xref: /petsc/src/dm/impls/plex/plexinterpolate.c (revision ba1e01c44f2f740c97c9026fe63e360558b7709b)
1 #include <petsc/private/dmpleximpl.h>   /*I      "petscdmplex.h"   I*/
2 #include <../src/sys/utils/hash.h>
3 
4 #undef __FUNCT__
5 #define __FUNCT__ "DMPlexGetFaces_Internal"
6 /*
7   DMPlexGetFaces_Internal - Gets groups of vertices that correspond to faces for the given cell
8 */
9 PetscErrorCode DMPlexGetFaces_Internal(DM dm, PetscInt dim, PetscInt p, PetscInt *numFaces, PetscInt *faceSize, const PetscInt *faces[])
10 {
11   const PetscInt *cone = NULL;
12   PetscInt        maxConeSize, maxSupportSize, coneSize;
13   PetscErrorCode  ierr;
14 
15   PetscFunctionBegin;
16   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
17   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, &maxSupportSize);CHKERRQ(ierr);
18   ierr = DMPlexGetConeSize(dm, p, &coneSize);CHKERRQ(ierr);
19   ierr = DMPlexGetCone(dm, p, &cone);CHKERRQ(ierr);
20   ierr = DMPlexGetRawFaces_Internal(dm, dim, coneSize, cone, numFaces, faceSize, faces);CHKERRQ(ierr);
21   PetscFunctionReturn(0);
22 }
23 
24 #undef __FUNCT__
25 #define __FUNCT__ "DMPlexRestoreFaces_Internal"
26 /*
27   DMPlexRestoreFaces_Internal - Restores the array
28 */
29 PetscErrorCode DMPlexRestoreFaces_Internal(DM dm, PetscInt dim, PetscInt p, PetscInt *numFaces, PetscInt *faceSize, const PetscInt *faces[])
30 {
31   PetscErrorCode  ierr;
32 
33   PetscFunctionBegin;
34   ierr = DMRestoreWorkArray(dm, 0, PETSC_INT, (void *) faces);CHKERRQ(ierr);
35   PetscFunctionReturn(0);
36 }
37 
38 #undef __FUNCT__
39 #define __FUNCT__ "DMPlexGetRawFaces_Internal"
40 /*
41   DMPlexGetRawFaces_Internal - Gets groups of vertices that correspond to faces for the given cone
42 */
43 PetscErrorCode DMPlexGetRawFaces_Internal(DM dm, PetscInt dim, PetscInt coneSize, const PetscInt cone[], PetscInt *numFaces, PetscInt *faceSize, const PetscInt *faces[])
44 {
45   PetscInt       *facesTmp;
46   PetscInt        maxConeSize, maxSupportSize;
47   PetscErrorCode  ierr;
48 
49   PetscFunctionBegin;
50   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
51   ierr = DMPlexGetMaxSizes(dm, &maxConeSize, &maxSupportSize);CHKERRQ(ierr);
52   if (faces) {ierr = DMGetWorkArray(dm, PetscSqr(PetscMax(maxConeSize, maxSupportSize)), PETSC_INT, &facesTmp);CHKERRQ(ierr);}
53   switch (dim) {
54   case 1:
55     switch (coneSize) {
56     case 2:
57       if (faces) {
58         facesTmp[0] = cone[0]; facesTmp[1] = cone[1];
59         *faces = facesTmp;
60       }
61       if (numFaces) *numFaces         = 2;
62       if (faceSize) *faceSize         = 1;
63       break;
64     default:
65       SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cone size %D not supported for dimension %D", coneSize, dim);
66     }
67     break;
68   case 2:
69     switch (coneSize) {
70     case 3:
71       if (faces) {
72         facesTmp[0] = cone[0]; facesTmp[1] = cone[1];
73         facesTmp[2] = cone[1]; facesTmp[3] = cone[2];
74         facesTmp[4] = cone[2]; facesTmp[5] = cone[0];
75         *faces = facesTmp;
76       }
77       if (numFaces) *numFaces         = 3;
78       if (faceSize) *faceSize         = 2;
79       break;
80     case 4:
81       /* Vertices follow right hand rule */
82       if (faces) {
83         facesTmp[0] = cone[0]; facesTmp[1] = cone[1];
84         facesTmp[2] = cone[1]; facesTmp[3] = cone[2];
85         facesTmp[4] = cone[2]; facesTmp[5] = cone[3];
86         facesTmp[6] = cone[3]; facesTmp[7] = cone[0];
87         *faces = facesTmp;
88       }
89       if (numFaces) *numFaces         = 4;
90       if (faceSize) *faceSize         = 2;
91       break;
92     default:
93       SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cone size %D not supported for dimension %D", coneSize, dim);
94     }
95     break;
96   case 3:
97     switch (coneSize) {
98     case 3:
99       if (faces) {
100         facesTmp[0] = cone[0]; facesTmp[1] = cone[1];
101         facesTmp[2] = cone[1]; facesTmp[3] = cone[2];
102         facesTmp[4] = cone[2]; facesTmp[5] = cone[0];
103         *faces = facesTmp;
104       }
105       if (numFaces) *numFaces         = 3;
106       if (faceSize) *faceSize         = 2;
107       break;
108     case 4:
109       /* Vertices of first face follow right hand rule and normal points away from last vertex */
110       if (faces) {
111         facesTmp[0] = cone[0]; facesTmp[1]  = cone[1]; facesTmp[2]  = cone[2];
