransformSetUp(tr));
3509     PetscCall(PetscObjectViewFromOptions((PetscObject)tr, NULL, "-dm_plex_tps_transform_view"));
3510     PetscCall(DMPlexTransformApply(tr, dm, &edm));
3511     PetscCall(DMCopyDisc(dm, edm));
3512     PetscCall(DMGetCoordinateDM(dm, &cdm));
3513     PetscCall(DMGetCoordinateDM(edm, &ecdm));
3514     PetscCall(DMCopyDisc(cdm, ecdm));
3515     PetscCall(DMPlexTransformCreateDiscLabels(tr, edm));
3516     PetscCall(DMPlexTransformDestroy(&tr));
3517     if (edm) {
3518       ((DM_Plex *)edm->data)->printFEM    = ((DM_Plex *)dm->data)->printFEM;
3519       ((DM_Plex *)edm->data)->printL2     = ((DM_Plex *)dm->data)->printL2;
3520       ((DM_Plex *)edm->data)->printLocate = ((DM_Plex *)dm->data)->printLocate;
3521     }
3522     PetscCall(DMPlexReplace_Internal(dm, &edm));
3523   }
3524   PetscFunctionReturn(PETSC_SUCCESS);
3525 }
3526 
3527 /*@
3528   DMPlexCreateTPSMesh - Create a distributed, interpolated mesh of a triply-periodic surface
3529 
3530   Collective
3531 
3532   Input Parameters:
3533 + comm           - The communicator for the `DM` object
3534 . tpstype        - Type of triply-periodic surface
3535 . extent         - Array of length 3 containing number of periods in each direction
3536 . periodic       - array of length 3 with periodicity, or `NULL` for non-periodic
3537 . tps_distribute - Distribute 2D manifold mesh prior to refinement and extrusion (more scalable)
3538 . refinements    - Number of factor-of-2 refinements of 2D manifold mesh
3539 . layers         - Number of cell layers extruded in normal direction
3540 - thickness      - Thickness in normal direction
3541 
3542   Output Parameter:
3543 . dm - The `DM` object
3544 
3545   Level: beginner
3546 
3547   Notes:
3548   This meshes the surface of the Schwarz P or Gyroid surfaces.  Schwarz P is is the simplest member of the triply-periodic minimal surfaces.
3549   <https://en.wikipedia.org/wiki/Schwarz_minimal_surface#Schwarz_P_(%22Primitive%22)> and can be cut with "clean" boundaries.
3550   The Gyroid <https://en.wikipedia.org/wiki/Gyroid> is another triply-periodic minimal surface with applications in additive manufacturing; it is much more difficult to "cut" since there are no planes of symmetry.
3551   Our implementation creates a very coarse mesh of the surface and refines (by 4-way splitting) as many times as requested.
3552   On each refinement, all vertices are projected to their nearest point on the surface.
3553   This projection could readily be extended to related surfaces.
3554 
3555   See {cite}`maskery2018insights`
3556 
3557   The face (edge) sets for the Schwarz P surface are numbered $1(-x), 2(+x), 3(-y), 4(+y), 5(-z), 6(+z)$.
3558   When the mesh is refined, "Face Sets" contain the new vertices (created during refinement).
3559   Use `DMPlexLabelComplete()` to propagate to coarse-level vertices.
3560 
3561   Developer Notes:
3562   The Gyroid mesh does not currently mark boundary sets.
3563 
3564 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexCreateSphereMesh()`, `DMSetType()`, `DMCreate()`
3565 @*/
3566 PetscErrorCode DMPlexCreateTPSMesh(MPI_Comm comm, DMPlexTPSType tpstype, const PetscInt extent[], const DMBoundaryType periodic[], PetscBool tps_distribute, PetscInt refinements, PetscInt layers, PetscReal thickness, DM *dm)
3567 {
3568   PetscFunctionBegin;
3569   PetscCall(DMCreate(comm, dm));
3570   PetscCall(DMSetType(*dm, DMPLEX));
3571   PetscCall(DMPlexCreateTPSMesh_Internal(*dm, tpstype, extent, periodic, tps_distribute, refinements, layers, thickness));
3572   PetscFunctionReturn(PETSC_SUCCESS);
3573 }
3574 
3575 /*@
3576   DMPlexCreateSphereMesh - Creates a mesh on the d-dimensional sphere, S^d.
3577 
3578   Collective
3579 
3580   Input Parameters:
3581 + comm    - The communicator for the `DM` object
3582 . dim     - The dimension
3583 . simplex - Use simplices, or tensor product cells
3584 - R       - The radius
3585 
3586   Output Parameter:
3587 . dm - The `DM` object
3588 
3589   Level: beginner
3590 
3591 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexCreateBallMesh()`, `DMPlexCreateBoxMesh()`, `DMSetType()`, `DMCreate()`
3592 @*/
3593 PetscErrorCode DMPlexCreateSphereMesh(MPI_Comm comm, PetscInt dim, PetscBool simplex, PetscReal R, DM *dm)
3594 {
3595   PetscFunctionBegin;
3596   PetscAssertPointer(dm, 5);
3597   PetscCall(DMCreate(comm, dm));
3598   PetscCall(DMSetType(*dm, DMPLEX));
3599   PetscCall(DMPlexCreateSphereMesh_Internal(*dm, dim, simplex, R));
3600   PetscFunctionReturn(PETSC_SUCCESS);
3601 }
3602 
3603 static PetscErrorCode DMPlexCreateBallMesh_Internal(DM dm, PetscInt dim, PetscReal R)
3604 {
3605   DM          sdm, vol;
3606   DMLabel     bdlabel;
3607   const char *prefix;
3608 
3609   PetscFunctionBegin;
3610   PetscCall(DMCreate(PetscObjectComm((PetscObject)dm), &sdm));
3611   PetscCall(DMSetType(sdm, DMPLEX));
3612   PetscCall(DMGetOptionsPrefix(dm, &prefix));
3613   PetscCall(DMSetOptionsPrefix(sdm, prefix));
3614   PetscCall(DMAppendOptionsPrefix(sdm, "bd_"));
3615   PetscCall(DMPlexDistributeSetDefault(sdm, PETSC_FALSE));
3616   PetscCall(DMPlexCreateSphereMesh_Internal(sdm, dim - 1, PETSC_TRUE, R));
3617   PetscCall(DMSetFromOptions(sdm));
3618   PetscCall(DMViewFromOptions(sdm, NULL, "-dm_view"));
3619   PetscCall(DMPlexGenerate(sdm, NULL, PETSC_TRUE, &vol));
3620   PetscCall(DMDestroy(&sdm));
3621   PetscCall(DMPlexReplace_Internal(dm, &vol));
3622   PetscCall(DMCreateLabel(dm, "marker"));
3623   PetscCall(DMGetLabel(dm, "marker", &bdlabel));
3624   PetscCall(DMPlexMarkBoundaryFaces(dm, PETSC_DETERMINE, bdlabel));
3625   PetscCall(DMPlexLabelComplete(dm, bdlabel));
3626   PetscFunctionReturn(PETSC_SUCCESS);
3627 }
3628 
3629 /*@
3630   DMPlexCreateBallMesh - Creates a simplex mesh on the d-dimensional ball, B^d.
3631 
3632   Collective
3633 
3634   Input Parameters:
3635 + comm - The communicator for the `DM` object
3636 . dim  - The dimension
3637 - R    - The radius
3638 
3639   Output Parameter:
3640 . dm - The `DM` object
3641 
3642   Options Database Key:
3643 . bd_dm_refine - This will refine the surface mesh preserving the sphere geometry
3644 
3645   Level: beginner
3646 
3647 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexCreateSphereMesh()`, `DMPlexCreateBoxMesh()`, `DMSetType()`, `DMCreate()`
3648 @*/
3649 PetscErrorCode DMPlexCreateBallMesh(MPI_Comm comm, PetscInt dim, PetscReal R, DM *dm)
3650 {
3651   PetscFunctionBegin;
3652   PetscCall(DMCreate(comm, dm));
3653   PetscCall(DMSetType(*dm, DMPLEX));
3654   PetscCall(DMPlexCreateBallMesh_Internal(*dm, dim, R));
3655   PetscFunctionReturn(PETSC_SUCCESS);
3656 }
3657 
3658 static PetscErrorCode DMPlexCreateReferenceCell_Internal(DM rdm, DMPolytopeType ct)
3659 {
3660   PetscFunctionBegin;
3661   switch (ct) {
3662   case DM_POLYTOPE_POINT: {
3663     PetscInt    numPoints[1]        = {1};
3664     PetscInt    coneSize[1]         = {0};
3665     PetscInt    cones[1]            = {0};
3666     PetscInt    coneOrientations[1] = {0};
3667     PetscScalar vertexCoords[1]     = {0.0};
3668 
3669     PetscCall(DMSetDimension(rdm, 0));
3670     PetscCall(DMPlexCreateFromDAG(rdm, 0, numPoints, coneSize, cones, coneOrientations, vertexCoords));
3671   } break;
3672   case DM_POLYTOPE_SEGMENT: {
3673     PetscInt    numPoints[2]        = {2, 1};
3674     PetscInt    coneSize[3]         = {2, 0, 0};
3675     PetscInt    cones[2]            = {1, 2};
3676     PetscInt    coneOrientations[2] = {0, 0};
3677     PetscScalar vertexCoords[2]     = {-1.0, 1.0};
3678 
3679     PetscCall(DMSetDimension(rdm, 1));
3680     PetscCall(DMPlexCreateFromDAG(rdm, 1, numPoints, coneSize, cones, coneOrientations, vertexCoords));
3681   } break;
3682   case DM_POLYTOPE_POINT_PRISM_TENSOR: {
3683     PetscInt    numPoints[2]        = {2, 1};
3684     PetscInt    coneSize[3]         = {2, 0, 0};
3685     PetscInt    cones[2]            = {1, 2};
3686     PetscInt    coneOrientations[2] = {0, 0};
3687     PetscScalar vertexCoords[2]     = {-1.0, 1.0};
3688 
3689     PetscCall(DMSetDimension(rdm, 1));
3690     PetscCall(DMPlexCreateFromDAG(rdm, 1, numPoints, coneSize, cones, coneOrientations, vertexCoords));
3691   } break;
3692   case DM_POLYTOPE_TRIANGLE: {
3693     PetscInt    numPoints[2]        = {3, 1};
3694     PetscInt    coneSize[4]         = {3, 0, 0, 0};
3695     PetscInt    cones[3]            = {1, 2, 3};
3696     PetscInt    coneOrientations[3] = {0, 0, 0};
3697     PetscScalar vertexCoords[6]     = {-1.0, -1.0, 1.0, -1.0, -1.0, 1.0};
3698 
3699     PetscCall(DMSetDimension(rdm, 2));
3700     PetscCall(DMPlexCreateFromDAG(rdm, 1, numPoints, coneSize, cones, coneOrientations, vertexCoords));
3701   } break;
3702   case DM_POLYTOPE_QUADRILATERAL: {
3703     PetscInt    numPoints[2]        = {4, 1};
3704     PetscInt    coneSize[5]         = {4, 0, 0, 0, 0};
3705     PetscInt    cones[4]            = {1, 2, 3, 4};
3706     PetscInt    coneOrientations[4] = {0, 0, 0, 0};
3707     PetscScalar vertexCoords[8]     = {-1.0, -1.0, 1.0, -1.0, 1.0, 1.0, -1.0, 1.0};
3708 
3709     PetscCall(DMSetDimension(rdm, 2));
3710     PetscCall(DMPlexCreateFromDAG(rdm, 1, numPoints, coneSize, cones, coneOrientations, vertexCoords));
3711   } break;
3712   case DM_POLYTOPE_SEG_PRISM_TENSOR: {
3713     PetscInt    numPoints[2]        = {4, 1};
3714     PetscInt    coneSize[5]         = {4, 0, 0, 0, 0};
3715     PetscInt    cones[4]            = {1, 2, 3, 4};
3716     PetscInt    coneOrientations[4] = {0, 0, 0, 0};
3717     PetscScalar vertexCoords[8]     = {-1.0, -1.0, 1.0, -1.0, -1.0, 1.0, 1.0, 1.0};
3718 
3719     PetscCall(DMSetDimension(rdm, 2));
3720     PetscCall(DMPlexCreateFromDAG(rdm, 1, numPoints, coneSize, cones, coneOrientations, vertexCoords));
3721   } break;
3722   case DM_POLYTOPE_TETRAHEDRON: {
3723     PetscInt    numPoints[2]        = {4, 1};
3724     PetscInt    coneSize[5]         = {4, 0, 0, 0, 0};
3725     PetscInt    cones[4]            = {1, 2, 3, 4};
3726     PetscInt    coneOrientations[4] = {0, 0, 0, 0};
3727     PetscScalar vertexCoords[12]    = {-1.0, -1.0, -1.0, -1.0, 1.0, -1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0};
3728 
3729     PetscCall(DMSetDimension(rdm, 3));
3730     PetscCall(DMPlexCreateFromDAG(rdm, 1, numPoints, coneSize, cones, coneOrientations, vertexCoords));
3731   } break;
3732   case DM_POLYTOPE_HEXAHEDRON: {
3733     PetscInt    numPoints[2]        = {8, 1};
3734     PetscInt    coneSize[9]         = {8, 0, 0, 0, 0, 0, 0, 0, 0};
3735     PetscInt    cones[8]            = {1, 2, 3, 4, 5, 6, 7, 8};
3736     PetscInt    coneOrientations[8] = {0, 0, 0, 0, 0, 0, 0, 0};
3737     PetscScalar vertexCoords[24]    = {-1.0, -1.0, -1.0, -1.0, 1.0, -1.0, 1.0, 1.0, -1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0, 1.0, -1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, 1.0};
3738 
3739     PetscCall(DMSetDimension(rdm, 3));
3740     PetscCall(DMPlexCreateFromDAG(rdm, 1, numPoints, coneSize, cones, coneOrientations, vertexCoords));
3741   } break;
3742   case DM_POLYTOPE_TRI_PRISM: {
3743     PetscInt    numPoints[2]        = {6, 1};
3744     PetscInt    coneSize[7]         = {6, 0, 0, 0, 0, 0, 0};
3745     PetscInt    cones[6]            = {1, 2, 3, 4, 5, 6};
3746     PetscInt    coneOrientations[6] = {0, 0, 0, 0, 0, 0};
3747     PetscScalar vertexCoords[18]    = {-1.0, -1.0, -1.0, -1.0, 1.0, -1.0, 1.0, -1.0, -1.0, -1.0, -1.0, 1.0, 1.0, -1.0, 1.0, -1.0, 1.0, 1.0};
3748 
3749     PetscCall(DMSetDimension(rdm, 3));
3750     PetscCall(DMPlexCreateFromDAG(rdm, 1, numPoints, coneSize, cones, coneOrientations, vertexCoords));
3751   } break;
3752   case DM_POLYTOPE_TRI_PRISM_TENSOR: {
3753     PetscInt    numPoints[2]        = {6, 1};
3754     PetscInt    coneSize[7]         = {6, 0, 0, 0, 0, 0, 0};
3755     PetscInt    cones[6]            = {1, 2, 3, 4, 5, 6};
3756     PetscInt    coneOrientations[6] = {0, 0, 0, 0, 0, 0};
3757     PetscScalar vertexCoords[18]    = {-1.0, -1.0, -1.0, 1.0, -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, -1.0, 1.0, 1.0, -1.0, 1.0, -1.0, 1.0, 1.0};
3758 
3759     PetscCall(DMSetDimension(rdm, 3));
3760     PetscCall(DMPlexCreateFromDAG(rdm, 1, numPoints, coneSize, cones, coneOrientations, vertexCoords));
3761   } break;
3762   case DM_POLYTOPE_QUAD_PRISM_TENSOR: {
3763     PetscInt    numPoints[2]        = {8, 1};
3764     PetscInt    coneSize[9]         = {8, 0, 0, 0, 0, 0, 0, 0, 0};
3765     PetscInt    cones[8]            = {1, 2, 3, 4, 5, 6, 7, 8};
3766     PetscInt    coneOrientations[8] = {0, 0, 0, 0, 0, 0, 0, 0};
3767     PetscScalar vertexCoords[24]    = {-1.0, -1.0, -1.0, 1.0, -1.0, -1.0, 1.0, 1.0, -1.0, -1.0, 1.0, -1.0, -1.0, -1.0, 1.0, 1.0, -1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, 1.0};
3768 
3769     PetscCall(DMSetDimension(rdm, 3));
3770     PetscCall(DMPlexCreateFromDAG(rdm, 1, numPoints, coneSize, cones, coneOrientations, vertexCoords));
3771   } break;
3772   case DM_POLYTOPE_PYRAMID: {
3773     PetscInt    numPoints[2]        = {5, 1};
3774     PetscInt    coneSize[6]         = {5, 0, 0, 0, 0, 0};
3775     PetscInt    cones[5]            = {1, 2, 3, 4, 5};
3776     PetscInt    coneOrientations[8] = {0, 0, 0, 0, 0, 0, 0, 0};
3777     PetscScalar vertexCoords[24]    = {-1.0, -1.0, -1.0, -1.0, 1.0, -1.0, 1.0, 1.0, -1.0, 1.0, -1.0, -1.0, 0.0, 0.0, 1.0};
3778 
3779     PetscCall(DMSetDimension(rdm, 3));
3780     PetscCall(DMPlexCreateFromDAG(rdm, 1, numPoints, coneSize, cones, coneOrientations, vertexCoords));
3781   } break;
3782   default:
3783     SETERRQ(PetscObjectComm((PetscObject)rdm), PETSC_ERR_ARG_WRONG, "Cannot create reference cell for cell type %s", DMPolytopeTypes[ct]);
3784   }
3785   {
3786     PetscInt Nv, v;
3787 
3788     /* Must create the celltype label here so that we do not automatically try to compute the types */
3789     PetscCall(DMCreateLabel(rdm, "celltype"));
3790     PetscCall(DMPlexSetCellType(rdm, 0, ct));
3791     PetscCall(DMPlexGetChart(rdm, NULL, &Nv));
3792     for (v = 1; v < Nv; ++v) PetscCall(DMPlexSetCellType(rdm, v, DM_POLYTOPE_POINT));
3793   }
3794   PetscCall(DMPlexInterpolateInPlace_Internal(rdm));
3795   PetscCall(PetscObjectSetName((PetscObject)rdm, DMPolytopeTypes[ct]));
3796   PetscFunctionReturn(PETSC_SUCCESS);
3797 }
3798 
3799 /*@
3800   DMPlexCreateReferenceCell - Create a `DMPLEX` with the appropriate FEM reference cell
3801 
3802   Collective
3803 
3804   Input Parameters:
3805 + comm - The communicator
3806 - ct   - The cell type of the reference cell
3807 
3808   Output Parameter:
3809 . refdm - The reference cell
3810 
3811   Level: intermediate
3812 
3813 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexCreateBoxMesh()`
3814 @*/
3815 PetscErrorCode DMPlexCreateReferenceCell(MPI_Comm comm, DMPolytopeType ct, DM *refdm)
3816 {
3817   PetscFunctionBegin;
3818   PetscCall(DMCreate(comm, refdm));
3819   PetscCall(DMSetType(*refdm, DMPLEX));
3820   PetscCall(DMPlexCreateReferenceCell_Internal(*refdm, ct));
3821   PetscFunctionReturn(PETSC_SUCCESS);
3822 }
3823 
3824 static PetscErrorCode DMPlexCreateBoundaryLabel_Private(DM dm, const char name[])
3825 {
3826   DM        plex;
3827   DMLabel   label;
3828   PetscBool hasLabel;
3829 
3830   PetscFunctionBegin;
3831   PetscCall(DMHasLabel(dm, name, &hasLabel));
3832   if (hasLabel) PetscFunctionReturn(PETSC_SUCCESS);
3833   PetscCall(DMCreateLabel(dm, name));
3834   PetscCall(DMGetLabel(dm, name, &label));
3835   PetscCall(DMConvert(dm, DMPLEX, &plex));
3836   PetscCall(DMPlexMarkBoundaryFaces(plex, 1, label));
3837   PetscCall(DMPlexLabelComplete(plex, label));
3838   PetscCall(DMDestroy(&plex));
3839   PetscFunctionReturn(PETSC_SUCCESS);
3840 }
3841 
3842 /*
3843   We use the last coordinate as the radius, the inner radius is lower[dim-1] and the outer radius is upper[dim-1]. Then we map the first coordinate around the circle.
