MFace_ptr MFs_Merge_R1R2(MFace_ptr f1, MFace_ptr f2, int topoflag) {
/* Faces are not explicit entities in reduced representations -
nothing to do */
MF_Delete(f2,0);
return f1;
}
MVertex_ptr ME_Collapse(MEdge_ptr e, MVertex_ptr vkeep_in, int topoflag,
List_ptr *deleted_entities) {
MVertex_ptr vdel, vkeep, ev00, ev01, ev10, ev11, vert;
MEdge_ptr edge, edge2, oldedges[3], nuedges[2];
MFace_ptr face, face2, rface1, rface2;
MRegion_ptr reg, reg2;
List_ptr vedges, efaces, eregs, fedges, rfaces, fverts1, fverts2, vfaces;
int idx1, idx2, idx3, dir, status, nfe, nrf, allfound, degenerate;
int i, j, nfe2, nfv1, nfv2;
status = 1;
if (vkeep_in == NULL) {
vdel = ME_Vertex(e,0);
vkeep = ME_Vertex(e,1);
}
else {
vkeep = vkeep_in;
vdel = ME_OppVertex(e,vkeep);
}
int dimkeep, dimdel;
dimkeep = MV_GEntDim(vkeep); /* Model entity dim of vertex to keep */
dimdel = MV_GEntDim(vdel); /* Model entity dim of vertex to delete */
if (topoflag == 1) {
if (dimkeep == dimdel) {
if (MV_GEntID(vkeep) != MV_GEntID(vdel))
status = 0; /* cannot allow since it will cause
a dimensional reduction in mesh */
}
else if (dimdel < dimkeep) {
if (vkeep_in == NULL) {
/* If no preference was indicated on which vertex to retain,
we can collapse in the other direction */
MVertex_ptr vtemp = vdel;
vdel = vkeep;
vkeep = vtemp;
}
else
status = 0; /* can't reverse order or vertices and boundary of
mesh will get messed up if we go through as is */
}
}
else if (vkeep_in == NULL) {
/* If no preference was indicated for the kept vertex and
topological conformity with the underlying geometric model was
not requested, we prefer to keep an external boundary vertex
over an interior vertex or interior boundary vertex. This is
because it is more likely that the external boundary vertex
would have a boundary condition applied to it. If a preference
was indicated, we just have to respect that. */
int vdel_external = 0;
/* Check if any edges connected to vdel have only one connected face */
vedges = MV_Edges(vdel);
idx1 = 0;
while ((edge = (MEdge_ptr) List_Next_Entry(vedges,&idx1))) {
List_ptr efaces = ME_Faces(edge);
int nef = List_Num_Entries(efaces);
List_Delete(efaces);
if (nef < 2) {
vdel_external = 1;
break;
}
}
List_Delete(vedges);
/* check if any face connected to vdel has only one region
connected to it */
if (!vdel_external) {
vfaces = MV_Faces(vdel);
idx1 = 0;
while ((face = (MFace_ptr) List_Next_Entry(vfaces,&idx1))) {
List_ptr fregs = MF_Regions(face);
int nfr = fregs ? List_Num_Entries(fregs) : 0;
if (fregs) List_Delete(fregs);
if (nfr == 1) {
vdel_external = 0;
break;
}
}
List_Delete(vfaces);
}
if (vdel_external) {
/* swap the vertices in the hope that vkeep is not also on an
external boundary. Since we have to go through with the
collapse anyway, there is no use of doing a detailed check
for whether vkeep is also on an external boundary */
MVertex_ptr vtemp = vdel;
vdel = vkeep;
vkeep = vtemp;
}
}
if (status == 0)
return NULL; /* Cannot collapse due to constraints of topological
conformity with geometric model */
*deleted_entities = List_New(10);
/* Need to collect this in advance because the info gets messed up later */
efaces = ME_Faces(e);