112         facesTmp[3] = cone[0]; facesTmp[4]  = cone[3]; facesTmp[5]  = cone[1];
113         facesTmp[6] = cone[0]; facesTmp[7]  = cone[2]; facesTmp[8]  = cone[3];
114         facesTmp[9] = cone[2]; facesTmp[10] = cone[1]; facesTmp[11] = cone[3];
115         *faces = facesTmp;
116       }
117       if (numFaces) *numFaces         = 4;
118       if (faceSize) *faceSize         = 3;
119       break;
120     case 8:
121       if (faces) {
122         facesTmp[0]  = cone[0]; facesTmp[1]  = cone[1]; facesTmp[2]  = cone[2]; facesTmp[3]  = cone[3]; /* Bottom */
123         facesTmp[4]  = cone[4]; facesTmp[5]  = cone[5]; facesTmp[6]  = cone[6]; facesTmp[7]  = cone[7]; /* Top */
124         facesTmp[8]  = cone[0]; facesTmp[9]  = cone[3]; facesTmp[10] = cone[5]; facesTmp[11] = cone[4]; /* Front */
125         facesTmp[12] = cone[2]; facesTmp[13] = cone[1]; facesTmp[14] = cone[7]; facesTmp[15] = cone[6]; /* Back */
126         facesTmp[16] = cone[3]; facesTmp[17] = cone[2]; facesTmp[18] = cone[6]; facesTmp[19] = cone[5]; /* Right */
127         facesTmp[20] = cone[0]; facesTmp[21] = cone[4]; facesTmp[22] = cone[7]; facesTmp[23] = cone[1]; /* Left */
128         *faces = facesTmp;
129       }
130       if (numFaces) *numFaces         = 6;
131       if (faceSize) *faceSize         = 4;
132       break;
133     default:
134       SETERRQ2(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Cone size %D not supported for dimension %D", coneSize, dim);
135     }
136     break;
137   default:
138     SETERRQ1(PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Dimension %D not supported", dim);
139   }
140   PetscFunctionReturn(0);
141 }
142 
143 #undef __FUNCT__
144 #define __FUNCT__ "DMPlexInterpolateFaces_Internal"
145 /* This interpolates faces for cells at some stratum */
146 static PetscErrorCode DMPlexInterpolateFaces_Internal(DM dm, PetscInt cellDepth, DM idm)
147 {
148   DMLabel        subpointMap;
149   PetscHashIJKL  faceTable;
150   PetscInt      *pStart, *pEnd;
151   PetscInt       cellDim, depth, faceDepth = cellDepth, numPoints = 0, faceSizeAll = 0, face, c, d;
152   PetscErrorCode ierr;
153 
154   PetscFunctionBegin;
155   ierr = DMGetDimension(dm, &cellDim);CHKERRQ(ierr);
156   /* HACK: I need a better way to determine face dimension, or an alternative to GetFaces() */
157   ierr = DMPlexGetSubpointMap(dm, &subpointMap);CHKERRQ(ierr);
158   if (subpointMap) ++cellDim;
159   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
160   ++depth;
161   ++cellDepth;
162   cellDim -= depth - cellDepth;
163   ierr = PetscMalloc2(depth+1,&pStart,depth+1,&pEnd);CHKERRQ(ierr);
164   for (d = depth-1; d >= faceDepth; --d) {
165     ierr = DMPlexGetDepthStratum(dm, d, &pStart[d+1], &pEnd[d+1]);CHKERRQ(ierr);
166   }
167   ierr = DMPlexGetDepthStratum(dm, -1, NULL, &pStart[faceDepth]);CHKERRQ(ierr);
168   pEnd[faceDepth] = pStart[faceDepth];
169   for (d = faceDepth-1; d >= 0; --d) {
170     ierr = DMPlexGetDepthStratum(dm, d, &pStart[d], &pEnd[d]);CHKERRQ(ierr);
171   }
172   if (pEnd[cellDepth] > pStart[cellDepth]) {ierr = DMPlexGetFaces_Internal(dm, cellDim, pStart[cellDepth], NULL, &faceSizeAll, NULL);CHKERRQ(ierr);}
173   if (faceSizeAll > 4) SETERRQ1(PetscObjectComm((PetscObject) dm), PETSC_ERR_ARG_WRONG, "Do not support interpolation of meshes with faces of %D vertices", faceSizeAll);
174   ierr = PetscHashIJKLCreate(&faceTable);CHKERRQ(ierr);
175   for (c = pStart[cellDepth], face = pStart[faceDepth]; c < pEnd[cellDepth]; ++c) {
176     const PetscInt *cellFaces;
177     PetscInt        numCellFaces, faceSize, cf;
178 
179     ierr = DMPlexGetFaces_Internal(dm, cellDim, c, &numCellFaces, &faceSize, &cellFaces);CHKERRQ(ierr);
180     if (faceSize != faceSizeAll) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Inconsistent face for cell %D of size %D != %D", c, faceSize, faceSizeAll);
181     for (cf = 0; cf < numCellFaces; ++cf) {
182       const PetscInt   *cellFace = &cellFaces[cf*faceSize];
183       PetscHashIJKLKey  key;
184       PetscHashIJKLIter missing, iter;
185 
186       if (faceSize == 2) {
187         key.i = PetscMin(cellFace[0], cellFace[1]);
188         key.j = PetscMax(cellFace[0], cellFace[1]);
189         key.k = 0;
190         key.l = 0;
191       } else {
192         key.i = cellFace[0]; key.j = cellFace[1]; key.k = cellFace[2]; key.l = faceSize > 3 ? cellFace[3] : 0;
193         ierr = PetscSortInt(faceSize, (PetscInt *) &key);CHKERRQ(ierr);
194       }