3844 
3845     (x, y) -> (r, theta) = (x[1], (x[0] - lower[0]) * 2\pi/(upper[0] - lower[0]))
3846 */
3847 static void boxToAnnulus(PetscInt dim, PetscInt Nf, PetscInt NfAux, const PetscInt uOff[], const PetscInt uOff_x[], const PetscScalar u[], const PetscScalar u_t[], const PetscScalar u_x[], const PetscInt aOff[], const PetscInt aOff_x[], const PetscScalar a[], const PetscScalar a_t[], const PetscScalar a_x[], PetscReal t, const PetscReal x[], PetscInt numConstants, const PetscScalar constants[], PetscScalar f0[])
3848 {
3849   const PetscReal low = PetscRealPart(constants[0]);
3850   const PetscReal upp = PetscRealPart(constants[1]);
3851   const PetscReal r   = PetscRealPart(u[1]);
3852   const PetscReal th  = 2. * PETSC_PI * (PetscRealPart(u[0]) - low) / (upp - low);
3853 
3854   f0[0] = r * PetscCosReal(th);
3855   f0[1] = r * PetscSinReal(th);
3856 }
3857 
3858 PETSC_EXTERN PetscErrorCode PetscOptionsFindPairPrefix_Private(PetscOptions, const char pre[], const char name[], const char *option[], const char *value[], PetscBool *flg);
3859 
3860 const char *const DMPlexShapes[] = {"box", "box_surface", "ball", "sphere", "cylinder", "schwarz_p", "gyroid", "doublet", "annulus", "hypercubic", "zbox", "unknown", "DMPlexShape", "DM_SHAPE_", NULL};
3861 
3862 static PetscErrorCode DMPlexCreateFromOptions_Internal(PetscOptionItems *PetscOptionsObject, PetscBool *useCoordSpace, DM dm)
3863 {
3864   DMPlexShape    shape   = DM_SHAPE_BOX;
3865   DMPolytopeType cell    = DM_POLYTOPE_TRIANGLE;
3866   PetscInt       dim     = 2;
3867   PetscBool      simplex = PETSC_TRUE, interpolate = PETSC_TRUE, adjCone = PETSC_FALSE, adjClosure = PETSC_TRUE, refDomain = PETSC_FALSE;
3868   PetscBool      flg, flg2, fflg, bdfflg, nameflg;
3869   MPI_Comm       comm;
3870   char           filename[PETSC_MAX_PATH_LEN]   = "<unspecified>";
3871   char           bdFilename[PETSC_MAX_PATH_LEN] = "<unspecified>";
3872   char           plexname[PETSC_MAX_PATH_LEN]   = "";
3873   const char    *option;
3874 
3875   PetscFunctionBegin;
3876   PetscCall(PetscLogEventBegin(DMPLEX_CreateFromOptions, dm, 0, 0, 0));
3877   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
3878   /* TODO Turn this into a registration interface */
3879   PetscCall(PetscOptionsString("-dm_plex_filename", "File containing a mesh", "DMPlexCreateFromFile", filename, filename, sizeof(filename), &fflg));
3880   PetscCall(PetscOptionsString("-dm_plex_boundary_filename", "File containing a mesh boundary", "DMPlexCreateFromFile", bdFilename, bdFilename, sizeof(bdFilename), &bdfflg));
3881   PetscCall(PetscOptionsString("-dm_plex_name", "Name of the mesh in the file", "DMPlexCreateFromFile", plexname, plexname, sizeof(plexname), &nameflg));
3882   PetscCall(PetscOptionsEnum("-dm_plex_cell", "Cell shape", "", DMPolytopeTypes, (PetscEnum)cell, (PetscEnum *)&cell, NULL));
3883   PetscCall(PetscOptionsBool("-dm_plex_reference_cell_domain", "Use a reference cell domain", "", refDomain, &refDomain, NULL));
3884   PetscCall(PetscOptionsEnum("-dm_plex_shape", "Shape for built-in mesh", "", DMPlexShapes, (PetscEnum)shape, (PetscEnum *)&shape, &flg));
3885   PetscCall(PetscOptionsBoundedInt("-dm_plex_dim", "Topological dimension of the mesh", "DMGetDimension", dim, &dim, &flg, 0));
3886   PetscCheck(dim >= 0, comm, PETSC_ERR_ARG_OUTOFRANGE, "Dimension %" PetscInt_FMT " should be in [0, infinity)", dim);
3887   PetscCall(PetscOptionsBool("-dm_plex_simplex", "Mesh cell shape", "", simplex, &simplex, &flg));
3888   PetscCall(PetscOptionsBool("-dm_plex_interpolate", "Flag to create edges and faces automatically", "", interpolate, &interpolate, &flg));
3889   PetscCall(PetscOptionsBool("-dm_plex_adj_cone", "Set adjacency direction", "DMSetBasicAdjacency", adjCone, &adjCone, &flg));
3890   PetscCall(PetscOptionsBool("-dm_plex_adj_closure", "Set adjacency size", "DMSetBasicAdjacency", adjClosure, &adjClosure, &flg2));
3891   if (flg || flg2) PetscCall(DMSetBasicAdjacency(dm, adjCone, adjClosure));
3892 
3893   switch (cell) {
3894   case DM_POLYTOPE_POINT:
3895   case DM_POLYTOPE_SEGMENT:
3896   case DM_POLYTOPE_POINT_PRISM_TENSOR:
3897   case DM_POLYTOPE_TRIANGLE:
3898   case DM_POLYTOPE_QUADRILATERAL:
3899   case DM_POLYTOPE_TETRAHEDRON:
3900   case DM_POLYTOPE_HEXAHEDRON:
3901     *useCoordSpace = PETSC_TRUE;
3902     break;
3903   default:
3904     *useCoordSpace = PETSC_FALSE;
3905     break;
3906   }
3907 
3908   if (fflg) {
3909     DM dmnew;
3910 
3911     PetscCall(DMPlexCreateFromFile(PetscObjectComm((PetscObject)dm), filename, plexname, interpolate, &dmnew));
3912     PetscCall(DMPlexCopy_Internal(dm, PETSC_FALSE, PETSC_FALSE, dmnew));
3913     PetscCall(DMPlexReplace_Internal(dm, &dmnew));
3914   } else if (refDomain) {
3915     PetscCall(DMPlexCreateReferenceCell_Internal(dm, cell));
3916   } else if (bdfflg) {
3917     DM bdm, dmnew;
3918 
3919     PetscCall(DMPlexCreateFromFile(PetscObjectComm((PetscObject)dm), bdFilename, plexname, interpolate, &bdm));
3920     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)bdm, "bd_"));
3921     PetscCall(DMSetFromOptions(bdm));
3922     PetscCall(DMPlexGenerate(bdm, NULL, interpolate, &dmnew));
3923     PetscCall(DMDestroy(&bdm));
3924     PetscCall(DMPlexCopy_Internal(dm, PETSC_FALSE, PETSC_FALSE, dmnew));
3925     PetscCall(DMPlexReplace_Internal(dm, &dmnew));
3926   } else {
3927     PetscCall(PetscObjectSetName((PetscObject)dm, DMPlexShapes[shape]));
3928     switch (shape) {
3929     case DM_SHAPE_BOX:
3930     case DM_SHAPE_ZBOX:
3931     case DM_SHAPE_ANNULUS: {
3932       PetscInt       faces[3]  = {0, 0, 0};
3933       PetscReal      lower[3]  = {0, 0, 0};
3934       PetscReal      upper[3]  = {1, 1, 1};
3935       DMBoundaryType bdt[3]    = {DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE};
3936       PetscBool      isAnnular = shape == DM_SHAPE_ANNULUS ? PETSC_TRUE : PETSC_FALSE;
3937       PetscInt       i, n;
3938 
3939       n = dim;
3940       for (i = 0; i < dim; ++i) faces[i] = (dim == 1 ? 1 : 4 - dim);
3941       PetscCall(PetscOptionsIntArray("-dm_plex_box_faces", "Number of faces along each dimension", "", faces, &n, &flg));
3942       n = 3;
3943       PetscCall(PetscOptionsRealArray("-dm_plex_box_lower", "Lower left corner of box", "", lower, &n, &flg));
3944       PetscCheck(!flg || !(n != dim), comm, PETSC_ERR_ARG_SIZ, "Lower box point had %" PetscInt_FMT " values, should have been %" PetscInt_FMT, n, dim);
3945       n = 3;
3946       PetscCall(PetscOptionsRealArray("-dm_plex_box_upper", "Upper right corner of box", "", upper, &n, &flg));
3947       PetscCheck(!flg || !(n != dim), comm, PETSC_ERR_ARG_SIZ, "Upper box point had %" PetscInt_FMT " values, should have been %" PetscInt_FMT, n, dim);
3948       n = 3;
3949       PetscCall(PetscOptionsEnumArray("-dm_plex_box_bd", "Boundary type for each dimension", "", DMBoundaryTypes, (PetscEnum *)bdt, &n, &flg));
3950       PetscCheck(!flg || !(n != dim), comm, PETSC_ERR_ARG_SIZ, "Box boundary types had %" PetscInt_FMT " values, should have been %" PetscInt_FMT, n, dim);
3951 
3952       PetscCheck(!isAnnular || dim == 2, comm, PETSC_ERR_ARG_OUTOFRANGE, "Only two dimensional annuli have been implemented");
3953       if (isAnnular)
3954         for (i = 0; i < dim - 1; ++i) bdt[i] = DM_BOUNDARY_PERIODIC;
3955 
3956       switch (cell) {
3957       case DM_POLYTOPE_TRI_PRISM_TENSOR:
3958         PetscCall(DMPlexCreateWedgeBoxMesh_Internal(dm, faces, lower, upper, bdt));
3959         if (!interpolate) {
3960           DM udm;
3961 
3962           PetscCall(DMPlexUninterpolate(dm, &udm));
3963           PetscCall(DMPlexReplace_Internal(dm, &udm));
3964         }
3965         break;
3966       default:
3967         PetscCall(DMPlexCreateBoxMesh_Internal(dm, shape, dim, simplex, faces, lower, upper, bdt, interpolate));
3968         break;
3969       }
3970       if (isAnnular) {
3971         DM          cdm;
3972         PetscDS     cds;
3973         PetscScalar bounds[2] = {lower[0], upper[0]};
3974 
3975         // Fix coordinates for annular region
3976         PetscCall(DMSetPeriodicity(dm, NULL, NULL, NULL));
3977         PetscCall(DMSetCellCoordinatesLocal(dm, NULL));
3978         PetscCall(DMSetCellCoordinates(dm, NULL));
3979         PetscCall(DMPlexCreateCoordinateSpace(dm, 1, PETSC_TRUE, NULL));
3980         PetscCall(DMGetCoordinateDM(dm, &cdm));
3981         PetscCall(DMGetDS(cdm, &cds));
3982         PetscCall(PetscDSSetConstants(cds, 2, bounds));
3983         PetscCall(DMPlexRemapGeometry(dm, 0.0, boxToAnnulus));
3984       }
3985     } break;
3986     case DM_SHAPE_BOX_SURFACE: {
3987       PetscInt  faces[3] = {0, 0, 0};
3988       PetscReal lower[3] = {0, 0, 0};
3989       PetscReal upper[3] = {1, 1, 1};
3990       PetscInt  i, n;
3991 
3992       n = dim + 1;
3993       for (i = 0; i < dim + 1; ++i) faces[i] = (dim + 1 == 1 ? 1 : 4 - (dim + 1));
3994       PetscCall(PetscOptionsIntArray("-dm_plex_box_faces", "Number of faces along each dimension", "", faces, &n, &flg));
3995       n = 3;
3996       PetscCall(PetscOptionsRealArray("-dm_plex_box_lower", "Lower left corner of box", "", lower, &n, &flg));
3997       PetscCheck(!flg || !(n != dim + 1), comm, PETSC_ERR_ARG_SIZ, "Lower box point had %" PetscInt_FMT " values, should have been %" PetscInt_FMT, n, dim + 1);
3998       n = 3;
3999       PetscCall(PetscOptionsRealArray("-dm_plex_box_upper", "Upper right corner of box", "", upper, &n, &flg));
4000       PetscCheck(!flg || !(n != dim + 1), comm, PETSC_ERR_ARG_SIZ, "Upper box point had %" PetscInt_FMT " values, should have been %" PetscInt_FMT, n, dim + 1);
4001       PetscCall(DMPlexCreateBoxSurfaceMesh_Internal(dm, dim + 1, faces, lower, upper, interpolate));
4002     } break;
4003     case DM_SHAPE_SPHERE: {
4004       PetscReal R = 1.0;
4005 
4006       PetscCall(PetscOptionsReal("-dm_plex_sphere_radius", "Radius of the sphere", "", R, &R, &flg));
4007       PetscCall(DMPlexCreateSphereMesh_Internal(dm, dim, simplex, R));
4008     } break;
4009     case DM_SHAPE_BALL: {
4010       PetscReal R = 1.0;
4011 
4012       PetscCall(PetscOptionsReal("-dm_plex_ball_radius", "Radius of the ball", "", R, &R, &flg));
4013       PetscCall(DMPlexCreateBallMesh_Internal(dm, dim, R));
4014     } break;
4015     case DM_SHAPE_CYLINDER: {
4016       DMBoundaryType bdt = DM_BOUNDARY_NONE;
4017       PetscInt       Nw  = 6;
4018 
4019       PetscCall(PetscOptionsEnum("-dm_plex_cylinder_bd", "Boundary type in the z direction", "", DMBoundaryTypes, (PetscEnum)bdt, (PetscEnum *)&bdt, NULL));
4020       PetscCall(PetscOptionsInt("-dm_plex_cylinder_num_wedges", "Number of wedges around the cylinder", "", Nw, &Nw, NULL));
4021       switch (cell) {
4022       case DM_POLYTOPE_TRI_PRISM_TENSOR:
4023         PetscCall(DMPlexCreateWedgeCylinderMesh_Internal(dm, Nw, interpolate));
4024         break;
4025       default:
4026         PetscCall(DMPlexCreateHexCylinderMesh_Internal(dm, bdt));
4027         break;
4028       }
4029     } break;
4030     case DM_SHAPE_SCHWARZ_P: // fallthrough
4031     case DM_SHAPE_GYROID: {
4032       PetscInt       extent[3] = {1, 1, 1}, refine = 0, layers = 0, three;
4033       PetscReal      thickness   = 0.;
4034       DMBoundaryType periodic[3] = {DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE};
4035       DMPlexTPSType  tps_type    = shape == DM_SHAPE_SCHWARZ_P ? DMPLEX_TPS_SCHWARZ_P : DMPLEX_TPS_GYROID;
4036       PetscBool      tps_distribute;
4037       PetscCall(PetscOptionsIntArray("-dm_plex_tps_extent", "Number of replicas for each of three dimensions", NULL, extent, (three = 3, &three), NULL));
4038       PetscCall(PetscOptionsInt("-dm_plex_tps_refine", "Number of refinements", NULL, refine, &refine, NULL));
4039       PetscCall(PetscOptionsEnumArray("-dm_plex_tps_periodic", "Periodicity in each of three dimensions", NULL, DMBoundaryTypes, (PetscEnum *)periodic, (three = 3, &three), NULL));
4040       PetscCall(PetscOptionsInt("-dm_plex_tps_layers", "Number of layers in volumetric extrusion (or zero to not extrude)", NULL, layers, &layers, NULL));
4041       PetscCall(PetscOptionsReal("-dm_plex_tps_thickness", "Thickness of volumetric extrusion", NULL, thickness, &thickness, NULL));
4042       PetscCall(DMPlexDistributeGetDefault(dm, &tps_distribute));
4043       PetscCall(PetscOptionsBool("-dm_plex_tps_distribute", "Distribute the 2D mesh prior to refinement and extrusion", NULL, tps_distribute, &tps_distribute, NULL));
4044       PetscCall(DMPlexCreateTPSMesh_Internal(dm, tps_type, extent, periodic, tps_distribute, refine, layers, thickness));
4045     } break;
4046     case DM_SHAPE_DOUBLET: {
4047       DM        dmnew;
4048       PetscReal rl = 0.0;
4049 
4050       PetscCall(PetscOptionsReal("-dm_plex_doublet_refinementlimit", "Refinement limit", NULL, rl, &rl, NULL));
4051       PetscCall(DMPlexCreateDoublet(PetscObjectComm((PetscObject)dm), dim, simplex, interpolate, rl, &dmnew));
4052       PetscCall(DMPlexCopy_Internal(dm, PETSC_FALSE, PETSC_FALSE, dmnew));
4053       PetscCall(DMPlexReplace_Internal(dm, &dmnew));
4054     } break;
4055     case DM_SHAPE_HYPERCUBIC: {
4056       PetscInt       *edges;
4057       PetscReal      *lower, *upper;
4058       DMBoundaryType *bdt;
4059       PetscInt        n, d;
4060 
4061       *useCoordSpace = PETSC_FALSE;
4062       PetscCall(PetscMalloc4(dim, &edges, dim, &lower, dim, &upper, dim, &bdt));
4063       for (d = 0; d < dim; ++d) {
4064         edges[d] = 1;
4065         lower[d] = 0.;
4066         upper[d] = 1.;
4067         bdt[d]   = DM_BOUNDARY_PERIODIC;
4068       }
4069       n = dim;
4070       PetscCall(PetscOptionsIntArray("-dm_plex_box_faces", "Number of faces along each dimension", "", edges, &n, &flg));
4071       n = dim;
4072       PetscCall(PetscOptionsRealArray("-dm_plex_box_lower", "Lower left corner of box", "", lower, &n, &flg));
4073       PetscCheck(!flg || n == dim, comm, PETSC_ERR_ARG_SIZ, "Lower box point had %" PetscInt_FMT " values, should have been %" PetscInt_FMT, n, dim);
4074       n = dim;
4075       PetscCall(PetscOptionsRealArray("-dm_plex_box_upper", "Upper right corner of box", "", upper, &n, &flg));
