Date: 2015-10-02T22:15:30+00:00

Actual source code: plexgmsh.c
petsc-3.6.2 2015-10-02
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      1: #define PETSCDM_DLL
      2: #include <petsc/private/dmpleximpl.h>    /*I   "petscdmplex.h"   I*/

      6: /*@C
      7:   DMPlexCreateGmshFromFile - Create a DMPlex mesh from a Gmsh file

      9: + comm        - The MPI communicator
     10: . filename    - Name of the Gmsh file
     11: - interpolate - Create faces and edges in the mesh

     13:   Output Parameter:
     14: . dm  - The DM object representing the mesh

     16:   Level: beginner

     18: .seealso: DMPlexCreateFromFile(), DMPlexCreateGmsh(), DMPlexCreate()
     19: @*/
     20: PetscErrorCode DMPlexCreateGmshFromFile(MPI_Comm comm, const char filename[], PetscBool interpolate, DM *dm)
     21: {
     22:   PetscViewer     viewer, vheader;
     23:   PetscMPIInt     rank;
     24:   PetscViewerType vtype;
     25:   char            line[PETSC_MAX_PATH_LEN];
     26:   int             snum;
     27:   PetscBool       match;
     28:   int             fT;
     29:   PetscInt        fileType;
     30:   float           version;
     31:   PetscErrorCode  ierr;

     34:   MPI_Comm_rank(comm, &rank);
     35:   /* Determine Gmsh file type (ASCII or binary) from file header */
     36:   PetscViewerCreate(comm, &vheader);
     37:   PetscViewerSetType(vheader, PETSCVIEWERASCII);
     38:   PetscViewerFileSetMode(vheader, FILE_MODE_READ);
     39:   PetscViewerFileSetName(vheader, filename);
     40:   if (!rank) {
     41:     /* Read only the first two lines of the Gmsh file */
     42:     PetscViewerRead(vheader, line, 1, NULL, PETSC_STRING);
     43:     PetscStrncmp(line, "$MeshFormat", PETSC_MAX_PATH_LEN, &match);
     44:     if (!match) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Gmsh file");
     45:     PetscViewerRead(vheader, line, 2, NULL, PETSC_STRING);
     46:     snum = sscanf(line, "%f %d", &version, &fT);
     47:     fileType = (PetscInt) fT;
     48:     if (snum != 2) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unable to parse Gmsh file header: %s", line);
     49:     if (version < 2.0) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Gmsh file must be at least version 2.0");
     50:   }
     51:   MPI_Bcast(&fileType, 1, MPIU_INT, 0, comm);
     52:   /* Create appropriate viewer and build plex */
     53:   if (fileType == 0) vtype = PETSCVIEWERASCII;
     54:   else vtype = PETSCVIEWERBINARY;
     55:   PetscViewerCreate(comm, &viewer);
     56:   PetscViewerSetType(viewer, vtype);
     57:   PetscViewerFileSetMode(viewer, FILE_MODE_READ);
     58:   PetscViewerFileSetName(viewer, filename);
     59:   DMPlexCreateGmsh(comm, viewer, interpolate, dm);
     60:   PetscViewerDestroy(&viewer);
     61:   PetscViewerDestroy(&vheader);
     62:   return(0);
     63: }

     68: /*@
     69:   DMPlexCreateGmsh - Create a DMPlex mesh from a Gmsh file viewer

     71:   Collective on comm

     73:   Input Parameters:
     74: + comm  - The MPI communicator
     75: . viewer - The Viewer associated with a Gmsh file
     76: - interpolate - Create faces and edges in the mesh

     78:   Output Parameter:
     79: . dm  - The DM object representing the mesh

     81:   Note: http://www.geuz.org/gmsh/doc/texinfo/#MSH-ASCII-file-format
     82:   and http://www.geuz.org/gmsh/doc/texinfo/#MSH-binary-file-format

     84:   Level: beginner

     86: .keywords: mesh,Gmsh
     87: .seealso: DMPLEX, DMCreate()
     88: @*/
     89: PetscErrorCode DMPlexCreateGmsh(MPI_Comm comm, PetscViewer viewer, PetscBool interpolate, DM *dm)
     90: {
     91:   PetscViewerType vtype;
     92:   GmshElement   *gmsh_elem;
     93:   PetscSection   coordSection;
     94:   Vec            coordinates;
     95:   PetscScalar   *coords, *coordsIn = NULL;
     96:   PetscInt       dim = 0, coordSize, c, v, d, cell;
     97:   int            i, numVertices = 0, numCells = 0, trueNumCells = 0, snum;
     98:   PetscMPIInt    num_proc, rank;
     99:   char           line[PETSC_MAX_PATH_LEN];
    100:   PetscBool      match, binary, bswap = PETSC_FALSE;