195       ierr = PetscHashIJKLPut(faceTable, key, &missing, &iter);CHKERRQ(ierr);
196       if (missing) {ierr = PetscHashIJKLSet(faceTable, iter, face++);CHKERRQ(ierr);}
197     }
198     ierr = DMPlexRestoreFaces_Internal(dm, cellDim, c, &numCellFaces, &faceSize, &cellFaces);CHKERRQ(ierr);
199   }
200   pEnd[faceDepth] = face;
201   ierr = PetscHashIJKLDestroy(&faceTable);CHKERRQ(ierr);
202   /* Count new points */
203   for (d = 0; d <= depth; ++d) {
204     numPoints += pEnd[d]-pStart[d];
205   }
206   ierr = DMPlexSetChart(idm, 0, numPoints);CHKERRQ(ierr);
207   /* Set cone sizes */
208   for (d = 0; d <= depth; ++d) {
209     PetscInt coneSize, p;
210 
211     if (d == faceDepth) {
212       for (p = pStart[d]; p < pEnd[d]; ++p) {
213         /* I see no way to do this if we admit faces of different shapes */
214         ierr = DMPlexSetConeSize(idm, p, faceSizeAll);CHKERRQ(ierr);
215       }
216     } else if (d == cellDepth) {
217       for (p = pStart[d]; p < pEnd[d]; ++p) {
218         /* Number of cell faces may be different from number of cell vertices*/
219         ierr = DMPlexGetFaces_Internal(dm, cellDim, p, &coneSize, NULL, NULL);CHKERRQ(ierr);
220         ierr = DMPlexSetConeSize(idm, p, coneSize);CHKERRQ(ierr);
221       }
222     } else {
223       for (p = pStart[d]; p < pEnd[d]; ++p) {
224         ierr = DMPlexGetConeSize(dm, p, &coneSize);CHKERRQ(ierr);
225         ierr = DMPlexSetConeSize(idm, p, coneSize);CHKERRQ(ierr);
226       }
227     }
228   }
229   ierr = DMSetUp(idm);CHKERRQ(ierr);
230   /* Get face cones from subsets of cell vertices */
231   if (faceSizeAll > 4) SETERRQ1(PetscObjectComm((PetscObject) dm), PETSC_ERR_ARG_WRONG, "Do not support interpolation of meshes with faces of %D vertices", faceSizeAll);
232   ierr = PetscHashIJKLCreate(&faceTable);CHKERRQ(ierr);
233   for (d = depth; d > cellDepth; --d) {
234     const PetscInt *cone;
235     PetscInt        p;
236 
237     for (p = pStart[d]; p < pEnd[d]; ++p) {
238       ierr = DMPlexGetCone(dm, p, &cone);CHKERRQ(ierr);
239       ierr = DMPlexSetCone(idm, p, cone);CHKERRQ(ierr);
240       ierr = DMPlexGetConeOrientation(dm, p, &cone);CHKERRQ(ierr);
241       ierr = DMPlexSetConeOrientation(idm, p, cone);CHKERRQ(ierr);
242     }
243   }
244   for (c = pStart[cellDepth], face = pStart[faceDepth]; c < pEnd[cellDepth]; ++c) {
245     const PetscInt *cellFaces;
246     PetscInt        numCellFaces, faceSize, cf;
247 
248     ierr = DMPlexGetFaces_Internal(dm, cellDim, c, &numCellFaces, &faceSize, &cellFaces);CHKERRQ(ierr);
249     if (faceSize != faceSizeAll) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Inconsistent face for cell %D of size %D != %D", c, faceSize, faceSizeAll);
250     for (cf = 0; cf < numCellFaces; ++cf) {
251       const PetscInt  *cellFace = &cellFaces[cf*faceSize];
252       PetscHashIJKLKey key;
253       PetscHashIJKLIter missing, iter;
254 
255       if (faceSize == 2) {
256         key.i = PetscMin(cellFace[0], cellFace[1]);
257         key.j = PetscMax(cellFace[0], cellFace[1]);
258         key.k = 0;
259         key.l = 0;
260       } else {
261         key.i = cellFace[0]; key.j = cellFace[1]; key.k = cellFace[2]; key.l = faceSize > 3 ? cellFace[3] : 0;
262         ierr = PetscSortInt(faceSize, (PetscInt *) &key);CHKERRQ(ierr);
263       }
264       ierr = PetscHashIJKLPut(faceTable, key, &missing, &iter);CHKERRQ(ierr);
265       if (missing) {
266         ierr = DMPlexSetCone(idm, face, cellFace);CHKERRQ(ierr);
267         ierr = PetscHashIJKLSet(faceTable, iter, face);CHKERRQ(ierr);
268         ierr = DMPlexInsertCone(idm, c, cf, face++);CHKERRQ(ierr);
269       } else {
270         const PetscInt *cone;
271         PetscInt        coneSize, ornt, i, j, f;
272 
273         ierr = PetscHashIJKLGet(faceTable, iter, &f);CHKERRQ(ierr);
274         ierr = DMPlexInsertCone(idm, c, cf, f);CHKERRQ(ierr);
275         /* Orient face: Do not allow reverse orientation at the first vertex */
276         ierr = DMPlexGetConeSize(idm, f, &coneSize);CHKERRQ(ierr);
277         ierr = DMPlexGetCone(idm, f, &cone);CHKERRQ(ierr);
278         if (coneSize != faceSize) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid number of face vertices %D for face %D should be %D", coneSize, f, faceSize);
279         /* - First find the initial vertex */
280         for (i = 0; i < faceSize; ++i) if (cellFace[0] == cone[i]) break;
281         /* - Try forward comparison */
