xref: /petsc/src/dm/impls/plex/plexorient.c (revision 6dd63270497ad23dcf16ae500a87ff2b2a0b7474)
1 #include <petsc/private/dmpleximpl.h> /*I      "petscdmplex.h"   I*/
2 #include <petscsf.h>
3 
4 /*@
5   DMPlexOrientPoint - Act with the given orientation on the cone points of this mesh point, and update its use in the mesh.
6 
7   Not Collective
8 
9   Input Parameters:
10 + dm - The `DM`
11 . p  - The mesh point
12 - o  - The orientation
13 
14   Level: intermediate
15 
16 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexOrient()`, `DMPlexGetCone()`, `DMPlexGetConeOrientation()`, `DMPlexInterpolate()`, `DMPlexGetChart()`
17 @*/
18 PetscErrorCode DMPlexOrientPoint(DM dm, PetscInt p, PetscInt o)
19 {
20   DMPolytopeType  ct;
21   const PetscInt *arr, *cone, *ornt, *support;
22   PetscInt       *newcone, *newornt;
23   PetscInt        coneSize, c, supportSize, s;
24 
25   PetscFunctionBegin;
26   PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
27   PetscCall(DMPlexGetCellType(dm, p, &ct));
28   arr = DMPolytopeTypeGetArrangement(ct, o);
29   if (!arr) PetscFunctionReturn(PETSC_SUCCESS);
30   PetscCall(DMPlexGetConeSize(dm, p, &coneSize));
31   PetscCall(DMPlexGetCone(dm, p, &cone));
32   PetscCall(DMPlexGetConeOrientation(dm, p, &ornt));
33   PetscCall(DMGetWorkArray(dm, coneSize, MPIU_INT, &newcone));
34   PetscCall(DMGetWorkArray(dm, coneSize, MPIU_INT, &newornt));
35   for (c = 0; c < coneSize; ++c) {
36     DMPolytopeType ft;
37     PetscInt       nO;
38 
39     PetscCall(DMPlexGetCellType(dm, cone[c], &ft));
40     nO         = DMPolytopeTypeGetNumArrangements(ft) / 2;
41     newcone[c] = cone[arr[c * 2 + 0]];
42     newornt[c] = DMPolytopeTypeComposeOrientation(ft, arr[c * 2 + 1], ornt[arr[c * 2 + 0]]);
43     PetscCheck(!newornt[c] || !(newornt[c] >= nO || newornt[c] < -nO), PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid orientation %" PetscInt_FMT " not in [%" PetscInt_FMT ",%" PetscInt_FMT ") for %s %" PetscInt_FMT, newornt[c], -nO, nO, DMPolytopeTypes[ft], cone[c]);
44   }
45   PetscCall(DMPlexSetCone(dm, p, newcone));
46   PetscCall(DMPlexSetConeOrientation(dm, p, newornt));
47   PetscCall(DMRestoreWorkArray(dm, coneSize, MPIU_INT, &newcone));
48   PetscCall(DMRestoreWorkArray(dm, coneSize, MPIU_INT, &newornt));
49   /* Update orientation of this point in the support points */
50   PetscCall(DMPlexGetSupportSize(dm, p, &supportSize));
51   PetscCall(DMPlexGetSupport(dm, p, &support));
52   for (s = 0; s < supportSize; ++s) {
53     PetscCall(DMPlexGetConeSize(dm, support[s], &coneSize));
54     PetscCall(DMPlexGetCone(dm, support[s], &cone));
55     PetscCall(DMPlexGetConeOrientation(dm, support[s], &ornt));
56     for (c = 0; c < coneSize; ++c) {
57       PetscInt po;
58 
59       if (cone[c] != p) continue;
60       /* ornt[c] * 0 = target = po * o so that po = ornt[c] * o^{-1} */
61       po = DMPolytopeTypeComposeOrientationInv(ct, ornt[c], o);
62       PetscCall(DMPlexInsertConeOrientation(dm, support[s], c, po));
63     }
64   }
65   PetscFunctionReturn(PETSC_SUCCESS);
66 }
67 
68 static PetscInt GetPointIndex(PetscInt point, PetscInt pStart, PetscInt pEnd, const PetscInt points[])
69 {
70   if (points) {
71     PetscInt loc;
72 
73     PetscCallAbort(PETSC_COMM_SELF, PetscFindInt(point, pEnd - pStart, points, &loc));
74     if (loc >= 0) return loc;
75   } else {
76     if (point >= pStart && point < pEnd) return point - pStart;
77   }
78   return -1;
79 }
80 
81 /*
82   - Checks face match
83     - Flips non-matching
84   - Inserts faces of support cells in FIFO
85 */
86 static PetscErrorCode DMPlexCheckFace_Internal(DM dm, PetscInt *faceFIFO, PetscInt *fTop, PetscInt *fBottom, IS cellIS, IS faceIS, PetscBT seenCells, PetscBT flippedCells, PetscBT seenFaces)
87 {
88   const PetscInt *supp, *coneA, *coneB, *coneOA, *coneOB;
89   PetscInt        suppSize, Ns = 0, coneSizeA, coneSizeB, posA = -1, posB = -1;
90   PetscInt        face, dim, indC[3], indS[3], seenA, flippedA, seenB, flippedB, mismatch;
91   const PetscInt *cells, *faces;
92   PetscInt        cStart, cEnd, fStart, fEnd;
93 
94   PetscFunctionBegin;
95   face = faceFIFO[(*fTop)++];
96   PetscCall(ISGetPointRange(cellIS, &cStart, &cEnd, &cells));
97   PetscCall(ISGetPointRange(faceIS, &fStart, &fEnd, &faces));
98   PetscCall(DMPlexGetPointDepth(dm, cells ? cells[cStart] : cStart, &dim));
99   PetscCall(DMPlexGetSupportSize(dm, face, &suppSize));
100   PetscCall(DMPlexGetSupport(dm, face, &supp));
101   // Filter the support
102   for (PetscInt s = 0; s < suppSize; ++s) {
103     // Filter support
104     indC[Ns] = GetPointIndex(supp[s], cStart, cEnd, cells);
105     indS[Ns] = s;
106     if (indC[Ns] >= 0) ++Ns;
107   }
108   if (Ns < 2) PetscFunctionReturn(PETSC_SUCCESS);
109   PetscCheck(Ns == 2, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Faces should separate only two cells, not %" PetscInt_FMT, Ns);
110   PetscCheck(indC[0] >= 0 && indC[1] >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Support cells %" PetscInt_FMT " (%" PetscInt_FMT ") and %" PetscInt_FMT " (%" PetscInt_FMT ") are not both valid", supp[0], indC[0], supp[1], indC[1]);
111   seenA    = PetscBTLookup(seenCells, indC[0]);
112   flippedA = PetscBTLookup(flippedCells, indC[0]) ? 1 : 0;
113   seenB    = PetscBTLookup(seenCells, indC[1]);
114   flippedB = PetscBTLookup(flippedCells, indC[1]) ? 1 : 0;
115 
116   PetscCall(DMPlexGetConeSize(dm, supp[indS[0]], &coneSizeA));
117   PetscCall(DMPlexGetConeSize(dm, supp[indS[1]], &coneSizeB));
118   PetscCall(DMPlexGetCone(dm, supp[indS[0]], &coneA));
119   PetscCall(DMPlexGetCone(dm, supp[indS[1]], &coneB));
120   PetscCall(DMPlexGetConeOrientation(dm, supp[indS[0]], &coneOA));
121   PetscCall(DMPlexGetConeOrientation(dm, supp[indS[1]], &coneOB));
122   for (PetscInt c = 0; c < coneSizeA; ++c) {
123     const PetscInt indF = GetPointIndex(coneA[c], fStart, fEnd, faces);
124 
125     // Filter cone
126     if (indF < 0) continue;
127     if (!PetscBTLookup(seenFaces, indF)) {
128       faceFIFO[(*fBottom)++] = coneA[c];
129       PetscCall(PetscBTSet(seenFaces, indF));
130     }
131     if (coneA[c] == face) posA = c;
132     PetscCheck(*fBottom <= fEnd - fStart, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Face %" PetscInt_FMT " was pushed exceeding capacity %" PetscInt_FMT " > %" PetscInt_FMT, coneA[c], *fBottom, fEnd - fStart);
133   }
134   PetscCheck(posA >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Face %" PetscInt_FMT " could not be located in cell %" PetscInt_FMT, face, supp[indS[0]]);
135   for (PetscInt c = 0; c < coneSizeB; ++c) {
136     const PetscInt indF = GetPointIndex(coneB[c], fStart, fEnd, faces);
137 
138     // Filter cone
139     if (indF < 0) continue;
140     if (!PetscBTLookup(seenFaces, indF)) {
141       faceFIFO[(*fBottom)++] = coneB[c];
142       PetscCall(PetscBTSet(seenFaces, indF));
143     }
144     if (coneB[c] == face) posB = c;
