implemented select (x-)mirrored. I used a topological approach, which will be later reused in x-mirror editing, weight painting, etc. also ported select randon, select linked flat faces, and select sharp (as in, surroundined by non-flat faces, not sharp as in the sharp flag) edges, and select non-manifold. need to merge in recent trunk changes next.

4 files changed, 653 insertions, 131 deletions

diff --git a/source/blender/editors/mesh/bmesh_select.c b/source/blender/editors/mesh/bmesh_select.c
index aa6a700eb6f..85f7ee1aabc 100644
--- a/source/blender/editors/mesh/bmesh_select.c
+++ b/source/blender/editors/mesh/bmesh_select.c
@@ -2073,3 +2073,251 @@ int EM_view3d_poll(bContext *C)
 		return 1;
 	return 0;
 }
+
+
+static int select_sharp_edges_exec(bContext *C, wmOperator *op)
+{
+	/* Find edges that have exactly two neighboring faces,
+	* check the angle between those faces, and if angle is
+	* small enough, select the edge
+	*/
+	Object *obedit= CTX_data_edit_object(C);
+	BMEditMesh *em= ((Mesh *)obedit->data)->edit_btmesh;
+	BMIter iter;
+	BMEdge *e;
+	BLI_array_declare(stack);
+	BMLoop *l1, *l2;
+	float sharp = RNA_float_get(op->ptr, "sharpness"), angle;
+
+	sharp = (sharp * M_PI) / 180.0;
+
+	BM_ITER(e, &iter, em->bm, BM_EDGES_OF_MESH, NULL) {
+		if (BM_TestHFlag(e, BM_HIDDEN) || !e->loop)
+			continue;
+
+		l1 = e->loop;
+		l2 = l1->radial.next->data;
+
+		if (l1 == l2)
+			continue;
+
+		/* edge has exactly two neighboring faces, check angle */
+		angle = saacos(l1->f->no[0]*l2->f->no[0]+l1->f->no[1]*l2->f->no[1]+l1->f->no[2]*l2->f->no[2]);
+
+		if (fabs(angle) < sharp) {
+			BM_Select(em->bm, e, 1);
+		}
+
+	}
+
+	WM_event_add_notifier(C, NC_GEOM|ND_SELECT, obedit->data);
+
+	return OPERATOR_FINISHED;
+}
+
+void MESH_OT_edges_select_sharp(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name= "Select Sharp Edges";
+	ot->description= "Marked selected edges as sharp.";
+	ot->idname= "MESH_OT_edges_select_sharp";
+	
+	/* api callbacks */
+	ot->exec= select_sharp_edges_exec;
+	ot->poll= ED_operator_editmesh;
+	
+	/* flags */
+	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
+	
+	/* props */
+	RNA_def_float(ot->srna, "sharpness", 1.0f, 0.01f, FLT_MAX, "sharpness", "", 1.0f, 180.0f);
+}
+
+static int select_linked_flat_faces_exec(bContext *C, wmOperator *op)
+{
+	Object *obedit= CTX_data_edit_object(C);
+	BMEditMesh *em= ((Mesh *)obedit->data)->edit_btmesh;
+	BMIter iter, liter, liter2;
+	BMFace *f, **stack = NULL;
+	BLI_array_declare(stack);
+	BMLoop *l, *l2;
+	float sharp = RNA_float_get(op->ptr, "sharpness");
+	int i;
+
+	sharp = (sharp * M_PI) / 180.0;
+
+	BM_ITER(f, &iter, em->bm, BM_FACES_OF_MESH, NULL) {
+		BMINDEX_SET(f, 0);
+	}
+
+	BM_ITER(f, &iter, em->bm, BM_FACES_OF_MESH, NULL) {