282         for (j = 0; j < faceSize; ++j) if (cellFace[j] != cone[(i+j)%faceSize]) break;
283         if (j == faceSize) {
284           if ((faceSize == 2) && (i == 1)) ornt = -2;
285           else                             ornt = i;
286         } else {
287           /* - Try backward comparison */
288           for (j = 0; j < faceSize; ++j) if (cellFace[j] != cone[(i+faceSize-j)%faceSize]) break;
289           if (j == faceSize) {
290             if (i == 0) ornt = -faceSize;
291             else        ornt = -i;
292           } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Could not determine face orientation");
293         }
294         ierr = DMPlexInsertConeOrientation(idm, c, cf, ornt);CHKERRQ(ierr);
295       }
296     }
297     ierr = DMPlexRestoreFaces_Internal(dm, cellDim, c, &numCellFaces, &faceSize, &cellFaces);CHKERRQ(ierr);
298   }
299   if (face != pEnd[faceDepth]) SETERRQ2(PetscObjectComm((PetscObject) dm), PETSC_ERR_PLIB, "Invalid number of faces %D should be %D", face-pStart[faceDepth], pEnd[faceDepth]-pStart[faceDepth]);
300   ierr = PetscFree2(pStart,pEnd);CHKERRQ(ierr);
301   ierr = PetscHashIJKLDestroy(&faceTable);CHKERRQ(ierr);
302   ierr = PetscFree2(pStart,pEnd);CHKERRQ(ierr);
303   ierr = DMPlexSymmetrize(idm);CHKERRQ(ierr);
304   ierr = DMPlexStratify(idm);CHKERRQ(ierr);
305   PetscFunctionReturn(0);
306 }
307 
308 #undef __FUNCT__
309 #define __FUNCT__ "DMPlexInterpolatePointSF"
310 /* This interpolates the PointSF in parallel following local interpolation */
311 static PetscErrorCode DMPlexInterpolatePointSF(DM dm, PetscSF pointSF, PetscInt depth)
312 {
313   PetscMPIInt        numProcs, rank;
314   PetscInt           p, c, d, dof, offset;
315   PetscInt           numLeaves, numRoots, candidatesSize, candidatesRemoteSize;
316   const PetscInt    *localPoints;
317   const PetscSFNode *remotePoints;
318   PetscSFNode       *candidates, *candidatesRemote, *claims;
319   PetscSection       candidateSection, candidateSectionRemote, claimSection;
320   PetscHashI         leafhash;
321   PetscHashIJ        roothash;
322   PetscHashIJKey     key;
323   PetscErrorCode     ierr;
324 
325   PetscFunctionBegin;
326   ierr = MPI_Comm_size(PetscObjectComm((PetscObject) dm), &numProcs);CHKERRQ(ierr);
327   ierr = MPI_Comm_rank(PetscObjectComm((PetscObject) dm), &rank);CHKERRQ(ierr);
328   ierr = PetscSFGetGraph(pointSF, &numRoots, &numLeaves, &localPoints, &remotePoints);CHKERRQ(ierr);
329   if (numProcs < 2 || numRoots < 0) PetscFunctionReturn(0);
330   ierr = PetscLogEventBegin(DMPLEX_InterpolateSF,dm,0,0,0);CHKERRQ(ierr);
331   /* Build hashes of points in the SF for efficient lookup */
332   PetscHashICreate(leafhash);
333   PetscHashIJCreate(&roothash);
334   ierr = PetscHashIJSetMultivalued(roothash, PETSC_FALSE);CHKERRQ(ierr);
335   for (p = 0; p < numLeaves; ++p) {
336     PetscHashIAdd(leafhash, localPoints[p], p);
337     key.i = remotePoints[p].index; key.j = remotePoints[p].rank;
338     PetscHashIJAdd(roothash, key, p);
339   }
340   /* Build a section / SFNode array of candidate points in the single-level adjacency of leaves,
341      where each candidate is defined by the root entry for the other vertex that defines the edge. */
342   ierr = PetscSectionCreate(PetscObjectComm((PetscObject) dm), &candidateSection);CHKERRQ(ierr);
343   ierr = PetscSectionSetChart(candidateSection, 0, numRoots);CHKERRQ(ierr);
344   {
345     PetscInt leaf, root, idx, a, *adj = NULL;
346     for (p = 0; p < numLeaves; ++p) {
347       PetscInt adjSize = PETSC_DETERMINE;
348       ierr = DMPlexGetAdjacency_Internal(dm, localPoints[p], PETSC_FALSE, PETSC_FALSE, PETSC_FALSE, &adjSize, &adj);CHKERRQ(ierr);
349       for (a = 0; a < adjSize; ++a) {
350         PetscHashIMap(leafhash, adj[a], leaf);
351         if (leaf >= 0) {ierr = PetscSectionAddDof(candidateSection, localPoints[p], 1);CHKERRQ(ierr);}
352       }
353     }
354     ierr = PetscSectionSetUp(candidateSection);CHKERRQ(ierr);
355     ierr = PetscSectionGetStorageSize(candidateSection, &candidatesSize);CHKERRQ(ierr);
356     ierr = PetscMalloc1(candidatesSize, &candidates);CHKERRQ(ierr);
357     for (p = 0; p < numLeaves; ++p) {
358       PetscInt adjSize = PETSC_DETERMINE;
359       ierr = PetscSectionGetOffset(candidateSection, localPoints[p], &offset);CHKERRQ(ierr);
360       ierr = DMPlexGetAdjacency_Internal(dm, localPoints[p], PETSC_FALSE, PETSC_FALSE, PETSC_FALSE, &adjSize, &adj);CHKERRQ(ierr);
361       for (idx = 0, a = 0; a < adjSize; ++a) {