145     PetscCheck(*fBottom <= fEnd - fStart, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Face %" PetscInt_FMT " was pushed exceeding capacity %" PetscInt_FMT " > %" PetscInt_FMT, coneA[c], *fBottom, fEnd - fStart);
146   }
147   PetscCheck(posB >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Face %" PetscInt_FMT " could not be located in cell %" PetscInt_FMT, face, supp[indS[1]]);
148 
149   if (dim == 1) {
150     mismatch = posA == posB;
151   } else {
152     mismatch = coneOA[posA] == coneOB[posB];
153   }
154 
155   if (mismatch ^ (flippedA ^ flippedB)) {
156     PetscCheck(!seenA || !seenB, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Previously seen cells %" PetscInt_FMT " and %" PetscInt_FMT " do not match: Fault mesh is non-orientable", supp[indS[0]], supp[indS[1]]);
157     if (!seenA && !flippedA) {
158       PetscCall(PetscBTSet(flippedCells, indC[0]));
159     } else if (!seenB && !flippedB) {
160       PetscCall(PetscBTSet(flippedCells, indC[1]));
161     } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Inconsistent mesh orientation: Fault mesh is non-orientable");
162   } else PetscCheck(!mismatch || !flippedA || !flippedB, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Attempt to flip already flipped cell: Fault mesh is non-orientable");
163   PetscCall(PetscBTSet(seenCells, indC[0]));
164   PetscCall(PetscBTSet(seenCells, indC[1]));
165   PetscFunctionReturn(PETSC_SUCCESS);
166 }
167 
168 static PetscErrorCode DMPlexCheckFace_Old_Internal(DM dm, PetscInt *faceFIFO, PetscInt *fTop, PetscInt *fBottom, PetscInt cStart, PetscInt fStart, PetscInt fEnd, PetscBT seenCells, PetscBT flippedCells, PetscBT seenFaces)
169 {
170   const PetscInt *support, *coneA, *coneB, *coneOA, *coneOB;
171   PetscInt        supportSize, coneSizeA, coneSizeB, posA = -1, posB = -1;
172   PetscInt        face, dim, seenA, flippedA, seenB, flippedB, mismatch, c;
173 
174   PetscFunctionBegin;
175   face = faceFIFO[(*fTop)++];
176   PetscCall(DMGetDimension(dm, &dim));
177   PetscCall(DMPlexGetSupportSize(dm, face, &supportSize));
178   PetscCall(DMPlexGetSupport(dm, face, &support));
179   if (supportSize < 2) PetscFunctionReturn(PETSC_SUCCESS);
180   PetscCheck(supportSize == 2, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Faces should separate only two cells, not %" PetscInt_FMT, supportSize);
181   seenA    = PetscBTLookup(seenCells, support[0] - cStart);
182   flippedA = PetscBTLookup(flippedCells, support[0] - cStart) ? 1 : 0;
183   seenB    = PetscBTLookup(seenCells, support[1] - cStart);
184   flippedB = PetscBTLookup(flippedCells, support[1] - cStart) ? 1 : 0;
185 
186   PetscCall(DMPlexGetConeSize(dm, support[0], &coneSizeA));
187   PetscCall(DMPlexGetConeSize(dm, support[1], &coneSizeB));
188   PetscCall(DMPlexGetCone(dm, support[0], &coneA));
189   PetscCall(DMPlexGetCone(dm, support[1], &coneB));
190   PetscCall(DMPlexGetConeOrientation(dm, support[0], &coneOA));
191   PetscCall(DMPlexGetConeOrientation(dm, support[1], &coneOB));
192   for (c = 0; c < coneSizeA; ++c) {
193     if (!PetscBTLookup(seenFaces, coneA[c] - fStart)) {
194       faceFIFO[(*fBottom)++] = coneA[c];
195       PetscCall(PetscBTSet(seenFaces, coneA[c] - fStart));
196     }
197     if (coneA[c] == face) posA = c;
198     PetscCheck(*fBottom <= fEnd - fStart, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Face %" PetscInt_FMT " was pushed exceeding capacity %" PetscInt_FMT " > %" PetscInt_FMT, coneA[c], *fBottom, fEnd - fStart);
199   }
200   PetscCheck(posA >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Face %" PetscInt_FMT " could not be located in cell %" PetscInt_FMT, face, support[0]);
201   for (c = 0; c < coneSizeB; ++c) {
202     if (!PetscBTLookup(seenFaces, coneB[c] - fStart)) {
203       faceFIFO[(*fBottom)++] = coneB[c];
204       PetscCall(PetscBTSet(seenFaces, coneB[c] - fStart));
205     }
206     if (coneB[c] == face) posB = c;
207     PetscCheck(*fBottom <= fEnd - fStart, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Face %" PetscInt_FMT " was pushed exceeding capacity %" PetscInt_FMT " > %" PetscInt_FMT, coneA[c], *fBottom, fEnd - fStart);
208   }
209   PetscCheck(posB >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Face %" PetscInt_FMT " could not be located in cell %" PetscInt_FMT, face, support[1]);
210 
211   if (dim == 1) {
212     mismatch = posA == posB;
213   } else {
214     mismatch = coneOA[posA] == coneOB[posB];
215   }
216 
217   if (mismatch ^ (flippedA ^ flippedB)) {
218     PetscCheck(!seenA || !seenB, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Previously seen cells %" PetscInt_FMT " and %" PetscInt_FMT " do not match: Fault mesh is non-orientable", support[0], support[1]);
219     if (!seenA && !flippedA) {
220       PetscCall(PetscBTSet(flippedCells, support[0] - cStart));
221     } else if (!seenB && !flippedB) {
222       PetscCall(PetscBTSet(flippedCells, support[1] - cStart));
223     } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Inconsistent mesh orientation: Fault mesh is non-orientable");
224   } else PetscCheck(!mismatch || !flippedA || !flippedB, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Attempt to flip already flipped cell: Fault mesh is non-orientable");
225   PetscCall(PetscBTSet(seenCells, support[0] - cStart));
226   PetscCall(PetscBTSet(seenCells, support[1] - cStart));
227   PetscFunctionReturn(PETSC_SUCCESS);
228 }
229 
230 /*
231   DMPlexOrient_Serial - Compute valid orientation for local connected components
232 
233   Not collective
234 
235   Input Parameters:
236   + dm         - The `DM`
237   - cellHeight - The height of k-cells to be oriented
238 
239   Output Parameters:
240   + Ncomp        - The number of connected component
241   . cellComp     - The connected component for each local cell
242   . faceComp     - The connected component for each local face
243   - flippedCells - Marked cells should be inverted
244 
245   Level: developer
246 
247 .seealso: `DMPlexOrient()`
248 */
249 static PetscErrorCode DMPlexOrient_Serial(DM dm, IS cellIS, IS faceIS, PetscInt *Ncomp, PetscInt cellComp[], PetscInt faceComp[], PetscBT flippedCells)
250 {
251   PetscBT         seenCells, seenFaces;
252   PetscInt       *faceFIFO;
253   const PetscInt *cells = NULL, *faces = NULL;
254   PetscInt        cStart = 0, cEnd = 0, fStart = 0, fEnd = 0;
255 
256   PetscFunctionBegin;
257   if (cellIS) PetscCall(ISGetPointRange(cellIS, &cStart, &cEnd, &cells));
258   if (faceIS) PetscCall(ISGetPointRange(faceIS, &fStart, &fEnd, &faces));
259   PetscCall(PetscBTCreate(cEnd - cStart, &seenCells));
260   PetscCall(PetscBTMemzero(cEnd - cStart, seenCells));
261   PetscCall(PetscBTCreate(fEnd - fStart, &seenFaces));
262   PetscCall(PetscBTMemzero(fEnd - fStart, seenFaces));
263   PetscCall(PetscMalloc1(fEnd - fStart, &faceFIFO));
264   *Ncomp = 0;
265   for (PetscInt c = 0; c < cEnd - cStart; ++c) cellComp[c] = -1;
266   do {
267     PetscInt cc, fTop, fBottom;
268 
269     // Look for first unmarked cell