+		if (BM_TestHFlag(f, BM_HIDDEN) || !BM_TestHFlag(f, BM_SELECT) || BMINDEX_GET(f))
+			continue;
+
+		BLI_array_empty(stack);
+		i = 1;
+
+		BLI_array_growone(stack);
+		stack[i-1] = f;
+
+		while (i) {
+			f = stack[i-1];
+			i--;
+
+			BM_Select(em->bm, f, 1);
+
+			BMINDEX_SET(f, 1);
+
+			BM_ITER(l, &liter, em->bm, BM_LOOPS_OF_FACE, f) {
+				BM_ITER(l2, &liter2, em->bm, BM_LOOPS_OF_LOOP, l) {
+					float angle;
+
+					if (BMINDEX_GET(l2->f) || BM_TestHFlag(l2->f, BM_HIDDEN))
+						continue;
+
+					/* edge has exactly two neighboring faces, check angle */
+					angle = saacos(f->no[0]*l2->f->no[0]+f->no[1]*l2->f->no[1]+f->no[2]*l2->f->no[2]);
+
+					/* invalidate: edge too sharp */
+					if (fabs(angle) < sharp) {
+						BLI_array_growone(stack);
+						stack[i] = l2->f;
+						i++;
+					}
+				}
+			}
+		}
+	}
+
+	BLI_array_free(stack);
+
+	WM_event_add_notifier(C, NC_GEOM|ND_SELECT, obedit->data);
+
+	return OPERATOR_FINISHED;
+}
+
+void MESH_OT_faces_select_linked_flat(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name= "Select Linked Flat Faces";
+	ot->description= "Select linked faces by angle.";
+	ot->idname= "MESH_OT_faces_select_linked_flat";
+	
+	/* api callbacks */
+	ot->exec= select_linked_flat_faces_exec;
+	ot->poll= ED_operator_editmesh;
+	
+	/* flags */
+	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
+	
+	/* props */
+	RNA_def_float(ot->srna, "sharpness", 1.0f, 0.01f, FLT_MAX, "sharpness", "", 1.0f, 180.0f);
+}
+
+static int select_non_manifold_exec(bContext *C, wmOperator *op)
+{
+	Object *obedit= CTX_data_edit_object(C);
+	BMEditMesh *em= ((Mesh *)obedit->data)->edit_btmesh;
+	BMVert *v;
+	BMEdge *e;
+	BMIter iter;
+
+	/* Selects isolated verts, and edges that do not have 2 neighboring
+	 * faces
+	 */
+	
+	if(em->selectmode==SCE_SELECT_FACE) {
+		BKE_report(op->reports, RPT_ERROR, "Doesn't work in face selection mode");
+		return OPERATOR_CANCELLED;
+	}
+	
+	BM_ITER(v, &iter, em->bm, BM_VERTS_OF_MESH, NULL) {
+		if (!BM_TestHFlag(em->bm, BM_HIDDEN) && BM_Nonmanifold_Vert(em->bm, v))
+			BM_Select(em->bm, v, 1);
+	}
+	
+	BM_ITER(e, &iter, em->bm, BM_EDGES_OF_MESH, NULL) {
+		if (!BM_TestHFlag(em->bm, BM_HIDDEN) && BM_Nonmanifold_Edge(em->bm, e))
+			BM_Select(em->bm, e, 1);
+	}
+
+	WM_event_add_notifier(C, NC_GEOM|ND_SELECT, obedit->data);
+
+	return OPERATOR_FINISHED;	
+}
+
+void MESH_OT_select_non_manifold(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name= "Select Non Manifold";
+	ot->description= "Select all non-manifold vertices or edges.";
+	ot->idname= "MESH_OT_select_non_manifold";
+	
+	/* api callbacks */
+	ot->exec= select_non_manifold_exec;
+	ot->poll= ED_operator_editmesh;
+	
+	/* flags */
+	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
+}
+