362         PetscHashIMap(leafhash, adj[a], root);
363         if (root >= 0) candidates[offset+idx++] = remotePoints[root];
364       }
365     }
366     ierr = PetscFree(adj);CHKERRQ(ierr);
367   }
368   /* Gather candidate section / array pair into the root partition via inverse(multi(pointSF)). */
369   {
370     PetscSF   sfMulti, sfInverse, sfCandidates;
371     PetscInt *remoteOffsets;
372     ierr = PetscSFGetMultiSF(pointSF, &sfMulti);CHKERRQ(ierr);
373     ierr = PetscSFCreateInverseSF(sfMulti, &sfInverse);CHKERRQ(ierr);
374     ierr = PetscSectionCreate(PetscObjectComm((PetscObject) dm), &candidateSectionRemote);CHKERRQ(ierr);
375     ierr = PetscSFDistributeSection(sfInverse, candidateSection, &remoteOffsets, candidateSectionRemote);CHKERRQ(ierr);
376     ierr = PetscSFCreateSectionSF(sfInverse, candidateSection, remoteOffsets, candidateSectionRemote, &sfCandidates);CHKERRQ(ierr);
377     ierr = PetscSectionGetStorageSize(candidateSectionRemote, &candidatesRemoteSize);CHKERRQ(ierr);
378     ierr = PetscMalloc1(candidatesRemoteSize, &candidatesRemote);CHKERRQ(ierr);
379     ierr = PetscSFBcastBegin(sfCandidates, MPIU_2INT, candidates, candidatesRemote);CHKERRQ(ierr);
380     ierr = PetscSFBcastEnd(sfCandidates, MPIU_2INT, candidates, candidatesRemote);CHKERRQ(ierr);
381     ierr = PetscSFDestroy(&sfInverse);CHKERRQ(ierr);
382     ierr = PetscSFDestroy(&sfCandidates);CHKERRQ(ierr);
383     ierr = PetscFree(remoteOffsets);CHKERRQ(ierr);
384   }
385   /* Walk local roots and check for each remote candidate whether we know all required points,
386      either from owning it or having a root entry in the point SF. If we do we place a claim
387      by replacing the vertex number with our edge ID. */
388   {
389     PetscInt        idx, root, joinSize, vertices[2];
390     const PetscInt *rootdegree, *join = NULL;
391     ierr = PetscSFComputeDegreeBegin(pointSF, &rootdegree);CHKERRQ(ierr);
392     ierr = PetscSFComputeDegreeEnd(pointSF, &rootdegree);CHKERRQ(ierr);
393     /* Loop remote edge connections and put in a claim if both vertices are known */
394     for (idx = 0, p = 0; p < numRoots; ++p) {
395       for (d = 0; d < rootdegree[p]; ++d) {
396         ierr = PetscSectionGetDof(candidateSectionRemote, idx, &dof);CHKERRQ(ierr);
397         ierr = PetscSectionGetOffset(candidateSectionRemote, idx, &offset);CHKERRQ(ierr);
398         for (c = 0; c < dof; ++c) {
399           /* We own both vertices, so we claim the edge by replacing vertex with edge */
400           if (candidatesRemote[offset+c].rank == rank) {
401             vertices[0] = p; vertices[1] = candidatesRemote[offset+c].index;
402             ierr = DMPlexGetJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
403             if (joinSize == 1) candidatesRemote[offset+c].index = join[0];
404             ierr = DMPlexRestoreJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
405             continue;
406           }
407           /* If we own one vertex and share a root with the other, we claim it */
408           key.i = candidatesRemote[offset+c].index; key.j = candidatesRemote[offset+c].rank;
409           PetscHashIJGet(roothash, key, &root);
410           if (root >= 0) {
411             vertices[0] = p; vertices[1] = localPoints[root];
412             ierr = DMPlexGetJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
413             if (joinSize == 1) {
414               candidatesRemote[offset+c].index = join[0];
415               candidatesRemote[offset+c].rank = rank;
416             }
417             ierr = DMPlexRestoreJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
418           }
419         }
420         idx++;
421       }
422     }
423   }
424   /* Push claims back to receiver via the MultiSF and derive new pointSF mapping on receiver */
425   {
426     PetscSF         sfMulti, sfClaims, sfPointNew;
427     PetscHashI      claimshash;
428     PetscInt        size, pStart, pEnd, root, joinSize, numLocalNew;
429     PetscInt       *remoteOffsets, *localPointsNew, vertices[2];
430     const PetscInt *join = NULL;
431     PetscSFNode    *remotePointsNew;
432     ierr = PetscSFGetMultiSF(pointSF, &sfMulti);CHKERRQ(ierr);
433     ierr = PetscSectionCreate(PetscObjectComm((PetscObject) dm), &claimSection);CHKERRQ(ierr);
434     ierr = PetscSFDistributeSection(sfMulti, candidateSectionRemote, &remoteOffsets, claimSection);CHKERRQ(ierr);
