xref: /petsc/src/dm/impls/plex/plexfluent.c (revision 0baf8eba40dbc839082666f9f7396a225d6f663c)
1 #define PETSC_DESIRE_FEATURE_TEST_MACROS /* for fileno() */
2 #define PETSCDM_DLL
3 #include <petsc/private/dmpleximpl.h> /*I   "petscdmplex.h"   I*/
4 
5 /*@
6   DMPlexCreateFluentFromFile - Create a `DMPLEX` mesh from a Fluent mesh file
7 
8   Collective
9 
10   Input Parameters:
11 + comm        - The MPI communicator
12 . filename    - Name of the Fluent mesh file
13 - interpolate - Create faces and edges in the mesh
14 
15   Output Parameter:
16 . dm - The `DM` object representing the mesh
17 
18   Level: beginner
19 
20 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexCreateFromFile()`, `DMPlexCreateFluent()`, `DMPlexCreate()`
21 @*/
22 PetscErrorCode DMPlexCreateFluentFromFile(MPI_Comm comm, const char filename[], PetscBool interpolate, DM *dm)
23 {
24   PetscViewer viewer;
25 
26   PetscFunctionBegin;
27   /* Create file viewer and build plex */
28   PetscCall(PetscViewerCreate(comm, &viewer));
29   PetscCall(PetscViewerSetType(viewer, PETSCVIEWERASCII));
30   PetscCall(PetscViewerFileSetMode(viewer, FILE_MODE_READ));
31   PetscCall(PetscViewerFileSetName(viewer, filename));
32   PetscCall(DMPlexCreateFluent(comm, viewer, interpolate, dm));
33   PetscCall(PetscViewerDestroy(&viewer));
34   PetscFunctionReturn(PETSC_SUCCESS);
35 }
36 
37 static PetscErrorCode DMPlexCreateFluent_ReadString(PetscViewer viewer, char *buffer, char delim)
38 {
39   PetscInt ret, i = 0;
40 
41   PetscFunctionBegin;
42   do PetscCall(PetscViewerRead(viewer, &buffer[i++], 1, &ret, PETSC_CHAR));
43   while (ret > 0 && buffer[i - 1] != '\0' && buffer[i - 1] != delim && i < PETSC_MAX_PATH_LEN - 1);
44   if (!ret) buffer[i - 1] = '\0';
45   else buffer[i] = '\0';
46   PetscCheck(i < PETSC_MAX_PATH_LEN - 1, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Buffer overflow! This is not a valid Fluent file.");
47   PetscFunctionReturn(PETSC_SUCCESS);
48 }
49 
50 static PetscErrorCode DMPlexCreateFluent_ReadValues(PetscViewer viewer, void *data, PetscInt count, PetscDataType dtype, PetscBool binary, PetscInt *numClosingParens)
51 {
52   int      fdes = 0;
53   FILE    *file;
54   PetscInt i;
55 
56   PetscFunctionBegin;
57   *numClosingParens = 0;
58   if (binary) {
59     /* Extract raw file descriptor to read binary block */
60     PetscCall(PetscViewerASCIIGetPointer(viewer, &file));
61     PetscCall(PetscFFlush(file));
62     fdes = fileno(file);
63   }
64 
65   if (!binary && dtype == PETSC_INT) {
66     char         cbuf[256];
67     unsigned int ibuf;
68     int          snum;
69     /* Parse hexadecimal ascii integers */
70     for (i = 0; i < count; i++) {
71       size_t len;
72 
73       PetscCall(PetscViewerRead(viewer, cbuf, 1, NULL, PETSC_STRING));
74       snum = sscanf(cbuf, "%x", &ibuf);
75       PetscCheck(snum == 1, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Fluent file");
76       ((PetscInt *)data)[i] = (PetscInt)ibuf;
77       // Check for trailing parentheses
78       PetscCall(PetscStrlen(cbuf, &len));
79       while (cbuf[len - 1] == ')' && len > 0) {
80         ++(*numClosingParens);
81         --len;
82       }
83     }
84   } else if (binary && dtype == PETSC_INT) {
85     /* Always read 32-bit ints and cast to PetscInt */
86     int *ibuf;
87     PetscCall(PetscMalloc1(count, &ibuf));
88     PetscCall(PetscBinaryRead(fdes, ibuf, count, NULL, PETSC_ENUM));
89     PetscCall(PetscByteSwap(ibuf, PETSC_ENUM, count));
90     for (i = 0; i < count; i++) ((PetscInt *)data)[i] = ibuf[i];
91     PetscCall(PetscFree(ibuf));
92 
93   } else if (binary && dtype == PETSC_SCALAR) {
94     float *fbuf;
95     /* Always read 32-bit floats and cast to PetscScalar */
96     PetscCall(PetscMalloc1(count, &fbuf));
97     PetscCall(PetscBinaryRead(fdes, fbuf, count, NULL, PETSC_FLOAT));
98     PetscCall(PetscByteSwap(fbuf, PETSC_FLOAT, count));
99     for (i = 0; i < count; i++) ((PetscScalar *)data)[i] = fbuf[i];
100     PetscCall(PetscFree(fbuf));
101   } else {
102     PetscCall(PetscViewerASCIIRead(viewer, data, count, NULL, dtype));
103   }
104   PetscFunctionReturn(PETSC_SUCCESS);
105 }
106 
107 static PetscErrorCode DMPlexCreateFluent_ReadSection(PetscViewer viewer, FluentSection *s)
108 {
109   char buffer[PETSC_MAX_PATH_LEN];
110   int  snum;
111 
112   PetscFunctionBegin;
113   /* Fast-forward to next section and derive its index */
114   PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, '('));
115   PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, ' '));
116   snum = sscanf(buffer, "%d", &s->index);
117   /* If we can't match an index return -1 to signal end-of-file */
118   if (snum < 1) {
119     s->index = -1;
120     PetscFunctionReturn(PETSC_SUCCESS);
121   }
122 
123   if (s->index == 0) { /* Comment */