270     for (cc = cStart; cc < cEnd; ++cc)
271       if (cellComp[cc - cStart] < 0) break;
272     if (cc >= cEnd) break;
273     // Initialize FIFO with first cell in component
274     {
275       const PetscInt  cell = cells ? cells[cc] : cc;
276       const PetscInt *cone;
277       PetscInt        coneSize;
278 
279       fTop = fBottom = 0;
280       PetscCall(DMPlexGetConeSize(dm, cell, &coneSize));
281       PetscCall(DMPlexGetCone(dm, cell, &cone));
282       for (PetscInt c = 0; c < coneSize; ++c) {
283         const PetscInt idx = GetPointIndex(cone[c], fStart, fEnd, faces);
284 
285         // Cell faces are guaranteed to be in the face set
286         PetscCheck(idx >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Face %" PetscInt_FMT " of cell %" PetscInt_FMT " is not present in the label", cone[c], cell);
287         faceFIFO[fBottom++] = cone[c];
288         PetscCall(PetscBTSet(seenFaces, idx));
289       }
290       PetscCall(PetscBTSet(seenCells, cc - cStart));
291     }
292     // Consider each face in FIFO
293     while (fTop < fBottom) PetscCall(DMPlexCheckFace_Internal(dm, faceFIFO, &fTop, &fBottom, cellIS, faceIS, seenCells, flippedCells, seenFaces));
294     // Set component for cells and faces
295     for (PetscInt c = 0; c < cEnd - cStart; ++c) {
296       if (PetscBTLookup(seenCells, c)) cellComp[c] = *Ncomp;
297     }
298     for (PetscInt f = 0; f < fEnd - fStart; ++f) {
299       if (PetscBTLookup(seenFaces, f)) faceComp[f] = *Ncomp;
300     }
301     // Wipe seenCells and seenFaces for next component
302     PetscCall(PetscBTMemzero(fEnd - fStart, seenFaces));
303     PetscCall(PetscBTMemzero(cEnd - cStart, seenCells));
304     ++(*Ncomp);
305   } while (1);
306   PetscCall(PetscBTDestroy(&seenCells));
307   PetscCall(PetscBTDestroy(&seenFaces));
308   PetscCall(PetscFree(faceFIFO));
309   PetscFunctionReturn(PETSC_SUCCESS);
310 }
311 
312 /*@
313   DMPlexOrient - Give a consistent orientation to the input mesh
314 
315   Input Parameter:
316 . dm - The `DM`
317 
318   Note:
319   The orientation data for the `DM` are change in-place.
320 
321   This routine will fail for non-orientable surfaces, such as the Moebius strip.
322 
323   Level: advanced
324 
325 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMCreate()`
326 @*/
327 PetscErrorCode DMPlexOrient(DM dm)
328 {
329 #if 0
330   IS cellIS, faceIS;
331 
332   PetscFunctionBegin;
333   PetscCall(DMPlexGetAllCells_Internal(dm, &cellIS));
334   PetscCall(DMPlexGetAllFaces_Internal(dm, &faceIS));
335   PetscCall(DMPlexOrientCells_Internal(dm, cellIS, faceIS));
336   PetscCall(ISDestroy(&cellIS));
337   PetscCall(ISDestroy(&faceIS));
338   PetscFunctionReturn(PETSC_SUCCESS);
339 #else
340   MPI_Comm           comm;
341   PetscSF            sf;
342   const PetscInt    *lpoints;
343   const PetscSFNode *rpoints;
344   PetscSFNode       *rorntComp = NULL, *lorntComp = NULL;
345   PetscInt          *numNeighbors, **neighbors, *locSupport = NULL;
346   PetscSFNode       *nrankComp;
347   PetscBool         *match, *flipped;
348   PetscBT            seenCells, flippedCells, seenFaces;
349   PetscInt          *faceFIFO, fTop, fBottom, *cellComp, *faceComp;
350   PetscInt           numLeaves, numRoots, dim, h, cStart, cEnd, c, cell, fStart, fEnd, face, off, totNeighbors = 0;
351   PetscMPIInt        rank, size, numComponents, comp = 0;
352   PetscBool          flg, flg2;
353   PetscViewer        viewer = NULL, selfviewer = NULL;
354 
355   PetscFunctionBegin;
356   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
357   PetscCallMPI(MPI_Comm_rank(comm, &rank));
358   PetscCallMPI(MPI_Comm_size(comm, &size));
359   PetscCall(PetscOptionsHasName(((PetscObject)dm)->options, ((PetscObject)dm)->prefix, "-orientation_view", &flg));
360   PetscCall(PetscOptionsHasName(((PetscObject)dm)->options, ((PetscObject)dm)->prefix, "-orientation_view_synchronized", &flg2));
361   PetscCall(DMGetPointSF(dm, &sf));
362   PetscCall(PetscSFGetGraph(sf, &numRoots, &numLeaves, &lpoints, &rpoints));
363   /* Truth Table
364      mismatch    flips   do action   mismatch   flipA ^ flipB   action
365          F       0 flips     no         F             F           F
366          F       1 flip      yes        F             T           T
367          F       2 flips     no         T             F           T
368          T       0 flips     yes        T             T           F
369          T       1 flip      no
370          T       2 flips     yes
371   */
372   PetscCall(DMGetDimension(dm, &dim));
373   PetscCall(DMPlexGetVTKCellHeight(dm, &h));
374   PetscCall(DMPlexGetHeightStratum(dm, h, &cStart, &cEnd));
375   PetscCall(DMPlexGetHeightStratum(dm, h + 1, &fStart, &fEnd));
376   PetscCall(PetscBTCreate(cEnd - cStart, &seenCells));
377   PetscCall(PetscBTMemzero(cEnd - cStart, seenCells));
378   PetscCall(PetscBTCreate(cEnd - cStart, &flippedCells));
379   PetscCall(PetscBTMemzero(cEnd - cStart, flippedCells));
380   PetscCall(PetscBTCreate(fEnd - fStart, &seenFaces));
381   PetscCall(PetscBTMemzero(fEnd - fStart, seenFaces));
382   PetscCall(PetscCalloc3(fEnd - fStart, &faceFIFO, cEnd - cStart, &cellComp, fEnd - fStart, &faceComp));
383   /*
384    OLD STYLE
385    - Add an integer array over cells and faces (component) for connected component number
386    Foreach component
387      - Mark the initial cell as seen
388      - Process component as usual
389      - Set component for all seenCells
390      - Wipe seenCells and seenFaces (flippedCells can stay)
391    - Generate parallel adjacency for component using SF and seenFaces
392    - Collect numComponents adj data from each proc to 0
393    - Build same serial graph
394    - Use same solver
395    - Use Scatterv to send back flipped flags for each component
396    - Negate flippedCells by component
397 
398    NEW STYLE
399    - Create the adj on each process
400    - Bootstrap to complete graph on proc 0
401   */
402   /* Loop over components */
403   for (cell = cStart; cell < cEnd; ++cell) cellComp[cell - cStart] = -1;
404   do {
405     /* Look for first unmarked cell */
406     for (cell = cStart; cell < cEnd; ++cell)
407       if (cellComp[cell - cStart] < 0) break;
408     if (cell >= cEnd) break;
409     /* Initialize FIFO with first cell in component */
410     {
411       const PetscInt *cone;
412       PetscInt        coneSize;
413 
414       fTop = fBottom = 0;
415       PetscCall(DMPlexGetConeSize(dm, cell, &coneSize));
416       PetscCall(DMPlexGetCone(dm, cell, &cone));
417       for (c = 0; c < coneSize; ++c) {
418         faceFIFO[fBottom++] = cone[c];
419         PetscCall(PetscBTSet(seenFaces, cone[c] - fStart));
420       }
421       PetscCall(PetscBTSet(seenCells, cell - cStart));
422     }
423     /* Consider each face in FIFO */
424     while (fTop < fBottom) PetscCall(DMPlexCheckFace_Old_Internal(dm, faceFIFO, &fTop, &fBottom, cStart, fStart, fEnd, seenCells, flippedCells, seenFaces));
