xref: /petsc/src/dm/impls/plex/plexgmsh.c (revision aaa7dc30da3270cff6cb10b1db605b2ca746f216)
1 #define PETSCDM_DLL
2 #include <petsc-private/dmpleximpl.h>    /*I   "petscdmplex.h"   I*/
3 
4 #undef __FUNCT__
5 #define __FUNCT__ "DMPlexCreateGmsh"
6 /*@
7   DMPlexCreateGmsh - Create a DMPlex mesh from a Gmsh file.
8 
9   Collective on comm
10 
11   Input Parameters:
12 + comm  - The MPI communicator
13 . viewer - The Viewer associated with a Gmsh file
14 - interpolate - Create faces and edges in the mesh
15 
16   Output Parameter:
17 . dm  - The DM object representing the mesh
18 
19   Note: http://www.geuz.org/gmsh/doc/texinfo/#MSH-ASCII-file-format
20 
21   Level: beginner
22 
23 .keywords: mesh,Gmsh
24 .seealso: DMPLEX, DMCreate()
25 @*/
26 PetscErrorCode DMPlexCreateGmsh(MPI_Comm comm, PetscViewer viewer, PetscBool interpolate, DM *dm)
27 {
28   FILE          *fd;
29   PetscSection   coordSection;
30   Vec            coordinates;
31   PetscScalar   *coords, *coordsIn = NULL;
32   PetscInt       dim = 0, coordSize, c, v, d;
33   int            numVertices = 0, numCells = 0, snum;
34   long           fpos = 0;
35   PetscMPIInt    num_proc, rank;
36   char           line[PETSC_MAX_PATH_LEN];
37   PetscBool      match;
38   PetscErrorCode ierr;
39 
40   PetscFunctionBegin;
41   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
42   ierr = MPI_Comm_size(comm, &num_proc);CHKERRQ(ierr);
43   ierr = DMCreate(comm, dm);CHKERRQ(ierr);
44   ierr = DMSetType(*dm, DMPLEX);CHKERRQ(ierr);
45   if (!rank) {
46     PetscBool match;
47     int       fileType, dataSize;
48 
49     ierr = PetscViewerASCIIGetPointer(viewer, &fd);CHKERRQ(ierr);
50     /* Read header */
51     fgets(line, PETSC_MAX_PATH_LEN, fd);
52     ierr = PetscStrncmp(line, "$MeshFormat\n", PETSC_MAX_PATH_LEN, &match);CHKERRQ(ierr);
53     if (!match) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Gmsh file");
54     snum = fscanf(fd, "2.2 %d %d\n", &fileType, &dataSize);CHKERRQ(snum != 2);
55     if (fileType) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File type %d is not a valid Gmsh ASCII file", fileType);
56     if (dataSize != sizeof(double)) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Data size %d is not valid for a Gmsh file", dataSize);
57     fgets(line, PETSC_MAX_PATH_LEN, fd);
58     ierr = PetscStrncmp(line, "$EndMeshFormat\n", PETSC_MAX_PATH_LEN, &match);CHKERRQ(ierr);
59     if (!match) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Gmsh file");
60     /* Read vertices */
61     fgets(line, PETSC_MAX_PATH_LEN, fd);
62     ierr = PetscStrncmp(line, "$Nodes\n", PETSC_MAX_PATH_LEN, &match);CHKERRQ(ierr);
63     if (!match) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Gmsh file");
64     snum = fscanf(fd, "%d\n", &numVertices);CHKERRQ(snum != 1);
65     ierr = PetscMalloc(numVertices*3 * sizeof(PetscScalar), &coordsIn);CHKERRQ(ierr);
66     for (v = 0; v < numVertices; ++v) {
67       double x, y, z;
68       int    i;
69 
70       snum = fscanf(fd, "%d %lg %lg %lg\n", &i, &x, &y, &z);CHKERRQ(snum != 4);
71       coordsIn[v*3+0] = x; coordsIn[v*3+1] = y; coordsIn[v*3+2] = z;
72       if (i != v+1) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid node number %d should be %d", i, v+1);
73     }
74     fgets(line, PETSC_MAX_PATH_LEN, fd);
75     ierr = PetscStrncmp(line, "$EndNodes\n", PETSC_MAX_PATH_LEN, &match);CHKERRQ(ierr);