124     PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, ')'));
125 
126   } else if (s->index == 2) { /* Dimension */
127     PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, ')'));
128     snum = sscanf(buffer, "%d", &s->nd);
129     PetscCheck(snum == 1, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Fluent file");
130 
131   } else if (s->index == 10 || s->index == 2010) { /* Vertices */
132     PetscInt numClosingParens = 0;
133 
134     PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, ')'));
135     snum = sscanf(buffer, "(%x %x %x %d %d)", &s->zoneID, &s->first, &s->last, &s->type, &s->nd);
136     PetscCheck(snum == 5, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Fluent file");
137     if (s->zoneID > 0) {
138       PetscInt numCoords = s->last - s->first + 1;
139       PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, '('));
140       PetscCall(PetscMalloc1(s->nd * numCoords, (PetscScalar **)&s->data));
141       PetscCall(DMPlexCreateFluent_ReadValues(viewer, s->data, s->nd * numCoords, PETSC_SCALAR, s->index == 2010 ? PETSC_TRUE : PETSC_FALSE, &numClosingParens));
142       if (!numClosingParens) PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, ')'));
143       else --numClosingParens;
144     }
145     if (!numClosingParens) PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, ')'));
146     else --numClosingParens;
147     PetscCheck(!numClosingParens, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Fluent file");
148   } else if (s->index == 12 || s->index == 2012) { /* Cells */
149     PetscInt numClosingParens = 0;
150 
151     PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, ')'));
152     snum = sscanf(buffer, "(%x", &s->zoneID);
153     PetscCheck(snum == 1, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Fluent file");
154     if (s->zoneID == 0) { /* Header section */
155       snum = sscanf(buffer, "(%x %x %x %d)", &s->zoneID, &s->first, &s->last, &s->nd);
156       PetscCheck(snum == 4, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Fluent file");
157     } else { /* Data section */
158       snum = sscanf(buffer, "(%x %x %x %d %d)", &s->zoneID, &s->first, &s->last, &s->type, &s->nd);
159       PetscCheck(snum == 5, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Fluent file");
160       if (s->nd == 0) {
161         /* Read cell type definitions for mixed cells */
162         PetscInt numCells = s->last - s->first + 1;
163         PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, '('));
164         PetscCall(PetscMalloc1(numCells, (PetscInt **)&s->data));
165         PetscCall(DMPlexCreateFluent_ReadValues(viewer, s->data, numCells, PETSC_INT, s->index == 2012 ? PETSC_TRUE : PETSC_FALSE, &numClosingParens));
166         PetscCall(PetscFree(s->data));
167         if (!numClosingParens) PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, ')'));
168         else --numClosingParens;
169       }
170     }
171     if (!numClosingParens) PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, ')'));
172     else --numClosingParens;
173     PetscCheck(!numClosingParens, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Fluent file");
174   } else if (s->index == 13 || s->index == 2013) { /* Faces */
175     PetscInt numClosingParens = 0;
176 
177     PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, ')'));
178     snum = sscanf(buffer, "(%x", &s->zoneID);
179     PetscCheck(snum == 1, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Fluent file");
180     if (s->zoneID == 0) { /* Header section */
181       snum = sscanf(buffer, "(%x %x %x %d)", &s->zoneID, &s->first, &s->last, &s->nd);
182       PetscCheck(snum == 4, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Fluent file");
183     } else { /* Data section */
184       PetscInt f, numEntries, numFaces;
185       snum = sscanf(buffer, "(%x %x %x %d %d)", &s->zoneID, &s->first, &s->last, &s->type, &s->nd);
186       PetscCheck(snum == 5, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Fluent file");
187       PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, '('));
188       switch (s->nd) {
189       case 0:
190         numEntries = PETSC_DETERMINE;
191         break;
192       case 2:
193         numEntries = 2 + 2;
194         break; /* linear */
195       case 3:
196         numEntries = 2 + 3;
197         break; /* triangular */
198       case 4:
199         numEntries = 2 + 4;
200         break; /* quadrilateral */
201       default:
202         SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unknown face type in Fluent file");
203       }
204       numFaces = s->last - s->first + 1;
205       if (numEntries != PETSC_DETERMINE) {
206         /* Allocate space only if we already know the size of the block */
207         PetscCall(PetscMalloc1(numEntries * numFaces, (PetscInt **)&s->data));
208       }