425     /* Set component for cells and faces */
426     for (cell = 0; cell < cEnd - cStart; ++cell) {
427       if (PetscBTLookup(seenCells, cell)) cellComp[cell] = comp;
428     }
429     for (face = 0; face < fEnd - fStart; ++face) {
430       if (PetscBTLookup(seenFaces, face)) faceComp[face] = comp;
431     }
432     /* Wipe seenCells and seenFaces for next component */
433     PetscCall(PetscBTMemzero(fEnd - fStart, seenFaces));
434     PetscCall(PetscBTMemzero(cEnd - cStart, seenCells));
435     ++comp;
436   } while (1);
437   numComponents = comp;
438   if (flg) {
439     PetscViewer v;
440 
441     PetscCall(PetscViewerASCIIGetStdout(comm, &v));
442     PetscCall(PetscViewerASCIIPushSynchronized(v));
443     PetscCall(PetscViewerASCIISynchronizedPrintf(v, "[%d]BT for serial flipped cells:\n", rank));
444     PetscCall(PetscBTView(cEnd - cStart, flippedCells, v));
445     PetscCall(PetscViewerFlush(v));
446     PetscCall(PetscViewerASCIIPopSynchronized(v));
447   }
448   /* Now all subdomains are oriented, but we need a consistent parallel orientation */
449   if (numLeaves >= 0) {
450     PetscInt maxSupportSize, neighbor;
451 
452     /* Store orientations of boundary faces*/
453     PetscCall(DMPlexGetMaxSizes(dm, NULL, &maxSupportSize));
454     PetscCall(PetscCalloc3(numRoots, &rorntComp, numRoots, &lorntComp, maxSupportSize, &locSupport));
455     for (face = fStart; face < fEnd; ++face) {
456       const PetscInt *cone, *support, *ornt;
457       PetscInt        coneSize, supportSize, Ns = 0, s, l;
458 
459       PetscCall(DMPlexGetSupportSize(dm, face, &supportSize));
460       /* Ignore overlapping cells */
461       PetscCall(DMPlexGetSupport(dm, face, &support));
462       for (s = 0; s < supportSize; ++s) {
463         PetscCall(PetscFindInt(support[s], numLeaves, lpoints, &l));
464         if (l >= 0) continue;
465         locSupport[Ns++] = support[s];
466       }
467       if (Ns != 1) continue;
468       neighbor = locSupport[0];
469       PetscCall(DMPlexGetCone(dm, neighbor, &cone));
470       PetscCall(DMPlexGetConeSize(dm, neighbor, &coneSize));
471       PetscCall(DMPlexGetConeOrientation(dm, neighbor, &ornt));
472       for (c = 0; c < coneSize; ++c)
473         if (cone[c] == face) break;
474       if (dim == 1) {
475         /* Use cone position instead, shifted to -1 or 1 */
476         if (PetscBTLookup(flippedCells, neighbor - cStart)) rorntComp[face].rank = 1 - c * 2;
477         else rorntComp[face].rank = c * 2 - 1;
478       } else {
479         if (PetscBTLookup(flippedCells, neighbor - cStart)) rorntComp[face].rank = ornt[c] < 0 ? -1 : 1;
480         else rorntComp[face].rank = ornt[c] < 0 ? 1 : -1;
481       }
482       rorntComp[face].index = faceComp[face - fStart];
483     }
484     /* Communicate boundary edge orientations */
485     PetscCall(PetscSFBcastBegin(sf, MPIU_SF_NODE, rorntComp, lorntComp, MPI_REPLACE));
486     PetscCall(PetscSFBcastEnd(sf, MPIU_SF_NODE, rorntComp, lorntComp, MPI_REPLACE));
487   }
488   /* Get process adjacency */
489   PetscCall(PetscMalloc2(numComponents, &numNeighbors, numComponents, &neighbors));
490   viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)dm));
491   if (flg2) PetscCall(PetscViewerASCIIPushSynchronized(viewer));
492   PetscCall(PetscViewerGetSubViewer(viewer, PETSC_COMM_SELF, &selfviewer));
493   for (comp = 0; comp < numComponents; ++comp) {
494     PetscInt l, n;
495 
496     numNeighbors[comp] = 0;
497     PetscCall(PetscMalloc1(PetscMax(numLeaves, 0), &neighbors[comp]));
498     /* I know this is p^2 time in general, but for bounded degree its alright */
499     for (l = 0; l < numLeaves; ++l) {
500       const PetscInt face = lpoints[l];
501 
502       /* Find a representative face (edge) separating pairs of procs */
503       if ((face >= fStart) && (face < fEnd) && (faceComp[face - fStart] == comp) && rorntComp[face].rank) {
504         const PetscInt rrank = rpoints[l].rank;
505         const PetscInt rcomp = lorntComp[face].index;
506 
507         for (n = 0; n < numNeighbors[comp]; ++n)
508           if ((rrank == rpoints[neighbors[comp][n]].rank) && (rcomp == lorntComp[lpoints[neighbors[comp][n]]].index)) break;
509         if (n >= numNeighbors[comp]) {
510           PetscInt supportSize;
511 
512           PetscCall(DMPlexGetSupportSize(dm, face, &supportSize));
513           PetscCheck(supportSize == 1, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Boundary faces should see one cell, not %" PetscInt_FMT, supportSize);
514           if (flg)
515             PetscCall(PetscViewerASCIIPrintf(selfviewer, "[%d]: component %d, Found representative leaf %" PetscInt_FMT " (face %" PetscInt_FMT ") connecting to face %" PetscInt_FMT " on (%" PetscInt_FMT ", %" PetscInt_FMT ") with orientation %" PetscInt_FMT "\n", rank, comp, l, face,
516                                              rpoints[l].index, rrank, rcomp, lorntComp[face].rank));
517           neighbors[comp][numNeighbors[comp]++] = l;
518         }
519       }
520     }
521     totNeighbors += numNeighbors[comp];
522   }
523   PetscCall(PetscViewerRestoreSubViewer(viewer, PETSC_COMM_SELF, &selfviewer));
524   if (flg2) PetscCall(PetscViewerASCIIPopSynchronized(viewer));
525   PetscCall(PetscMalloc2(totNeighbors, &nrankComp, totNeighbors, &match));
526   for (comp = 0, off = 0; comp < numComponents; ++comp) {
527     PetscInt n;
528 
529     for (n = 0; n < numNeighbors[comp]; ++n, ++off) {
530       const PetscInt face = lpoints[neighbors[comp][n]];
531       const PetscInt o    = rorntComp[face].rank * lorntComp[face].rank;
532 
533       if (o < 0) match[off] = PETSC_TRUE;
534       else if (o > 0) match[off] = PETSC_FALSE;
535       else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid face %" PetscInt_FMT " (%" PetscInt_FMT ", %" PetscInt_FMT ") neighbor: %" PetscInt_FMT " comp: %d", face, rorntComp[face].rank, lorntComp[face].rank, neighbors[comp][n], comp);
536       nrankComp[off].rank  = rpoints[neighbors[comp][n]].rank;
537       nrankComp[off].index = lorntComp[lpoints[neighbors[comp][n]]].index;
538     }
539     PetscCall(PetscFree(neighbors[comp]));
540   }
541   /* Collect the graph on 0 */
542   if (numLeaves >= 0) {
543     Mat          G;
544     PetscBT      seenProcs, flippedProcs;
545     PetscInt    *procFIFO, pTop, pBottom;
546     PetscInt    *N          = NULL, *Noff;
547     PetscSFNode *adj        = NULL;
548     PetscBool   *val        = NULL;
549     PetscMPIInt *recvcounts = NULL, *displs = NULL, *Nc, p, o, itotNeighbors;
550     PetscMPIInt  size = 0;
551 
552     PetscCall(PetscCalloc1(numComponents, &flipped));
553     if (rank == 0) PetscCallMPI(MPI_Comm_size(comm, &size));
554     PetscCall(PetscCalloc4(size, &recvcounts, size + 1, &displs, size, &Nc, size + 1, &Noff));
555     PetscCallMPI(MPI_Gather(&numComponents, 1, MPI_INT, Nc, 1, MPI_INT, 0, comm));
556     for (p = 0; p < size; ++p) displs[p + 1] = displs[p] + Nc[p];