4076       PetscCheck(!flg || n == dim, comm, PETSC_ERR_ARG_SIZ, "Upper box point had %" PetscInt_FMT " values, should have been %" PetscInt_FMT, n, dim);
4077       n = dim;
4078       PetscCall(PetscOptionsEnumArray("-dm_plex_box_bd", "Boundary type for each dimension", "", DMBoundaryTypes, (PetscEnum *)bdt, &n, &flg));
4079       PetscCheck(!flg || n == dim, comm, PETSC_ERR_ARG_SIZ, "Box boundary types had %" PetscInt_FMT " values, should have been %" PetscInt_FMT, n, dim);
4080       PetscCall(DMPlexCreateHypercubicMesh_Internal(dm, dim, lower, upper, edges, bdt));
4081       PetscCall(PetscFree4(edges, lower, upper, bdt));
4082     } break;
4083     default:
4084       SETERRQ(comm, PETSC_ERR_SUP, "Domain shape %s is unsupported", DMPlexShapes[shape]);
4085     }
4086   }
4087   PetscCall(DMPlexSetRefinementUniform(dm, PETSC_TRUE));
4088   if (!((PetscObject)dm)->name && nameflg) PetscCall(PetscObjectSetName((PetscObject)dm, plexname));
4089   // Allow label creation
4090   PetscCall(PetscOptionsFindPairPrefix_Private(NULL, ((PetscObject)dm)->prefix, "-dm_plex_label_", &option, NULL, &flg));
4091   if (flg) {
4092     DMLabel     label;
4093     PetscInt    points[1024], n = 1024;
4094     char        fulloption[PETSC_MAX_PATH_LEN];
4095     const char *name = &option[14];
4096 
4097     PetscCall(DMCreateLabel(dm, name));
4098     PetscCall(DMGetLabel(dm, name, &label));
4099     fulloption[0] = '-';
4100     fulloption[1] = 0;
4101     PetscCall(PetscStrlcat(fulloption, option, PETSC_MAX_PATH_LEN));
4102     PetscCall(PetscOptionsGetIntArray(NULL, ((PetscObject)dm)->prefix, fulloption, points, &n, NULL));
4103     for (PetscInt p = 0; p < n; ++p) PetscCall(DMLabelSetValue(label, points[p], 1));
4104   }
4105   PetscCall(PetscLogEventEnd(DMPLEX_CreateFromOptions, dm, 0, 0, 0));
4106   PetscFunctionReturn(PETSC_SUCCESS);
4107 }
4108 
4109 PetscErrorCode DMSetFromOptions_NonRefinement_Plex(DM dm, PetscOptionItems *PetscOptionsObject)
4110 {
4111   DM_Plex  *mesh = (DM_Plex *)dm->data;
4112   PetscBool flg, flg2;
4113   char      bdLabel[PETSC_MAX_PATH_LEN];
4114 
4115   PetscFunctionBegin;
4116   /* Handle viewing */
4117   PetscCall(PetscOptionsBool("-dm_plex_print_set_values", "Output all set values info", "DMPlexMatSetClosure", PETSC_FALSE, &mesh->printSetValues, NULL));
4118   PetscCall(PetscOptionsBoundedInt("-dm_plex_print_fem", "Debug output level for all fem computations", "DMPlexSNESComputeResidualFEM", 0, &mesh->printFEM, NULL, 0));
4119   PetscCall(PetscOptionsBoundedInt("-dm_plex_print_fvm", "Debug output level for all fvm computations", "DMPlexSNESComputeResidualFVM", 0, &mesh->printFVM, NULL, 0));
4120   PetscCall(PetscOptionsReal("-dm_plex_print_tol", "Tolerance for FEM output", "DMPlexSNESComputeResidualFEM", mesh->printTol, &mesh->printTol, NULL));
4121   PetscCall(PetscOptionsBoundedInt("-dm_plex_print_l2", "Debug output level all L2 diff computations", "DMComputeL2Diff", 0, &mesh->printL2, NULL, 0));
4122   PetscCall(PetscOptionsBoundedInt("-dm_plex_print_locate", "Debug output level all point location computations", "DMLocatePoints", 0, &mesh->printLocate, NULL, 0));
4123   PetscCall(DMMonitorSetFromOptions(dm, "-dm_plex_monitor_throughput", "Monitor the simulation throughput", "DMPlexMonitorThroughput", DMPlexMonitorThroughput, NULL, &flg));
4124   if (flg) PetscCall(PetscLogDefaultBegin());
4125   /* Labeling */
4126   PetscCall(PetscOptionsString("-dm_plex_boundary_label", "Label to mark the mesh boundary", "", bdLabel, bdLabel, sizeof(bdLabel), &flg));
4127   if (flg) PetscCall(DMPlexCreateBoundaryLabel_Private(dm, bdLabel));
4128   /* Point Location */
4129   PetscCall(PetscOptionsBool("-dm_plex_hash_location", "Use grid hashing for point location", "DMInterpolate", PETSC_FALSE, &mesh->useHashLocation, NULL));
4130   /* Partitioning and distribution */
4131   PetscCall(PetscOptionsBool("-dm_plex_partition_balance", "Attempt to evenly divide points on partition boundary between processes", "DMPlexSetPartitionBalance", PETSC_FALSE, &mesh->partitionBalance, NULL));
4132   /* Reordering */
4133   PetscCall(PetscOptionsBool("-dm_plex_reorder_section", "Compute point permutation for local section", "DMPlexReorderSectionSetDefault", PETSC_FALSE, &flg2, &flg));
4134   if (flg) PetscCall(DMPlexReorderSectionSetDefault(dm, flg2 ? DMPLEX_REORDER_DEFAULT_TRUE : DMPLEX_REORDER_DEFAULT_FALSE));
4135   /* Generation and remeshing */
4136   PetscCall(PetscOptionsBool("-dm_plex_remesh_bd", "Allow changes to the boundary on remeshing", "DMAdapt", PETSC_FALSE, &mesh->remeshBd, NULL));
4137   /* Projection behavior */
4138   PetscCall(PetscOptionsBoundedInt("-dm_plex_max_projection_height", "Maximum mesh point height used to project locally", "DMPlexSetMaxProjectionHeight", 0, &mesh->maxProjectionHeight, NULL, 0));
4139   PetscCall(PetscOptionsBool("-dm_plex_regular_refinement", "Use special nested projection algorithm for regular refinement", "DMPlexSetRegularRefinement", mesh->regularRefinement, &mesh->regularRefinement, NULL));
4140   /* Checking structure */
4141   {
4142     PetscBool all = PETSC_FALSE;
4143 
4144     PetscCall(PetscOptionsBool("-dm_plex_check_all", "Perform all basic checks", "DMPlexCheck", PETSC_FALSE, &all, NULL));
4145     if (all) {
4146       PetscCall(DMPlexCheck(dm));
4147     } else {
4148       PetscCall(PetscOptionsBool("-dm_plex_check_symmetry", "Check that the adjacency information in the mesh is symmetric", "DMPlexCheckSymmetry", PETSC_FALSE, &flg, &flg2));
4149       if (flg && flg2) PetscCall(DMPlexCheckSymmetry(dm));
4150       PetscCall(PetscOptionsBool("-dm_plex_check_skeleton", "Check that each cell has the correct number of vertices (only for homogeneous simplex or tensor meshes)", "DMPlexCheckSkeleton", PETSC_FALSE, &flg, &flg2));
4151       if (flg && flg2) PetscCall(DMPlexCheckSkeleton(dm, 0));
4152       PetscCall(PetscOptionsBool("-dm_plex_check_faces", "Check that the faces of each cell give a vertex order this is consistent with what we expect from the cell type", "DMPlexCheckFaces", PETSC_FALSE, &flg, &flg2));
4153       if (flg && flg2) PetscCall(DMPlexCheckFaces(dm, 0));
4154       PetscCall(PetscOptionsBool("-dm_plex_check_geometry", "Check that cells have positive volume", "DMPlexCheckGeometry", PETSC_FALSE, &flg, &flg2));
4155       if (flg && flg2) PetscCall(DMPlexCheckGeometry(dm));
4156       PetscCall(PetscOptionsBool("-dm_plex_check_pointsf", "Check some necessary conditions for PointSF", "DMPlexCheckPointSF", PETSC_FALSE, &flg, &flg2));
4157       if (flg && flg2) PetscCall(DMPlexCheckPointSF(dm, NULL, PETSC_FALSE));
4158       PetscCall(PetscOptionsBool("-dm_plex_check_interface_cones", "Check points on inter-partition interfaces have conforming order of cone points", "DMPlexCheckInterfaceCones", PETSC_FALSE, &flg, &flg2));
4159       if (flg && flg2) PetscCall(DMPlexCheckInterfaceCones(dm));
4160     }
4161     PetscCall(PetscOptionsBool("-dm_plex_check_cell_shape", "Check cell shape", "DMPlexCheckCellShape", PETSC_FALSE, &flg, &flg2));
4162     if (flg && flg2) PetscCall(DMPlexCheckCellShape(dm, PETSC_TRUE, PETSC_DETERMINE));
4163   }
4164   {
4165     PetscReal scale = 1.0;
4166 
4167     PetscCall(PetscOptionsReal("-dm_plex_scale", "Scale factor for mesh coordinates", "DMPlexScale", scale, &scale, &flg));
4168     if (flg) {
4169       Vec coordinates, coordinatesLocal;
4170 
4171       PetscCall(DMGetCoordinates(dm, &coordinates));
4172       PetscCall(DMGetCoordinatesLocal(dm, &coordinatesLocal));
4173       PetscCall(VecScale(coordinates, scale));
4174       PetscCall(VecScale(coordinatesLocal, scale));
4175     }
4176   }
4177   PetscCall(PetscPartitionerSetFromOptions(mesh->partitioner));
4178   PetscFunctionReturn(PETSC_SUCCESS);
4179 }
4180 
4181 PetscErrorCode DMSetFromOptions_Overlap_Plex(DM dm, PetscOptionItems *PetscOptionsObject, PetscInt *overlap)
4182 {
4183   PetscInt  numOvLabels = 16, numOvExLabels = 16;
4184   char     *ovLabelNames[16], *ovExLabelNames[16];
4185   PetscInt  numOvValues = 16, numOvExValues = 16, l;
4186   PetscBool flg;
4187 
4188   PetscFunctionBegin;
4189   PetscCall(PetscOptionsBoundedInt("-dm_distribute_overlap", "The size of the overlap halo", "DMPlexDistribute", *overlap, overlap, NULL, 0));
4190   PetscCall(PetscOptionsStringArray("-dm_distribute_overlap_labels", "List of overlap label names", "DMPlexDistribute", ovLabelNames, &numOvLabels, &flg));
4191   if (!flg) numOvLabels = 0;
4192   if (numOvLabels) {
4193     ((DM_Plex *)dm->data)->numOvLabels = numOvLabels;
4194     for (l = 0; l < numOvLabels; ++l) {
4195       PetscCall(DMGetLabel(dm, ovLabelNames[l], &((DM_Plex *)dm->data)->ovLabels[l]));
4196       PetscCheck(((DM_Plex *)dm->data)->ovLabels[l], PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid label name %s", ovLabelNames[l]);
4197       PetscCall(PetscFree(ovLabelNames[l]));
4198     }
4199     PetscCall(PetscOptionsIntArray("-dm_distribute_overlap_values", "List of overlap label values", "DMPlexDistribute", ((DM_Plex *)dm->data)->ovValues, &numOvValues, &flg));
4200     if (!flg) numOvValues = 0;
4201     PetscCheck(numOvLabels == numOvValues, PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "The number of labels %" PetscInt_FMT " must match the number of values %" PetscInt_FMT, numOvLabels, numOvValues);
4202 
4203     PetscCall(PetscOptionsStringArray("-dm_distribute_overlap_exclude_labels", "List of overlap exclude label names", "DMPlexDistribute", ovExLabelNames, &numOvExLabels, &flg));
4204     if (!flg) numOvExLabels = 0;
4205     ((DM_Plex *)dm->data)->numOvExLabels = numOvExLabels;
4206     for (l = 0; l < numOvExLabels; ++l) {
4207       PetscCall(DMGetLabel(dm, ovExLabelNames[l], &((DM_Plex *)dm->data)->ovExLabels[l]));
4208       PetscCheck(((DM_Plex *)dm->data)->ovExLabels[l], PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid label name %s", ovExLabelNames[l]);
4209       PetscCall(PetscFree(ovExLabelNames[l]));
4210     }
4211     PetscCall(PetscOptionsIntArray("-dm_distribute_overlap_exclude_values", "List of overlap exclude label values", "DMPlexDistribute", ((DM_Plex *)dm->data)->ovExValues, &numOvExValues, &flg));
4212     if (!flg) numOvExValues = 0;
4213     PetscCheck(numOvExLabels == numOvExValues, PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "The number of exclude labels %" PetscInt_FMT " must match the number of values %" PetscInt_FMT, numOvExLabels, numOvExValues);
4214   }
4215   PetscFunctionReturn(PETSC_SUCCESS);
4216 }
4217 
4218 static PetscErrorCode DMSetFromOptions_Plex(DM dm, PetscOptionItems *PetscOptionsObject)
4219 {
4220   PetscFunctionList        ordlist;
4221   char                     oname[256];
4222   char                     sublabelname[PETSC_MAX_PATH_LEN] = "";
4223   DMPlexReorderDefaultFlag reorder;
4224   PetscReal                volume    = -1.0;
4225   PetscInt                 prerefine = 0, refine = 0, r, coarsen = 0, overlap = 0, extLayers = 0, dim;
4226   PetscBool uniformOrig = PETSC_FALSE, created = PETSC_FALSE, uniform = PETSC_TRUE, distribute, saveSF = PETSC_FALSE, interpolate = PETSC_TRUE, coordSpace = PETSC_TRUE, remap = PETSC_TRUE, ghostCells = PETSC_FALSE, isHierarchy, ignoreModel = PETSC_FALSE, flg;
4227 
4228   PetscFunctionBegin;
4229   PetscOptionsHeadBegin(PetscOptionsObject, "DMPlex Options");
4230   if (dm->cloneOpts) goto non_refine;
4231   /* Handle automatic creation */
4232   PetscCall(DMGetDimension(dm, &dim));
4233   if (dim < 0) {
4234     PetscCall(DMPlexCreateFromOptions_Internal(PetscOptionsObject, &coordSpace, dm));
4235     created = PETSC_TRUE;
4236   }
4237   PetscCall(DMGetDimension(dm, &dim));
4238   /* Handle interpolation before distribution */
4239   PetscCall(PetscOptionsBool("-dm_plex_interpolate_pre", "Flag to interpolate mesh before distribution", "", interpolate, &interpolate, &flg));
4240   if (flg) {
4241     DMPlexInterpolatedFlag interpolated;
4242 
4243     PetscCall(DMPlexIsInterpolated(dm, &interpolated));
4244     if (interpolated == DMPLEX_INTERPOLATED_FULL && !interpolate) {
4245       DM udm;
4246 
4247       PetscCall(DMPlexUninterpolate(dm, &udm));
4248       PetscCall(DMPlexReplace_Internal(dm, &udm));
4249     } else if (interpolated != DMPLEX_INTERPOLATED_FULL && interpolate) {
4250       DM idm;
4251 
4252       PetscCall(DMPlexInterpolate(dm, &idm));
4253       PetscCall(DMPlexReplace_Internal(dm, &idm));
4254     }
4255   }
4256   // Handle submesh selection before distribution
4257   PetscCall(PetscOptionsString("-dm_plex_submesh", "Label to use for submesh selection", "", sublabelname, sublabelname, PETSC_MAX_PATH_LEN, &flg));
4258   if (flg) {
4259     DM              subdm;
4260     DMLabel         label;
4261     IS              valueIS, pointIS;
4262     const PetscInt *values, *points;
4263     PetscBool       markedFaces = PETSC_FALSE;
4264     PetscInt        Nv, value, Np;
4265 
4266     PetscCall(DMGetLabel(dm, sublabelname, &label));
4267     PetscCall(DMLabelGetNumValues(label, &Nv));
4268     PetscCheck(Nv == 1, PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Only a single label value is currently supported for submesh selection, not %" PetscInt_FMT, Nv);
4269     PetscCall(DMLabelGetValueIS(label, &valueIS));
4270     PetscCall(ISGetIndices(valueIS, &values));
4271     value = values[0];
4272     PetscCall(ISRestoreIndices(valueIS, &values));
4273     PetscCall(ISDestroy(&valueIS));
4274     PetscCall(DMLabelGetStratumSize(label, value, &Np));
4275     PetscCall(DMLabelGetStratumIS(label, value, &pointIS));
4276     PetscCall(ISGetIndices(pointIS, &points));
4277     for (PetscInt p = 0; p < Np; ++p) {
4278       PetscInt pdepth;
4279 
4280       PetscCall(DMPlexGetPointDepth(dm, points[p], &pdepth));
4281       if (pdepth) {
4282         markedFaces = PETSC_TRUE;
4283         break;
4284       }
4285     }
4286     PetscCall(ISRestoreIndices(pointIS, &points));
4287     PetscCall(ISDestroy(&pointIS));
4288     PetscCall(DMPlexCreateSubmesh(dm, label, value, markedFaces, &subdm));
4289     PetscCall(DMPlexReplace_Internal(dm, &subdm));