+static int mesh_select_random_exec(bContext *C, wmOperator *op)
+{
+	Object *obedit= CTX_data_edit_object(C);
+	BMEditMesh *em= ((Mesh *)obedit->data)->edit_btmesh;
+	BMVert *eve;
+	BMEdge *eed;
+	BMFace *efa;
+	BMIter iter;
+	float randfac =  RNA_float_get(op->ptr, "percent")/100.0f;
+
+	BLI_srand( BLI_rand() ); /* random seed */
+	
+	if(!RNA_boolean_get(op->ptr, "extend"))
+		EDBM_clear_flag_all(em, BM_SELECT);
+
+	if(em->selectmode & SCE_SELECT_VERTEX) {
+		BM_ITER(eve, &iter, em->bm, BM_VERTS_OF_MESH, NULL) {
+			if (!BM_TestHFlag(eve, BM_HIDDEN) && BLI_frand() < randfac)
+				BM_Select(em->bm, eve, 1);
+		}
+		EDBM_selectmode_flush(em);
+	}
+	else if(em->selectmode & SCE_SELECT_EDGE) {
+		BM_ITER(eed, &iter, em->bm, BM_EDGES_OF_MESH, NULL) {
+			if (!BM_TestHFlag(eed, BM_HIDDEN) && BLI_frand() < randfac)
+				BM_Select(em->bm, eed, 1);
+		}
+		EDBM_selectmode_flush(em);
+	}
+	else {
+		BM_ITER(efa, &iter, em->bm, BM_FACES_OF_MESH, NULL) {
+			if (!BM_TestHFlag(efa, BM_HIDDEN) && BLI_frand() < randfac)
+				BM_Select(em->bm, efa, 1);
+		}
+		EDBM_selectmode_flush(em);
+	}
+	
+	WM_event_add_notifier(C, NC_GEOM|ND_SELECT, obedit->data);
+	
+	return OPERATOR_FINISHED;	
+}
+
+void MESH_OT_select_random(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name= "Select Random";
+	ot->description= "Randomly select vertices.";
+	ot->idname= "MESH_OT_select_random";
+
+	/* api callbacks */
+	ot->exec= mesh_select_random_exec;
+	ot->poll= ED_operator_editmesh;
+
+	/* flags */
+	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
+	
+	/* props */
+	RNA_def_float_percentage(ot->srna, "percent", 50.f, 0.0f, 100.0f, "Percent", "Percentage of elements to select randomly.", 0.f, 100.0f);
+	RNA_def_boolean(ot->srna, "extend", FALSE, "Extend Selection", "Extend selection instead of deselecting everything first.");
+}
diff --git a/source/blender/editors/mesh/bmesh_tools.c b/source/blender/editors/mesh/bmesh_tools.c
index c5d1ce9b2f5..87eb5fb6da7 100644
--- a/source/blender/editors/mesh/bmesh_tools.c
+++ b/source/blender/editors/mesh/bmesh_tools.c
@@ -4645,18 +4645,41 @@ void MESH_OT_select_by_number_vertices(wmOperatorType *ot)
 }
 
 
+#define MIRROR_THRESH	1.0f
+
 int select_mirror_exec(bContext *C, wmOperator *op)
 {
-#if 0
+	
 	Object *obedit= CTX_data_edit_object(C);
-	EditMesh *em= BKE_mesh_get_editmesh(((Mesh *)obedit->data));
-
+	BMEditMesh *em= ((Mesh *)obedit->data)->edit_btmesh;
+	BMBVHTree *tree = BMBVH_NewBVH(em);
+	BMVert *v1, *v2;
+	BMIter iter;
 	int extend= RNA_boolean_get(op->ptr, "extend");
+	float mirror_co[3];
+
+	BM_ITER(v1, &iter, em->bm, BM_VERTS_OF_MESH, NULL) {
+		if (!BM_TestHFlag(v1, BM_SELECT) || BM_TestHFlag(v1, BM_HIDDEN))
+			BMINDEX_SET(v1, 0);
+		else BMINDEX_SET(v1, 1);
+	}
 