209       for (f = 0; f < numFaces; f++) {
210         if (s->nd == 0) {
211           /* Determine the size of the block for "mixed" facets */
212           PetscInt numFaceVert = 0;
213           PetscCall(DMPlexCreateFluent_ReadValues(viewer, &numFaceVert, 1, PETSC_INT, s->index == 2013 ? PETSC_TRUE : PETSC_FALSE, &numClosingParens));
214           if (numEntries == PETSC_DETERMINE) {
215             numEntries = numFaceVert + 2;
216             PetscCall(PetscMalloc1(numEntries * numFaces, (PetscInt **)&s->data));
217           } else {
218             PetscCheck(numEntries == numFaceVert + 2, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "No support for mixed faces in Fluent files");
219           }
220         }
221         PetscCall(DMPlexCreateFluent_ReadValues(viewer, &(((PetscInt *)s->data)[f * numEntries]), numEntries, PETSC_INT, s->index == 2013 ? PETSC_TRUE : PETSC_FALSE, &numClosingParens));
222       }
223       PetscCall(PetscMPIIntCast(numEntries - 2, &s->nd));
224       if (!numClosingParens) PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, ')'));
225       else --numClosingParens;
226     }
227     if (!numClosingParens) PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, ')'));
228     else --numClosingParens;
229     PetscCheck(!numClosingParens, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Fluent file");
230   } else if (s->index == 39) { /* Label information */
231     char labelName[PETSC_MAX_PATH_LEN];
232     char caseName[PETSC_MAX_PATH_LEN];
233 
234     PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, ')'));
235     snum = sscanf(buffer, "(%u %s %s %d)", &s->zoneID, caseName, labelName, &s->nd);
236     PetscCheck(snum == 4, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Fluent file: %d", snum);
237     PetscInt depth = 1;
238     do {
239       /* Match parentheses when parsing unknown sections */
240       do PetscCall(PetscViewerRead(viewer, &buffer[0], 1, NULL, PETSC_CHAR));
241       while (buffer[0] != '(' && buffer[0] != ')');
242       if (buffer[0] == '(') depth++;
243       if (buffer[0] == ')') depth--;
244     } while (depth > 0);
245     PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, '\n'));
246     PetscCall(PetscStrallocpy(labelName, (char **)&s->data));
247     PetscCall(PetscInfo((PetscObject)viewer, "CASE: Zone ID %u is label %s\n", s->zoneID, labelName));
248   } else { /* Unknown section type */
249     PetscInt depth = 1;
250     do {
251       /* Match parentheses when parsing unknown sections */
252       do PetscCall(PetscViewerRead(viewer, &buffer[0], 1, NULL, PETSC_CHAR));
253       while (buffer[0] != '(' && buffer[0] != ')');
254       if (buffer[0] == '(') depth++;
255       if (buffer[0] == ')') depth--;
256     } while (depth > 0);
257     PetscCall(DMPlexCreateFluent_ReadString(viewer, buffer, '\n'));
258   }
259   PetscFunctionReturn(PETSC_SUCCESS);
260 }
261 
262 // Inserts point `face` with orientation `ornt` into the cone of point `cell` at position `c`, which is the first empty slot
263 static PetscErrorCode InsertFace(DM dm, PetscInt cell, PetscInt face, PetscInt ornt)
264 {
265   const PetscInt *cone;
266   PetscInt        coneSize, c;
267 
268   PetscFunctionBegin;
269   PetscCall(DMPlexGetCone(dm, cell, &cone));
270   PetscCall(DMPlexGetConeSize(dm, cell, &coneSize));
271   for (c = 0; c < coneSize; ++c)
272     if (cone[c] < 0) break;
273   PetscCheck(c < coneSize, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Face %" PetscInt_FMT " could not be inserted in cone of cell %" PetscInt_FMT, face, cell);
274   PetscCall(DMPlexInsertCone(dm, cell, c, face));
275   PetscCall(DMPlexInsertConeOrientation(dm, cell, c, ornt));
276   PetscFunctionReturn(PETSC_SUCCESS);
277 }
278 
279 static PetscErrorCode ReorderPolygon(DM dm, PetscInt cell)
280 {
281   const PetscInt *cone, *ornt;
282   PetscInt        coneSize, newCone[16], newOrnt[16];
283 
284   PetscFunctionBegin;
285   PetscCall(DMPlexGetOrientedCone(dm, cell, &cone, &ornt));
286   PetscCall(DMPlexGetConeSize(dm, cell, &coneSize));
287   newCone[0] = cone[0];
288   newOrnt[0] = ornt[0];
289   for (PetscInt c = 1; c < coneSize; ++c) {
290     const PetscInt *fcone;
291     PetscInt        firstVertex, lastVertex, c2;
292 
293     PetscCall(DMPlexGetCone(dm, newCone[c - 1], &fcone));
294     lastVertex = newOrnt[c - 1] ? fcone[0] : fcone[1];
295     for (c2 = 0; c2 < coneSize; ++c2) {
296       const PetscInt *fcone2;
297 
298       PetscCall(DMPlexGetCone(dm, cone[c2], &fcone2));
299       firstVertex = ornt[c2] ? fcone2[1] : fcone2[0];
300       if (lastVertex == firstVertex) {
301         // Point `cell` matched point `lastVertex` on face `cone[c2]` with orientation `ornt[c2]`
302         break;
303       }
304     }
305     PetscCheck(c2 < coneSize, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cell %" PetscInt_FMT " could not find a face match as position %" PetscInt_FMT, cell, c);