557     if (rank == 0) PetscCall(PetscMalloc1(displs[size], &N));
558     PetscCallMPI(MPI_Gatherv(numNeighbors, numComponents, MPIU_INT, N, Nc, displs, MPIU_INT, 0, comm));
559     for (p = 0, o = 0; p < size; ++p) {
560       recvcounts[p] = 0;
561       for (c = 0; c < Nc[p]; ++c, ++o) recvcounts[p] += N[o];
562       displs[p + 1] = displs[p] + recvcounts[p];
563     }
564     if (rank == 0) PetscCall(PetscMalloc2(displs[size], &adj, displs[size], &val));
565     PetscCall(PetscMPIIntCast(totNeighbors, &itotNeighbors));
566     PetscCallMPI(MPI_Gatherv(nrankComp, itotNeighbors, MPIU_SF_NODE, adj, recvcounts, displs, MPIU_SF_NODE, 0, comm));
567     PetscCallMPI(MPI_Gatherv(match, itotNeighbors, MPIU_BOOL, val, recvcounts, displs, MPIU_BOOL, 0, comm));
568     PetscCall(PetscFree2(numNeighbors, neighbors));
569     if (rank == 0) {
570       for (p = 1; p <= size; ++p) Noff[p] = Noff[p - 1] + Nc[p - 1];
571       if (flg) {
572         PetscInt n;
573 
574         for (p = 0, off = 0; p < size; ++p) {
575           for (c = 0; c < Nc[p]; ++c) {
576             PetscCall(PetscPrintf(PETSC_COMM_SELF, "Proc %d Comp %" PetscInt_FMT ":\n", p, c));
577             for (n = 0; n < N[Noff[p] + c]; ++n, ++off) PetscCall(PetscPrintf(PETSC_COMM_SELF, "  edge (%" PetscInt_FMT ", %" PetscInt_FMT ") (%s):\n", adj[off].rank, adj[off].index, PetscBools[val[off]]));
578           }
579         }
580       }
581       /* Symmetrize the graph */
582       PetscCall(MatCreate(PETSC_COMM_SELF, &G));
583       PetscCall(MatSetSizes(G, Noff[size], Noff[size], Noff[size], Noff[size]));
584       PetscCall(MatSetUp(G));
585       for (p = 0, off = 0; p < size; ++p) {
586         for (c = 0; c < Nc[p]; ++c) {
587           const PetscInt r = Noff[p] + c;
588           PetscInt       n;
589 
590           for (n = 0; n < N[r]; ++n, ++off) {
591             const PetscInt    q = Noff[adj[off].rank] + adj[off].index;
592             const PetscScalar o = val[off] ? 1.0 : 0.0;
593 
594             PetscCall(MatSetValues(G, 1, &r, 1, &q, &o, INSERT_VALUES));
595             PetscCall(MatSetValues(G, 1, &q, 1, &r, &o, INSERT_VALUES));
596           }
597         }
598       }
599       PetscCall(MatAssemblyBegin(G, MAT_FINAL_ASSEMBLY));
600       PetscCall(MatAssemblyEnd(G, MAT_FINAL_ASSEMBLY));
601 
602       PetscCall(PetscBTCreate(Noff[size], &seenProcs));
603       PetscCall(PetscBTMemzero(Noff[size], seenProcs));
604       PetscCall(PetscBTCreate(Noff[size], &flippedProcs));
605       PetscCall(PetscBTMemzero(Noff[size], flippedProcs));
606       PetscCall(PetscMalloc1(Noff[size], &procFIFO));
607       pTop = pBottom = 0;
608       for (p = 0; p < Noff[size]; ++p) {
609         if (PetscBTLookup(seenProcs, p)) continue;
610         /* Initialize FIFO with next proc */
611         procFIFO[pBottom++] = p;
612         PetscCall(PetscBTSet(seenProcs, p));
613         /* Consider each proc in FIFO */
614         while (pTop < pBottom) {
615           const PetscScalar *ornt;
616           const PetscInt    *neighbors;
617           PetscInt           proc, nproc, seen, flippedA, flippedB, mismatch, numNeighbors, n;
618 
619           proc     = procFIFO[pTop++];
620           flippedA = PetscBTLookup(flippedProcs, proc) ? 1 : 0;
621           PetscCall(MatGetRow(G, proc, &numNeighbors, &neighbors, &ornt));
622           /* Loop over neighboring procs */
623           for (n = 0; n < numNeighbors; ++n) {
624             nproc    = neighbors[n];
625             mismatch = PetscRealPart(ornt[n]) > 0.5 ? 0 : 1;
626             seen     = PetscBTLookup(seenProcs, nproc);
627             flippedB = PetscBTLookup(flippedProcs, nproc) ? 1 : 0;
628 
629             if (mismatch ^ (flippedA ^ flippedB)) {
630               PetscCheck(!seen, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Previously seen procs %" PetscInt_FMT " and %" PetscInt_FMT " do not match: Fault mesh is non-orientable", proc, nproc);
631               if (!flippedB) {
632                 PetscCall(PetscBTSet(flippedProcs, nproc));
633               } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Inconsistent mesh orientation: Fault mesh is non-orientable");
634             } else PetscCheck(!mismatch || !flippedA || !flippedB, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Attempt to flip already flipped cell: Fault mesh is non-orientable");
635             if (!seen) {
636               procFIFO[pBottom++] = nproc;
637               PetscCall(PetscBTSet(seenProcs, nproc));
638             }
639           }
640         }
641       }
642       PetscCall(PetscFree(procFIFO));
643       PetscCall(MatDestroy(&G));
644       PetscCall(PetscFree2(adj, val));
645       PetscCall(PetscBTDestroy(&seenProcs));
646     }
647     /* Scatter flip flags */
648     {
649       PetscBool *flips = NULL;
650 
651       if (rank == 0) {
652         PetscCall(PetscMalloc1(Noff[size], &flips));
653         for (p = 0; p < Noff[size]; ++p) {
654           flips[p] = PetscBTLookup(flippedProcs, p) ? PETSC_TRUE : PETSC_FALSE;
655           if (flg && flips[p]) PetscCall(PetscPrintf(comm, "Flipping Proc+Comp %d:\n", p));
656         }
657         for (p = 0; p < size; ++p) displs[p + 1] = displs[p] + Nc[p];
658       }
659       PetscCallMPI(MPI_Scatterv(flips, Nc, displs, MPIU_BOOL, flipped, numComponents, MPIU_BOOL, 0, comm));
660       PetscCall(PetscFree(flips));
661     }
662     if (rank == 0) PetscCall(PetscBTDestroy(&flippedProcs));
663     PetscCall(PetscFree(N));
664     PetscCall(PetscFree4(recvcounts, displs, Nc, Noff));
665     PetscCall(PetscFree2(nrankComp, match));
666 
667     /* Decide whether to flip cells in each component */
668     for (c = 0; c < cEnd - cStart; ++c) {
669       if (flipped[cellComp[c]]) PetscCall(PetscBTNegate(flippedCells, c));
670     }
671     PetscCall(PetscFree(flipped));
672   }
673   if (flg) {
674     PetscViewer v;
675 
676     PetscCall(PetscViewerASCIIGetStdout(comm, &v));
677     PetscCall(PetscViewerASCIIPushSynchronized(v));
678     PetscCall(PetscViewerASCIISynchronizedPrintf(v, "[%d]BT for parallel flipped cells:\n", rank));
679     PetscCall(PetscBTView(cEnd - cStart, flippedCells, v));
680     PetscCall(PetscViewerFlush(v));
681     PetscCall(PetscViewerASCIIPopSynchronized(v));
682   }
683   /* Reverse flipped cells in the mesh */
684   for (c = cStart; c < cEnd; ++c) {
685     if (PetscBTLookup(flippedCells, c - cStart)) PetscCall(DMPlexOrientPoint(dm, c, -1));
686   }
687   PetscCall(PetscBTDestroy(&seenCells));
688   PetscCall(PetscBTDestroy(&flippedCells));
689   PetscCall(PetscBTDestroy(&seenFaces));
690   PetscCall(PetscFree2(numNeighbors, neighbors));
691   PetscCall(PetscFree3(rorntComp, lorntComp, locSupport));
692   PetscCall(PetscFree3(faceFIFO, cellComp, faceComp));
693   PetscFunctionReturn(PETSC_SUCCESS);
694 #endif
695 }
696 
697 static PetscErrorCode CreateCellAndFaceIS_Private(DM dm, DMLabel label, IS *cellIS, IS *faceIS)
698 {