    104:   MPI_Comm_rank(comm, &rank);
    105:   MPI_Comm_size(comm, &num_proc);
    106:   DMCreate(comm, dm);
    107:   DMSetType(*dm, DMPLEX);
    108:   PetscLogEventBegin(DMPLEX_CreateGmsh,*dm,0,0,0);
    109:   PetscViewerGetType(viewer, &vtype);
    110:   PetscStrcmp(vtype, PETSCVIEWERBINARY, &binary);
    111:   if (!rank || binary) {
    112:     PetscBool match;
    113:     int       fileType, dataSize;
    114:     float     version;

    116:     /* Read header */
    117:     PetscViewerRead(viewer, line, 1, NULL, PETSC_STRING);
    118:     PetscStrncmp(line, "$MeshFormat", PETSC_MAX_PATH_LEN, &match);
    119:     if (!match) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Gmsh file");
    120:     PetscViewerRead(viewer, line, 3, NULL, PETSC_STRING);
    121:     snum = sscanf(line, "%f %d %d", &version, &fileType, &dataSize);
    122:     if (snum != 3) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unable to parse Gmsh file header: %s", line);
    123:     if (version < 2.0) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Gmsh file must be at least version 2.0");
    124:     if (dataSize != sizeof(double)) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Data size %d is not valid for a Gmsh file", dataSize);
    125:     if (binary) {
    126:       int checkInt;
    127:       PetscViewerRead(viewer, &checkInt, 1, NULL, PETSC_ENUM);
    128:       if (checkInt != 1) {
    129:         PetscByteSwap(&checkInt, PETSC_ENUM, 1);
    130:         if (checkInt == 1) bswap = PETSC_TRUE;
    131:         else SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File type %d is not a valid Gmsh binary file", fileType);
    132:       }
    133:     } else if (fileType) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File type %d is not a valid Gmsh ASCII file", fileType);
    134:     PetscViewerRead(viewer, line, 1, NULL, PETSC_STRING);
    135:     PetscStrncmp(line, "$EndMeshFormat", PETSC_MAX_PATH_LEN, &match);
    136:     if (!match) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Gmsh file");
    137:     /* Read vertices */
    138:     PetscViewerRead(viewer, line, 1, NULL, PETSC_STRING);
    139:     PetscStrncmp(line, "$Nodes", PETSC_MAX_PATH_LEN, &match);
    140:     if (!match) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Gmsh file");
    141:     PetscViewerRead(viewer, line, 1, NULL, PETSC_STRING);
    142:     snum = sscanf(line, "%d", &numVertices);
    143:     if (snum != 1) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Gmsh file");
    144:     PetscMalloc1(numVertices*3, &coordsIn);
    145:     if (binary) {
    146:       size_t doubleSize, intSize;
    147:       PetscInt elementSize;
    148:       char *buffer;
    149:       PetscScalar *baseptr;
    150:       PetscDataTypeGetSize(PETSC_ENUM, &intSize);
    151:       PetscDataTypeGetSize(PETSC_DOUBLE, &doubleSize);
    152:       elementSize = (intSize + 3*doubleSize);
    153:       PetscMalloc1(elementSize*numVertices, &buffer);
    154:       PetscViewerRead(viewer, buffer, elementSize*numVertices, NULL, PETSC_CHAR);
    155:       if (bswap) PetscByteSwap(buffer, PETSC_CHAR, elementSize*numVertices);
    156:       for (v = 0; v < numVertices; ++v) {
    157:         baseptr = ((PetscScalar*)(buffer+v*elementSize+intSize));
    158:         coordsIn[v*3+0] = baseptr[0];
    159:         coordsIn[v*3+1] = baseptr[1];
    160:         coordsIn[v*3+2] = baseptr[2];
    161:       }
    162:       PetscFree(buffer);
    163:     } else {
    164:       for (v = 0; v < numVertices; ++v) {
    165:         PetscViewerRead(viewer, &i, 1, NULL, PETSC_ENUM);
    166:         PetscViewerRead(viewer, &(coordsIn[v*3]), 3, NULL, PETSC_DOUBLE);
    167:         if (i != (int)v+1) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid node number %d should be %d", i, v+1);
    168:       }
    169:     }
    170:     PetscViewerRead(viewer, line, 1, NULL, PETSC_STRING);;
    171:     PetscStrncmp(line, "$EndNodes", PETSC_MAX_PATH_LEN, &match);
    172:     if (!match) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Gmsh file");
    173:     /* Read cells */
    174:     PetscViewerRead(viewer, line, 1, NULL, PETSC_STRING);;
    175:     PetscStrncmp(line, "$Elements", PETSC_MAX_PATH_LEN, &match);
    176:     if (!match) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Gmsh file");
    177:     PetscViewerRead(viewer, line, 1, NULL, PETSC_STRING);;
    178:     snum = sscanf(line, "%d", &numCells);
    179:     if (snum != 1) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Gmsh file");
    180:   }