435     ierr = PetscSFCreateSectionSF(sfMulti, candidateSectionRemote, remoteOffsets, claimSection, &sfClaims);CHKERRQ(ierr);
436     ierr = PetscSectionGetStorageSize(claimSection, &size);CHKERRQ(ierr);
437     ierr = PetscMalloc1(size, &claims);CHKERRQ(ierr);
438     ierr = PetscSFBcastBegin(sfClaims, MPIU_2INT, candidatesRemote, claims);CHKERRQ(ierr);
439     ierr = PetscSFBcastEnd(sfClaims, MPIU_2INT, candidatesRemote, claims);CHKERRQ(ierr);
440     ierr = PetscSFDestroy(&sfClaims);CHKERRQ(ierr);
441     ierr = PetscFree(remoteOffsets);CHKERRQ(ierr);
442     /* Walk the original section of local supports and add an SF entry for each updated item */
443     PetscHashICreate(claimshash);
444     for (p = 0; p < numRoots; ++p) {
445       ierr = PetscSectionGetDof(candidateSection, p, &dof);CHKERRQ(ierr);
446       ierr = PetscSectionGetOffset(candidateSection, p, &offset);CHKERRQ(ierr);
447       for (d = 0; d < dof; ++d) {
448         if (candidates[offset+d].index != claims[offset+d].index) {
449           key.i = candidates[offset+d].index; key.j = candidates[offset+d].rank;
450           PetscHashIJGet(roothash, key, &root);
451           if (root >= 0) {
452             vertices[0] = p; vertices[1] = localPoints[root];
453             ierr = DMPlexGetJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
454             if (joinSize == 1) PetscHashIAdd(claimshash, join[0], offset+d);
455             ierr = DMPlexRestoreJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
456           }
457         }
458       }
459     }
460     /* Create new pointSF from hashed claims */
461     PetscHashISize(claimshash, numLocalNew);
462     ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
463     ierr = PetscMalloc1(numLeaves + numLocalNew, &localPointsNew);CHKERRQ(ierr);
464     ierr = PetscMalloc1(numLeaves + numLocalNew, &remotePointsNew);CHKERRQ(ierr);
465     for (p = 0; p < numLeaves; ++p) {
466       localPointsNew[p] = localPoints[p];
467       remotePointsNew[p].index = remotePoints[p].index;
468       remotePointsNew[p].rank = remotePoints[p].rank;
469     }
470     p = numLeaves; ierr = PetscHashIGetKeys(claimshash, &p, localPointsNew);CHKERRQ(ierr);
471     for (p = numLeaves; p < numLeaves + numLocalNew; ++p) {
472       PetscHashIMap(claimshash, localPointsNew[p], offset);
473       remotePointsNew[p] = claims[offset];
474     }
475     ierr = PetscSFCreate(PetscObjectComm((PetscObject) dm), &sfPointNew);CHKERRQ(ierr);
476     ierr = PetscSFSetGraph(sfPointNew, pEnd-pStart, numLeaves+numLocalNew, localPointsNew, PETSC_OWN_POINTER, remotePointsNew, PETSC_OWN_POINTER);CHKERRQ(ierr);
477     ierr = DMSetPointSF(dm, sfPointNew);CHKERRQ(ierr);
478     ierr = PetscSFDestroy(&sfPointNew);CHKERRQ(ierr);
479     PetscHashIDestroy(claimshash);
480   }
481   PetscHashIDestroy(leafhash);
482   ierr = PetscHashIJDestroy(&roothash);CHKERRQ(ierr);
483   ierr = PetscSectionDestroy(&candidateSection);CHKERRQ(ierr);
484   ierr = PetscSectionDestroy(&candidateSectionRemote);CHKERRQ(ierr);
485   ierr = PetscSectionDestroy(&claimSection);CHKERRQ(ierr);
486   ierr = PetscFree(candidates);CHKERRQ(ierr);
487   ierr = PetscFree(candidatesRemote);CHKERRQ(ierr);
488   ierr = PetscFree(claims);CHKERRQ(ierr);
489   ierr = PetscLogEventEnd(DMPLEX_InterpolateSF,dm,0,0,0);CHKERRQ(ierr);
490   PetscFunctionReturn(0);
491 }
492 
493 #undef __FUNCT__
494 #define __FUNCT__ "DMPlexInterpolate"
495 /*@C
496   DMPlexInterpolate - Take in a cell-vertex mesh and return one with all intermediate faces, edges, etc.
497 
498   Collective on DM
499 
500   Input Parameters:
501 + dm - The DMPlex object with only cells and vertices
502 - dmInt - If NULL a new DM is created, otherwise the interpolated DM is put into the given DM
503 
504   Output Parameter:
505 . dmInt - The complete DMPlex object
506 
507   Level: intermediate
508 
509 .keywords: mesh
510 .seealso: DMPlexUninterpolate(), DMPlexCreateFromCellList()
511 @*/
512 PetscErrorCode DMPlexInterpolate(DM dm, DM *dmInt)
513 {
514   DM             idm, odm = dm;
515   PetscSF        sfPoint;
516   PetscInt       depth, dim, d;
517   PetscErrorCode ierr;
518 
519   PetscFunctionBegin;
520   ierr = PetscLogEventBegin(DMPLEX_Interpolate,dm,0,0,0);CHKERRQ(ierr);
521   ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
522   ierr = DMGetDimension(dm, &dim);CHKERRQ(ierr);
523   if (dim <= 1) {
524     ierr = PetscObjectReference((PetscObject) dm);CHKERRQ(ierr);
525     idm  = dm;
526   }