-	EM_select_mirrored(obedit, em, extend);
+	if (!extend)
+		EDBM_clear_flag_all(em, BM_SELECT);
+
+	BM_ITER(v1, &iter, em->bm, BM_VERTS_OF_MESH, NULL) {
+		if (!BMINDEX_GET(v1) || BM_TestHFlag(v1, BM_HIDDEN))
+			continue;
+
+		VECCOPY(mirror_co, v1->co);
+		mirror_co[0] *= -1.0f;
+
+		v2 = BMBVH_FindClosestVertTopo(tree, mirror_co, MIRROR_THRESH, v1);
+		if (v2 && !BM_TestHFlag(v2, BM_HIDDEN))
+			BM_Select(em->bm, v2, 1);
+	}
 
 	WM_event_add_notifier(C, NC_GEOM|ND_SELECT, obedit->data);
-#endif
 	return OPERATOR_FINISHED;
 }
 
@@ -4677,129 +4700,3 @@ void MESH_OT_select_mirror(wmOperatorType *ot)
 	/* props */
 	RNA_def_boolean(ot->srna, "extend", 0, "Extend", "Extend the existing selection");
 }
-
-static int select_sharp_edges_exec(bContext *C, wmOperator *op)
-{
-	/* Find edges that have exactly two neighboring faces,
-	* check the angle between those faces, and if angle is
-	* small enough, select the edge
-	*/
-}
-
-void MESH_OT_edges_select_sharp(wmOperatorType *ot)
-{
-	/* identifiers */
-	ot->name= "Select Sharp Edges";
-	ot->description= "Marked selected edges as sharp.";
-	ot->idname= "MESH_OT_edges_select_sharp";
-	
-	/* api callbacks */
-	ot->exec= select_sharp_edges_exec;
-	ot->poll= ED_operator_editmesh;
-	
-	/* flags */
-	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
-	
-	/* props */
-	RNA_def_float(ot->srna, "sharpness", 0.01f, 0.0f, FLT_MAX, "sharpness", "", 0.0f, 180.0f);
-}
-
-static int select_linked_flat_faces_exec(bContext *C, wmOperator *op)
-{
-#if 0
-	Object *obedit= CTX_data_edit_object(C);
-	EditMesh *em= BKE_mesh_get_editmesh(((Mesh *)obedit->data));
-	
-	select_linked_flat_faces(em, op, RNA_float_get(op->ptr, "sharpness"));
-	
-	WM_event_add_notifier(C, NC_GEOM|ND_SELECT, obedit->data);
-
-	BKE_mesh_end_editmesh(obedit->data, em);
-	return OPERATOR_FINISHED;
-#endif
-}
-
-void MESH_OT_faces_select_linked_flat(wmOperatorType *ot)
-{
-	/* identifiers */
-	ot->name= "Select Linked Flat Faces";
-	ot->description= "Select linked faces by angle.";
-	ot->idname= "MESH_OT_faces_select_linked_flat";
-	
-	/* api callbacks */
-	ot->exec= select_linked_flat_faces_exec;
-	ot->poll= ED_operator_editmesh;
-	
-	/* flags */
-	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
-	
-	/* props */
-	RNA_def_float(ot->srna, "sharpness", 0.0f, 0.0f, FLT_MAX, "sharpness", "", 0.0f, 180.0f);
-}
-
-static int select_non_manifold_exec(bContext *C, wmOperator *op)
-{
-#if 0
-	Object *obedit= CTX_data_edit_object(C);
-	EditMesh *em= BKE_mesh_get_editmesh(((Mesh *)obedit->data));
-	
-	select_non_manifold(em, op);
-	
-	WM_event_add_notifier(C, NC_GEOM|ND_SELECT, obedit->data);
-
-	BKE_mesh_end_editmesh(obedit->data, em);
-	return OPERATOR_FINISHED;
-#endif
-}
-
-void MESH_OT_select_non_manifold(wmOperatorType *ot)