    182:   if (!rank || binary) {
    183:     /* Gmsh elements can be of any dimension/co-dimension, so we need to traverse the
    184:        file contents multiple times to figure out the true number of cells and facets
    185:        in the given mesh. To make this more efficient we read the file contents only
    186:        once and store them in memory, while determining the true number of cells. */
    187:     DMPlexCreateGmsh_ReadElement(viewer, numCells, binary, bswap, &gmsh_elem);
    188:     for (trueNumCells=0, c = 0; c < numCells; ++c) {
    189:       if (gmsh_elem[c].dim > dim) {dim = gmsh_elem[c].dim; trueNumCells = 0;}
    190:       if (gmsh_elem[c].dim == dim) trueNumCells++;
    191:     }
    192:     PetscViewerRead(viewer, line, 1, NULL, PETSC_STRING);;
    193:     PetscStrncmp(line, "$EndElements", PETSC_MAX_PATH_LEN, &match);
    194:     if (!match) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Gmsh file");
    195:   }
    196:   /* For binary we read on all ranks, but only build the plex on rank 0 */
    197:   if (binary && rank) {trueNumCells = 0; numVertices = 0;};
    198:   /* Allocate the cell-vertex mesh */
    199:   DMPlexSetChart(*dm, 0, trueNumCells+numVertices);
    200:   if (!rank) {
    201:     for (cell = 0, c = 0; c < numCells; ++c) {
    202:       if (gmsh_elem[c].dim == dim) {
    203:         DMPlexSetConeSize(*dm, cell, gmsh_elem[c].numNodes);
    204:         cell++;
    205:       }
    206:     }
    207:   }
    208:   DMSetUp(*dm);
    209:   /* Add cell-vertex connections */
    210:   if (!rank) {
    211:     PetscInt pcone[8], corner;
    212:     for (cell = 0, c = 0; c < numCells; ++c) {
    213:       if (gmsh_elem[c].dim == dim) {
    214:         for (corner = 0; corner < gmsh_elem[c].numNodes; ++corner) {
    215:           pcone[corner] = gmsh_elem[c].nodes[corner] + trueNumCells-1;
    216:         }
    217:         DMPlexSetCone(*dm, cell, pcone);
    218:         cell++;
    219:       }
    220:     }
    221:   }
    222:   MPI_Bcast(&dim, 1, MPIU_INT, 0, comm);
    223:   DMSetDimension(*dm, dim);
    224:   DMPlexSymmetrize(*dm);
    225:   DMPlexStratify(*dm);
    226:   if (interpolate) {
    227:     DM idm = NULL;

    229:     DMPlexInterpolate(*dm, &idm);
    230:     DMDestroy(dm);
    231:     *dm  = idm;
    232:   }

    234:   if (!rank) {
    235:     /* Apply boundary IDs by finding the relevant facets with vertex joins */
    236:     PetscInt pcone[8], corner, vStart, vEnd;

    238:     DMPlexGetDepthStratum(*dm, 0, &vStart, &vEnd);
    239:     for (c = 0; c < numCells; ++c) {
    240:       if (gmsh_elem[c].dim == dim-1) {
    241:         PetscInt joinSize;
    242:         const PetscInt *join;
    243:         for (corner = 0; corner < gmsh_elem[c].numNodes; ++corner) {
    244:           pcone[corner] = gmsh_elem[c].nodes[corner] + vStart - 1;
    245:         }
    246:         DMPlexGetFullJoin(*dm, gmsh_elem[c].numNodes, (const PetscInt *) pcone, &joinSize, &join);
    247:         if (joinSize != 1) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not determine Plex facet for element %d", gmsh_elem[c].id);
    248:         DMPlexSetLabelValue(*dm, "Face Sets", join[0], gmsh_elem[c].tags[0]);
    249:         DMPlexRestoreJoin(*dm, gmsh_elem[c].numNodes, (const PetscInt *) pcone, &joinSize, &join);
    250:       }
    251:     }
    252:   }