76     if (!match) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Gmsh file");
77     /* Read cells */
78     fgets(line, PETSC_MAX_PATH_LEN, fd);
79     ierr = PetscStrncmp(line, "$Elements\n", PETSC_MAX_PATH_LEN, &match);CHKERRQ(ierr);
80     if (!match) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Gmsh file");
81     snum = fscanf(fd, "%d\n", &numCells);CHKERRQ(snum != 1);
82   }
83   ierr = DMPlexSetChart(*dm, 0, numCells+numVertices);CHKERRQ(ierr);
84   if (!rank) {
85     fpos = ftell(fd);
86     for (c = 0; c < numCells; ++c) {
87       PetscInt numCorners, t;
88       int      cone[8], i, cellType, numTags, tag;
89 
90       snum = fscanf(fd, "%d %d %d", &i, &cellType, &numTags);CHKERRQ(snum != 3);
91       if (numTags) for (t = 0; t < numTags; ++t) {snum = fscanf(fd, "%d", &tag);CHKERRQ(snum != 1);}
92       switch (cellType) {
93       case 1: /* 2-node line */
94         dim = 1;
95         numCorners = 2;
96         snum = fscanf(fd, "%d %d\n", &cone[0], &cone[1]);CHKERRQ(snum != numCorners);
97         break;
98       case 2: /* 3-node triangle */
99         dim = 2;
100         numCorners = 3;
101         snum = fscanf(fd, "%d %d %d\n", &cone[0], &cone[1], &cone[2]);CHKERRQ(snum != numCorners);
102         break;
103       case 3: /* 4-node quadrangle */
104         dim = 2;
105         numCorners = 4;
106         snum = fscanf(fd, "%d %d %d %d\n", &cone[0], &cone[1], &cone[2], &cone[3]);CHKERRQ(snum != numCorners);
107         break;
108       case 4: /* 4-node tetrahedron */
109         dim  = 3;
110         numCorners = 4;
111         snum = fscanf(fd, "%d %d %d %d\n", &cone[0], &cone[1], &cone[2], &cone[3]);CHKERRQ(snum != numCorners);
112         break;
113       case 5: /* 8-node hexahedron */
114         dim = 3;
115         numCorners = 8;
116         snum = fscanf(fd, "%d %d %d %d %d %d %d %d\n", &cone[0], &cone[1], &cone[2], &cone[3], &cone[4], &cone[5], &cone[6], &cone[7]);CHKERRQ(snum != numCorners);
117         break;
118       default:
119         SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unsupported Gmsh element type %d", cellType);
120       }
121       ierr = DMPlexSetConeSize(*dm, c, numCorners);CHKERRQ(ierr);
122       if (i != c+1) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid cell number %d should be %d", i, c+1);
123     }
124   }
125   ierr = DMSetUp(*dm);CHKERRQ(ierr);
126   if (!rank) {
127     ierr = fseek(fd, fpos, SEEK_SET);CHKERRQ(ierr);
128     for (c = 0; c < numCells; ++c) {
129       PetscInt pcone[8], numCorners, corner, t;
130       int      cone[8], i, cellType, numTags, tag;
131 
132       snum = fscanf(fd, "%d %d %d", &i, &cellType, &numTags);CHKERRQ(snum != 3);
133       if (numTags) for (t = 0; t < numTags; ++t) {snum = fscanf(fd, "%d", &tag);CHKERRQ(snum != 1);}
134       switch (cellType) {
135       case 1: /* 2-node line */
136         dim = 1;
137         numCorners = 2;
138         snum = fscanf(fd, "%d %d\n", &cone[0], &cone[1]);CHKERRQ(snum != numCorners);
139         break;
140       case 2: /* 3-node triangle */
141         dim = 2;
142         numCorners = 3;
143         snum = fscanf(fd, "%d %d %d\n", &cone[0], &cone[1], &cone[2]);CHKERRQ(snum != numCorners);
144         break;
145       case 3: /* 4-node quadrangle */
146         dim = 2;
147         numCorners = 4;
