1 files changed, 77 insertions, 24 deletions

diff --git a/source/blender/blenkernel/intern/bvhutils.c b/source/blender/blenkernel/intern/bvhutils.c
index 1aad0a242f9..5c50c14f1a8 100644
--- a/source/blender/blenkernel/intern/bvhutils.c
+++ b/source/blender/blenkernel/intern/bvhutils.c
@@ -41,7 +41,7 @@
 #include "BLI_linklist.h"
 
 #include "BKE_DerivedMesh.h"
-
+#include "BKE_tessmesh.h"
 
 #include "BLI_math.h"
 #include "MEM_guardedalloc.h"
@@ -555,7 +555,7 @@ BVHTree* bvhtree_from_mesh_verts(BVHTreeFromMesh *data, DerivedMesh *mesh, float
 
 		data->mesh = mesh;
 		data->vert = mesh->getVertDataArray(mesh, CD_MVERT);
-		data->face = mesh->getFaceDataArray(mesh, CD_MFACE);
+		data->face = mesh->getTessFaceDataArray(mesh, CD_MFACE);
 
 		data->sphere_radius = epsilon;
 	}
@@ -572,22 +572,87 @@ BVHTree* bvhtree_from_mesh_faces(BVHTreeFromMesh *data, DerivedMesh *mesh, float
 	if(tree == NULL)
 	{
 		int i;
-		int numFaces= mesh->getNumFaces(mesh);
-		MVert *vert	= mesh->getVertDataArray(mesh, CD_MVERT);
-		MFace *face = mesh->getFaceDataArray(mesh, CD_MFACE);
+		int numFaces= mesh->getNumTessFaces(mesh);
 
-		if(vert != NULL && face != NULL)
+		/* BMESH spesific check that we have tessfaces,
+		 * we _could_ tesselate here but rather not - campbell
+		 *
+		 * this assert checks we have tessfaces,
+		 * if not caller should use DM_ensure_tessface() */
+		BLI_assert(!(numFaces == 0 && mesh->getNumPolys(mesh) != 0));
+
+		if(numFaces != 0)
 		{
 			/* Create a bvh-tree of the given target */
 			tree = BLI_bvhtree_new(numFaces, epsilon, tree_type, axis);
 			if(tree != NULL)
 			{
-				/* XXX, for snap only, em & dm are assumed to be aligned, since dm is the em's cage */
-				EditMesh *em= data->em_evil;
+				BMEditMesh *em= data->em_evil;
 				if(em) {
-					EditFace *efa= em->faces.first;
-					for(i = 0; i < numFaces; i++, efa= efa->next) {
-						if(!(efa->f & 1) && efa->h==0 && !((efa->v1->f&1)+(efa->v2->f&1)+(efa->v3->f&1)+(efa->v4?efa->v4->f&1:0))) {
+					/*data->em_evil is only set for snapping, and only for the mesh of the object
+					  which is currently open in edit mode. When set, the bvhtree should not contain
+					  faces that will interfere with snapping (e.g. faces that are hidden/selected
+					  or faces that have selected verts).*/
+
+					/* XXX, for snap only, em & dm are assumed to be aligned, since dm is the em's cage */
+
+					/*Insert BMesh-tesselation triangles into the bvh tree, unless they are hidden
+					  and/or selected. Even if the faces themselves are not selected for the snapped
+					  transform, having a vertex selected means the face (and thus it's tesselated
+					  triangles) will be moving and will not be a good snap targets.*/
+					for (i = 0; i < em->tottri; i++) {
+						BMLoop **tri = em->looptris[i];
+						BMFace *f;
+						BMVert *v;
+						BMIter iter;
+						int insert;
+
+						/*Each loop of the triangle points back to the BMFace it was tesselated from.
+						  All three should point to the same face, so just use the face from the first
+						  loop.*/
+						f = tri[0]->f;
+
+						/*If the looptris is ordered such that all triangles tesselated from a single
+						  faces are consecutive elements in the array, then we could speed up the tests
+						  below by using the insert value from the previous iteration.*/
+
+						/*Start with the assumption the triangle should be included for snapping.*/
+						insert = 1;
+
+						if (BM_elem_flag_test(f, BM_ELEM_SELECT) || BM_elem_flag_test(f, BM_ELEM_HIDDEN)) {
+							/*Don't insert triangles tesselated from faces that are hidden
+							  or selected*/
+							insert = 0;
+						}
+						else {
+							BM_ITER(v, &iter, em->bm, BM_VERTS_OF_FACE, f) {
+								if (BM_elem_flag_test(v, BM_ELEM_SELECT)) {
+									/*Don't insert triangles tesselated from faces that have
+									  any selected verts.*/
+									insert = 0;
+								}
+							}
+						}
+
+						if (insert)
+						{
+							/*No reason found to block hit-testing the triangle for snap,
+							  so insert it now.*/
+							float co[4][3];
+							copy_v3_v3(co[0], tri[0]->v->co);
+							copy_v3_v3(co[1], tri[1]->v->co);
+							copy_v3_v3(co[2], tri[2]->v->co);
+					
+							BLI_bvhtree_insert(tree, i, co[0], 3);
+						}
+					}
+				}
+				else {
+					MVert *vert	= mesh->getVertDataArray(mesh, CD_MVERT);
+					MFace *face = mesh->getTessFaceDataArray(mesh, CD_MFACE);
+
+					if (vert != NULL && face != NULL) {
+						for(i = 0; i < numFaces; i++) {
 							float co[4][3];
 							copy_v3_v3(co[0], vert[ face[i].v1 ].co);
 							copy_v3_v3(co[1], vert[ face[i].v2 ].co);
@@ -599,18 +664,6 @@ BVHTree* bvhtree_from_mesh_faces(BVHTreeFromMesh *data, DerivedMesh *mesh, float
 						}
 					}
 				}
-				else {
-					for(i = 0; i < numFaces; i++) {
-						float co[4][3];
-						copy_v3_v3(co[0], vert[ face[i].v1 ].co);
-						copy_v3_v3(co[1], vert[ face[i].v2 ].co);
-						copy_v3_v3(co[2], vert[ face[i].v3 ].co);
-						if(face[i].v4)
-							copy_v3_v3(co[3], vert[ face[i].v4 ].co);
-				
-						BLI_bvhtree_insert(tree, i, co[0], face[i].v4 ? 4 : 3);
-					}
-				}
 				BLI_bvhtree_balance(tree);
 
 				//Save on cache for later use
@@ -638,7 +691,7 @@ BVHTree* bvhtree_from_mesh_faces(BVHTreeFromMesh *data, DerivedMesh *mesh, float
 
 		data->mesh = mesh;
 		data->vert = mesh->getVertDataArray(mesh, CD_MVERT);
-		data->face = mesh->getFaceDataArray(mesh, CD_MFACE);
+		data->face = mesh->getTessFaceDataArray(mesh, CD_MFACE);
 
 		data->sphere_radius = epsilon;
 	}