    254:   /* Read coordinates */
    255:   DMGetCoordinateSection(*dm, &coordSection);
    256:   PetscSectionSetNumFields(coordSection, 1);
    257:   PetscSectionSetFieldComponents(coordSection, 0, dim);
    258:   PetscSectionSetChart(coordSection, trueNumCells, trueNumCells + numVertices);
    259:   for (v = trueNumCells; v < trueNumCells+numVertices; ++v) {
    260:     PetscSectionSetDof(coordSection, v, dim);
    261:     PetscSectionSetFieldDof(coordSection, v, 0, dim);
    262:   }
    263:   PetscSectionSetUp(coordSection);
    264:   PetscSectionGetStorageSize(coordSection, &coordSize);
    265:   VecCreate(comm, &coordinates);
    266:   PetscObjectSetName((PetscObject) coordinates, "coordinates");
    267:   VecSetSizes(coordinates, coordSize, PETSC_DETERMINE);
    268:   VecSetType(coordinates, VECSTANDARD);
    269:   VecGetArray(coordinates, &coords);
    270:   if (!rank) {
    271:     for (v = 0; v < numVertices; ++v) {
    272:       for (d = 0; d < dim; ++d) {
    273:         coords[v*dim+d] = coordsIn[v*3+d];
    274:       }
    275:     }
    276:   }
    277:   VecRestoreArray(coordinates, &coords);
    278:   PetscFree(coordsIn);
    279:   DMSetCoordinatesLocal(*dm, coordinates);
    280:   VecDestroy(&coordinates);
    281:   /* Clean up intermediate storage */
    282:   if (!rank || binary) PetscFree(gmsh_elem);
    283:   PetscLogEventEnd(DMPLEX_CreateGmsh,*dm,0,0,0);
    284:   return(0);
    285: }

    289: PetscErrorCode DMPlexCreateGmsh_ReadElement(PetscViewer viewer, PetscInt numCells, PetscBool binary, PetscBool byteSwap, GmshElement **gmsh_elems)
    290: {
    291:   PetscInt       c, p;
    292:   GmshElement   *elements;
    293:   int            i, cellType, dim, numNodes, numElem, numTags;
    294:   int            ibuf[16];

    298:   PetscMalloc1(numCells, &elements);
    299:   for (c = 0; c < numCells;) {
    300:     PetscViewerRead(viewer, &ibuf, 3, NULL, PETSC_ENUM);
    301:     if (byteSwap) PetscByteSwap(&ibuf, PETSC_ENUM, 3);
    302:     if (binary) {
    303:       cellType = ibuf[0];
    304:       numElem = ibuf[1];
    305:       numTags = ibuf[2];
    306:     } else {
    307:       elements[c].id = ibuf[0];
    308:       cellType = ibuf[1];
    309:       numTags = ibuf[2];
    310:       numElem = 1;
    311:     }
    312:     switch (cellType) {
    313:     case 1: /* 2-node line */
    314:       dim = 1;
    315:       numNodes = 2;
    316:       break;
    317:     case 2: /* 3-node triangle */
    318:       dim = 2;
    319:       numNodes = 3;
    320:       break;
    321:     case 3: /* 4-node quadrangle */
    322:       dim = 2;
    323:       numNodes = 4;
    324:       break;
    325:     case 4: /* 4-node tetrahedron */
    326:       dim  = 3;
    327:       numNodes = 4;
    328:       break;
    329:     case 5: /* 8-node hexahedron */
    330:       dim = 3;
    331:       numNodes = 8;
    332:       break;
    333:     case 15: /* 1-node vertex */
    334:       dim = 0;
    335:       numNodes = 1;
    336:       break;
    337:     default:
    338:       SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unsupported Gmsh element type %d", cellType);
    339:     }
    340:     if (binary) {
    341:       const PetscInt nint = numNodes + numTags + 1;
    342:       for (i = 0; i < numElem; ++i, ++c) {
    343:         /* Loop over inner binary element block */
    344:         elements[c].dim = dim;
    345:         elements[c].numNodes = numNodes;
    346:         elements[c].numTags = numTags;

    348:         PetscViewerRead(viewer, &ibuf, nint, NULL, PETSC_ENUM);
    349:         if (byteSwap) PetscByteSwap( &ibuf, PETSC_ENUM, nint);
    350:         elements[c].id = ibuf[0];
    351:         for (p = 0; p < numTags; p++) elements[c].tags[p] = ibuf[1 + p];
    352:         for (p = 0; p < numNodes; p++) elements[c].nodes[p] = ibuf[1 + numTags + p];
    353:       }
    354:     } else {
    355:       elements[c].dim = dim;
    356:       elements[c].numNodes = numNodes;
    357:       elements[c].numTags = numTags;
    358:       PetscViewerRead(viewer, elements[c].tags, elements[c].numTags, NULL, PETSC_ENUM);
    359:       PetscViewerRead(viewer, elements[c].nodes, elements[c].numNodes, NULL, PETSC_ENUM);
    360:       c++;
    361:     }
    362:   }
    363:   *gmsh_elems = elements;
    364:   return(0);
    365: }