148         snum = fscanf(fd, "%d %d %d %d\n", &cone[0], &cone[1], &cone[2], &cone[3]);CHKERRQ(snum != numCorners);
149         break;
150       case 4: /* 4-node tetrahedron */
151         dim  = 3;
152         numCorners = 4;
153         snum = fscanf(fd, "%d %d %d %d\n", &cone[0], &cone[1], &cone[2], &cone[3]);CHKERRQ(snum != numCorners);
154         ierr = DMPlexInvertCell(dim, numCorners, cone);CHKERRQ(ierr);
155         break;
156       case 5: /* 8-node hexahedron */
157         dim = 3;
158         numCorners = 8;
159         snum = fscanf(fd, "%d %d %d %d %d %d %d %d\n", &cone[0], &cone[1], &cone[2], &cone[3], &cone[4], &cone[5], &cone[6], &cone[7]);CHKERRQ(snum != numCorners);
160         ierr = DMPlexInvertCell(dim, numCorners, cone);CHKERRQ(ierr);
161         break;
162       default:
163         SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unsupported Gmsh element type %d", cellType);
164       }
165       for (corner = 0; corner < numCorners; ++corner) pcone[corner] = cone[corner] + numCells-1;
166       ierr = DMPlexSetCone(*dm, c, pcone);CHKERRQ(ierr);
167       if (i != c+1) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid cell number %d should be %d", i, c+1);
168     }
169     fgets(line, PETSC_MAX_PATH_LEN, fd);
170     ierr = PetscStrncmp(line, "$EndElements\n", PETSC_MAX_PATH_LEN, &match);CHKERRQ(ierr);
171     if (!match) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "File is not a valid Gmsh file");
172   }
173   ierr = MPI_Bcast(&dim, 1, MPIU_INT, 0, comm);CHKERRQ(ierr);
174   ierr = DMPlexSetDimension(*dm, dim);CHKERRQ(ierr);
175   ierr = DMPlexSymmetrize(*dm);CHKERRQ(ierr);
176   ierr = DMPlexStratify(*dm);CHKERRQ(ierr);
177   if (interpolate) {
178     DM idm;
179 
180     ierr = DMPlexInterpolate(*dm, &idm);CHKERRQ(ierr);
181     ierr = DMDestroy(dm);CHKERRQ(ierr);
182     *dm  = idm;
183   }
184   /* Read coordinates */
185   ierr = DMGetCoordinateSection(*dm, &coordSection);CHKERRQ(ierr);
186   ierr = PetscSectionSetNumFields(coordSection, 1);CHKERRQ(ierr);
187   ierr = PetscSectionSetFieldComponents(coordSection, 0, dim);CHKERRQ(ierr);
188   ierr = PetscSectionSetChart(coordSection, numCells, numCells + numVertices);CHKERRQ(ierr);
189   for (v = numCells; v < numCells+numVertices; ++v) {
190     ierr = PetscSectionSetDof(coordSection, v, dim);CHKERRQ(ierr);
191     ierr = PetscSectionSetFieldDof(coordSection, v, 0, dim);CHKERRQ(ierr);
192   }
193   ierr = PetscSectionSetUp(coordSection);CHKERRQ(ierr);
194   ierr = PetscSectionGetStorageSize(coordSection, &coordSize);CHKERRQ(ierr);
195   ierr = VecCreate(comm, &coordinates);CHKERRQ(ierr);
196   ierr = PetscObjectSetName((PetscObject) coordinates, "coordinates");CHKERRQ(ierr);
197   ierr = VecSetSizes(coordinates, coordSize, PETSC_DETERMINE);CHKERRQ(ierr);
198   ierr = VecSetType(coordinates, VECSTANDARD);CHKERRQ(ierr);
199   ierr = VecGetArray(coordinates, &coords);CHKERRQ(ierr);
200   if (!rank) {
201     for (v = 0; v < numVertices; ++v) {
202       for (d = 0; d < dim; ++d) {
203         coords[v*dim+d] = coordsIn[v*3+d];
204       }
205     }
206   }
207   ierr = VecRestoreArray(coordinates, &coords);CHKERRQ(ierr);
208   ierr = PetscFree(coordsIn);CHKERRQ(ierr);
209   ierr = DMSetCoordinatesLocal(*dm, coordinates);CHKERRQ(ierr);
210   ierr = VecDestroy(&coordinates);CHKERRQ(ierr);
211   PetscFunctionReturn(0);
212 }
213