eregs = ME_Regions(e);
/* Replace vdel with vkeep in all edges connected to vdel */
vedges = MV_Edges(vdel);
idx1 = 0;
while ((edge = List_Next_Entry(vedges,&idx1))) {
ME_Replace_Vertex(edge,vdel,vkeep);
}
List_Delete(vedges);
/* Remove edge 'e' from all faces connected to e */
/* This part of the code is using some reliance on the internal
implementation of MF_Edges. While unlikely, it _might_ break if
the innards of MF_Edges are changed */
idx1 = 0;
while ((face = List_Next_Entry(efaces,&idx1))) {
fedges = MF_Edges(face,1,0);
nfe = List_Num_Entries(fedges);
/* Find the edge before and after e in the face */
oldedges[0] = oldedges[2] = NULL;
for (i = 0; i < nfe; i++) {
edge = List_Entry(fedges,i);
if (edge == e) continue;
dir = MF_EdgeDir_i(face,i);
if (ME_Vertex(edge,dir) == vkeep)
oldedges[0] = edge;
else if (ME_Vertex(edge,!dir) == vkeep)
oldedges[2] = edge;
}
oldedges[1] = e;
nuedges[0] = oldedges[0];
nuedges[1] = oldedges[2];
/* Replace oldedges[0], oldedges[1] (=e), oldedges[2] with
oldedges[0], oldedges[2] since e is degenerate */
MF_Replace_Edges(face,3,oldedges,2,nuedges);
List_Delete(fedges);
}
/* Delete topologically degenerate regions */
/* Defined as two faces of the regions having the same vertices */
if (eregs) {
idx1 = 0;
while ((reg = List_Next_Entry(eregs,&idx1))) {
rfaces = MR_Faces(reg);
nrf = List_Num_Entries(rfaces);
if (nrf == 4) {
List_ptr rverts = MR_Vertices(reg);
if (List_Num_Entries(rverts) == 4) {
MR_Delete(reg,0); /* This is a tet - it will become degenerate */
}
List_Delete(rverts);
}
else {
degenerate = 0;
for (i = 0; i < nrf; i++) {
rface1 = List_Entry(rfaces,i);
fverts1 = MF_Vertices(rface1,1,0);
nfv1 = List_Num_Entries(fverts1);
for (j = i+1; j < nrf; j++) {
rface2 = List_Entry(rfaces,j);
fverts2 = MF_Vertices(rface2,1,0);
nfv2 = List_Num_Entries(fverts2);
if (nfv1 != nfv2) {
List_Delete(fverts2);
continue; /* can't be exactly coincident */
}
allfound = 1;
idx2 = 0;
while ((vert = List_Next_Entry(fverts2,&idx2))) {
if (!List_Contains(fverts1,vert)) {
allfound = 0;
break;
}
}
List_Delete(fverts2);
if (allfound) {
degenerate = 1;
break;
}
} /* for (j = i+1 ... */
List_Delete(fverts1);
if (degenerate) break;
} /* for (i = 0; i < nrf;.... */
if (degenerate) {
List_Add(*deleted_entities,reg);
MR_Delete(reg,0);
}
} /* if (nrf == 4) .. else ... */
List_Delete(rfaces);
} /* while ((reg = ...)) */
}
/* Delete topologically degenerate faces */
if (efaces) {
idx1 = 0;
while ((face = List_Next_Entry(efaces,&idx1))) {
fedges = MF_Edges(face,1,0);
if (List_Num_Entries(fedges) == 2) {
/* Disconnect the regions from the face before deleting */
List_ptr fregs = MF_Regions(face);
if (fregs) {
idx2 = 0;
while ((reg = List_Next_Entry(fregs,&idx2)))
MR_Rem_Face(reg,face);
List_Delete(fregs);
}
List_Add(*deleted_entities,face);
MF_Delete(face,0);
}
List_Delete(fedges);
}
List_Delete(efaces);
}
/* Now merge edges which have the same end vertices */
/* Prefer to preserve edges on external boundaries over internal edges */
vedges = MV_Edges(vkeep);
idx1 = 0;
while ((edge = List_Next_Entry(vedges,&idx1))) {
if (edge == e) continue;
ev00 = ME_Vertex(edge,0);
ev01 = ME_Vertex(edge,1);
idx2 = 0;