4290     PetscCall(DMSetFromOptions_NonRefinement_Plex(dm, PetscOptionsObject));
4291   }
4292   /* Handle DMPlex refinement before distribution */
4293   PetscCall(PetscOptionsBool("-dm_refine_ignore_model", "Flag to ignore the geometry model when refining", "DMCreate", ignoreModel, &ignoreModel, &flg));
4294   if (flg) ((DM_Plex *)dm->data)->ignoreModel = ignoreModel;
4295   PetscCall(DMPlexGetRefinementUniform(dm, &uniformOrig));
4296   PetscCall(PetscOptionsBoundedInt("-dm_refine_pre", "The number of refinements before distribution", "DMCreate", prerefine, &prerefine, NULL, 0));
4297   PetscCall(PetscOptionsBool("-dm_refine_remap_pre", "Flag to control coordinate remapping", "DMCreate", remap, &remap, NULL));
4298   PetscCall(PetscOptionsBool("-dm_refine_uniform_pre", "Flag for uniform refinement before distribution", "DMCreate", uniform, &uniform, &flg));
4299   if (flg) PetscCall(DMPlexSetRefinementUniform(dm, uniform));
4300   PetscCall(PetscOptionsReal("-dm_refine_volume_limit_pre", "The maximum cell volume after refinement before distribution", "DMCreate", volume, &volume, &flg));
4301   if (flg) {
4302     PetscCall(DMPlexSetRefinementUniform(dm, PETSC_FALSE));
4303     PetscCall(DMPlexSetRefinementLimit(dm, volume));
4304     prerefine = PetscMax(prerefine, 1);
4305   }
4306   if (prerefine) PetscCall(DMLocalizeCoordinates(dm));
4307   for (r = 0; r < prerefine; ++r) {
4308     DM             rdm;
4309     PetscPointFunc coordFunc = ((DM_Plex *)dm->data)->coordFunc;
4310 
4311     PetscCall(DMSetFromOptions_NonRefinement_Plex(dm, PetscOptionsObject));
4312     PetscCall(DMRefine(dm, PetscObjectComm((PetscObject)dm), &rdm));
4313     PetscCall(DMPlexReplace_Internal(dm, &rdm));
4314     PetscCall(DMSetFromOptions_NonRefinement_Plex(dm, PetscOptionsObject));
4315     if (coordFunc && remap) {
4316       PetscCall(DMPlexRemapGeometry(dm, 0.0, coordFunc));
4317       ((DM_Plex *)dm->data)->coordFunc = coordFunc;
4318     }
4319   }
4320   PetscCall(DMPlexSetRefinementUniform(dm, uniformOrig));
4321   /* Handle DMPlex extrusion before distribution */
4322   PetscCall(PetscOptionsBoundedInt("-dm_extrude", "The number of layers to extrude", "", extLayers, &extLayers, NULL, 0));
4323   if (extLayers) {
4324     DM edm;
4325 
4326     PetscCall(DMExtrude(dm, extLayers, &edm));
4327     PetscCall(DMPlexReplace_Internal(dm, &edm));
4328     ((DM_Plex *)dm->data)->coordFunc = NULL;
4329     PetscCall(DMSetFromOptions_NonRefinement_Plex(dm, PetscOptionsObject));
4330     extLayers = 0;
4331     PetscCall(DMGetDimension(dm, &dim));
4332   }
4333   /* Handle DMPlex reordering before distribution */
4334   PetscCall(DMPlexReorderGetDefault(dm, &reorder));
4335   PetscCall(MatGetOrderingList(&ordlist));
4336   PetscCall(PetscStrncpy(oname, MATORDERINGNATURAL, sizeof(oname)));
4337   PetscCall(PetscOptionsFList("-dm_plex_reorder", "Set mesh reordering type", "DMPlexGetOrdering", ordlist, MATORDERINGNATURAL, oname, sizeof(oname), &flg));
4338   if (reorder == DMPLEX_REORDER_DEFAULT_TRUE || flg) {
4339     DM pdm;
4340     IS perm;
4341 
4342     PetscCall(DMPlexGetOrdering(dm, oname, NULL, &perm));
4343     PetscCall(DMPlexPermute(dm, perm, &pdm));
4344     PetscCall(ISDestroy(&perm));
4345     PetscCall(DMPlexReplace_Internal(dm, &pdm));
4346     PetscCall(DMSetFromOptions_NonRefinement_Plex(dm, PetscOptionsObject));
4347   }
4348   /* Handle DMPlex distribution */
4349   PetscCall(DMPlexDistributeGetDefault(dm, &distribute));
4350   PetscCall(PetscOptionsBool("-dm_distribute", "Flag to redistribute a mesh among processes", "DMPlexDistribute", distribute, &distribute, NULL));
4351   PetscCall(PetscOptionsBool("-dm_distribute_save_sf", "Flag to save the migration SF", "DMPlexSetMigrationSF", saveSF, &saveSF, NULL));
4352   PetscCall(DMSetFromOptions_Overlap_Plex(dm, PetscOptionsObject, &overlap));
4353   if (distribute) {
4354     DM               pdm = NULL;
4355     PetscPartitioner part;
4356     PetscSF          sfMigration;
4357 
4358     PetscCall(DMPlexGetPartitioner(dm, &part));
4359     PetscCall(PetscPartitionerSetFromOptions(part));
4360     PetscCall(DMPlexDistribute(dm, overlap, &sfMigration, &pdm));
4361     if (pdm) PetscCall(DMPlexReplace_Internal(dm, &pdm));
4362     if (saveSF) PetscCall(DMPlexSetMigrationSF(dm, sfMigration));
4363     PetscCall(PetscSFDestroy(&sfMigration));
4364   }
4365   /* Must check CEED options before creating function space for coordinates */
4366   {
4367     PetscBool useCeed = PETSC_FALSE, flg;
4368 
4369     PetscCall(PetscOptionsBool("-dm_plex_use_ceed", "Use LibCEED as the FEM backend", "DMPlexSetUseCeed", useCeed, &useCeed, &flg));
4370     if (flg) PetscCall(DMPlexSetUseCeed(dm, useCeed));
4371   }
4372   /* Create coordinate space */
4373   if (created) {
4374     DM_Plex  *mesh   = (DM_Plex *)dm->data;
4375     PetscInt  degree = 1, deg;
4376     PetscInt  height = 0;
4377     DM        cdm;
4378     PetscBool flg;
4379 
4380     PetscCall(PetscOptionsBool("-dm_coord_space", "Use an FEM space for coordinates", "", coordSpace, &coordSpace, &flg));
4381     PetscCall(PetscOptionsInt("-dm_coord_petscspace_degree", "FEM degree for coordinate space", "", degree, &degree, NULL));
4382     PetscCall(DMGetCoordinateDegree_Internal(dm, &deg));
4383     if (coordSpace && deg <= 1) PetscCall(DMPlexCreateCoordinateSpace(dm, degree, PETSC_TRUE, mesh->coordFunc));
4384     PetscCall(DMGetCoordinateDM(dm, &cdm));
4385     if (flg && !coordSpace) {
4386       PetscDS      cds;
4387       PetscObject  obj;
4388       PetscClassId id;
4389 
4390       PetscCall(DMGetDS(cdm, &cds));
4391       PetscCall(PetscDSGetDiscretization(cds, 0, &obj));
4392       PetscCall(PetscObjectGetClassId(obj, &id));
4393       if (id == PETSCFE_CLASSID) {
4394         PetscContainer dummy;
4395 
4396         PetscCall(PetscContainerCreate(PETSC_COMM_SELF, &dummy));
4397         PetscCall(PetscObjectSetName((PetscObject)dummy, "coordinates"));
4398         PetscCall(DMSetField(cdm, 0, NULL, (PetscObject)dummy));
4399         PetscCall(PetscContainerDestroy(&dummy));
4400         PetscCall(DMClearDS(cdm));
4401       }
4402       mesh->coordFunc = NULL;
4403     }
4404     PetscCall(PetscOptionsBool("-dm_sparse_localize", "Localize only necessary cells", "", dm->sparseLocalize, &dm->sparseLocalize, &flg));
4405     PetscCall(PetscOptionsInt("-dm_localize_height", "Localize edges and faces in addition to cells", "", height, &height, &flg));
4406     if (flg) PetscCall(DMPlexSetMaxProjectionHeight(cdm, height));
4407     PetscCall(DMLocalizeCoordinates(dm));
4408   }
4409   /* Handle DMPlex refinement */
4410   remap = PETSC_TRUE;
4411   PetscCall(PetscOptionsBoundedInt("-dm_refine", "The number of uniform refinements", "DMCreate", refine, &refine, NULL, 0));
4412   PetscCall(PetscOptionsBool("-dm_refine_remap", "Flag to control coordinate remapping", "DMCreate", remap, &remap, NULL));
4413   PetscCall(PetscOptionsBoundedInt("-dm_refine_hierarchy", "The number of uniform refinements", "DMCreate", refine, &refine, &isHierarchy, 0));
4414   if (refine) PetscCall(DMPlexSetRefinementUniform(dm, PETSC_TRUE));
4415   if (refine && isHierarchy) {
4416     DM *dms, coarseDM;
4417 
4418     PetscCall(DMGetCoarseDM(dm, &coarseDM));
4419     PetscCall(PetscObjectReference((PetscObject)coarseDM));
4420     PetscCall(PetscMalloc1(refine, &dms));
4421     PetscCall(DMRefineHierarchy(dm, refine, dms));
4422     /* Total hack since we do not pass in a pointer */
4423     PetscCall(DMPlexSwap_Static(dm, dms[refine - 1]));
4424     if (refine == 1) {
4425       PetscCall(DMSetCoarseDM(dm, dms[0]));
4426       PetscCall(DMPlexSetRegularRefinement(dm, PETSC_TRUE));
4427     } else {
4428       PetscCall(DMSetCoarseDM(dm, dms[refine - 2]));
4429       PetscCall(DMPlexSetRegularRefinement(dm, PETSC_TRUE));
4430       PetscCall(DMSetCoarseDM(dms[0], dms[refine - 1]));
4431       PetscCall(DMPlexSetRegularRefinement(dms[0], PETSC_TRUE));
4432     }
4433     PetscCall(DMSetCoarseDM(dms[refine - 1], coarseDM));
4434     PetscCall(PetscObjectDereference((PetscObject)coarseDM));
4435     /* Free DMs */
4436     for (r = 0; r < refine; ++r) {
4437       PetscCall(DMSetFromOptions_NonRefinement_Plex(dms[r], PetscOptionsObject));
4438       PetscCall(DMDestroy(&dms[r]));
4439     }
4440     PetscCall(PetscFree(dms));
4441   } else {
4442     for (r = 0; r < refine; ++r) {
4443       DM             rdm;
4444       PetscPointFunc coordFunc = ((DM_Plex *)dm->data)->coordFunc;
4445 
4446       PetscCall(DMSetFromOptions_NonRefinement_Plex(dm, PetscOptionsObject));
4447       PetscCall(DMRefine(dm, PetscObjectComm((PetscObject)dm), &rdm));
4448       /* Total hack since we do not pass in a pointer */
4449       PetscCall(DMPlexReplace_Internal(dm, &rdm));
4450       PetscCall(DMSetFromOptions_NonRefinement_Plex(dm, PetscOptionsObject));
4451       if (coordFunc && remap) {
4452         PetscCall(DMPlexRemapGeometry(dm, 0.0, coordFunc));
4453         ((DM_Plex *)dm->data)->coordFunc = coordFunc;
4454       }
4455     }
4456   }
4457   /* Handle DMPlex coarsening */
4458   PetscCall(PetscOptionsBoundedInt("-dm_coarsen", "Coarsen the mesh", "DMCreate", coarsen, &coarsen, NULL, 0));
4459   PetscCall(PetscOptionsBoundedInt("-dm_coarsen_hierarchy", "The number of coarsenings", "DMCreate", coarsen, &coarsen, &isHierarchy, 0));
4460   if (coarsen && isHierarchy) {
4461     DM *dms;
4462 
4463     PetscCall(PetscMalloc1(coarsen, &dms));
4464     PetscCall(DMCoarsenHierarchy(dm, coarsen, dms));
4465     /* Free DMs */
4466     for (r = 0; r < coarsen; ++r) {
4467       PetscCall(DMSetFromOptions_NonRefinement_Plex(dms[r], PetscOptionsObject));
4468       PetscCall(DMDestroy(&dms[r]));
4469     }
4470     PetscCall(PetscFree(dms));
4471   } else {
4472     for (r = 0; r < coarsen; ++r) {
4473       DM             cdm;
4474       PetscPointFunc coordFunc = ((DM_Plex *)dm->data)->coordFunc;
4475 
4476       PetscCall(DMSetFromOptions_NonRefinement_Plex(dm, PetscOptionsObject));
4477       PetscCall(DMCoarsen(dm, PetscObjectComm((PetscObject)dm), &cdm));
4478       /* Total hack since we do not pass in a pointer */
4479       PetscCall(DMPlexReplace_Internal(dm, &cdm));
4480       PetscCall(DMSetFromOptions_NonRefinement_Plex(dm, PetscOptionsObject));
4481       if (coordFunc) {
4482         PetscCall(DMPlexRemapGeometry(dm, 0.0, coordFunc));
4483         ((DM_Plex *)dm->data)->coordFunc = coordFunc;
4484       }
4485     }
4486   }
4487   // Handle coordinate remapping
4488   remap = PETSC_FALSE;
4489   PetscCall(PetscOptionsBool("-dm_coord_remap", "Flag to control coordinate remapping", "", remap, &remap, NULL));
4490   if (remap) {
4491     DMPlexCoordMap map     = DM_COORD_MAP_NONE;
4492     PetscPointFunc mapFunc = NULL;
4493     PetscScalar    params[16];
4494     PetscInt       Np = sizeof(params) / sizeof(params[0]), cdim;
4495     MPI_Comm       comm;
4496 
4497     PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
4498     PetscCall(DMGetCoordinateDim(dm, &cdim));
4499     PetscCall(PetscOptionsScalarArray("-dm_coord_map_params", "Parameters for the coordinate remapping", "", params, &Np, &flg));
4500     if (!flg) Np = 0;
4501     // TODO Allow user to pass a map function by name
4502     PetscCall(PetscOptionsEnum("-dm_coord_map", "Coordinate mapping for built-in mesh", "", DMPlexCoordMaps, (PetscEnum)map, (PetscEnum *)&map, &flg));
4503     if (flg) {
4504       switch (map) {
4505       case DM_COORD_MAP_NONE:
4506         mapFunc = coordMap_identity;
4507         break;
4508       case DM_COORD_MAP_SHEAR:
4509         mapFunc = coordMap_shear;
4510         if (!Np) {
4511           Np        = cdim + 1;
4512           params[0] = 0;
4513           for (PetscInt d = 1; d <= cdim; ++d) params[d] = 1.0;
4514         }
4515         PetscCheck(Np == cdim + 1, comm, PETSC_ERR_ARG_WRONG, "The shear coordinate map must have cdim + 1 = %" PetscInt_FMT " parameters, not %" PetscInt_FMT, cdim + 1, Np);
4516         break;
4517       case DM_COORD_MAP_FLARE:
4518         mapFunc = coordMap_flare;
4519         if (!Np) {
4520           Np        = cdim + 1;
4521           params[0] = 0;
4522           for (PetscInt d = 1; d <= cdim; ++d) params[d] = 1.0;
4523         }
4524         PetscCheck(Np == cdim + 1, comm, PETSC_ERR_ARG_WRONG, "The flare coordinate map must have cdim + 1 = %" PetscInt_FMT " parameters, not %" PetscInt_FMT, cdim + 1, Np);
4525         break;
4526       case DM_COORD_MAP_ANNULUS:
4527         mapFunc = coordMap_annulus;
4528         if (!Np) {
4529           Np        = 2;
4530           params[0] = 1.;
4531           params[1] = 2.;
4532         }
4533         PetscCheck(Np == 2, comm, PETSC_ERR_ARG_WRONG, "The annulus coordinate map must have 2 parameters, not %" PetscInt_FMT, Np);
4534         break;
4535       case DM_COORD_MAP_SHELL:
4536         mapFunc = coordMap_shell;
4537         if (!Np) {
4538           Np        = 2;
4539           params[0] = 1.;
4540           params[1] = 2.;
4541         }
4542         PetscCheck(Np == 2, comm, PETSC_ERR_ARG_WRONG, "The spherical shell coordinate map must have 2 parameters, not %" PetscInt_FMT, Np);
4543         break;
4544       default:
4545         mapFunc = coordMap_identity;
4546       }
4547     }
4548     if (Np) {
4549       DM      cdm;
4550       PetscDS cds;
4551 
4552       PetscCall(DMGetCoordinateDM(dm, &cdm));
4553       PetscCall(DMGetDS(cdm, &cds));
4554       PetscCall(PetscDSSetConstants(cds, Np, params));
4555     }
4556     PetscCall(DMPlexRemapGeometry(dm, 0.0, mapFunc));
4557   }
4558   /* Handle ghost cells */
4559   PetscCall(PetscOptionsBool("-dm_plex_create_fv_ghost_cells", "Flag to create finite volume ghost cells on the boundary", "DMCreate", ghostCells, &ghostCells, NULL));
4560   if (ghostCells) {
4561     DM   gdm;
4562     char lname[PETSC_MAX_PATH_LEN];
4563 
4564     lname[0] = '\0';
4565     PetscCall(PetscOptionsString("-dm_plex_fv_ghost_cells_label", "Label name for ghost cells boundary", "DMCreate", lname, lname, sizeof(lname), &flg));