527   for (d = 1; d < dim; ++d) {
528     /* Create interpolated mesh */
529     if ((d == dim-1) && *dmInt) {idm  = *dmInt;}
530     else                        {ierr = DMCreate(PetscObjectComm((PetscObject)dm), &idm);CHKERRQ(ierr);}
531     ierr = DMSetType(idm, DMPLEX);CHKERRQ(ierr);
532     ierr = DMSetDimension(idm, dim);CHKERRQ(ierr);
533     if (depth > 0) {
534       ierr = DMPlexInterpolateFaces_Internal(odm, 1, idm);CHKERRQ(ierr);
535       ierr = DMGetPointSF(odm, &sfPoint);CHKERRQ(ierr);
536       ierr = DMPlexInterpolatePointSF(idm, sfPoint, depth);CHKERRQ(ierr);
537     }
538     if (odm != dm) {ierr = DMDestroy(&odm);CHKERRQ(ierr);}
539     odm  = idm;
540   }
541   *dmInt = idm;
542   ierr = PetscLogEventEnd(DMPLEX_Interpolate,dm,0,0,0);CHKERRQ(ierr);
543   PetscFunctionReturn(0);
544 }
545 
546 #undef __FUNCT__
547 #define __FUNCT__ "DMPlexCopyCoordinates"
548 /*@
549   DMPlexCopyCoordinates - Copy coordinates from one mesh to another with the same vertices
550 
551   Collective on DM
552 
553   Input Parameter:
554 . dmA - The DMPlex object with initial coordinates
555 
556   Output Parameter:
557 . dmB - The DMPlex object with copied coordinates
558 
559   Level: intermediate
560 
561   Note: This is typically used when adding pieces other than vertices to a mesh
562 
563 .keywords: mesh
564 .seealso: DMCopyLabels(), DMGetCoordinates(), DMGetCoordinatesLocal(), DMGetCoordinateDM(), DMGetCoordinateSection()
565 @*/
566 PetscErrorCode DMPlexCopyCoordinates(DM dmA, DM dmB)
567 {
568   Vec            coordinatesA, coordinatesB;
569   PetscSection   coordSectionA, coordSectionB;
570   PetscScalar   *coordsA, *coordsB;
571   PetscInt       spaceDim, vStartA, vStartB, vEndA, vEndB, coordSizeB, v, d;
572   PetscErrorCode ierr;
573 
574   PetscFunctionBegin;
575   if (dmA == dmB) PetscFunctionReturn(0);
576   ierr = DMPlexGetDepthStratum(dmA, 0, &vStartA, &vEndA);CHKERRQ(ierr);
577   ierr = DMPlexGetDepthStratum(dmB, 0, &vStartB, &vEndB);CHKERRQ(ierr);
578   if ((vEndA-vStartA) != (vEndB-vStartB)) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "The number of vertices in first DM %d != %d in the second DM", vEndA-vStartA, vEndB-vStartB);
579   ierr = DMGetCoordinateSection(dmA, &coordSectionA);CHKERRQ(ierr);
580   ierr = DMGetCoordinateSection(dmB, &coordSectionB);CHKERRQ(ierr);
581   if (coordSectionA == coordSectionB) PetscFunctionReturn(0);
582   if (!coordSectionB) {
583     PetscInt dim;
584 
585     ierr = PetscSectionCreate(PetscObjectComm((PetscObject) coordSectionA), &coordSectionB);CHKERRQ(ierr);
586     ierr = DMGetCoordinateDim(dmA, &dim);CHKERRQ(ierr);
587     ierr = DMSetCoordinateSection(dmB, dim, coordSectionB);CHKERRQ(ierr);
588     ierr = PetscObjectDereference((PetscObject) coordSectionB);CHKERRQ(ierr);
589   }
590   ierr = PetscSectionSetNumFields(coordSectionB, 1);CHKERRQ(ierr);
591   ierr = PetscSectionGetFieldComponents(coordSectionA, 0, &spaceDim);CHKERRQ(ierr);
592   ierr = PetscSectionSetFieldComponents(coordSectionB, 0, spaceDim);CHKERRQ(ierr);
593   ierr = PetscSectionSetChart(coordSectionB, vStartB, vEndB);CHKERRQ(ierr);
594   for (v = vStartB; v < vEndB; ++v) {
595     ierr = PetscSectionSetDof(coordSectionB, v, spaceDim);CHKERRQ(ierr);
596     ierr = PetscSectionSetFieldDof(coordSectionB, v, 0, spaceDim);CHKERRQ(ierr);
597   }
598   ierr = PetscSectionSetUp(coordSectionB);CHKERRQ(ierr);
599   ierr = PetscSectionGetStorageSize(coordSectionB, &coordSizeB);CHKERRQ(ierr);
600   ierr = DMGetCoordinatesLocal(dmA, &coordinatesA);CHKERRQ(ierr);
601   ierr = VecCreate(PETSC_COMM_SELF, &coordinatesB);CHKERRQ(ierr);
602   ierr = PetscObjectSetName((PetscObject) coordinatesB, "coordinates");CHKERRQ(ierr);
603   ierr = VecSetSizes(coordinatesB, coordSizeB, PETSC_DETERMINE);CHKERRQ(ierr);
604   ierr = VecSetType(coordinatesB,VECSTANDARD);CHKERRQ(ierr);
605   ierr = VecGetArray(coordinatesA, &coordsA);CHKERRQ(ierr);
606   ierr = VecGetArray(coordinatesB, &coordsB);CHKERRQ(ierr);
607   for (v = 0; v < vEndB-vStartB; ++v) {
608     for (d = 0; d < spaceDim; ++d) {
609       coordsB[v*spaceDim+d] = coordsA[v*spaceDim+d];
610     }
611   }
612   ierr = VecRestoreArray(coordinatesA, &coordsA);CHKERRQ(ierr);
613   ierr = VecRestoreArray(coordinatesB, &coordsB);CHKERRQ(ierr);
614   ierr = DMSetCoordinatesLocal(dmB, coordinatesB);CHKERRQ(ierr);
615   ierr = VecDestroy(&coordinatesB);CHKERRQ(ierr);
616   PetscFunctionReturn(0);
617 }
618 
619 #undef __FUNCT__