while ((edge2 = List_Next_Entry(vedges,&idx2))) {
if (edge == e || edge == edge2) continue;
ev10 = ME_Vertex(edge2,0);
ev11 = ME_Vertex(edge2,1);
if ((ev00 == ev10 && ev01 == ev11) ||
(ev00 == ev11 && ev10 == ev01)) {
int external_edge, external_edge2;
int edim = 4;
external_edge = 0;
edim = ME_GEntDim(edge);
if (edim == 1 || edim == 2 || edim == 4) { /* check if external edge */
efaces = ME_Faces(edge);
int nef = List_Num_Entries(efaces);
if (nef == 1) {
external_edge = 1;
}
else {
idx3 = 0;
while ((face = List_Next_Entry(efaces,&idx2))) {
List_ptr fregs = MF_Regions(face);
int nfr = fregs ? List_Num_Entries(fregs) : 0;
if (fregs) List_Delete(fregs);
if (nfr == 1) {
external_edge = 1;
break;
}
}
}
List_Delete(efaces);
}
external_edge2 = 0;
edim = ME_GEntDim(edge2);
if (edim == 1 || edim == 2 || edim == 4) { /* check if external edge */
efaces = ME_Faces(edge2);
int nef = List_Num_Entries(efaces);
if (nef == 1) {
external_edge2 = 1;
}
else {
idx3 = 0;
while ((face = List_Next_Entry(efaces,&idx2))) {
List_ptr fregs = MF_Regions(face);
int nfr = fregs ? List_Num_Entries(fregs) : 0;
if (fregs) List_Delete(fregs);
if (nfr == 1) {
external_edge2 = 1;
break;
}
}
}
List_Delete(efaces);
}
/* If edge2 is not external or both edges are external, go
ahead and merge (edge2 will be deleted subject to
topological checks if topoflag is 1) */
if (!external_edge2 || (external_edge && external_edge2)) {
MEs_Merge(edge,edge2,topoflag);
List_Rem(vedges,edge2);
List_Add(*deleted_entities,edge2);
break;
}
}
}
}
List_Delete(vedges);
/* Merge faces with the same set of edges */
vfaces = MV_Faces(vkeep);
if (vfaces) {
idx1 = 0;
while ((face = List_Next_Entry(vfaces,&idx1))) {
fedges = MF_Edges(face,1,0);
nfe = List_Num_Entries(fedges);
idx2 = 0;
while ((face2 = List_Next_Entry(vfaces,&idx2))) {
List_ptr fedges2;
if (face2 == face) continue;
fedges2 = MF_Edges(face2,1,0);
nfe2 = List_Num_Entries(fedges2);
if (nfe != nfe2) {
List_Delete(fedges2);
continue;
}
allfound = 1;
for (i = 0; i < nfe2; i++) {
edge = List_Entry(fedges2,i);
if (!List_Contains(fedges,edge)) {
allfound = 0;
break;
}
}
List_Delete(fedges2);
if (allfound) {
List_ptr fregs = MF_Regions(face);
int external_face = fregs ? (List_Num_Entries(fregs) == 1) : 0;
if (fregs) List_Delete(fregs);
List_ptr fregs2 = MF_Regions(face2);
int external_face2 = fregs2 ? (List_Num_Entries(fregs2) == 1) : 0;
if (fregs2) List_Delete(fregs2);
/* Proceed with merge (which will delete face2) only if face2 is
not an external face or both face and face2 are external */
if (!external_face2 || (external_face && external_face2)) {
MFs_Merge(face,face2,topoflag);
List_Rem(vfaces,face2);
List_Add(*deleted_entities,face2);
break;
}
}
} /* while (face2 = List_Next_Entry(vfaces,... */
List_Delete(fedges);
} /* while (face = List_Next_Entry(vfaces,... */
List_Delete(vfaces);
}
/* Now actually delete the collapse edge and the to-be-merged vertex */
ME_Delete(e,0);
List_Add(*deleted_entities,e);
MV_Delete(vdel,0);
List_Add(*deleted_entities,vdel);
if (eregs) {
idx1 = 0;
while ((reg = List_Next_Entry(eregs,&idx1)))
MR_Update_ElementType(reg);
List_Delete(eregs);
}
return vkeep;
}