4566     PetscCall(DMPlexConstructGhostCells(dm, flg ? lname : NULL, NULL, &gdm));
4567     PetscCall(DMPlexReplace_Internal(dm, &gdm));
4568   }
4569   /* Handle 1D order */
4570   if (reorder != DMPLEX_REORDER_DEFAULT_FALSE && dim == 1) {
4571     DM           cdm, rdm;
4572     PetscDS      cds;
4573     PetscObject  obj;
4574     PetscClassId id = PETSC_OBJECT_CLASSID;
4575     IS           perm;
4576     PetscInt     Nf;
4577     PetscBool    distributed;
4578 
4579     PetscCall(DMPlexIsDistributed(dm, &distributed));
4580     PetscCall(DMGetCoordinateDM(dm, &cdm));
4581     PetscCall(DMGetDS(cdm, &cds));
4582     PetscCall(PetscDSGetNumFields(cds, &Nf));
4583     if (Nf) {
4584       PetscCall(PetscDSGetDiscretization(cds, 0, &obj));
4585       PetscCall(PetscObjectGetClassId(obj, &id));
4586     }
4587     if (!distributed && id != PETSCFE_CLASSID) {
4588       PetscCall(DMPlexGetOrdering1D(dm, &perm));
4589       PetscCall(DMPlexPermute(dm, perm, &rdm));
4590       PetscCall(DMPlexReplace_Internal(dm, &rdm));
4591       PetscCall(ISDestroy(&perm));
4592     }
4593   }
4594 /* Handle */
4595 non_refine:
4596   PetscCall(DMSetFromOptions_NonRefinement_Plex(dm, PetscOptionsObject));
4597   PetscOptionsHeadEnd();
4598   PetscFunctionReturn(PETSC_SUCCESS);
4599 }
4600 
4601 static PetscErrorCode DMCreateGlobalVector_Plex(DM dm, Vec *vec)
4602 {
4603   PetscFunctionBegin;
4604   PetscCall(DMCreateGlobalVector_Section_Private(dm, vec));
4605   /* PetscCall(VecSetOperation(*vec, VECOP_DUPLICATE, (void(*)(void)) VecDuplicate_MPI_DM)); */
4606   PetscCall(VecSetOperation(*vec, VECOP_VIEW, (void (*)(void))VecView_Plex));
4607   PetscCall(VecSetOperation(*vec, VECOP_VIEWNATIVE, (void (*)(void))VecView_Plex_Native));
4608   PetscCall(VecSetOperation(*vec, VECOP_LOAD, (void (*)(void))VecLoad_Plex));
4609   PetscCall(VecSetOperation(*vec, VECOP_LOADNATIVE, (void (*)(void))VecLoad_Plex_Native));
4610   PetscFunctionReturn(PETSC_SUCCESS);
4611 }
4612 
4613 static PetscErrorCode DMCreateLocalVector_Plex(DM dm, Vec *vec)
4614 {
4615   PetscFunctionBegin;
4616   PetscCall(DMCreateLocalVector_Section_Private(dm, vec));
4617   PetscCall(VecSetOperation(*vec, VECOP_VIEW, (void (*)(void))VecView_Plex_Local));
4618   PetscCall(VecSetOperation(*vec, VECOP_LOAD, (void (*)(void))VecLoad_Plex_Local));
4619   PetscFunctionReturn(PETSC_SUCCESS);
4620 }
4621 
4622 static PetscErrorCode DMGetDimPoints_Plex(DM dm, PetscInt dim, PetscInt *pStart, PetscInt *pEnd)
4623 {
4624   PetscInt depth, d;
4625 
4626   PetscFunctionBegin;
4627   PetscCall(DMPlexGetDepth(dm, &depth));
4628   if (depth == 1) {
4629     PetscCall(DMGetDimension(dm, &d));
4630     if (dim == 0) PetscCall(DMPlexGetDepthStratum(dm, dim, pStart, pEnd));
4631     else if (dim == d) PetscCall(DMPlexGetDepthStratum(dm, 1, pStart, pEnd));
4632     else {
4633       *pStart = 0;
4634       *pEnd   = 0;
4635     }
4636   } else {
4637     PetscCall(DMPlexGetDepthStratum(dm, dim, pStart, pEnd));
4638   }
4639   PetscFunctionReturn(PETSC_SUCCESS);
4640 }
4641 
4642 static PetscErrorCode DMGetNeighbors_Plex(DM dm, PetscInt *nranks, const PetscMPIInt *ranks[])
4643 {
4644   PetscSF            sf;
4645   PetscInt           niranks, njranks, n;
4646   const PetscMPIInt *iranks, *jranks;
4647   DM_Plex           *data = (DM_Plex *)dm->data;
4648 
4649   PetscFunctionBegin;
4650   PetscCall(DMGetPointSF(dm, &sf));
4651   if (!data->neighbors) {
4652     PetscCall(PetscSFSetUp(sf));
4653     PetscCall(PetscSFGetRootRanks(sf, &njranks, &jranks, NULL, NULL, NULL));
4654     PetscCall(PetscSFGetLeafRanks(sf, &niranks, &iranks, NULL, NULL));
4655     PetscCall(PetscMalloc1(njranks + niranks + 1, &data->neighbors));
4656     PetscCall(PetscArraycpy(data->neighbors + 1, jranks, njranks));
4657     PetscCall(PetscArraycpy(data->neighbors + njranks + 1, iranks, niranks));
4658     n = njranks + niranks;
4659     PetscCall(PetscSortRemoveDupsMPIInt(&n, data->neighbors + 1));
4660     /* The following cast should never fail: can't have more neighbors than PETSC_MPI_INT_MAX */
4661     PetscCall(PetscMPIIntCast(n, data->neighbors));
4662   }
4663   if (nranks) *nranks = data->neighbors[0];
4664   if (ranks) {
4665     if (data->neighbors[0]) *ranks = data->neighbors + 1;
4666     else *ranks = NULL;
4667   }
4668   PetscFunctionReturn(PETSC_SUCCESS);
4669 }
4670 
4671 PETSC_INTERN PetscErrorCode DMInterpolateSolution_Plex(DM, DM, Mat, Vec, Vec);
4672 
4673 static PetscErrorCode DMInitialize_Plex(DM dm)
4674 {
4675   PetscFunctionBegin;
4676   dm->ops->view                      = DMView_Plex;
4677   dm->ops->load                      = DMLoad_Plex;
4678   dm->ops->setfromoptions            = DMSetFromOptions_Plex;
4679   dm->ops->clone                     = DMClone_Plex;
4680   dm->ops->setup                     = DMSetUp_Plex;
4681   dm->ops->createlocalsection        = DMCreateLocalSection_Plex;
4682   dm->ops->createdefaultconstraints  = DMCreateDefaultConstraints_Plex;
4683   dm->ops->createglobalvector        = DMCreateGlobalVector_Plex;
4684   dm->ops->createlocalvector         = DMCreateLocalVector_Plex;
4685   dm->ops->getlocaltoglobalmapping   = NULL;
4686   dm->ops->createfieldis             = NULL;
4687   dm->ops->createcoordinatedm        = DMCreateCoordinateDM_Plex;
4688   dm->ops->createcoordinatefield     = DMCreateCoordinateField_Plex;
4689   dm->ops->getcoloring               = NULL;
4690   dm->ops->creatematrix              = DMCreateMatrix_Plex;
4691   dm->ops->createinterpolation       = DMCreateInterpolation_Plex;
4692   dm->ops->createmassmatrix          = DMCreateMassMatrix_Plex;
4693   dm->ops->createmassmatrixlumped    = DMCreateMassMatrixLumped_Plex;
4694   dm->ops->createinjection           = DMCreateInjection_Plex;
4695   dm->ops->refine                    = DMRefine_Plex;
4696   dm->ops->coarsen                   = DMCoarsen_Plex;
4697   dm->ops->refinehierarchy           = DMRefineHierarchy_Plex;
4698   dm->ops->coarsenhierarchy          = DMCoarsenHierarchy_Plex;
4699   dm->ops->extrude                   = DMExtrude_Plex;
4700   dm->ops->globaltolocalbegin        = NULL;
4701   dm->ops->globaltolocalend          = NULL;
4702   dm->ops->localtoglobalbegin        = NULL;
4703   dm->ops->localtoglobalend          = NULL;
4704   dm->ops->destroy                   = DMDestroy_Plex;
4705   dm->ops->createsubdm               = DMCreateSubDM_Plex;
4706   dm->ops->createsuperdm             = DMCreateSuperDM_Plex;
4707   dm->ops->getdimpoints              = DMGetDimPoints_Plex;
4708   dm->ops->locatepoints              = DMLocatePoints_Plex;
4709   dm->ops->projectfunctionlocal      = DMProjectFunctionLocal_Plex;
4710   dm->ops->projectfunctionlabellocal = DMProjectFunctionLabelLocal_Plex;
4711   dm->ops->projectfieldlocal         = DMProjectFieldLocal_Plex;
4712   dm->ops->projectfieldlabellocal    = DMProjectFieldLabelLocal_Plex;
4713   dm->ops->projectbdfieldlabellocal  = DMProjectBdFieldLabelLocal_Plex;
4714   dm->ops->computel2diff             = DMComputeL2Diff_Plex;
4715   dm->ops->computel2gradientdiff     = DMComputeL2GradientDiff_Plex;
4716   dm->ops->computel2fielddiff        = DMComputeL2FieldDiff_Plex;
4717   dm->ops->getneighbors              = DMGetNeighbors_Plex;
4718   dm->ops->createdomaindecomposition = DMCreateDomainDecomposition_Plex;
4719   dm->ops->createddscatters          = DMCreateDomainDecompositionScatters_Plex;
4720   PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMPlexInsertBoundaryValues_C", DMPlexInsertBoundaryValues_Plex));
4721   PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMPlexInsertTimeDerivativeBoundaryValues_C", DMPlexInsertTimeDerivativeBoundaryValues_Plex));
4722   PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMSetUpGLVisViewer_C", DMSetUpGLVisViewer_Plex));
4723   PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMCreateNeumannOverlap_C", DMCreateNeumannOverlap_Plex));
4724   PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMPlexDistributeGetDefault_C", DMPlexDistributeGetDefault_Plex));
4725   PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMPlexDistributeSetDefault_C", DMPlexDistributeSetDefault_Plex));
4726   PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMPlexReorderGetDefault_C", DMPlexReorderGetDefault_Plex));
4727   PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMPlexReorderSetDefault_C", DMPlexReorderSetDefault_Plex));
4728   PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMPlexReorderSectionGetDefault_C", DMPlexReorderSectionGetDefault_Plex));
4729   PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMPlexReorderSectionSetDefault_C", DMPlexReorderSectionSetDefault_Plex));
4730   PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMInterpolateSolution_C", DMInterpolateSolution_Plex));
4731   PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMPlexGetOverlap_C", DMPlexGetOverlap_Plex));
4732   PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMPlexSetOverlap_C", DMPlexSetOverlap_Plex));
4733   PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMPlexGetUseCeed_C", DMPlexGetUseCeed_Plex));
4734   PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMPlexSetUseCeed_C", DMPlexSetUseCeed_Plex));
4735   PetscFunctionReturn(PETSC_SUCCESS);
4736 }
4737 
4738 PETSC_INTERN PetscErrorCode DMClone_Plex(DM dm, DM *newdm)
4739 {
4740   DM_Plex *mesh = (DM_Plex *)dm->data;
4741   PetscSF  face_sf;
4742 
4743   PetscFunctionBegin;
4744   mesh->refct++;
4745   (*newdm)->data = mesh;
4746   PetscCall(DMPlexGetIsoperiodicFaceSF(dm, &face_sf));
4747   PetscCall(DMPlexSetIsoperiodicFaceSF(*newdm, face_sf));
4748   PetscCall(PetscObjectChangeTypeName((PetscObject)*newdm, DMPLEX));
4749   PetscCall(DMInitialize_Plex(*newdm));
4750   PetscFunctionReturn(PETSC_SUCCESS);
4751 }
4752 
4753 /*MC
4754   DMPLEX = "plex" - A `DM` object that encapsulates an unstructured mesh, or CW Complex, which can be expressed using a Hasse Diagram.
4755                     In the local representation, `Vec`s contain all unknowns in the interior and shared boundary. This is
4756                     specified by a PetscSection object. Ownership in the global representation is determined by
4757                     ownership of the underlying `DMPLEX` points. This is specified by another `PetscSection` object.
4758 
4759   Options Database Keys:
4760 + -dm_refine_pre                     - Refine mesh before distribution
4761 + -dm_refine_uniform_pre             - Choose uniform or generator-based refinement
4762 + -dm_refine_volume_limit_pre        - Cell volume limit after pre-refinement using generator
4763 . -dm_distribute                     - Distribute mesh across processes
4764 . -dm_distribute_overlap             - Number of cells to overlap for distribution
4765 . -dm_refine                         - Refine mesh after distribution
4766 . -dm_plex_hash_location             - Use grid hashing for point location
4767 . -dm_plex_hash_box_faces <n,m,p>    - The number of divisions in each direction of the grid hash
4768 . -dm_plex_partition_balance         - Attempt to evenly divide points on partition boundary between processes
4769 . -dm_plex_remesh_bd                 - Allow changes to the boundary on remeshing
4770 . -dm_plex_max_projection_height     - Maximum mesh point height used to project locally
4771 . -dm_plex_regular_refinement        - Use special nested projection algorithm for regular refinement
4772 . -dm_plex_reorder_section           - Use specialized blocking if available
4773 . -dm_plex_check_all                 - Perform all checks below
4774 . -dm_plex_check_symmetry            - Check that the adjacency information in the mesh is symmetric
4775 . -dm_plex_check_skeleton <celltype> - Check that each cell has the correct number of vertices
4776 . -dm_plex_check_faces <celltype>    - Check that the faces of each cell give a vertex order this is consistent with what we expect from the cell type
4777 . -dm_plex_check_geometry            - Check that cells have positive volume
4778 . -dm_view :mesh.tex:ascii_latex     - View the mesh in LaTeX/TikZ
4779 . -dm_plex_view_scale <num>          - Scale the TikZ
4780 . -dm_plex_print_fem <num>           - View FEM assembly information, such as element vectors and matrices
4781 - -dm_plex_print_fvm <num>           - View FVM assembly information, such as flux updates
4782 
4783   Level: intermediate
4784 
4785 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMType`, `DMPlexCreate()`, `DMCreate()`, `DMSetType()`, `PetscSection`
4786 M*/
4787 
4788 PETSC_EXTERN PetscErrorCode DMCreate_Plex(DM dm)
4789 {
4790   DM_Plex *mesh;
4791   PetscInt unit;
4792 
4793   PetscFunctionBegin;
4794   PetscCall(PetscCitationsRegister(PlexCitation, &Plexcite));
4795   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
4796   PetscCall(PetscNew(&mesh));
4797   dm->data = mesh;
4798 
4799   mesh->refct = 1;
4800   PetscCall(PetscSectionCreate(PetscObjectComm((PetscObject)dm), &mesh->coneSection));
4801   PetscCall(PetscSectionCreate(PetscObjectComm((PetscObject)dm), &mesh->supportSection));
4802   mesh->refinementUniform      = PETSC_TRUE;
4803   mesh->refinementLimit        = -1.0;
4804   mesh->distDefault            = PETSC_TRUE;
4805   mesh->reorderDefault         = DMPLEX_REORDER_DEFAULT_NOTSET;
4806   mesh->reorderSection         = DMPLEX_REORDER_DEFAULT_NOTSET;
4807   mesh->distributionName       = NULL;
4808   mesh->interpolated           = DMPLEX_INTERPOLATED_INVALID;
4809   mesh->interpolatedCollective = DMPLEX_INTERPOLATED_INVALID;
4810 
4811   PetscCall(PetscPartitionerCreate(PetscObjectComm((PetscObject)dm), &mesh->partitioner));
4812   mesh->remeshBd = PETSC_FALSE;
4813 
4814   for (unit = 0; unit < NUM_PETSC_UNITS; ++unit) mesh->scale[unit] = 1.0;
4815 
4816   mesh->depthState    = -1;
4817   mesh->celltypeState = -1;
4818   mesh->printTol      = 1.0e-10;
4819 
4820   PetscCall(DMInitialize_Plex(dm));
4821   PetscFunctionReturn(PETSC_SUCCESS);
4822 }
4823 
4824 /*@
4825   DMPlexCreate - Creates a `DMPLEX` object, which encapsulates an unstructured mesh, or CW complex, which can be expressed using a Hasse Diagram.
