Fix T40679.

Cleanest way here is not do bounding box collision for editmeshes at
all. Decision is taken because:

* Usually we want to do the snapping to the edited mesh anyway (when we
don't the mesh is skipped completely, so we don't need to worry for
extra checks)

* Bounding box is calculated from derived mesh. This means that for
subsurfed meshes for instance, the bounding box may be significantly
smaller than the size of the edit mesh.

1 files changed, 9 insertions, 7 deletions

diff --git a/source/blender/editors/transform/transform_snap.c b/source/blender/editors/transform/transform_snap.c
index b116721868e..451837fd311 100644
--- a/source/blender/editors/transform/transform_snap.c
+++ b/source/blender/editors/transform/transform_snap.c
@@ -507,7 +507,6 @@ static void initSnappingMode(TransInfo *t)
 		if (t->tsnap.applySnap != NULL && // A snapping function actually exist
 		    (obedit != NULL && ELEM5(obedit->type, OB_MESH, OB_ARMATURE, OB_CURVE, OB_LATTICE, OB_MBALL)) ) // Temporary limited to edit mode meshes, armature, curves, mballs
 		{
-			BoundBox *bb_init;
 			/* Exclude editmesh if using proportional edit */
 			if ((obedit->type == OB_MESH) && (t->flag & T_PROP_EDIT)) {
 				t->tsnap.modeSelect = SNAP_NOT_OBEDIT;
@@ -1490,13 +1489,12 @@ static bool snapCurve(short snap_mode, ARegion *ar, Object *ob, Curve *cu, float
 
 static bool snapDerivedMesh(short snap_mode, ARegion *ar, Object *ob, DerivedMesh *dm, BMEditMesh *em, float obmat[4][4],
                             const float ray_start[3], const float ray_normal[3], const float ray_origin[3],
-                            const float mval[2], float r_loc[3], float r_no[3], float *r_dist_px, float *r_depth)
+                            const float mval[2], float r_loc[3], float r_no[3], float *r_dist_px, float *r_depth, bool do_bb)
 {
 	bool retval = false;
 	int totvert = dm->getNumVerts(dm);
 
 	if (totvert > 0) {
-		BoundBox *bb;
 		float imat[4][4];
 		float timat[3][3]; /* transpose inverse matrix for normals */
 		float ray_start_local[3], ray_normal_local[3], local_scale, len_diff = TRANSFORM_DIST_MAX_RAY;
@@ -1514,9 +1512,11 @@ static bool snapDerivedMesh(short snap_mode, ARegion *ar, Object *ob, DerivedMes
 		/* local scale in normal direction */
 		local_scale = normalize_v3(ray_normal_local);
 
-		bb = BKE_object_boundbox_get(ob);
-		if (!BKE_boundbox_ray_hit_check(bb, ray_start_local, ray_normal_local, &len_diff)) {
-			return retval;
+		if (do_bb) {
+			BoundBox *bb = BKE_object_boundbox_get(ob);
+			if (!BKE_boundbox_ray_hit_check(bb, ray_start_local, ray_normal_local, &len_diff)) {
+				return retval;
+			}
 		}
 
 		switch (snap_mode) {
@@ -1814,17 +1814,19 @@ static bool snapObject(Scene *scene, short snap_mode, ARegion *ar, Object *ob, f
 	if (ob->type == OB_MESH) {
 		BMEditMesh *em;
 		DerivedMesh *dm;
+		bool do_bb = true;
 		
 		if (use_obedit) {
 			em = BKE_editmesh_from_object(ob);
 			dm = editbmesh_get_derived_cage(scene, ob, em, CD_MASK_BAREMESH);
+			do_bb = false;
 		}
 		else {
 			em = NULL;
 			dm = mesh_get_derived_final(scene, ob, CD_MASK_BAREMESH);
 		}
 		
-		retval = snapDerivedMesh(snap_mode, ar, ob, dm, em, obmat, ray_start, ray_normal, ray_origin, mval, r_loc, r_no, r_dist_px, r_depth);
+		retval = snapDerivedMesh(snap_mode, ar, ob, dm, em, obmat, ray_start, ray_normal, ray_origin, mval, r_loc, r_no, r_dist_px, r_depth, do_bb);
 
 		dm->release(dm);
 	}