MVertex_ptr ME_Split_SimplexMesh(MEdge_ptr esplit, double *splitxyz) {
int i, j, k, rfdir, ntets=0, ntris=0, *fdim, *fid, *rid=NULL, found;
MVertex_ptr vsplit, ev[2], (*tetverts)[4]=NULL, (*triverts)[3]=NULL, fv;
MVertex_ptr fvarr[3], rvarr[4];
MFace_ptr f;
MRegion_ptr r;
List_ptr etets, rfaces, etris, fverts;
Mesh_ptr mesh = ME_Mesh(esplit);
ev[0] = ME_Vertex(esplit,0);
ev[1] = ME_Vertex(esplit,1);
etets = ME_Regions(esplit);
if (etets) {
ntets = List_Num_Entries(etets);
tetverts = (MVertex_ptr (*)[4]) malloc(ntets*sizeof(MVertex_ptr [4]));
rid = (int *) malloc(ntets*sizeof(int));
}
for (i = 0; i < ntets; i++) {
r = List_Entry(etets,i);
rfaces = MR_Faces(r);
/* Find a tet face that uses ev[0] but not ev[1] */
found = 0;
for (j = 0; !found && j < 4; j++) {
f = List_Entry(rfaces,j);
fverts = MF_Vertices(f,1,0);
if (List_Contains(fverts,ev[0]) &&
!List_Contains(fverts,ev[1])) {
found = 1;
/* Get the two vertices (a,b) of this face excluding ev[0] in
such an order that ev[0],a,b,ev[1] will form a valid
tet. This requires checking whether the face points into or
out of this tet (look at rfdir) */
rfdir = MR_FaceDir_i(r,j);
for (k = 0; k < 3; k++) {
fv = List_Entry(fverts,k);
if (fv == ev[0]) {
tetverts[i][0] = ev[0];
tetverts[i][1] = rfdir ? List_Entry(fverts,(k+2)%3) : List_Entry(fverts,(k+1)%3);
tetverts[i][2] = rfdir ? List_Entry(fverts,(k+1)%3) : List_Entry(fverts,(k+2)%3);
tetverts[i][3] = ev[1];
}
}
}
List_Delete(fverts);
if (found) break;
}
List_Delete(rfaces);
}
/* Now that we finished collecting info about the connected tets we
can delete them */
if (etets) {
for (i = 0; i < ntets; i++)
MR_Delete(List_Entry(etets,i),0);
List_Delete(etets);
}
/* Now get the triangular face connected to the edge. For each
triangular face, record the vertex opposite to edge esplit and
delete the triangular face */
etris = ME_Faces(esplit);
if (etris) {
ntris = List_Num_Entries(etris);
triverts = (MVertex_ptr (*)[3]) malloc(ntris*sizeof(MVertex_ptr[3]));
fdim = (int *) malloc(ntris*sizeof(int));
fid = (int *) malloc(ntris*sizeof(int));
}
for (i = 0; i < ntris; i++) {
f = List_Entry(etris,i);
fverts = MF_Vertices(f,1,0);
for (j = 0; j < 3; j++) {
fv = List_Entry(fverts,j);
if (fv != ev[0] && fv != ev[1]) {
triverts[i][0] = fv;
triverts[i][1] = List_Entry(fverts,(j+1)%3);
triverts[i][2] = List_Entry(fverts,(j+2)%3);
fdim[i] = MF_GEntDim(f);
fid[i] = MF_GEntID(f);
break;
}
}
List_Delete(fverts);
MF_Delete(f,0);
}
if (etris) List_Delete(etris);
/* Now split the edge itself */
vsplit = ME_Split(esplit, splitxyz);
/* Now for each tri face that we deleted, create two tri faces that
incorporate the split vertex, one of the split edge vertices and
opposite vertex */
for (i = 0; i < ntris; i++) {
/* First triangle */
fvarr[0] = triverts[i][0];
fvarr[1] = triverts[i][1];
fvarr[2] = vsplit;
f = MF_New(mesh);
MF_Set_Vertices(f,3,fvarr);
MF_Set_GEntDim(f,fdim[i]);
MF_Set_GEntID(f,fid[i]);
/* Second triangle */
fvarr[0] = triverts[i][0];
fvarr[1] = vsplit;
fvarr[2] = triverts[i][2];
f = MF_New(mesh);
MF_Set_Vertices(f,3,fvarr);
MF_Set_GEntDim(f,fdim[i]);
MF_Set_GEntID(f,fid[i]);
}
if (ntris) {
free(triverts);
free(fdim);
free(fid);
}