4826 
4827   Collective
4828 
4829   Input Parameter:
4830 . comm - The communicator for the `DMPLEX` object
4831 
4832   Output Parameter:
4833 . mesh - The `DMPLEX` object
4834 
4835   Level: beginner
4836 
4837 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMType`, `DMCreate()`, `DMSetType()`
4838 @*/
4839 PetscErrorCode DMPlexCreate(MPI_Comm comm, DM *mesh)
4840 {
4841   PetscFunctionBegin;
4842   PetscAssertPointer(mesh, 2);
4843   PetscCall(DMCreate(comm, mesh));
4844   PetscCall(DMSetType(*mesh, DMPLEX));
4845   PetscFunctionReturn(PETSC_SUCCESS);
4846 }
4847 
4848 /*@C
4849   DMPlexBuildFromCellListParallel - Build distributed `DMPLEX` topology from a list of vertices for each cell (common mesh generator output)
4850 
4851   Collective; No Fortran Support
4852 
4853   Input Parameters:
4854 + dm          - The `DM`
4855 . numCells    - The number of cells owned by this process
4856 . numVertices - The number of vertices to be owned by this process, or `PETSC_DECIDE`
4857 . NVertices   - The global number of vertices, or `PETSC_DETERMINE`
4858 . numCorners  - The number of vertices for each cell
4859 - cells       - An array of numCells*numCorners numbers, the global vertex numbers for each cell
4860 
4861   Output Parameters:
4862 + vertexSF         - (Optional) `PetscSF` describing complete vertex ownership
4863 - verticesAdjSaved - (Optional) vertex adjacency array
4864 
4865   Level: advanced
4866 
4867   Notes:
4868   Two triangles sharing a face
4869 .vb
4870 
4871         2
4872       / | \
4873      /  |  \
4874     /   |   \
4875    0  0 | 1  3
4876     \   |   /
4877      \  |  /
4878       \ | /
4879         1
4880 .ve
4881   would have input
4882 .vb
4883   numCells = 2, numVertices = 4
4884   cells = [0 1 2  1 3 2]
4885 .ve
4886   which would result in the `DMPLEX`
4887 .vb
4888 
4889         4
4890       / | \
4891      /  |  \
4892     /   |   \
4893    2  0 | 1  5
4894     \   |   /
4895      \  |  /
4896       \ | /
4897         3
4898 .ve
4899 
4900   Vertices are implicitly numbered consecutively 0,...,NVertices.
4901   Each rank owns a chunk of numVertices consecutive vertices.
4902   If numVertices is `PETSC_DECIDE`, PETSc will distribute them as evenly as possible using PetscLayout.
4903   If NVertices is `PETSC_DETERMINE` and numVertices is PETSC_DECIDE, NVertices is computed by PETSc as the maximum vertex index in cells + 1.
4904   If only NVertices is `PETSC_DETERMINE`, it is computed as the sum of numVertices over all ranks.
4905 
4906   The cell distribution is arbitrary non-overlapping, independent of the vertex distribution.
4907 
4908 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexBuildFromCellList()`, `DMPlexCreateFromCellListParallelPetsc()`, `DMPlexBuildCoordinatesFromCellListParallel()`,
4909           `PetscSF`
4910 @*/
4911 PetscErrorCode DMPlexBuildFromCellListParallel(DM dm, PetscInt numCells, PetscInt numVertices, PetscInt NVertices, PetscInt numCorners, const PetscInt cells[], PetscSF *vertexSF, PetscInt **verticesAdjSaved)
4912 {
4913   PetscSF     sfPoint;
4914   PetscLayout layout;
4915   PetscInt    numVerticesAdj, *verticesAdj, *cones, c, p;
4916 
4917   PetscFunctionBegin;
4918   PetscValidLogicalCollectiveInt(dm, NVertices, 4);
4919   PetscCall(PetscLogEventBegin(DMPLEX_BuildFromCellList, dm, 0, 0, 0));
4920   /* Get/check global number of vertices */
4921   {
4922     PetscInt       NVerticesInCells, i;
4923     const PetscInt len = numCells * numCorners;
4924 
4925     /* NVerticesInCells = max(cells) + 1 */
4926     NVerticesInCells = PETSC_MIN_INT;
4927     for (i = 0; i < len; i++)
4928       if (cells[i] > NVerticesInCells) NVerticesInCells = cells[i];
4929     ++NVerticesInCells;
4930     PetscCall(MPIU_Allreduce(MPI_IN_PLACE, &NVerticesInCells, 1, MPIU_INT, MPI_MAX, PetscObjectComm((PetscObject)dm)));
4931 
4932     if (numVertices == PETSC_DECIDE && NVertices == PETSC_DECIDE) NVertices = NVerticesInCells;
4933     else
4934       PetscCheck(NVertices == PETSC_DECIDE || NVertices >= NVerticesInCells, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Specified global number of vertices %" PetscInt_FMT " must be greater than or equal to the number of vertices in cells %" PetscInt_FMT, NVertices, NVerticesInCells);
4935   }
4936   /* Count locally unique vertices */
4937   {
4938     PetscHSetI vhash;
4939     PetscInt   off = 0;
4940 
4941     PetscCall(PetscHSetICreate(&vhash));
4942     for (c = 0; c < numCells; ++c) {
4943       for (p = 0; p < numCorners; ++p) PetscCall(PetscHSetIAdd(vhash, cells[c * numCorners + p]));
4944     }
4945     PetscCall(PetscHSetIGetSize(vhash, &numVerticesAdj));
4946     if (!verticesAdjSaved) PetscCall(PetscMalloc1(numVerticesAdj, &verticesAdj));
4947     else verticesAdj = *verticesAdjSaved;
4948     PetscCall(PetscHSetIGetElems(vhash, &off, verticesAdj));
4949     PetscCall(PetscHSetIDestroy(&vhash));
4950     PetscCheck(off == numVerticesAdj, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid number of local vertices %" PetscInt_FMT " should be %" PetscInt_FMT, off, numVerticesAdj);
4951   }
4952   PetscCall(PetscSortInt(numVerticesAdj, verticesAdj));
4953   /* Create cones */
4954   PetscCall(DMPlexSetChart(dm, 0, numCells + numVerticesAdj));
4955   for (c = 0; c < numCells; ++c) PetscCall(DMPlexSetConeSize(dm, c, numCorners));
4956   PetscCall(DMSetUp(dm));
4957   PetscCall(DMPlexGetCones(dm, &cones));
4958   for (c = 0; c < numCells; ++c) {
4959     for (p = 0; p < numCorners; ++p) {
4960       const PetscInt gv = cells[c * numCorners + p];
4961       PetscInt       lv;
4962 
4963       /* Positions within verticesAdj form 0-based local vertex numbering;
4964          we need to shift it by numCells to get correct DAG points (cells go first) */
4965       PetscCall(PetscFindInt(gv, numVerticesAdj, verticesAdj, &lv));
4966       PetscCheck(lv >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Could not find global vertex %" PetscInt_FMT " in local connectivity", gv);
4967       cones[c * numCorners + p] = lv + numCells;
4968     }
4969   }
4970   /* Build point sf */
4971   PetscCall(PetscLayoutCreate(PetscObjectComm((PetscObject)dm), &layout));
4972   PetscCall(PetscLayoutSetSize(layout, NVertices));
4973   PetscCall(PetscLayoutSetLocalSize(layout, numVertices));
4974   PetscCall(PetscLayoutSetBlockSize(layout, 1));
4975   PetscCall(PetscSFCreateByMatchingIndices(layout, numVerticesAdj, verticesAdj, NULL, numCells, numVerticesAdj, verticesAdj, NULL, numCells, vertexSF, &sfPoint));
4976   PetscCall(PetscLayoutDestroy(&layout));
4977   if (!verticesAdjSaved) PetscCall(PetscFree(verticesAdj));
4978   PetscCall(PetscObjectSetName((PetscObject)sfPoint, "point SF"));
4979   if (dm->sf) {
4980     const char *prefix;
4981 
4982     PetscCall(PetscObjectGetOptionsPrefix((PetscObject)dm->sf, &prefix));
4983     PetscCall(PetscObjectSetOptionsPrefix((PetscObject)sfPoint, prefix));
4984   }
4985   PetscCall(DMSetPointSF(dm, sfPoint));
4986   PetscCall(PetscSFDestroy(&sfPoint));
4987   if (vertexSF) PetscCall(PetscObjectSetName((PetscObject)(*vertexSF), "Vertex Ownership SF"));
4988   /* Fill in the rest of the topology structure */
4989   PetscCall(DMPlexSymmetrize(dm));
4990   PetscCall(DMPlexStratify(dm));
4991   PetscCall(PetscLogEventEnd(DMPLEX_BuildFromCellList, dm, 0, 0, 0));
4992   PetscFunctionReturn(PETSC_SUCCESS);
4993 }
4994 
4995 /*@C
4996   DMPlexBuildCoordinatesFromCellListParallel - Build `DM` coordinates from a list of coordinates for each owned vertex (common mesh generator output)
4997 
4998   Collective; No Fortran Support
4999 
5000   Input Parameters:
5001 + dm           - The `DM`
5002 . spaceDim     - The spatial dimension used for coordinates
5003 . sfVert       - `PetscSF` describing complete vertex ownership
5004 - vertexCoords - An array of numVertices*spaceDim numbers, the coordinates of each vertex
5005 
5006   Level: advanced
5007 
5008 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexBuildCoordinatesFromCellList()`, `DMPlexCreateFromCellListParallelPetsc()`, `DMPlexBuildFromCellListParallel()`
5009 @*/
5010 PetscErrorCode DMPlexBuildCoordinatesFromCellListParallel(DM dm, PetscInt spaceDim, PetscSF sfVert, const PetscReal vertexCoords[])
5011 {
5012   PetscSection coordSection;
5013   Vec          coordinates;
5014   PetscScalar *coords;
5015   PetscInt     numVertices, numVerticesAdj, coordSize, v, vStart, vEnd;
5016 
5017   PetscFunctionBegin;
5018   PetscCall(PetscLogEventBegin(DMPLEX_BuildCoordinatesFromCellList, dm, 0, 0, 0));
5019   PetscCall(DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd));
5020   PetscCheck(vStart >= 0 && vEnd >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "DM is not set up properly. DMPlexBuildFromCellList() should be called first.");
5021   PetscCall(DMSetCoordinateDim(dm, spaceDim));
5022   PetscCall(PetscSFGetGraph(sfVert, &numVertices, &numVerticesAdj, NULL, NULL));
5023   PetscCheck(vEnd - vStart == numVerticesAdj, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Supplied sfVert has wrong number of leaves = %" PetscInt_FMT " != %" PetscInt_FMT " = vEnd - vStart", numVerticesAdj, vEnd - vStart);
5024   PetscCall(DMGetCoordinateSection(dm, &coordSection));
5025   PetscCall(PetscSectionSetNumFields(coordSection, 1));
5026   PetscCall(PetscSectionSetFieldComponents(coordSection, 0, spaceDim));
5027   PetscCall(PetscSectionSetChart(coordSection, vStart, vEnd));
5028   for (v = vStart; v < vEnd; ++v) {
5029     PetscCall(PetscSectionSetDof(coordSection, v, spaceDim));
5030     PetscCall(PetscSectionSetFieldDof(coordSection, v, 0, spaceDim));
5031   }
5032   PetscCall(PetscSectionSetUp(coordSection));
5033   PetscCall(PetscSectionGetStorageSize(coordSection, &coordSize));
5034   PetscCall(VecCreate(PetscObjectComm((PetscObject)dm), &coordinates));
5035   PetscCall(VecSetBlockSize(coordinates, spaceDim));
5036   PetscCall(PetscObjectSetName((PetscObject)coordinates, "coordinates"));
5037   PetscCall(VecSetSizes(coordinates, coordSize, PETSC_DETERMINE));
5038   PetscCall(VecSetType(coordinates, VECSTANDARD));
5039   PetscCall(VecGetArray(coordinates, &coords));
5040   {
5041     MPI_Datatype coordtype;
5042 
5043     /* Need a temp buffer for coords if we have complex/single */
5044     PetscCallMPI(MPI_Type_contiguous(spaceDim, MPIU_SCALAR, &coordtype));
5045     PetscCallMPI(MPI_Type_commit(&coordtype));
5046 #if defined(PETSC_USE_COMPLEX)
5047     {
5048       PetscScalar *svertexCoords;
5049       PetscInt     i;
5050       PetscCall(PetscMalloc1(numVertices * spaceDim, &svertexCoords));
5051       for (i = 0; i < numVertices * spaceDim; i++) svertexCoords[i] = vertexCoords[i];
5052       PetscCall(PetscSFBcastBegin(sfVert, coordtype, svertexCoords, coords, MPI_REPLACE));
5053       PetscCall(PetscSFBcastEnd(sfVert, coordtype, svertexCoords, coords, MPI_REPLACE));
5054       PetscCall(PetscFree(svertexCoords));
5055     }
5056 #else
5057     PetscCall(PetscSFBcastBegin(sfVert, coordtype, vertexCoords, coords, MPI_REPLACE));
5058     PetscCall(PetscSFBcastEnd(sfVert, coordtype, vertexCoords, coords, MPI_REPLACE));
5059 #endif
5060     PetscCallMPI(MPI_Type_free(&coordtype));
5061   }
5062   PetscCall(VecRestoreArray(coordinates, &coords));
5063   PetscCall(DMSetCoordinatesLocal(dm, coordinates));
5064   PetscCall(VecDestroy(&coordinates));
5065   PetscCall(PetscLogEventEnd(DMPLEX_BuildCoordinatesFromCellList, dm, 0, 0, 0));
5066   PetscFunctionReturn(PETSC_SUCCESS);
5067 }
5068 
5069 /*@
5070   DMPlexCreateFromCellListParallelPetsc - Create distributed `DMPLEX` from a list of vertices for each cell (common mesh generator output)
5071 
5072   Collective
5073 
5074   Input Parameters:
5075 + comm         - The communicator
5076 . dim          - The topological dimension of the mesh
5077 . numCells     - The number of cells owned by this process
5078 . numVertices  - The number of vertices owned by this process, or `PETSC_DECIDE`
5079 . NVertices    - The global number of vertices, or `PETSC_DECIDE`
5080 . numCorners   - The number of vertices for each cell
5081 . interpolate  - Flag indicating that intermediate mesh entities (faces, edges) should be created automatically
5082 . cells        - An array of numCells*numCorners numbers, the global vertex numbers for each cell
5083 . spaceDim     - The spatial dimension used for coordinates
5084 - vertexCoords - An array of numVertices*spaceDim numbers, the coordinates of each vertex
5085 
5086   Output Parameters:
5087 + dm          - The `DM`
5088 . vertexSF    - (Optional) `PetscSF` describing complete vertex ownership
5089 - verticesAdj - (Optional) vertex adjacency array
5090 
5091   Level: intermediate
5092 
5093   Notes:
5094   This function is just a convenient sequence of `DMCreate()`, `DMSetType()`, `DMSetDimension()`,
5095   `DMPlexBuildFromCellListParallel()`, `DMPlexInterpolate()`, `DMPlexBuildCoordinatesFromCellListParallel()`
5096 
5097   See `DMPlexBuildFromCellListParallel()` for an example and details about the topology-related parameters.
5098 
5099   See `DMPlexBuildCoordinatesFromCellListParallel()` for details about the geometry-related parameters.
5100 
5101 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexCreateFromCellListPetsc()`, `DMPlexBuildFromCellListParallel()`, `DMPlexBuildCoordinatesFromCellListParallel()`, `DMPlexCreateFromDAG()`, `DMPlexCreate()`
5102 @*/
5103 PetscErrorCode DMPlexCreateFromCellListParallelPetsc(MPI_Comm comm, PetscInt dim, PetscInt numCells, PetscInt numVertices, PetscInt NVertices, PetscInt numCorners, PetscBool interpolate, const PetscInt cells[], PetscInt spaceDim, const PetscReal vertexCoords[], PetscSF *vertexSF, PetscInt **verticesAdj, DM *dm)
5104 {
5105   PetscSF sfVert;
5106 
5107   PetscFunctionBegin;
5108   PetscCall(DMCreate(comm, dm));
5109   PetscCall(DMSetType(*dm, DMPLEX));
5110   PetscValidLogicalCollectiveInt(*dm, dim, 2);
5111   PetscValidLogicalCollectiveInt(*dm, spaceDim, 9);
5112   PetscCall(DMSetDimension(*dm, dim));
5113   PetscCall(DMPlexBuildFromCellListParallel(*dm, numCells, numVertices, NVertices, numCorners, cells, &sfVert, verticesAdj));
5114   if (interpolate) {
5115     DM idm;
5116 
5117     PetscCall(DMPlexInterpolate(*dm, &idm));
5118     PetscCall(DMDestroy(dm));
5119     *dm = idm;
5120   }
5121   PetscCall(DMPlexBuildCoordinatesFromCellListParallel(*dm, spaceDim, sfVert, vertexCoords));
5122   if (vertexSF) *vertexSF = sfVert;
5123   else PetscCall(PetscSFDestroy(&sfVert));
5124   PetscFunctionReturn(PETSC_SUCCESS);
5125 }
5126 
5127 /*@C
5128   DMPlexBuildFromCellList - Build `DMPLEX` topology from a list of vertices for each cell (common mesh generator output)
5129 
5130   Collective; No Fortran Support
5131 
5132   Input Parameters:
5133 + dm          - The `DM`
5134 . numCells    - The number of cells owned by this process
5135 . numVertices - The number of vertices owned by this process, or `PETSC_DETERMINE`
5136 . numCorners  - The number of vertices for each cell
5137 - cells       - An array of numCells*numCorners numbers, the global vertex numbers for each cell
5138 
5139   Level: advanced
5140 
5141   Notes:
5142   Two triangles sharing a face
5143 .vb
5144 
5145         2
5146       / | \
5147      /  |  \
5148     /   |   \
5149    0  0 | 1  3
5150     \   |   /
5151      \  |  /
5152       \ | /
5153         1
5154 .ve
5155   would have input
5156 .vb
5157   numCells = 2, numVertices = 4
5158   cells = [0 1 2  1 3 2]