620 #define __FUNCT__ "DMPlexUninterpolate"
621 /*@
622   DMPlexUninterpolate - Take in a mesh with all intermediate faces, edges, etc. and return a cell-vertex mesh
623 
624   Collective on DM
625 
626   Input Parameter:
627 . dm - The complete DMPlex object
628 
629   Output Parameter:
630 . dmUnint - The DMPlex object with only cells and vertices
631 
632   Level: intermediate
633 
634 .keywords: mesh
635 .seealso: DMPlexInterpolate(), DMPlexCreateFromCellList()
636 @*/
637 PetscErrorCode DMPlexUninterpolate(DM dm, DM *dmUnint)
638 {
639   DM             udm;
640   PetscInt       dim, vStart, vEnd, cStart, cEnd, c, maxConeSize = 0, *cone;
641   PetscErrorCode ierr;
642 
643   PetscFunctionBegin;
644   ierr = DMGetDimension(dm, &dim);CHKERRQ(ierr);
645   if (dim <= 1) {
646     ierr = PetscObjectReference((PetscObject) dm);CHKERRQ(ierr);
647     *dmUnint = dm;
648     PetscFunctionReturn(0);
649   }
650   ierr = DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd);CHKERRQ(ierr);
651   ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr);
652   ierr = DMCreate(PetscObjectComm((PetscObject) dm), &udm);CHKERRQ(ierr);
653   ierr = DMSetType(udm, DMPLEX);CHKERRQ(ierr);
654   ierr = DMSetDimension(udm, dim);CHKERRQ(ierr);
655   ierr = DMPlexSetChart(udm, cStart, vEnd);CHKERRQ(ierr);
656   for (c = cStart; c < cEnd; ++c) {
657     PetscInt *closure = NULL, closureSize, cl, coneSize = 0;
658 
659     ierr = DMPlexGetTransitiveClosure(dm, c, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
660     for (cl = 0; cl < closureSize*2; cl += 2) {
661       const PetscInt p = closure[cl];
662 
663       if ((p >= vStart) && (p < vEnd)) ++coneSize;
664     }
665     ierr = DMPlexRestoreTransitiveClosure(dm, c, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
666     ierr = DMPlexSetConeSize(udm, c, coneSize);CHKERRQ(ierr);
667     maxConeSize = PetscMax(maxConeSize, coneSize);
668   }
669   ierr = DMSetUp(udm);CHKERRQ(ierr);
670   ierr = PetscMalloc1(maxConeSize, &cone);CHKERRQ(ierr);
671   for (c = cStart; c < cEnd; ++c) {
672     PetscInt *closure = NULL, closureSize, cl, coneSize = 0;
673 
674     ierr = DMPlexGetTransitiveClosure(dm, c, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
675     for (cl = 0; cl < closureSize*2; cl += 2) {
676       const PetscInt p = closure[cl];
677 
678       if ((p >= vStart) && (p < vEnd)) cone[coneSize++] = p;
679     }
680     ierr = DMPlexRestoreTransitiveClosure(dm, c, PETSC_TRUE, &closureSize, &closure);CHKERRQ(ierr);
681     ierr = DMPlexSetCone(udm, c, cone);CHKERRQ(ierr);
682   }
683   ierr = PetscFree(cone);CHKERRQ(ierr);
684   ierr = DMPlexSymmetrize(udm);CHKERRQ(ierr);
685   ierr = DMPlexStratify(udm);CHKERRQ(ierr);
686   /* Reduce SF */
687   {
688     PetscSF            sfPoint, sfPointUn;
689     const PetscSFNode *remotePoints;
690     const PetscInt    *localPoints;
691     PetscSFNode       *remotePointsUn;
692     PetscInt          *localPointsUn;
693     PetscInt           vEnd, numRoots, numLeaves, l;
694     PetscInt           numLeavesUn = 0, n = 0;
695     PetscErrorCode     ierr;
696 
697     /* Get original SF information */
698     ierr = DMGetPointSF(dm, &sfPoint);CHKERRQ(ierr);
699     ierr = DMGetPointSF(udm, &sfPointUn);CHKERRQ(ierr);
700     ierr = DMPlexGetDepthStratum(dm, 0, NULL, &vEnd);CHKERRQ(ierr);
701     ierr = PetscSFGetGraph(sfPoint, &numRoots, &numLeaves, &localPoints, &remotePoints);CHKERRQ(ierr);
702     /* Allocate space for cells and vertices */
703     for (l = 0; l < numLeaves; ++l) if (localPoints[l] < vEnd) numLeavesUn++;
704     /* Fill in leaves */
705     if (vEnd >= 0) {
706       ierr = PetscMalloc1(numLeavesUn, &remotePointsUn);CHKERRQ(ierr);
707       ierr = PetscMalloc1(numLeavesUn, &localPointsUn);CHKERRQ(ierr);
708       for (l = 0; l < numLeaves; l++) {
709         if (localPoints[l] < vEnd) {
710           localPointsUn[n]        = localPoints[l];
711           remotePointsUn[n].rank  = remotePoints[l].rank;
712           remotePointsUn[n].index = remotePoints[l].index;
713           ++n;
714         }
715       }
716       if (n != numLeavesUn) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Inconsistent number of leaves %d != %d", n, numLeavesUn);
717       ierr = PetscSFSetGraph(sfPointUn, vEnd, numLeavesUn, localPointsUn, PETSC_OWN_POINTER, remotePointsUn, PETSC_OWN_POINTER);CHKERRQ(ierr);
718     }
719   }
720   *dmUnint = udm;
721   PetscFunctionReturn(0);
722 }
723