306     newCone[c] = cone[c2];
307     newOrnt[c] = ornt[c2];
308   }
309   {
310     const PetscInt *fcone, *fcone2;
311     PetscInt        vertex, vertex2;
312 
313     PetscCall(DMPlexGetCone(dm, newCone[coneSize - 1], &fcone));
314     PetscCall(DMPlexGetCone(dm, newCone[0], &fcone2));
315     vertex  = newOrnt[coneSize - 1] ? fcone[0] : fcone[1];
316     vertex2 = newOrnt[0] ? fcone2[1] : fcone2[0];
317     PetscCheck(vertex == vertex2, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cell %" PetscInt_FMT " did not match at the endpoint", cell);
318   }
319   PetscCall(DMPlexSetCone(dm, cell, newCone));
320   PetscCall(DMPlexSetConeOrientation(dm, cell, newOrnt));
321   PetscCall(DMPlexRestoreOrientedCone(dm, cell, &cone, &ornt));
322   PetscFunctionReturn(PETSC_SUCCESS);
323 }
324 
325 static PetscErrorCode ReorderTetrahedron(DM dm, PetscInt cell)
326 {
327   const PetscInt *cone, *ornt, *fcone, *fornt, *farr, faces[4] = {0, 1, 3, 2};
328   PetscInt        newCone[16], newOrnt[16];
329 
330   PetscFunctionBegin;
331   PetscCall(DMPlexGetOrientedCone(dm, cell, &cone, &ornt));
332   newCone[0] = cone[0];
333   newOrnt[0] = ornt[0];
334   PetscCall(DMPlexGetOrientedCone(dm, newCone[0], &fcone, &fornt));
335   farr = DMPolytopeTypeGetArrangement(DM_POLYTOPE_TRIANGLE, newOrnt[0]);
336   // Loop over each edge in the initial triangle
337   for (PetscInt e = 0; e < 3; ++e) {
338     const PetscInt edge = fcone[farr[e * 2 + 0]], eornt = DMPolytopeTypeComposeOrientation(DM_POLYTOPE_SEGMENT, farr[e * 2 + 1], fornt[farr[e * 2 + 0]]);
339     PetscInt       c;
340 
341     // Loop over each remaining face in the tetrahedron
342     //   On face `newCone[0]`, trying to match edge `edge` with final orientation `eornt` to an edge on another face
343     for (c = 1; c < 4; ++c) {
344       const PetscInt *fcone2, *fornt2, *farr2;
345       PetscInt        c2;
346 
347       // Checking face `cone[c]` with orientation `ornt[c]`
348       PetscCall(DMPlexGetOrientedCone(dm, cone[c], &fcone2, &fornt2));
349       farr2 = DMPolytopeTypeGetArrangement(DM_POLYTOPE_TRIANGLE, ornt[c]);
350       // Check for edge
351       for (c2 = 0; c2 < 3; ++c2) {
352         const PetscInt edge2 = fcone2[farr2[c2 * 2 + 0]], eornt2 = DMPolytopeTypeComposeOrientation(DM_POLYTOPE_SEGMENT, farr[c2 * 2 + 1], fornt2[farr2[c2 * 2 + 0]]);
353         // Trying to match edge `edge2` with final orientation `eornt2`
354         if (edge == edge2) {
355           PetscCheck(eornt == -(eornt2 + 1), PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Edge %" PetscInt_FMT " found twice with the same orientation", edge);
356           // Matched face `newCone[0]` with orientation `newOrnt[0]` to face `cone[c]` with orientation `ornt[c]` along edge `edge`
357           break;
358         }
359       }
360       if (c2 < 3) {
361         newCone[faces[e + 1]] = cone[c];
362         // Compute new orientation of face based on which edge was matched (only the first edge matches a side different from 0)
363         newOrnt[faces[e + 1]] = DMPolytopeTypeComposeOrientation(DM_POLYTOPE_TRIANGLE, !e ? (c2 + 1) % 3 : c2, ornt[c]);
364         break;
365       }
366     }
367     PetscCheck(c < 4, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cell %" PetscInt_FMT " could not find a face match for edge %" PetscInt_FMT, cell, e);
368   }
369   PetscCall(DMPlexRestoreOrientedCone(dm, newCone[0], &fcone, &fornt));
370   PetscCall(DMPlexSetCone(dm, cell, newCone));
371   PetscCall(DMPlexSetConeOrientation(dm, cell, newOrnt));
372   PetscCall(DMPlexRestoreOrientedCone(dm, cell, &cone, &ornt));
373   PetscFunctionReturn(PETSC_SUCCESS);
374 }
375 
376 static PetscErrorCode ReorderHexahedron(DM dm, PetscInt cell)
377 {
378   const PetscInt *cone, *ornt, *fcone, *fornt, *farr;
379   const PetscInt  faces[6] = {0, 5, 3, 4, 2, 1};
380   PetscInt        used[6]  = {1, 0, 0, 0, 0, 0};
381   PetscInt        newCone[16], newOrnt[16];
382 
383   PetscFunctionBegin;
384   PetscCall(DMPlexGetOrientedCone(dm, cell, &cone, &ornt));
385   newCone[0] = cone[0];
386   newOrnt[0] = ornt[0];
387   PetscCall(DMPlexGetOrientedCone(dm, newCone[0], &fcone, &fornt));
388   farr = DMPolytopeTypeGetArrangement(DM_POLYTOPE_QUADRILATERAL, newOrnt[0]);
389   // Loop over each edge in the initial quadrilateral
390   for (PetscInt e = 0; e < 4; ++e) {
391     const PetscInt edge = fcone[farr[e * 2 + 0]], eornt = DMPolytopeTypeComposeOrientation(DM_POLYTOPE_SEGMENT, farr[e * 2 + 1], fornt[farr[e * 2 + 0]]);
392     PetscInt       c;
393 
394     // Loop over each remaining face in the hexahedron
395     //   On face `newCone[0]`, trying to match edge `edge` with final orientation `eornt` to an edge on another face
396     for (c = 1; c < 6; ++c) {