5159 .ve
5160   which would result in the `DMPLEX`
5161 .vb
5162 
5163         4
5164       / | \
5165      /  |  \
5166     /   |   \
5167    2  0 | 1  5
5168     \   |   /
5169      \  |  /
5170       \ | /
5171         3
5172 .ve
5173 
5174   If numVertices is `PETSC_DETERMINE`, it is computed by PETSc as the maximum vertex index in cells + 1.
5175 
5176 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexBuildFromCellListParallel()`, `DMPlexBuildCoordinatesFromCellList()`, `DMPlexCreateFromCellListPetsc()`
5177 @*/
5178 PetscErrorCode DMPlexBuildFromCellList(DM dm, PetscInt numCells, PetscInt numVertices, PetscInt numCorners, const PetscInt cells[])
5179 {
5180   PetscInt *cones, c, p, dim;
5181 
5182   PetscFunctionBegin;
5183   PetscCall(PetscLogEventBegin(DMPLEX_BuildFromCellList, dm, 0, 0, 0));
5184   PetscCall(DMGetDimension(dm, &dim));
5185   /* Get/check global number of vertices */
5186   {
5187     PetscInt       NVerticesInCells, i;
5188     const PetscInt len = numCells * numCorners;
5189 
5190     /* NVerticesInCells = max(cells) + 1 */
5191     NVerticesInCells = PETSC_MIN_INT;
5192     for (i = 0; i < len; i++)
5193       if (cells[i] > NVerticesInCells) NVerticesInCells = cells[i];
5194     ++NVerticesInCells;
5195 
5196     if (numVertices == PETSC_DECIDE) numVertices = NVerticesInCells;
5197     else
5198       PetscCheck(numVertices >= NVerticesInCells, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONG, "Specified number of vertices %" PetscInt_FMT " must be greater than or equal to the number of vertices in cells %" PetscInt_FMT, numVertices, NVerticesInCells);
5199   }
5200   PetscCall(DMPlexSetChart(dm, 0, numCells + numVertices));
5201   for (c = 0; c < numCells; ++c) PetscCall(DMPlexSetConeSize(dm, c, numCorners));
5202   PetscCall(DMSetUp(dm));
5203   PetscCall(DMPlexGetCones(dm, &cones));
5204   for (c = 0; c < numCells; ++c) {
5205     for (p = 0; p < numCorners; ++p) cones[c * numCorners + p] = cells[c * numCorners + p] + numCells;
5206   }
5207   PetscCall(DMPlexSymmetrize(dm));
5208   PetscCall(DMPlexStratify(dm));
5209   PetscCall(PetscLogEventEnd(DMPLEX_BuildFromCellList, dm, 0, 0, 0));
5210   PetscFunctionReturn(PETSC_SUCCESS);
5211 }
5212 
5213 /*@C
5214   DMPlexBuildCoordinatesFromCellList - Build `DM` coordinates from a list of coordinates for each owned vertex (common mesh generator output)
5215 
5216   Collective; No Fortran Support
5217 
5218   Input Parameters:
5219 + dm           - The `DM`
5220 . spaceDim     - The spatial dimension used for coordinates
5221 - vertexCoords - An array of numVertices*spaceDim numbers, the coordinates of each vertex
5222 
5223   Level: advanced
5224 
5225 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexBuildCoordinatesFromCellListParallel()`, `DMPlexCreateFromCellListPetsc()`, `DMPlexBuildFromCellList()`
5226 @*/
5227 PetscErrorCode DMPlexBuildCoordinatesFromCellList(DM dm, PetscInt spaceDim, const PetscReal vertexCoords[])
5228 {
5229   PetscSection coordSection;
5230   Vec          coordinates;
5231   DM           cdm;
5232   PetscScalar *coords;
5233   PetscInt     v, vStart, vEnd, d;
5234 
5235   PetscFunctionBegin;
5236   PetscCall(PetscLogEventBegin(DMPLEX_BuildCoordinatesFromCellList, dm, 0, 0, 0));
5237   PetscCall(DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd));
5238   PetscCheck(vStart >= 0 && vEnd >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "DM is not set up properly. DMPlexBuildFromCellList() should be called first.");
5239   PetscCall(DMSetCoordinateDim(dm, spaceDim));
5240   PetscCall(DMGetCoordinateSection(dm, &coordSection));
5241   PetscCall(PetscSectionSetNumFields(coordSection, 1));
5242   PetscCall(PetscSectionSetFieldComponents(coordSection, 0, spaceDim));
5243   PetscCall(PetscSectionSetChart(coordSection, vStart, vEnd));
5244   for (v = vStart; v < vEnd; ++v) {
5245     PetscCall(PetscSectionSetDof(coordSection, v, spaceDim));
5246     PetscCall(PetscSectionSetFieldDof(coordSection, v, 0, spaceDim));
5247   }
5248   PetscCall(PetscSectionSetUp(coordSection));
5249 
5250   PetscCall(DMGetCoordinateDM(dm, &cdm));
5251   PetscCall(DMCreateLocalVector(cdm, &coordinates));
5252   PetscCall(VecSetBlockSize(coordinates, spaceDim));
5253   PetscCall(PetscObjectSetName((PetscObject)coordinates, "coordinates"));
5254   PetscCall(VecGetArrayWrite(coordinates, &coords));
5255   for (v = 0; v < vEnd - vStart; ++v) {
5256     for (d = 0; d < spaceDim; ++d) coords[v * spaceDim + d] = vertexCoords[v * spaceDim + d];
5257   }
5258   PetscCall(VecRestoreArrayWrite(coordinates, &coords));
5259   PetscCall(DMSetCoordinatesLocal(dm, coordinates));
5260   PetscCall(VecDestroy(&coordinates));
5261   PetscCall(PetscLogEventEnd(DMPLEX_BuildCoordinatesFromCellList, dm, 0, 0, 0));
5262   PetscFunctionReturn(PETSC_SUCCESS);
5263 }
5264 
5265 /*@
5266   DMPlexCreateFromCellListPetsc - Create `DMPLEX` from a list of vertices for each cell (common mesh generator output), but only process 0 takes in the input
5267 
5268   Collective
5269 
5270   Input Parameters:
5271 + comm         - The communicator
5272 . dim          - The topological dimension of the mesh
5273 . numCells     - The number of cells, only on process 0
5274 . numVertices  - The number of vertices owned by this process, or `PETSC_DECIDE`, only on process 0
5275 . numCorners   - The number of vertices for each cell, only on process 0
5276 . interpolate  - Flag indicating that intermediate mesh entities (faces, edges) should be created automatically
5277 . cells        - An array of numCells*numCorners numbers, the vertices for each cell, only on process 0
5278 . spaceDim     - The spatial dimension used for coordinates
5279 - vertexCoords - An array of numVertices*spaceDim numbers, the coordinates of each vertex, only on process 0
5280 
5281   Output Parameter:
5282 . dm - The `DM`, which only has points on process 0
5283 
5284   Level: intermediate
5285 
5286   Notes:
5287   This function is just a convenient sequence of `DMCreate()`, `DMSetType()`, `DMSetDimension()`, `DMPlexBuildFromCellList()`,
5288   `DMPlexInterpolate()`, `DMPlexBuildCoordinatesFromCellList()`
5289 
5290   See `DMPlexBuildFromCellList()` for an example and details about the topology-related parameters.
5291   See `DMPlexBuildCoordinatesFromCellList()` for details about the geometry-related parameters.
5292   See `DMPlexCreateFromCellListParallelPetsc()` for parallel input
5293 
5294 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexCreateFromCellListParallelPetsc()`, `DMPlexBuildFromCellList()`, `DMPlexBuildCoordinatesFromCellList()`, `DMPlexCreateFromDAG()`, `DMPlexCreate()`
5295 @*/
5296 PetscErrorCode DMPlexCreateFromCellListPetsc(MPI_Comm comm, PetscInt dim, PetscInt numCells, PetscInt numVertices, PetscInt numCorners, PetscBool interpolate, const PetscInt cells[], PetscInt spaceDim, const PetscReal vertexCoords[], DM *dm)
5297 {
5298   PetscMPIInt rank;
5299 
5300   PetscFunctionBegin;
5301   PetscCheck(dim, comm, PETSC_ERR_ARG_OUTOFRANGE, "This is not appropriate for 0-dimensional meshes. Consider either creating the DM using DMPlexCreateFromDAG(), by hand, or using DMSwarm.");
5302   PetscCallMPI(MPI_Comm_rank(comm, &rank));
5303   PetscCall(DMCreate(comm, dm));
5304   PetscCall(DMSetType(*dm, DMPLEX));
5305   PetscCall(DMSetDimension(*dm, dim));
5306   if (rank == 0) PetscCall(DMPlexBuildFromCellList(*dm, numCells, numVertices, numCorners, cells));
5307   else PetscCall(DMPlexBuildFromCellList(*dm, 0, 0, 0, NULL));
5308   if (interpolate) {
5309     DM idm;
5310 
5311     PetscCall(DMPlexInterpolate(*dm, &idm));
5312     PetscCall(DMDestroy(dm));
5313     *dm = idm;
5314   }
5315   if (rank == 0) PetscCall(DMPlexBuildCoordinatesFromCellList(*dm, spaceDim, vertexCoords));
5316   else PetscCall(DMPlexBuildCoordinatesFromCellList(*dm, spaceDim, NULL));
5317   PetscFunctionReturn(PETSC_SUCCESS);
5318 }
5319 
5320 /*@
5321   DMPlexCreateFromDAG - This takes as input the adjacency-list representation of the Directed Acyclic Graph (Hasse Diagram) encoding a mesh, and produces a `DM`
5322 
5323   Input Parameters:
5324 + dm               - The empty `DM` object, usually from `DMCreate()` and `DMSetDimension()`
5325 . depth            - The depth of the DAG
5326 . numPoints        - Array of size depth + 1 containing the number of points at each `depth`
5327 . coneSize         - The cone size of each point
5328 . cones            - The concatenation of the cone points for each point, the cone list must be oriented correctly for each point
5329 . coneOrientations - The orientation of each cone point
5330 - vertexCoords     - An array of `numPoints`[0]*spacedim numbers representing the coordinates of each vertex, with spacedim the value set via `DMSetCoordinateDim()`
5331 
5332   Output Parameter:
5333 . dm - The `DM`
5334 
5335   Level: advanced
5336 
5337   Note:
5338   Two triangles sharing a face would have input
5339 .vb
5340   depth = 1, numPoints = [4 2], coneSize = [3 3 0 0 0 0]
5341   cones = [2 3 4  3 5 4], coneOrientations = [0 0 0  0 0 0]
5342  vertexCoords = [-1.0 0.0  0.0 -1.0  0.0 1.0  1.0 0.0]
5343 .ve
5344   which would result in the DMPlex
5345 .vb
5346         4
5347       / | \
5348      /  |  \
5349     /   |   \
5350    2  0 | 1  5
5351     \   |   /
5352      \  |  /
5353       \ | /
5354         3
5355 .ve
5356   Notice that all points are numbered consecutively, unlike `DMPlexCreateFromCellListPetsc()`
5357 
5358 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexCreateFromCellListPetsc()`, `DMPlexCreate()`
5359 @*/
5360 PetscErrorCode DMPlexCreateFromDAG(DM dm, PetscInt depth, const PetscInt numPoints[], const PetscInt coneSize[], const PetscInt cones[], const PetscInt coneOrientations[], const PetscScalar vertexCoords[])
5361 {
5362   Vec          coordinates;
5363   PetscSection coordSection;
5364   PetscScalar *coords;
5365   PetscInt     coordSize, firstVertex = -1, pStart = 0, pEnd = 0, p, v, dim, dimEmbed, d, off;
5366 
5367   PetscFunctionBegin;
5368   PetscCall(DMGetDimension(dm, &dim));
5369   PetscCall(DMGetCoordinateDim(dm, &dimEmbed));
5370   PetscCheck(dimEmbed >= dim, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Embedding dimension %" PetscInt_FMT " cannot be less than intrinsic dimension %" PetscInt_FMT, dimEmbed, dim);
5371   for (d = 0; d <= depth; ++d) pEnd += numPoints[d];
5372   PetscCall(DMPlexSetChart(dm, pStart, pEnd));
5373   for (p = pStart; p < pEnd; ++p) {
5374     PetscCall(DMPlexSetConeSize(dm, p, coneSize[p - pStart]));
5375     if (firstVertex < 0 && !coneSize[p - pStart]) firstVertex = p - pStart;
5376   }
5377   PetscCheck(firstVertex >= 0 || !numPoints[0], PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Expected %" PetscInt_FMT " vertices but could not find any", numPoints[0]);
5378   PetscCall(DMSetUp(dm)); /* Allocate space for cones */
5379   for (p = pStart, off = 0; p < pEnd; off += coneSize[p - pStart], ++p) {
5380     PetscCall(DMPlexSetCone(dm, p, &cones[off]));
5381     PetscCall(DMPlexSetConeOrientation(dm, p, &coneOrientations[off]));
5382   }
5383   PetscCall(DMPlexSymmetrize(dm));
5384   PetscCall(DMPlexStratify(dm));
5385   /* Build coordinates */
5386   PetscCall(DMGetCoordinateSection(dm, &coordSection));
5387   PetscCall(PetscSectionSetNumFields(coordSection, 1));
5388   PetscCall(PetscSectionSetFieldComponents(coordSection, 0, dimEmbed));
5389   PetscCall(PetscSectionSetChart(coordSection, firstVertex, firstVertex + numPoints[0]));
5390   for (v = firstVertex; v < firstVertex + numPoints[0]; ++v) {
5391     PetscCall(PetscSectionSetDof(coordSection, v, dimEmbed));
5392     PetscCall(PetscSectionSetFieldDof(coordSection, v, 0, dimEmbed));
5393   }
5394   PetscCall(PetscSectionSetUp(coordSection));
5395   PetscCall(PetscSectionGetStorageSize(coordSection, &coordSize));
5396   PetscCall(VecCreate(PETSC_COMM_SELF, &coordinates));
5397   PetscCall(PetscObjectSetName((PetscObject)coordinates, "coordinates"));
5398   PetscCall(VecSetSizes(coordinates, coordSize, PETSC_DETERMINE));
5399   PetscCall(VecSetBlockSize(coordinates, dimEmbed));
5400   PetscCall(VecSetType(coordinates, VECSTANDARD));
5401   if (vertexCoords) {
5402     PetscCall(VecGetArray(coordinates, &coords));
5403     for (v = 0; v < numPoints[0]; ++v) {
5404       PetscInt off;
5405 
5406       PetscCall(PetscSectionGetOffset(coordSection, v + firstVertex, &off));
5407       for (d = 0; d < dimEmbed; ++d) coords[off + d] = vertexCoords[v * dimEmbed + d];