/* Now for each tet that we deleted, create two tets (these will use
the split faces that are already created */
for (i = 0; i < ntets; i++) {
rvarr[0] = vsplit;
rvarr[1] = tetverts[i][2];
rvarr[2] = tetverts[i][1];
rvarr[3] = tetverts[i][0];
r = MR_New(mesh);
MR_Set_Vertices(r,4,rvarr,0,NULL);
MR_Set_GEntID(r,rid[i]);
rvarr[0] = vsplit;
rvarr[1] = tetverts[i][1];
rvarr[2] = tetverts[i][2];
rvarr[3] = tetverts[i][3];
r = MR_New(mesh);
MR_Set_Vertices(r,4,rvarr,0,NULL);
MR_Set_GEntID(r,rid[i]);
}
if (ntets) {
free(tetverts);
free(rid);
}
return vsplit;
}
MVertex_ptr MF_Split(MFace_ptr fsplit, double *splitxyz) {
Mesh_ptr mesh;
MVertex_ptr vsplit, fv[3];
MEdge_ptr enew, *fedges0, *fedges1, fe;
MFace_ptr fnew[MAXPV2];
MRegion_ptr fr;
int gid, gdim, i, j, idx, nnew;
int nfv, fnewdir[MAXPV2], rfdir;
List_ptr fregs, fverts;
gdim = MF_GEntDim(fsplit);
gid = MF_GEntID(fsplit);
/* Collect information */
mesh = MF_Mesh(fsplit);
/* Regions connected to face */
fregs = MF_Regions(fsplit);
/* Vertices of face */
fverts = MF_Vertices(fsplit,1,0);
nfv = List_Num_Entries(fverts);
/* Create the splitting vertex */
vsplit = MV_New(mesh);
MV_Set_Coords(vsplit,splitxyz);
MV_Set_GEntDim(vsplit,gdim);
MV_Set_GEntID(vsplit,gid);
/* Create the 'nfe' faces */
for (i = 0; i < nfv; i++) {
fv[0] = vsplit;
fv[1] = List_Entry(fverts,i);
fv[2] = List_Entry(fverts,(i+1)%nfv);
fnew[i] = MF_New(mesh);
MF_Set_GEntDim(fnew[i],gdim);
MF_Set_GEntID(fnew[i],gid);
MF_Set_Vertices(fnew[i],3,fv);
}
List_Delete(fverts);
nnew = nfv;
if (fregs) {
for (i = 0; i < List_Num_Entries(fregs); i++) {
fr = List_Entry(fregs,i);
rfdir = MR_FaceDir(fr,fsplit);
for (j = 0; j < nnew; j++)
fnewdir[j] = rfdir;
MR_Replace_Faces(fr,1,&fsplit,nnew,fnew,fnewdir);
}
List_Delete(fregs);
}
MF_Delete(fsplit,0);
return vsplit;
}
MRegion_ptr MRs_Join(MRegion_ptr r1, MRegion_ptr r2, MFace_ptr f) {
int i, j, nrf1, nrf2, gdim, gid, *rfdir2;
MFace_ptr *rf2, fcmn=f;
Mesh_ptr mesh;
List_ptr rfaces2;
mesh = MF_Mesh(r1);
gid = MF_GEntID(r1);
if (mesh != MF_Mesh(r2)) {
MSTK_Report("MRs_Join","Regions not from same mesh",MSTK_ERROR);
return 0;
}
else if (gid != MR_GEntID(r2)) {
MSTK_Report("MRs_Join","Regions not from same geometric entity",MSTK_ERROR);
return 0;
}
rfaces2 = MR_Faces(r2);
nrf2 = List_Num_Entries(rfaces2);
if (fcmn) {
if (!MR_UsesEntity(r1,fcmn,MFACE)) {
MSTK_Report("MRs_Join","Cannot find common face in region",MSTK_ERROR);
return 0;
}
}
else { /* find the common face */
List_ptr rfaces1 = MR_Faces(r1);
int idx = 0;
MFace_ptr rf;
while ((rf = List_Next_Entry(rfaces2,&idx))) {
if (List_Contains(rfaces1,rf)) {
fcmn = rf;
break;
}
}
List_Delete(rfaces1);
}
rf2 = (MFace_ptr) malloc(nrf2*sizeof(MFace_ptr));
rfdir2 = (int *) malloc(nrf2*sizeof(int));
int found;
for (i = 0, j = 0, found = 0; i < nrf2; i++) {
MFace_ptr rface = List_Entry(rfaces2,i);
if (rface == fcmn)
found = 1;
else {
rf2[j] = rface;
rfdir2[j] = MR_FaceDir_i(r2,i);
j++;
}
}
List_Delete(rfaces2);
if (!found) {
MSTK_Report("MRs_Join","Cannot find common face in region",MSTK_ERROR);
return 0;
}
MR_Delete(r2,0);
MR_Replace_Faces(r1,1,&fcmn,nrf2-1,rf2,rfdir2);
MF_Delete(fcmn,0);
free(rf2); free(rfdir2);
return r1;
}