397       const PetscInt *fcone2, *fornt2, *farr2;
398       PetscInt        c2;
399 
400       // Checking face `cone[c]` with orientation `ornt[c]`
401       PetscCall(DMPlexGetOrientedCone(dm, cone[c], &fcone2, &fornt2));
402       farr2 = DMPolytopeTypeGetArrangement(DM_POLYTOPE_QUADRILATERAL, ornt[c]);
403       // Check for edge
404       for (c2 = 0; c2 < 4; ++c2) {
405         const PetscInt edge2 = fcone2[farr2[c2 * 2 + 0]], eornt2 = DMPolytopeTypeComposeOrientation(DM_POLYTOPE_SEGMENT, farr2[c2 * 2 + 1], fornt2[farr2[c2 * 2 + 0]]);
406         // Trying to match edge `edge2` with final orientation `eornt2`
407         if (edge == edge2) {
408           PetscCheck(eornt == -(eornt2 + 1), PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Edge %" PetscInt_FMT " found twice with the same orientation", edge);
409           // Matched face `newCone[0]` with orientation `newOrnt[0]` to face `cone[c]` with orientation `ornt[c]` along edge `edge`
410           break;
411         }
412       }
413       if (c2 < 4) {
414         used[c]               = 1;
415         newCone[faces[e + 1]] = cone[c];
416         // Compute new orientation of face based on which edge was matched (only the first edge matches a side different from 0)
417         newOrnt[faces[e + 1]] = DMPolytopeTypeComposeOrientation(DM_POLYTOPE_QUADRILATERAL, !e ? (c2 + 1) % 4 : c2, ornt[c]);
418         break;
419       }
420     }
421     PetscCheck(c < 6, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cell %" PetscInt_FMT " could not find a face match for edge %" PetscInt_FMT, cell, e);
422   }
423   PetscCall(DMPlexRestoreOrientedCone(dm, newCone[0], &fcone, &fornt));
424   // Add last face
425   {
426     PetscInt c, c2;
427 
428     for (c = 1; c < 6; ++c)
429       if (!used[c]) break;
430     PetscCheck(c < 6, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Cell %" PetscInt_FMT " could not find an available face", cell);
431     // Match first edge to 3rd edge in newCone[2]
432     {
433       const PetscInt *fcone2, *fornt2, *farr2;
434 
435       PetscCall(DMPlexGetOrientedCone(dm, newCone[2], &fcone, &fornt));
436       farr = DMPolytopeTypeGetArrangement(DM_POLYTOPE_QUADRILATERAL, newOrnt[2]);
437       PetscCall(DMPlexGetOrientedCone(dm, cone[c], &fcone2, &fornt2));
438       farr2 = DMPolytopeTypeGetArrangement(DM_POLYTOPE_QUADRILATERAL, ornt[c]);
439 
440       const PetscInt e    = 2;
441       const PetscInt edge = fcone[farr[e * 2 + 0]], eornt = DMPolytopeTypeComposeOrientation(DM_POLYTOPE_SEGMENT, farr[e * 2 + 1], fornt[farr[e * 2 + 0]]);
442       // Trying to match edge `edge` with final orientation `eornt` of face `newCone[2]` to some edge of face `cone[c]` with orientation `ornt[c]`
443       for (c2 = 0; c2 < 4; ++c2) {
444         const PetscInt edge2 = fcone2[farr2[c2 * 2 + 0]], eornt2 = DMPolytopeTypeComposeOrientation(DM_POLYTOPE_SEGMENT, farr2[c2 * 2 + 1], fornt2[farr2[c2 * 2 + 0]]);
445         // Trying to match edge `edge2` with final orientation `eornt2`
446         if (edge == edge2) {
447           PetscCheck(eornt == -(eornt2 + 1), PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Edge %" PetscInt_FMT " found twice with the same orientation", edge);
448           // Matched face `newCone[2]` with orientation `newOrnt[2]` to face `cone[c]` with orientation `ornt[c]` along edge `edge`
449           break;
450         }
451       }
452       PetscCheck(c2 < 4, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not fit last face in");
453     }
454     newCone[faces[5]] = cone[c];
455     // Compute new orientation of face based on which edge was matched
456     newOrnt[faces[5]] = DMPolytopeTypeComposeOrientation(DM_POLYTOPE_QUADRILATERAL, c2, ornt[c]);
457     PetscCall(DMPlexRestoreOrientedCone(dm, newCone[0], &fcone, &fornt));
458   }
459   PetscCall(DMPlexSetCone(dm, cell, newCone));
460   PetscCall(DMPlexSetConeOrientation(dm, cell, newOrnt));
461   PetscCall(DMPlexRestoreOrientedCone(dm, cell, &cone, &ornt));
462   PetscFunctionReturn(PETSC_SUCCESS);
463 }
464 
465 static PetscErrorCode ReorderCell(DM dm, PetscInt cell, DMPolytopeType ct)
466 {
467   PetscFunctionBegin;
468   switch (ct) {
469   case DM_POLYTOPE_TRIANGLE:
470   case DM_POLYTOPE_QUADRILATERAL:
471     PetscCall(ReorderPolygon(dm, cell));
472     break;
473   case DM_POLYTOPE_TETRAHEDRON:
474     PetscCall(ReorderTetrahedron(dm, cell));
475     break;
476   case DM_POLYTOPE_HEXAHEDRON:
477     PetscCall(ReorderHexahedron(dm, cell));
478     break;
479   default:
480     PetscCheck(0, PETSC_COMM_SELF, PETSC_ERR_SUP, "Celltype %s is unsupported", DMPolytopeTypes[ct]);
481     break;
482   }
483   PetscFunctionReturn(PETSC_SUCCESS);
484 }
485 
486 /*@C
487   DMPlexCreateFluent - Create a `DMPLEX` mesh from a Fluent mesh file <http://aerojet.engr.ucdavis.edu/fluenthelp/html/ug/node1490.htm>.