5408     }
5409   }
5410   PetscCall(VecRestoreArray(coordinates, &coords));
5411   PetscCall(DMSetCoordinatesLocal(dm, coordinates));
5412   PetscCall(VecDestroy(&coordinates));
5413   PetscFunctionReturn(PETSC_SUCCESS);
5414 }
5415 
5416 /*
5417   DMPlexCreateCellVertexFromFile - Create a `DMPLEX` mesh from a simple cell-vertex file.
5418 
5419   Collective
5420 
5421 + comm        - The MPI communicator
5422 . filename    - Name of the .dat file
5423 - interpolate - Create faces and edges in the mesh
5424 
5425   Output Parameter:
5426 . dm  - The `DM` object representing the mesh
5427 
5428   Level: beginner
5429 
5430   Note:
5431   The format is the simplest possible:
5432 .vb
5433   Ne
5434   v0 v1 ... vk
5435   Nv
5436   x y z marker
5437 .ve
5438 
5439   Developer Note:
5440   Should use a `PetscViewer` not a filename
5441 
5442 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexCreateFromFile()`, `DMPlexCreateGmsh()`, `DMPlexCreate()`
5443 */
5444 static PetscErrorCode DMPlexCreateCellVertexFromFile(MPI_Comm comm, const char filename[], PetscBool interpolate, DM *dm)
5445 {
5446   DMLabel      marker;
5447   PetscViewer  viewer;
5448   Vec          coordinates;
5449   PetscSection coordSection;
5450   PetscScalar *coords;
5451   char         line[PETSC_MAX_PATH_LEN];
5452   PetscInt     dim = 3, cdim = 3, coordSize, v, c, d;
5453   PetscMPIInt  rank;
5454   int          snum, Nv, Nc, Ncn, Nl;
5455 
5456   PetscFunctionBegin;
5457   PetscCallMPI(MPI_Comm_rank(comm, &rank));
5458   PetscCall(PetscViewerCreate(comm, &viewer));
5459   PetscCall(PetscViewerSetType(viewer, PETSCVIEWERASCII));
5460   PetscCall(PetscViewerFileSetMode(viewer, FILE_MODE_READ));
5461   PetscCall(PetscViewerFileSetName(viewer, filename));
5462   if (rank == 0) {
5463     PetscCall(PetscViewerRead(viewer, line, 4, NULL, PETSC_STRING));
5464     snum = sscanf(line, "%d %d %d %d", &Nc, &Nv, &Ncn, &Nl);
5465     PetscCheck(snum == 4, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unable to parse cell-vertex file: %s", line);
5466   } else {
5467     Nc = Nv = Ncn = Nl = 0;
5468   }
5469   PetscCall(DMCreate(comm, dm));
5470   PetscCall(DMSetType(*dm, DMPLEX));
5471   PetscCall(DMPlexSetChart(*dm, 0, Nc + Nv));
5472   PetscCall(DMSetDimension(*dm, dim));
5473   PetscCall(DMSetCoordinateDim(*dm, cdim));
5474   /* Read topology */
5475   if (rank == 0) {
5476     char     format[PETSC_MAX_PATH_LEN];
5477     PetscInt cone[8];
5478     int      vbuf[8], v;
5479 
5480     for (c = 0; c < Ncn; ++c) {
5481       format[c * 3 + 0] = '%';
5482       format[c * 3 + 1] = 'd';
5483       format[c * 3 + 2] = ' ';
5484     }
5485     format[Ncn * 3 - 1] = '\0';
5486     for (c = 0; c < Nc; ++c) PetscCall(DMPlexSetConeSize(*dm, c, Ncn));
5487     PetscCall(DMSetUp(*dm));
5488     for (c = 0; c < Nc; ++c) {
5489       PetscCall(PetscViewerRead(viewer, line, Ncn, NULL, PETSC_STRING));
5490       switch (Ncn) {
5491       case 2:
5492         snum = sscanf(line, format, &vbuf[0], &vbuf[1]);
5493         break;
5494       case 3:
5495         snum = sscanf(line, format, &vbuf[0], &vbuf[1], &vbuf[2]);
5496         break;
5497       case 4:
5498         snum = sscanf(line, format, &vbuf[0], &vbuf[1], &vbuf[2], &vbuf[3]);
5499         break;
5500       case 6:
5501         snum = sscanf(line, format, &vbuf[0], &vbuf[1], &vbuf[2], &vbuf[3], &vbuf[4], &vbuf[5]);
5502         break;
5503       case 8:
5504         snum = sscanf(line, format, &vbuf[0], &vbuf[1], &vbuf[2], &vbuf[3], &vbuf[4], &vbuf[5], &vbuf[6], &vbuf[7]);
5505         break;
5506       default:
5507         SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "No cell shape with %d vertices", Ncn);
5508       }
5509       PetscCheck(snum == Ncn, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unable to parse cell-vertex file: %s", line);
5510       for (v = 0; v < Ncn; ++v) cone[v] = vbuf[v] + Nc;
5511       /* Hexahedra are inverted */
5512       if (Ncn == 8) {
5513         PetscInt tmp = cone[1];
5514         cone[1]      = cone[3];
5515         cone[3]      = tmp;
5516       }
5517       PetscCall(DMPlexSetCone(*dm, c, cone));
5518     }
5519   }
5520   PetscCall(DMPlexSymmetrize(*dm));
5521   PetscCall(DMPlexStratify(*dm));
5522   /* Read coordinates */
5523   PetscCall(DMGetCoordinateSection(*dm, &coordSection));
5524   PetscCall(PetscSectionSetNumFields(coordSection, 1));
5525   PetscCall(PetscSectionSetFieldComponents(coordSection, 0, cdim));
5526   PetscCall(PetscSectionSetChart(coordSection, Nc, Nc + Nv));
5527   for (v = Nc; v < Nc + Nv; ++v) {
5528     PetscCall(PetscSectionSetDof(coordSection, v, cdim));
5529     PetscCall(PetscSectionSetFieldDof(coordSection, v, 0, cdim));
5530   }
5531   PetscCall(PetscSectionSetUp(coordSection));
5532   PetscCall(PetscSectionGetStorageSize(coordSection, &coordSize));
5533   PetscCall(VecCreate(PETSC_COMM_SELF, &coordinates));
5534   PetscCall(PetscObjectSetName((PetscObject)coordinates, "coordinates"));
5535   PetscCall(VecSetSizes(coordinates, coordSize, PETSC_DETERMINE));
5536   PetscCall(VecSetBlockSize(coordinates, cdim));
5537   PetscCall(VecSetType(coordinates, VECSTANDARD));
5538   PetscCall(VecGetArray(coordinates, &coords));
5539   if (rank == 0) {
5540     char   format[PETSC_MAX_PATH_LEN];
5541     double x[3];
5542     int    l, val[3];
5543 
5544     if (Nl) {
5545       for (l = 0; l < Nl; ++l) {
5546         format[l * 3 + 0] = '%';
5547         format[l * 3 + 1] = 'd';
5548         format[l * 3 + 2] = ' ';
5549       }
5550       format[Nl * 3 - 1] = '\0';
5551       PetscCall(DMCreateLabel(*dm, "marker"));
5552       PetscCall(DMGetLabel(*dm, "marker", &marker));
5553     }
5554     for (v = 0; v < Nv; ++v) {
5555       PetscCall(PetscViewerRead(viewer, line, 3 + Nl, NULL, PETSC_STRING));
5556       snum = sscanf(line, "%lg %lg %lg", &x[0], &x[1], &x[2]);
5557       PetscCheck(snum == 3, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unable to parse cell-vertex file: %s", line);
5558       switch (Nl) {
5559       case 0:
5560         snum = 0;
5561         break;
5562       case 1:
5563         snum = sscanf(line, format, &val[0]);
5564         break;
5565       case 2:
5566         snum = sscanf(line, format, &val[0], &val[1]);
5567         break;
5568       case 3:
5569         snum = sscanf(line, format, &val[0], &val[1], &val[2]);
5570         break;
5571       default:
5572         SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "Request support for %d labels", Nl);
5573       }
5574       PetscCheck(snum == Nl, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unable to parse cell-vertex file: %s", line);
5575       for (d = 0; d < cdim; ++d) coords[v * cdim + d] = x[d];
5576       for (l = 0; l < Nl; ++l) PetscCall(DMLabelSetValue(marker, v + Nc, val[l]));
5577     }
5578   }
5579   PetscCall(VecRestoreArray(coordinates, &coords));
5580   PetscCall(DMSetCoordinatesLocal(*dm, coordinates));
5581   PetscCall(VecDestroy(&coordinates));
5582   PetscCall(PetscViewerDestroy(&viewer));
5583   if (interpolate) {
5584     DM      idm;
5585     DMLabel bdlabel;
5586 
5587     PetscCall(DMPlexInterpolate(*dm, &idm));
5588     PetscCall(DMDestroy(dm));
5589     *dm = idm;
5590 
5591     if (!Nl) {
5592       PetscCall(DMCreateLabel(*dm, "marker"));
5593       PetscCall(DMGetLabel(*dm, "marker", &bdlabel));
5594       PetscCall(DMPlexMarkBoundaryFaces(*dm, PETSC_DETERMINE, bdlabel));
5595       PetscCall(DMPlexLabelComplete(*dm, bdlabel));
5596     }
5597   }
5598   PetscFunctionReturn(PETSC_SUCCESS);
5599 }
5600 
5601 /*@C
5602   DMPlexCreateFromFile - This takes a filename and produces a `DM`
5603 
5604   Collective
5605 
5606   Input Parameters:
5607 + comm        - The communicator
5608 . filename    - A file name
5609 . plexname    - The object name of the resulting `DM`, also used for intra-datafile lookup by some formats
5610 - interpolate - Flag to create intermediate mesh pieces (edges, faces)
5611 
5612   Output Parameter:
5613 . dm - The `DM`
5614 
5615   Options Database Key:
5616 . -dm_plex_create_from_hdf5_xdmf - use the `PETSC_VIEWER_HDF5_XDMF` format for reading HDF5
5617 
5618   Use `-dm_plex_create_ prefix` to pass options to the internal `PetscViewer`, e.g.
5619 $ -dm_plex_create_viewer_hdf5_collective
5620 
5621   Level: beginner
5622 
5623   Notes:
5624   Using `PETSCVIEWERHDF5` type with `PETSC_VIEWER_HDF5_PETSC` format, one can save multiple `DMPLEX`
5625   meshes in a single HDF5 file. This in turn requires one to name the `DMPLEX` object with `PetscObjectSetName()`
5626   before saving it with `DMView()` and before loading it with `DMLoad()` for identification of the mesh object.
5627   The input parameter name is thus used to name the `DMPLEX` object when `DMPlexCreateFromFile()` internally
5628   calls `DMLoad()`. Currently, name is ignored for other viewer types and/or formats.
5629 
5630 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexCreateFromDAG()`, `DMPlexCreateFromCellListPetsc()`, `DMPlexCreate()`, `PetscObjectSetName()`, `DMView()`, `DMLoad()`
5631 @*/
5632 PetscErrorCode DMPlexCreateFromFile(MPI_Comm comm, const char filename[], const char plexname[], PetscBool interpolate, DM *dm)
5633 {
5634   const char  extGmsh[]      = ".msh";
5635   const char  extGmsh2[]     = ".msh2";
5636   const char  extGmsh4[]     = ".msh4";
5637   const char  extCGNS[]      = ".cgns";
5638   const char  extExodus[]    = ".exo";
5639   const char  extExodus_e[]  = ".e";
5640   const char  extGenesis[]   = ".gen";
5641   const char  extFluent[]    = ".cas";
5642   const char  extHDF5[]      = ".h5";
5643   const char  extXDMFHDF5[]  = ".xdmf.h5";
5644   const char  extPLY[]       = ".ply";
5645   const char  extEGADSLite[] = ".egadslite";
5646   const char  extEGADS[]     = ".egads";
5647   const char  extIGES[]      = ".igs";
5648   const char  extSTEP[]      = ".stp";
5649   const char  extCV[]        = ".dat";
5650   size_t      len;
5651   PetscBool   isGmsh, isGmsh2, isGmsh4, isCGNS, isExodus, isGenesis, isFluent, isHDF5, isPLY, isEGADSLite, isEGADS, isIGES, isSTEP, isCV, isXDMFHDF5;
5652   PetscMPIInt rank;
5653 
5654   PetscFunctionBegin;
5655   PetscAssertPointer(filename, 2);
5656   if (plexname) PetscAssertPointer(plexname, 3);
5657   PetscAssertPointer(dm, 5);
5658   PetscCall(DMInitializePackage());
5659   PetscCall(PetscLogEventBegin(DMPLEX_CreateFromFile, 0, 0, 0, 0));
5660   PetscCallMPI(MPI_Comm_rank(comm, &rank));
5661   PetscCall(PetscStrlen(filename, &len));
5662   PetscCheck(len, comm, PETSC_ERR_ARG_WRONG, "Filename must be a valid path");
5663 
5664 #define CheckExtension(extension__, is_extension__) \
5665   do { \
5666     PetscAssert(sizeof(extension__), comm, PETSC_ERR_PLIB, "Zero-size extension: %s", extension__); \
5667     /* don't count the null-terminator at the end */ \
5668     const size_t ext_len = sizeof(extension__) - 1; \
5669     if (len < ext_len) { \
5670       is_extension__ = PETSC_FALSE; \
5671     } else { \
5672       PetscCall(PetscStrncmp(filename + len - ext_len, extension__, ext_len, &is_extension__)); \
5673     } \
5674   } while (0)
5675 
5676   CheckExtension(extGmsh, isGmsh);
5677   CheckExtension(extGmsh2, isGmsh2);
5678   CheckExtension(extGmsh4, isGmsh4);
5679   CheckExtension(extCGNS, isCGNS);
5680   CheckExtension(extExodus, isExodus);
5681   if (!isExodus) CheckExtension(extExodus_e, isExodus);
5682   CheckExtension(extGenesis, isGenesis);
5683   CheckExtension(extFluent, isFluent);
5684   CheckExtension(extHDF5, isHDF5);
5685   CheckExtension(extPLY, isPLY);
5686   CheckExtension(extEGADSLite, isEGADSLite);
5687   CheckExtension(extEGADS, isEGADS);
5688   CheckExtension(extIGES, isIGES);
5689   CheckExtension(extSTEP, isSTEP);
5690   CheckExtension(extCV, isCV);
5691   CheckExtension(extXDMFHDF5, isXDMFHDF5);
5692 
5693 #undef CheckExtension
5694 
5695   if (isGmsh || isGmsh2 || isGmsh4) {
5696     PetscCall(DMPlexCreateGmshFromFile(comm, filename, interpolate, dm));
5697   } else if (isCGNS) {
5698     PetscCall(DMPlexCreateCGNSFromFile(comm, filename, interpolate, dm));
5699   } else if (isExodus || isGenesis) {
5700     PetscCall(DMPlexCreateExodusFromFile(comm, filename, interpolate, dm));
5701   } else if (isFluent) {
5702     PetscCall(DMPlexCreateFluentFromFile(comm, filename, interpolate, dm));
5703   } else if (isHDF5) {
5704     PetscViewer viewer;
5705 
5706     /* PETSC_VIEWER_HDF5_XDMF is used if the filename ends with .xdmf.h5, or if -dm_plex_create_from_hdf5_xdmf option is present */
5707     PetscCall(PetscOptionsGetBool(NULL, NULL, "-dm_plex_create_from_hdf5_xdmf", &isXDMFHDF5, NULL));
5708     PetscCall(PetscViewerCreate(comm, &viewer));
5709     PetscCall(PetscViewerSetType(viewer, PETSCVIEWERHDF5));
5710     PetscCall(PetscViewerSetOptionsPrefix(viewer, "dm_plex_create_"));
5711     PetscCall(PetscViewerSetFromOptions(viewer));
5712     PetscCall(PetscViewerFileSetMode(viewer, FILE_MODE_READ));
5713     PetscCall(PetscViewerFileSetName(viewer, filename));
5714 
5715     PetscCall(DMCreate(comm, dm));
5716     PetscCall(PetscObjectSetName((PetscObject)(*dm), plexname));
5717     PetscCall(DMSetType(*dm, DMPLEX));
5718     if (isXDMFHDF5) PetscCall(PetscViewerPushFormat(viewer, PETSC_VIEWER_HDF5_XDMF));
5719     PetscCall(DMLoad(*dm, viewer));
5720     if (isXDMFHDF5) PetscCall(PetscViewerPopFormat(viewer));
5721     PetscCall(PetscViewerDestroy(&viewer));
5722 
5723     if (interpolate) {
5724       DM idm;
5725 
5726       PetscCall(DMPlexInterpolate(*dm, &idm));
5727       PetscCall(DMDestroy(dm));
5728       *dm = idm;
5729     }
5730   } else if (isPLY) {
5731     PetscCall(DMPlexCreatePLYFromFile(comm, filename, interpolate, dm));
5732   } else if (isEGADSLite || isEGADS || isIGES || isSTEP) {
5733     if (isEGADSLite) PetscCall(DMPlexCreateEGADSLiteFromFile(comm, filename, dm));
5734     else PetscCall(DMPlexCreateEGADSFromFile(comm, filename, dm));
5735     if (!interpolate) {
5736       DM udm;
5737 
5738       PetscCall(DMPlexUninterpolate(*dm, &udm));
5739       PetscCall(DMDestroy(dm));
5740       *dm = udm;
5741     }
5742   } else if (isCV) {
5743     PetscCall(DMPlexCreateCellVertexFromFile(comm, filename, interpolate, dm));
5744   } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cannot load file %s: unrecognized extension", filename);
5745   PetscCall(PetscStrlen(plexname, &len));
5746   if (len) PetscCall(PetscObjectSetName((PetscObject)(*dm), plexname));
5747   PetscCall(PetscLogEventEnd(DMPLEX_CreateFromFile, 0, 0, 0, 0));
5748   PetscFunctionReturn(PETSC_SUCCESS);
5749 }
5750 
5751 /*@C
5752   DMPlexCreateEphemeral - This takes a `DMPlexTransform` and a base `DMPlex` and produces an ephemeral `DM`, meaning one that is created on the fly in response to queries.
5753 
5754   Input Parameters:
5755 + tr     - The `DMPlexTransform`
5756 - prefix - An options prefix, or NULL
5757 
5758   Output Parameter:
5759 . dm - The `DM`
5760 
5761   Level: beginner
5762 
5763   Notes:
5764   An emphemeral mesh is one that is not stored concretely, as in the default `DMPLEX` implementation, but rather is produced on the fly in response to queries, using information from the transform and the base mesh.
5765 
5766 .seealso: `DMPlexCreateFromFile`, `DMPlexCreateFromDAG()`, `DMPlexCreateFromCellListPetsc()`, `DMPlexCreate()`
5767 @*/
5768 PetscErrorCode DMPlexCreateEphemeral(DMPlexTransform tr, const char prefix[], DM *dm)
5769 {
5770   DM           bdm, bcdm, cdm;
5771   Vec          coordinates, coordinatesNew;
5772   PetscSection cs;
5773   PetscInt     dim, cdim, Nl;
5774 
5775   PetscFunctionBegin;
5776   PetscCall(DMCreate(PetscObjectComm((PetscObject)tr), dm));
5777   PetscCall(DMSetType(*dm, DMPLEX));
5778   ((DM_Plex *)(*dm)->data)->interpolated = DMPLEX_INTERPOLATED_FULL;
5779   // Handle coordinates
5780   PetscCall(DMPlexTransformGetDM(tr, &bdm));
5781   PetscCall(DMGetCoordinateDim(bdm, &cdim));
5782   PetscCall(DMSetCoordinateDim(*dm, cdim));
5783   PetscCall(DMGetDimension(bdm, &dim));
5784   PetscCall(DMSetDimension(*dm, dim));
5785   PetscCall(DMGetCoordinateDM(bdm, &bcdm));
5786   PetscCall(DMGetCoordinateDM(*dm, &cdm));
5787   PetscCall(DMCopyDisc(bcdm, cdm));
5788   PetscCall(DMGetLocalSection(cdm, &cs));
5789   PetscCall(PetscSectionSetNumFields(cs, 1));
5790   PetscCall(PetscSectionSetFieldComponents(cs, 0, cdim));
5791   PetscCall(DMGetCoordinatesLocal(bdm, &coordinates));
5792   PetscCall(VecDuplicate(coordinates, &coordinatesNew));
5793   PetscCall(VecCopy(coordinates, coordinatesNew));
5794   PetscCall(DMSetCoordinatesLocal(*dm, coordinatesNew));
5795   PetscCall(VecDestroy(&coordinatesNew));
5796 
5797   PetscCall(PetscObjectReference((PetscObject)tr));
5798   PetscCall(DMPlexTransformDestroy(&((DM_Plex *)(*dm)->data)->tr));
5799   ((DM_Plex *)(*dm)->data)->tr = tr;
5800   PetscCall(DMPlexDistributeSetDefault(*dm, PETSC_FALSE));
5801   PetscCall(PetscObjectSetOptionsPrefix((PetscObject)*dm, prefix));
5802   PetscCall(DMSetFromOptions(*dm));
5803 
5804   PetscCall(DMGetNumLabels(bdm, &Nl));
5805   for (PetscInt l = 0; l < Nl; ++l) {
5806     DMLabel     label, labelNew;
5807     const char *lname;
5808     PetscBool   isDepth, isCellType;
5809 
5810     PetscCall(DMGetLabelName(bdm, l, &lname));
5811     PetscCall(PetscStrcmp(lname, "depth", &isDepth));
5812     if (isDepth) continue;
5813     PetscCall(PetscStrcmp(lname, "celltype", &isCellType));
5814     if (isCellType) continue;
5815     PetscCall(DMCreateLabel(*dm, lname));
5816     PetscCall(DMGetLabel(bdm, lname, &label));
5817     PetscCall(DMGetLabel(*dm, lname, &labelNew));
5818     PetscCall(DMLabelSetType(labelNew, DMLABELEPHEMERAL));
5819     PetscCall(DMLabelEphemeralSetLabel(labelNew, label));
5820     PetscCall(DMLabelEphemeralSetTransform(labelNew, tr));
5821     PetscCall(DMLabelSetUp(labelNew));
5822   }
5823   PetscFunctionReturn(PETSC_SUCCESS);
5824 }
5825