699   IS              valueIS;
700   const PetscInt *values;
701   PetscInt        Nv, depth = 0;
702 
703   PetscFunctionBegin;
704   PetscCall(DMLabelGetValueIS(label, &valueIS));
705   PetscCall(ISGetLocalSize(valueIS, &Nv));
706   PetscCall(ISGetIndices(valueIS, &values));
707   for (PetscInt v = 0; v < Nv; ++v) {
708     const PetscInt val = values[v] < 0 || values[v] >= 100 ? 0 : values[v];
709     PetscInt       n;
710 
711     PetscCall(DMLabelGetStratumSize(label, val, &n));
712     if (!n) continue;
713     depth = PetscMax(val, depth);
714   }
715   PetscCall(ISDestroy(&valueIS));
716   PetscCheck(depth >= 1 || !Nv, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Depth for interface must be at least 1, not %" PetscInt_FMT, depth);
717   PetscCall(DMLabelGetStratumIS(label, depth, cellIS));
718   PetscCall(DMLabelGetStratumIS(label, depth - 1, faceIS));
719   if (!*cellIS) PetscCall(ISCreateStride(PETSC_COMM_SELF, 0, 0, 1, cellIS));
720   if (!*faceIS) PetscCall(ISCreateStride(PETSC_COMM_SELF, 0, 0, 1, faceIS));
721   PetscFunctionReturn(PETSC_SUCCESS);
722 }
723 
724 PetscErrorCode DMPlexOrientLabel(DM dm, DMLabel label)
725 {
726   IS cellIS, faceIS;
727 
728   PetscFunctionBegin;
729   PetscCall(CreateCellAndFaceIS_Private(dm, label, &cellIS, &faceIS));
730   PetscCall(DMPlexOrientCells_Internal(dm, cellIS, faceIS));
731   PetscCall(ISDestroy(&cellIS));
732   PetscCall(ISDestroy(&faceIS));
733   PetscFunctionReturn(PETSC_SUCCESS);
734 }
735 
736 PetscErrorCode DMPlexOrientCells_Internal(DM dm, IS cellIS, IS faceIS)
737 {
738   MPI_Comm           comm;
739   PetscSF            sf;
740   const PetscInt    *lpoints;
741   const PetscSFNode *rpoints;
742   PetscSFNode       *rorntComp = NULL, *lorntComp = NULL;
743   PetscInt          *numNeighbors, **neighbors, *locSupp = NULL;
744   PetscSFNode       *nrankComp;
745   PetscBool         *match, *flipped;
746   PetscBT            flippedCells;
747   PetscInt          *cellComp, *faceComp;
748   const PetscInt    *cells = NULL, *faces = NULL;
749   PetscInt           cStart = 0, cEnd = 0, fStart = 0, fEnd = 0;
750   PetscInt           numLeaves, numRoots, dim, Ncomp, totNeighbors = 0;
751   PetscMPIInt        rank, size;
752   PetscBool          view, viewSync;
753   PetscViewer        viewer = NULL, selfviewer = NULL;
754 
755   PetscFunctionBegin;
756   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
757   PetscCallMPI(MPI_Comm_rank(comm, &rank));
758   PetscCallMPI(MPI_Comm_size(comm, &size));
759   PetscCall(PetscOptionsHasName(((PetscObject)dm)->options, ((PetscObject)dm)->prefix, "-orientation_view", &view));
760   PetscCall(PetscOptionsHasName(((PetscObject)dm)->options, ((PetscObject)dm)->prefix, "-orientation_view_synchronized", &viewSync));
761 
762   if (cellIS) PetscCall(ISGetPointRange(cellIS, &cStart, &cEnd, &cells));
763   if (faceIS) PetscCall(ISGetPointRange(faceIS, &fStart, &fEnd, &faces));
764   PetscCall(DMGetPointSF(dm, &sf));
765   PetscCall(PetscSFGetGraph(sf, &numRoots, &numLeaves, &lpoints, &rpoints));
766   /* Truth Table
767      mismatch    flips   do action   mismatch   flipA ^ flipB   action
768          F       0 flips     no         F             F           F
769          F       1 flip      yes        F             T           T
770          F       2 flips     no         T             F           T
771          T       0 flips     yes        T             T           F
772          T       1 flip      no
773          T       2 flips     yes
774   */
775   PetscCall(DMGetDimension(dm, &dim));
776   PetscCall(PetscBTCreate(cEnd - cStart, &flippedCells));
777   PetscCall(PetscBTMemzero(cEnd - cStart, flippedCells));
778   PetscCall(PetscCalloc2(cEnd - cStart, &cellComp, fEnd - fStart, &faceComp));
779   /*
780    OLD STYLE
781    - Add an integer array over cells and faces (component) for connected component number
782    Foreach component
783      - Mark the initial cell as seen
784      - Process component as usual
785      - Set component for all seenCells
786      - Wipe seenCells and seenFaces (flippedCells can stay)
787    - Generate parallel adjacency for component using SF and seenFaces
788    - Collect Ncomp adj data from each proc to 0
789    - Build same serial graph
790    - Use same solver
791    - Use Scatterv to send back flipped flags for each component
792    - Negate flippedCells by component
793 
794    NEW STYLE
795    - Create the adj on each process
796    - Bootstrap to complete graph on proc 0
797   */
798   PetscCall(DMPlexOrient_Serial(dm, cellIS, faceIS, &Ncomp, cellComp, faceComp, flippedCells));
799   if (view) {
800     PetscViewer v;
801     PetscInt    cdepth = -1;
802 
803     PetscCall(PetscViewerASCIIGetStdout(comm, &v));
804     PetscCall(PetscViewerASCIIPushSynchronized(v));
805     if (cEnd > cStart) PetscCall(DMPlexGetPointDepth(dm, cells ? cells[cStart] : cStart, &cdepth));
806     PetscCall(PetscViewerASCIISynchronizedPrintf(v, "[%d]New Orientation %" PetscInt_FMT " cells (depth %" PetscInt_FMT ") and %" PetscInt_FMT " faces\n", rank, cEnd - cStart, cdepth, fEnd - fStart));
807     PetscCall(PetscViewerASCIISynchronizedPrintf(v, "[%d]BT for serial flipped cells:\n", rank));
808     PetscCall(PetscBTView(cEnd - cStart, flippedCells, v));
809     PetscCall(PetscViewerFlush(v));
810     PetscCall(PetscViewerASCIIPopSynchronized(v));
811   }
812   /* Now all subdomains are oriented, but we need a consistent parallel orientation */
813   // TODO: This all has to be rewritten to filter cones/supports to the ISes
814   if (numLeaves >= 0) {
815     PetscInt maxSuppSize, neighbor;
816 
817     // Store orientations of boundary faces
818     PetscCall(DMPlexGetMaxSizes(dm, NULL, &maxSuppSize));
819     PetscCall(PetscCalloc3(numRoots, &rorntComp, numRoots, &lorntComp, maxSuppSize, &locSupp));
820     for (PetscInt f = fStart; f < fEnd; ++f) {
821       const PetscInt  face = faces ? faces[f] : f;
822       const PetscInt *cone, *supp, *ornt;
823       PetscInt        coneSize, suppSize, nind, c, Ns = 0;
824 
825       PetscCall(DMPlexGetSupportSize(dm, face, &suppSize));
826       PetscCall(DMPlexGetSupport(dm, face, &supp));
827       for (PetscInt s = 0; s < suppSize; ++s) {
828         PetscInt ind, l;
829 
830         // Filter support
831         ind = GetPointIndex(supp[s], cStart, cEnd, cells);
832         if (ind < 0) continue;
833         // Ignore overlapping cells
834         PetscCall(PetscFindInt(supp[s], numLeaves, lpoints, &l));
835         if (l >= 0) continue;
836         locSupp[Ns++] = supp[s];
837       }
838       PetscCheck(Ns < maxSuppSize, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Index %" PetscInt_FMT " exceeds array size %" PetscInt_FMT, Ns, maxSuppSize);
839       if (Ns != 1) continue;
840       neighbor = locSupp[0];
841       nind     = GetPointIndex(neighbor, cStart, cEnd, cells);
842       PetscCall(DMPlexGetCone(dm, neighbor, &cone));
843       PetscCall(DMPlexGetConeSize(dm, neighbor, &coneSize));