488 
489   Collective
490 
491   Input Parameters:
492 + comm        - The MPI communicator
493 . viewer      - The `PetscViewer` associated with a Fluent mesh file
494 - interpolate - Create faces and edges in the mesh
495 
496   Output Parameter:
497 . dm - The `DM` object representing the mesh
498 
499   Level: beginner
500 
501 .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMCreate()`
502 @*/
503 PetscErrorCode DMPlexCreateFluent(MPI_Comm comm, PetscViewer viewer, PetscBool interpolate, DM *dm)
504 {
505   PetscInt       dim             = PETSC_DETERMINE;
506   PetscInt       numCells        = 0;
507   PetscInt       numVertices     = 0;
508   PetscInt       numCellFaces    = PETSC_DETERMINE;
509   DMPolytopeType ct              = DM_POLYTOPE_UNKNOWN_CELL;
510   PetscInt       numFaces        = 0;
511   PetscInt       numFaceEntries  = PETSC_DETERMINE;
512   PetscInt       numFaceVertices = PETSC_DETERMINE;
513   PetscInt      *faces           = NULL;
514   PetscInt      *cellVertices    = NULL;
515   unsigned int  *faceZoneIDs     = NULL;
516   DMLabel        faceSets        = NULL;
517   DMLabel       *zoneLabels      = NULL;
518   const char   **zoneNames       = NULL;
519   unsigned int   maxZoneID       = 0;
520   PetscScalar   *coordsIn        = NULL;
521   PetscScalar   *coords;
522   PetscSection   coordSection;
523   Vec            coordinates;
524   PetscInt       coordSize, f;
525   PetscMPIInt    rank;
526 
527   PetscFunctionBegin;
528   PetscCallMPI(MPI_Comm_rank(comm, &rank));
529 
530   if (rank == 0) {
531     FluentSection s;
532     numFaces = PETSC_DETERMINE;
533     do {
534       PetscCall(DMPlexCreateFluent_ReadSection(viewer, &s));
535       if (s.index == 2) { /* Dimension */
536         dim = s.nd;
537         PetscCall(PetscInfo((PetscObject)viewer, "CASE: Found dimension: %" PetscInt_FMT "\n", dim));
538       } else if (s.index == 10 || s.index == 2010) { /* Vertices */
539         if (s.zoneID == 0) {
540           numVertices = s.last;
541           PetscCall(PetscInfo((PetscObject)viewer, "CASE: Found number of vertices: %" PetscInt_FMT "\n", numVertices));
542         } else {
543           PetscCall(PetscInfo((PetscObject)viewer, "CASE: Found vertex coordinates\n"));
544           PetscCheck(!coordsIn, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Currently no support for multiple coordinate sets in Fluent files");
545           coordsIn = (PetscScalar *)s.data;
546         }
547 
548       } else if (s.index == 12 || s.index == 2012) { /* Cells */
549         if (s.zoneID == 0) {
550           numCells = s.last;
551           PetscCall(PetscInfo((PetscObject)viewer, "CASE: Found number of cells %" PetscInt_FMT "\n", numCells));
552         } else {
553           switch (s.nd) {
554           case 0:
555             numCellFaces = PETSC_DETERMINE;
556             ct           = DM_POLYTOPE_POINT;
557             break;
558           case 1:
559             numCellFaces = 3;
560             ct           = DM_POLYTOPE_TRIANGLE;
561             break;
562           case 2:
563             numCellFaces = 4;
564             ct           = DM_POLYTOPE_TETRAHEDRON;
565             break;
566           case 3:
567             numCellFaces = 4;
568             ct           = DM_POLYTOPE_QUADRILATERAL;
569             break;
570           case 4:
571             numCellFaces = 6;
572             ct           = DM_POLYTOPE_HEXAHEDRON;
573             break;
574           case 5:
575             numCellFaces = 5;
576             ct           = DM_POLYTOPE_PYRAMID;
577             break;
578           case 6:
579             numCellFaces = 5;
580             ct           = DM_POLYTOPE_TRI_PRISM;
581             break;
582           default:
583             numCellFaces = PETSC_DETERMINE;
584           }
585           PetscCall(PetscInfo((PetscObject)viewer, "CASE: Found number of cell faces %" PetscInt_FMT "\n", numCellFaces));
586         }
587       } else if (s.index == 13 || s.index == 2013) { /* Facets */
588         if (s.zoneID == 0) {                         /* Header section */
589           numFaces = (PetscInt)(s.last - s.first + 1);
590           if (s.nd == 0 || s.nd == 5) numFaceVertices = PETSC_DETERMINE;
