Fix for #23
- rewrote tessMeshMergeConvexFaces() to avoid infinite loops
diff --git a/Source/mesh.c b/Source/mesh.c
index a3565ab..a0fa08e 100755
--- a/Source/mesh.c
+++ b/Source/mesh.c
@@ -699,54 +699,52 @@
int tessMeshMergeConvexFaces( TESSmesh *mesh, int maxVertsPerFace )
{
- TESSface *f;
- TESShalfEdge *eCur, *eNext, *eSym;
- TESSvertex *vStart;
- int curNv, symNv;
+ TESShalfEdge *e, *eNext, *eSym;
+ TESShalfEdge *eHead = &mesh->eHead;
+ TESSvertex *va, *vb, *vc, *vd, *ve, *vf;
+ int leftNv, rightNv;
- for( f = mesh->fHead.next; f != &mesh->fHead; f = f->next )
+ for( e = eHead->next; e != eHead; e = eNext )
{
- // Skip faces which are outside the result.
- if( !f->inside )
+ eNext = e->next;
+ eSym = e->Sym;
+ if( !eSym )
+ continue;
+
+ // Both faces must be inside
+ if( !e->Lface || !e->Lface->inside )
+ continue;
+ if( !eSym->Lface || !eSym->Lface->inside )
continue;
- eCur = f->anEdge;
- vStart = eCur->Org;
-
- while (1)
- {
- eNext = eCur->Lnext;
- eSym = eCur->Sym;
+ leftNv = CountFaceVerts( e->Lface );
+ rightNv = CountFaceVerts( eSym->Lface );
+ if( (leftNv+rightNv-2) > maxVertsPerFace )
+ continue;
- // Try to merge if the neighbour face is valid.
- if( eSym && eSym->Lface && eSym->Lface->inside )
- {
- // Try to merge the neighbour faces if the resulting polygons
- // does not exceed maximum number of vertices.
- curNv = CountFaceVerts( f );
- symNv = CountFaceVerts( eSym->Lface );
- if( (curNv+symNv-2) <= maxVertsPerFace )
- {
- // Merge if the resulting poly is convex.
- if( VertCCW( eCur->Lprev->Org, eCur->Org, eSym->Lnext->Lnext->Org ) &&
- VertCCW( eSym->Lprev->Org, eSym->Org, eCur->Lnext->Lnext->Org ) )
- {
- eNext = eSym->Lnext;
- if( !tessMeshDelete( mesh, eSym ) )
- return 0;
- eCur = 0;
- }
- }
- }
-
- if( eCur && eCur->Lnext->Org == vStart )
- break;
-
- // Continue to next edge.
- eCur = eNext;
+ // Merge if the resulting poly is convex.
+ //
+ // vf--ve--vd
+ // ^|
+ // left e || right
+ // |v
+ // va--vb--vc
+
+ va = e->Lprev->Org;
+ vb = e->Org;
+ vc = e->Sym->Lnext->Dst;
+
+ vd = e->Sym->Lprev->Org;
+ ve = e->Sym->Org;
+ vf = e->Lnext->Dst;
+
+ if( VertCCW( va, vb, vc ) && VertCCW( vd, ve, vf ) ) {
+ if( e == eNext || e == eNext->Sym ) { eNext = eNext->next; }
+ if( !tessMeshDelete( mesh, e ) )
+ return 0;
}
}
-
+
return 1;
}