844       PetscCall(DMPlexGetConeOrientation(dm, neighbor, &ornt));
845       for (c = 0; c < coneSize; ++c)
846         if (cone[c] == face) break;
847       if (dim == 1) {
848         /* Use cone position instead, shifted to -1 or 1 */
849         if (PetscBTLookup(flippedCells, nind)) rorntComp[face].rank = 1 - c * 2;
850         else rorntComp[face].rank = c * 2 - 1;
851       } else {
852         if (PetscBTLookup(flippedCells, nind)) rorntComp[face].rank = ornt[c] < 0 ? -1 : 1;
853         else rorntComp[face].rank = ornt[c] < 0 ? 1 : -1;
854       }
855       rorntComp[face].index = faceComp[GetPointIndex(face, fStart, fEnd, faces)];
856     }
857     // Communicate boundary edge orientations
858     PetscCall(PetscSFBcastBegin(sf, MPIU_SF_NODE, rorntComp, lorntComp, MPI_REPLACE));
859     PetscCall(PetscSFBcastEnd(sf, MPIU_SF_NODE, rorntComp, lorntComp, MPI_REPLACE));
860   }
861   /* Get process adjacency */
862   PetscCall(PetscMalloc2(Ncomp, &numNeighbors, Ncomp, &neighbors));
863   viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)dm));
864   if (viewSync) PetscCall(PetscViewerASCIIPushSynchronized(viewer));
865   PetscCall(PetscViewerGetSubViewer(viewer, PETSC_COMM_SELF, &selfviewer));
866   for (PetscInt comp = 0; comp < Ncomp; ++comp) {
867     PetscInt n;
868 
869     numNeighbors[comp] = 0;
870     PetscCall(PetscMalloc1(PetscMax(numLeaves, 0), &neighbors[comp]));
871     /* I know this is p^2 time in general, but for bounded degree its alright */
872     for (PetscInt l = 0; l < numLeaves; ++l) {
873       const PetscInt face = lpoints[l];
874       PetscInt       find;
875 
876       /* Find a representative face (edge) separating pairs of procs */
877       find = GetPointIndex(face, fStart, fEnd, faces);
878       if ((find >= 0) && (faceComp[find] == comp) && rorntComp[face].rank) {
879         const PetscInt rrank = rpoints[l].rank;
880         const PetscInt rcomp = lorntComp[face].index;
881 
882         for (n = 0; n < numNeighbors[comp]; ++n)
883           if ((rrank == rpoints[neighbors[comp][n]].rank) && (rcomp == lorntComp[lpoints[neighbors[comp][n]]].index)) break;
884         if (n >= numNeighbors[comp]) {
885           const PetscInt *supp;
886           PetscInt        suppSize, Ns = 0;
887 
888           PetscCall(DMPlexGetSupport(dm, face, &supp));
889           PetscCall(DMPlexGetSupportSize(dm, face, &suppSize));
890           for (PetscInt s = 0; s < suppSize; ++s) {
891             // Filter support
892             if (GetPointIndex(supp[s], cStart, cEnd, cells) >= 0) ++Ns;
893           }
894           PetscCheck(Ns == 1, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Boundary face %" PetscInt_FMT " should see one cell, not %" PetscInt_FMT, face, Ns);
895           if (view)
896             PetscCall(PetscViewerASCIIPrintf(selfviewer, "[%d]: component %" PetscInt_FMT ", Found representative leaf %" PetscInt_FMT " (face %" PetscInt_FMT ") connecting to face %" PetscInt_FMT " on (%" PetscInt_FMT ", %" PetscInt_FMT ") with orientation %" PetscInt_FMT "\n", rank, comp, l, face,
897                                              rpoints[l].index, rrank, rcomp, lorntComp[face].rank));
898           neighbors[comp][numNeighbors[comp]++] = l;
899         }
900       }
901     }
902     totNeighbors += numNeighbors[comp];
903   }
904   PetscCall(PetscViewerRestoreSubViewer(viewer, PETSC_COMM_SELF, &selfviewer));
905   if (viewSync) PetscCall(PetscViewerASCIIPopSynchronized(viewer));
906   PetscCall(PetscMalloc2(totNeighbors, &nrankComp, totNeighbors, &match));
907   for (PetscInt comp = 0, off = 0; comp < Ncomp; ++comp) {
908     for (PetscInt n = 0; n < numNeighbors[comp]; ++n, ++off) {
909       const PetscInt face = lpoints[neighbors[comp][n]];
910       const PetscInt o    = rorntComp[face].rank * lorntComp[face].rank;
911 
912       if (o < 0) match[off] = PETSC_TRUE;
913       else if (o > 0) match[off] = PETSC_FALSE;
914       else
915         SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid face %" PetscInt_FMT " (%" PetscInt_FMT ", %" PetscInt_FMT ") neighbor: %" PetscInt_FMT " comp: %" PetscInt_FMT, face, rorntComp[face].rank, lorntComp[face].rank, neighbors[comp][n], comp);
916       nrankComp[off].rank  = rpoints[neighbors[comp][n]].rank;
917       nrankComp[off].index = lorntComp[lpoints[neighbors[comp][n]]].index;
918     }
919     PetscCall(PetscFree(neighbors[comp]));
920   }
921   /* Collect the graph on 0 */
922   if (numLeaves >= 0) {
923     Mat          G;
924     PetscBT      seenProcs, flippedProcs;
925     PetscInt    *procFIFO, pTop, pBottom;
926     PetscInt    *N          = NULL, *Noff;
927     PetscSFNode *adj        = NULL;
928     PetscBool   *val        = NULL;
929     PetscMPIInt *recvcounts = NULL, *displs = NULL, *Nc;
930     PetscMPIInt  size = 0, iNcomp, itotNeighbors;
931 
932     PetscCall(PetscCalloc1(Ncomp, &flipped));
933     if (rank == 0) PetscCallMPI(MPI_Comm_size(comm, &size));
934     PetscCall(PetscCalloc4(size, &recvcounts, size + 1, &displs, size, &Nc, size + 1, &Noff));
935     PetscCallMPI(MPI_Gather(&Ncomp, 1, MPI_INT, Nc, 1, MPI_INT, 0, comm));
936     for (PetscInt p = 0; p < size; ++p) displs[p + 1] = displs[p] + Nc[p];
937     if (rank == 0) PetscCall(PetscMalloc1(displs[size], &N));
938     PetscCall(PetscMPIIntCast(Ncomp, &iNcomp));
939     PetscCallMPI(MPI_Gatherv(numNeighbors, iNcomp, MPIU_INT, N, Nc, displs, MPIU_INT, 0, comm));
940     for (PetscInt p = 0, o = 0; p < size; ++p) {
941       recvcounts[p] = 0;
942       for (PetscInt c = 0; c < Nc[p]; ++c, ++o) recvcounts[p] += N[o];
943       displs[p + 1] = displs[p] + recvcounts[p];
944     }
945     if (rank == 0) PetscCall(PetscMalloc2(displs[size], &adj, displs[size], &val));
946     PetscCall(PetscMPIIntCast(totNeighbors, &itotNeighbors));
947     PetscCallMPI(MPI_Gatherv(nrankComp, itotNeighbors, MPIU_SF_NODE, adj, recvcounts, displs, MPIU_SF_NODE, 0, comm));
948     PetscCallMPI(MPI_Gatherv(match, itotNeighbors, MPIU_BOOL, val, recvcounts, displs, MPIU_BOOL, 0, comm));
949     PetscCall(PetscFree2(numNeighbors, neighbors));
950     if (rank == 0) {
951       for (PetscInt p = 1; p <= size; ++p) Noff[p] = Noff[p - 1] + Nc[p - 1];
952       if (view) {
953         for (PetscInt p = 0, off = 0; p < size; ++p) {
954           for (PetscInt c = 0; c < Nc[p]; ++c) {
955             PetscCall(PetscPrintf(PETSC_COMM_SELF, "Proc %" PetscInt_FMT " Comp %" PetscInt_FMT ":\n", p, c));
956             for (PetscInt n = 0; n < N[Noff[p] + c]; ++n, ++off) PetscCall(PetscPrintf(PETSC_COMM_SELF, "  edge (%" PetscInt_FMT ", %" PetscInt_FMT ") (%s):\n", adj[off].rank, adj[off].index, PetscBools[val[off]]));
957           }
958         }
959       }
960       /* Symmetrize the graph */
961       PetscCall(MatCreate(PETSC_COMM_SELF, &G));
962       PetscCall(MatSetSizes(G, Noff[size], Noff[size], Noff[size], Noff[size]));
963       PetscCall(MatSetUp(G));