591           else numFaceVertices = s.nd;
592           PetscCall(PetscInfo((PetscObject)viewer, "CASE: Found number of faces %" PetscInt_FMT " face vertices: %" PetscInt_FMT "\n", numFaces, numFaceVertices));
593         } else { /* Data section */
594           unsigned int z;
595 
596           PetscCheck(numFaceVertices == PETSC_DETERMINE || s.nd == numFaceVertices, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Mixed facets in Fluent files are not supported");
597           PetscCheck(numFaces >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "No header section for facets in Fluent file");
598           if (numFaceVertices == PETSC_DETERMINE) numFaceVertices = s.nd;
599           numFaceEntries = numFaceVertices + 2;
600           if (!faces) PetscCall(PetscMalloc1(numFaces * numFaceEntries, &faces));
601           if (!faceZoneIDs) PetscCall(PetscMalloc1(numFaces, &faceZoneIDs));
602           PetscCall(PetscMemcpy(&faces[(s.first - 1) * numFaceEntries], s.data, (s.last - s.first + 1) * numFaceEntries * sizeof(PetscInt)));
603           /* Record the zoneID for each face set */
604           for (z = s.first - 1; z < s.last; z++) faceZoneIDs[z] = s.zoneID;
605           PetscCall(PetscFree(s.data));
606         }
607       } else if (s.index == 39) { /* Label information */
608         if (s.zoneID >= maxZoneID) {
609           DMLabel     *tmpL;
610           const char **tmp;
611           unsigned int newmax = maxZoneID + 1;
612 
613           while (newmax < s.zoneID + 1) newmax *= 2;
614           PetscCall(PetscCalloc2(newmax, &tmp, newmax, &tmpL));
615           for (PetscInt i = 0; i < (PetscInt)maxZoneID; ++i) {
616             tmp[i]  = zoneNames[i];
617             tmpL[i] = zoneLabels[i];
618           }
619           maxZoneID = newmax;
620           PetscCall(PetscFree2(zoneNames, zoneLabels));
621           zoneNames  = tmp;
622           zoneLabels = tmpL;
623         }
624         zoneNames[s.zoneID] = (const char *)s.data;
625       }
626     } while (s.index >= 0);
627   }
628   PetscCallMPI(MPI_Bcast(&dim, 1, MPIU_INT, 0, comm));
629   PetscCheck(dim >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Fluent file does not include dimension");
630 
631   /* Allocate cell-vertex mesh */
632   PetscCall(DMCreate(comm, dm));
633   PetscCall(DMSetType(*dm, DMPLEX));
634   PetscCall(DMSetDimension(*dm, dim));
635   PetscCall(DMPlexSetChart(*dm, 0, numCells + numFaces + numVertices));
636   if (rank == 0) {
637     PetscCheck(numCells >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unknown number of cells in Fluent file");
638     /* If no cell type was given we assume simplices */
639     if (numCellFaces == PETSC_DETERMINE) {
640       numCellFaces = numFaceVertices + 1;
641       ct           = numCellFaces == 3 ? DM_POLYTOPE_TRIANGLE : (numCellFaces == 4 ? DM_POLYTOPE_TETRAHEDRON : DM_POLYTOPE_UNKNOWN_CELL);
642     }
643     for (PetscInt c = 0; c < numCells; ++c) PetscCall(DMPlexSetConeSize(*dm, c, numCellFaces));
644     for (PetscInt f = 0; f < numFaces; ++f) PetscCall(DMPlexSetConeSize(*dm, f + numCells + numVertices, numFaceVertices));
645   }
646   PetscCall(DMSetUp(*dm));
647 
648   if (rank == 0 && faces) {
649     PetscInt *cones;
650 
651     PetscCall(DMPlexGetCones(*dm, &cones));
652     PetscCheck(numCellFaces < 16, PETSC_COMM_SELF, PETSC_ERR_SUP, "Number of cell faces %" PetscInt_FMT " exceeds temporary storage", numCellFaces);
653     PetscCheck(numFaceVertices < 16, PETSC_COMM_SELF, PETSC_ERR_SUP, "Number of face vertices %" PetscInt_FMT " exceeds temporary storage", numFaceVertices);
654     for (PetscInt c = 0; c < numCells * numCellFaces; ++c) cones[c] = -1;
655     for (PetscInt f = 0; f < numFaces; f++) {
656       const PetscInt  cl   = faces[f * numFaceEntries + numFaceVertices] - 1;
657       const PetscInt  cr   = faces[f * numFaceEntries + numFaceVertices + 1] - 1;
658       const PetscInt  face = f + numCells + numVertices;
659       const PetscInt *fc   = &faces[f * numFaceEntries];
660       PetscInt        fcone[16];
661 
662       // How could Fluent define the outward normal differently? Is there no end to the pain?
663       if (dim == 3) {
664         if (cl >= 0) PetscCall(InsertFace(*dm, cl, face, -1));
665         if (cr >= 0) PetscCall(InsertFace(*dm, cr, face, 0));
666       } else {
667         if (cl >= 0) PetscCall(InsertFace(*dm, cl, face, 0));
668         if (cr >= 0) PetscCall(InsertFace(*dm, cr, face, -1));
669       }
670       for (PetscInt v = 0; v < numFaceVertices; ++v) fcone[v] = fc[v] + numCells - 1;
671       PetscCall(DMPlexSetCone(*dm, face, fcone));
672     }
673   }
674   PetscCall(DMPlexSymmetrize(*dm));
675   PetscCall(DMPlexStratify(*dm));
676   if (dim == 3) {
677     DM idm;
678 
679     PetscCall(DMCreate(PetscObjectComm((PetscObject)*dm), &idm));
680     PetscCall(DMSetType(idm, DMPLEX));
681     PetscCall(DMSetDimension(idm, dim));
682     PetscCall(DMPlexInterpolateFaces_Internal(*dm, 1, idm));
683     PetscCall(DMDestroy(dm));
684     *dm = idm;
685   }
686   PetscCall(DMViewFromOptions(*dm, NULL, "-cas_dm_view"));
687   if (rank == 0 && faces) {
688     for (PetscInt c = 0; c < numCells; ++c) PetscCall(ReorderCell(*dm, c, ct));
689   }
690 
691   if (rank == 0 && faces) {
692     PetscInt        fi, joinSize, meetSize, *fverts, cells[2];
693     const PetscInt *join, *meet;
694     PetscCall(PetscMalloc1(numFaceVertices, &fverts));
695     /* Mark facets by finding the full join of all adjacent vertices */
696     for (f = 0; f < numFaces; f++) {
697       const PetscInt cl = faces[f * numFaceEntries + numFaceVertices] - 1;
698       const PetscInt cr = faces[f * numFaceEntries + numFaceVertices + 1] - 1;
699       const PetscInt id = (PetscInt)faceZoneIDs[f];
700 
701       if (cl > 0 && cr > 0) {
702         /* If we know both adjoining cells we can use a single-level meet */
703         cells[0] = cl;
704         cells[1] = cr;
705         PetscCall(DMPlexGetMeet(*dm, 2, cells, &meetSize, &meet));
706         PetscCheck(meetSize == 1, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not determine Plex facet for Fluent face %" PetscInt_FMT " cells: %" PetscInt_FMT ", %" PetscInt_FMT, f, cl, cr);
707         PetscCall(DMSetLabelValue_Fast(*dm, &faceSets, "Face Sets", meet[0], id));
708         if (zoneNames && zoneNames[id]) PetscCall(DMSetLabelValue_Fast(*dm, &zoneLabels[id], zoneNames[id], meet[0], 1));
709         PetscCall(DMPlexRestoreMeet(*dm, numFaceVertices, fverts, &meetSize, &meet));
710       } else {
711         for (fi = 0; fi < numFaceVertices; fi++) fverts[fi] = faces[f * numFaceEntries + fi] + numCells - 1;
712         PetscCall(DMPlexGetFullJoin(*dm, numFaceVertices, fverts, &joinSize, &join));
713         PetscCheck(joinSize == 1, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not determine Plex facet for Fluent face %" PetscInt_FMT, f);
714         PetscCall(DMSetLabelValue_Fast(*dm, &faceSets, "Face Sets", join[0], id));
715         if (zoneNames && zoneNames[id]) PetscCall(DMSetLabelValue_Fast(*dm, &zoneLabels[id], zoneNames[id], join[0], 1));
716         PetscCall(DMPlexRestoreJoin(*dm, numFaceVertices, fverts, &joinSize, &join));
717       }
718     }
719     PetscCall(PetscFree(fverts));
720   }
721 
722   { /* Create Face Sets label at all processes */
723     enum {
724       n = 1
725     };
726     PetscBool flag[n];
727 
728     flag[0] = faceSets ? PETSC_TRUE : PETSC_FALSE;
729     PetscCallMPI(MPI_Bcast(flag, n, MPIU_BOOL, 0, comm));
730     if (flag[0]) PetscCall(DMCreateLabel(*dm, "Face Sets"));
731     // TODO Code to create all the zone labels on each process
732   }
733 
734   if (!interpolate) {
735     DM udm;
736 
737     PetscCall(DMPlexUninterpolate(*dm, &udm));
738     PetscCall(DMDestroy(dm));
739     *dm = udm;
740   }
741 
742   /* Read coordinates */
743   PetscCall(DMGetCoordinateSection(*dm, &coordSection));
744   PetscCall(PetscSectionSetNumFields(coordSection, 1));
745   PetscCall(PetscSectionSetFieldComponents(coordSection, 0, dim));
746   PetscCall(PetscSectionSetChart(coordSection, numCells, numCells + numVertices));
747   for (PetscInt v = numCells; v < numCells + numVertices; ++v) {
748     PetscCall(PetscSectionSetDof(coordSection, v, dim));
749     PetscCall(PetscSectionSetFieldDof(coordSection, v, 0, dim));
750   }
751   PetscCall(PetscSectionSetUp(coordSection));
752   PetscCall(PetscSectionGetStorageSize(coordSection, &coordSize));
753   PetscCall(VecCreate(PETSC_COMM_SELF, &coordinates));
754   PetscCall(PetscObjectSetName((PetscObject)coordinates, "coordinates"));
755   PetscCall(VecSetSizes(coordinates, coordSize, PETSC_DETERMINE));
756   PetscCall(VecSetType(coordinates, VECSTANDARD));
757   PetscCall(VecGetArray(coordinates, &coords));
758   if (rank == 0 && coordsIn) {
759     for (PetscInt v = 0; v < numVertices; ++v) {
760       for (PetscInt d = 0; d < dim; ++d) coords[v * dim + d] = coordsIn[v * dim + d];
761     }
762   }
763   PetscCall(VecRestoreArray(coordinates, &coords));
764   PetscCall(DMSetCoordinatesLocal(*dm, coordinates));
765   PetscCall(VecDestroy(&coordinates));
766 
767   if (rank == 0) {
768     PetscCall(PetscFree(cellVertices));
769     PetscCall(PetscFree(faces));
770     PetscCall(PetscFree(faceZoneIDs));
771     PetscCall(PetscFree(coordsIn));
772     if (zoneNames)
773       for (PetscInt i = 0; i < (PetscInt)maxZoneID; ++i) PetscCall(PetscFree(zoneNames[i]));
774     PetscCall(PetscFree2(zoneNames, zoneLabels));
775   }
776   PetscFunctionReturn(PETSC_SUCCESS);
777 }
778