964       for (PetscInt p = 0, off = 0; p < size; ++p) {
965         for (PetscInt c = 0; c < Nc[p]; ++c) {
966           const PetscInt r = Noff[p] + c;
967 
968           for (PetscInt n = 0; n < N[r]; ++n, ++off) {
969             const PetscInt    q = Noff[adj[off].rank] + adj[off].index;
970             const PetscScalar o = val[off] ? 1.0 : 0.0;
971 
972             PetscCall(MatSetValues(G, 1, &r, 1, &q, &o, INSERT_VALUES));
973             PetscCall(MatSetValues(G, 1, &q, 1, &r, &o, INSERT_VALUES));
974           }
975         }
976       }
977       PetscCall(MatAssemblyBegin(G, MAT_FINAL_ASSEMBLY));
978       PetscCall(MatAssemblyEnd(G, MAT_FINAL_ASSEMBLY));
979 
980       PetscCall(PetscBTCreate(Noff[size], &seenProcs));
981       PetscCall(PetscBTMemzero(Noff[size], seenProcs));
982       PetscCall(PetscBTCreate(Noff[size], &flippedProcs));
983       PetscCall(PetscBTMemzero(Noff[size], flippedProcs));
984       PetscCall(PetscMalloc1(Noff[size], &procFIFO));
985       pTop = pBottom = 0;
986       for (PetscInt p = 0; p < Noff[size]; ++p) {
987         if (PetscBTLookup(seenProcs, p)) continue;
988         /* Initialize FIFO with next proc */
989         procFIFO[pBottom++] = p;
990         PetscCall(PetscBTSet(seenProcs, p));
991         /* Consider each proc in FIFO */
992         while (pTop < pBottom) {
993           const PetscScalar *ornt;
994           const PetscInt    *neighbors;
995           PetscInt           proc, nproc, seen, flippedA, flippedB, mismatch, numNeighbors;
996 
997           proc     = procFIFO[pTop++];
998           flippedA = PetscBTLookup(flippedProcs, proc) ? 1 : 0;
999           PetscCall(MatGetRow(G, proc, &numNeighbors, &neighbors, &ornt));
1000           /* Loop over neighboring procs */
1001           for (PetscInt n = 0; n < numNeighbors; ++n) {
1002             nproc    = neighbors[n];
1003             mismatch = PetscRealPart(ornt[n]) > 0.5 ? 0 : 1;
1004             seen     = PetscBTLookup(seenProcs, nproc);
1005             flippedB = PetscBTLookup(flippedProcs, nproc) ? 1 : 0;
1006 
1007             if (mismatch ^ (flippedA ^ flippedB)) {
1008               PetscCheck(!seen, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Previously seen procs %" PetscInt_FMT " and %" PetscInt_FMT " do not match: Fault mesh is non-orientable", proc, nproc);
1009               if (!flippedB) {
1010                 PetscCall(PetscBTSet(flippedProcs, nproc));
1011               } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Inconsistent mesh orientation: Fault mesh is non-orientable");
1012             } else PetscCheck(!mismatch || !flippedA || !flippedB, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Attempt to flip already flipped cell: Fault mesh is non-orientable");
1013             if (!seen) {
1014               procFIFO[pBottom++] = nproc;
1015               PetscCall(PetscBTSet(seenProcs, nproc));
1016             }
1017           }
1018         }
1019       }
1020       PetscCall(PetscFree(procFIFO));
1021       PetscCall(MatDestroy(&G));
1022       PetscCall(PetscFree2(adj, val));
1023       PetscCall(PetscBTDestroy(&seenProcs));
1024     }
1025     /* Scatter flip flags */
1026     {
1027       PetscBool *flips = NULL;
1028 
1029       if (rank == 0) {
1030         PetscCall(PetscMalloc1(Noff[size], &flips));
1031         for (PetscInt p = 0; p < Noff[size]; ++p) {
1032           flips[p] = PetscBTLookup(flippedProcs, p) ? PETSC_TRUE : PETSC_FALSE;
1033           if (view && flips[p]) PetscCall(PetscPrintf(comm, "Flipping Proc+Comp %" PetscInt_FMT ":\n", p));
1034         }
1035         for (PetscInt p = 0; p < size; ++p) displs[p + 1] = displs[p] + Nc[p];
1036       }
1037       PetscCall(PetscMPIIntCast(Ncomp, &iNcomp));
1038       PetscCallMPI(MPI_Scatterv(flips, Nc, displs, MPIU_BOOL, flipped, iNcomp, MPIU_BOOL, 0, comm));
1039       PetscCall(PetscFree(flips));
1040     }
1041     if (rank == 0) PetscCall(PetscBTDestroy(&flippedProcs));
1042     PetscCall(PetscFree(N));
1043     PetscCall(PetscFree4(recvcounts, displs, Nc, Noff));
1044     PetscCall(PetscFree2(nrankComp, match));
1045 
1046     /* Decide whether to flip cells in each component */
1047     for (PetscInt c = 0; c < cEnd - cStart; ++c) {
1048       if (flipped[cellComp[c]]) PetscCall(PetscBTNegate(flippedCells, c));
1049     }
1050     PetscCall(PetscFree(flipped));
1051   }
1052   if (view) {
1053     PetscViewer v;
1054 
1055     PetscCall(PetscViewerASCIIGetStdout(comm, &v));
1056     PetscCall(PetscViewerASCIIPushSynchronized(v));
1057     PetscCall(PetscViewerASCIISynchronizedPrintf(v, "[%d]BT for parallel flipped cells:\n", rank));
1058     PetscCall(PetscBTView(cEnd - cStart, flippedCells, v));
1059     PetscCall(PetscViewerFlush(v));
1060     PetscCall(PetscViewerASCIIPopSynchronized(v));
1061   }
1062   // Reverse flipped cells in the mesh
1063   PetscViewer     v;
1064   const PetscInt *degree = NULL;
1065   PetscInt       *points;
1066   PetscInt        pStart, pEnd;
1067 
1068   if (view) {
1069     PetscCall(PetscViewerASCIIGetStdout(comm, &v));
1070     PetscCall(PetscViewerASCIIPushSynchronized(v));
1071   }
1072   PetscCall(DMPlexGetChart(dm, &pStart, &pEnd));
1073   if (numRoots >= 0) {
1074     PetscCall(PetscSFComputeDegreeBegin(sf, &degree));
1075     PetscCall(PetscSFComputeDegreeEnd(sf, &degree));
1076   }
1077   PetscCall(PetscCalloc1(pEnd - pStart, &points));
1078   for (PetscInt c = cStart; c < cEnd; ++c) {
1079     if (PetscBTLookup(flippedCells, c - cStart)) {
1080       const PetscInt cell = cells ? cells[c] : c;
1081 
1082       PetscCall(DMPlexOrientPoint(dm, cell, -1));
1083       if (degree && degree[cell]) points[cell] = 1;
1084       if (view) PetscCall(PetscViewerASCIISynchronizedPrintf(v, "[%d]Flipping cell %" PetscInt_FMT "%s\n", rank, cell, degree && degree[cell] ? " and sending to overlap" : ""));
1085     }
1086   }
1087   // Must propagate flips for cells in the overlap
1088   if (numRoots >= 0) {
1089     PetscCall(PetscSFBcastBegin(sf, MPIU_INT, points, points, MPI_SUM));
1090     PetscCall(PetscSFBcastEnd(sf, MPIU_INT, points, points, MPI_SUM));
1091   }
1092   for (PetscInt c = cStart; c < cEnd; ++c) {
1093     const PetscInt cell = cells ? cells[c] : c;
1094 
1095     if (points[cell] && !PetscBTLookup(flippedCells, c - cStart)) {
1096       PetscCall(DMPlexOrientPoint(dm, cell, -1));
1097       if (view) PetscCall(PetscViewerASCIISynchronizedPrintf(v, "[%d]Flipping cell %" PetscInt_FMT " through overlap\n", rank, cell));
1098     }
1099   }
1100   if (view) {
1101     PetscCall(PetscViewerFlush(v));
1102     PetscCall(PetscViewerASCIIPopSynchronized(v));
1103   }
1104   PetscCall(PetscFree(points));
1105   PetscCall(PetscBTDestroy(&flippedCells));
1106   PetscCall(PetscFree2(numNeighbors, neighbors));
1107   PetscCall(PetscFree3(rorntComp, lorntComp, locSupp));
1108   PetscCall(PetscFree2(cellComp, faceComp));
1109   PetscFunctionReturn(PETSC_SUCCESS);
1110 }
1111