-{
-	/* identifiers */
-	ot->name= "Select Non Manifold";
-	ot->description= "Select all non-manifold vertices or edges.";
-	ot->idname= "MESH_OT_select_non_manifold";
-	
-	/* api callbacks */
-	ot->exec= select_non_manifold_exec;
-	ot->poll= ED_operator_editmesh;
-	
-	/* flags */
-	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
-}
-
-static int mesh_select_random_exec(bContext *C, wmOperator *op)
-{
-#if 0
-	Object *obedit= CTX_data_edit_object(C);
-	EditMesh *em= BKE_mesh_get_editmesh(((Mesh *)obedit->data));
-	
-	if(!RNA_boolean_get(op->ptr, "extend"))
-		EM_deselect_all(em);
-	
-	selectrandom_mesh(em, RNA_float_get(op->ptr, "percent")/100.0f);
-		
-	WM_event_add_notifier(C, NC_GEOM|ND_SELECT, obedit->data);
-	
-	BKE_mesh_end_editmesh(obedit->data, em);
-#endif
-	return OPERATOR_FINISHED;	
-}
-
-void MESH_OT_select_random(wmOperatorType *ot)
-{
-	/* identifiers */
-	ot->name= "Select Random";
-	ot->description= "Randomly select vertices.";
-	ot->idname= "MESH_OT_select_random";
-
-	/* api callbacks */
-	ot->exec= mesh_select_random_exec;
-	ot->poll= ED_operator_editmesh;
-
-	/* flags */
-	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
-	
-	/* props */
-	RNA_def_float_percentage(ot->srna, "percent", 50.f, 0.0f, 100.0f, "Percent", "Percentage of elements to select randomly.", 0.f, 100.0f);
-	RNA_def_boolean(ot->srna, "extend", FALSE, "Extend Selection", "Extend selection instead of deselecting everything first.");
-}
diff --git a/source/blender/editors/mesh/editbmesh_bvh.c b/source/blender/editors/mesh/editbmesh_bvh.c
index 6ce2f04fc59..d77ac5ed0bc 100644
--- a/source/blender/editors/mesh/editbmesh_bvh.c
+++ b/source/blender/editors/mesh/editbmesh_bvh.c
@@ -98,6 +98,14 @@ typedef struct BMBVHTree {
 	BMesh *bm;
 	BVHTree *tree;
 	float epsilon;
+	float maxdist; //for nearest point search
+
+	/*stuff for topological vert search*/
+	BMVert *v, *curv;
+	GHash *gh;
+	float curw, curd;
+	float co[3];
+	int curtag;
 } BMBVHTree;
 
 BMBVHTree *BMBVH_NewBVH(BMEditMesh *em)
@@ -219,6 +227,369 @@ BMFace *BMBVH_RayCast(BMBVHTree *tree, float *co, float *dir, float *hitout)
 	return NULL;
 }
 
+
+static void vertsearchcallback(void *userdata, int index, const float *co, BVHTreeNearest *hit)
+{
+	BMBVHTree *tree = userdata;
+	BMLoop **ls = tree->em->looptris[index];
+	float dist, maxdist, v[3];
+	int i;
+
+	maxdist = tree->maxdist;
+
+	for (i=0; i<3; i++) {
+		sub_v3_v3v3(v, hit->co, ls[i]->v->co);
+
+		dist = sqrt(v[0]*v[0] + v[1]*v[1] + v[2]*v[2]);
+		if (dist < hit->dist && dist < maxdist) {
+			VECCOPY(hit->co, ls[i]->v->co);
+			VECCOPY(hit->no, ls[i]->v->no);
+			hit->dist = dist;
+		}
+	}
+}
+
+BMVert *BMBVH_FindClosestVert(BMBVHTree *tree, float *co, float maxdist)
+{
+	BVHTreeNearest hit;
+
+	VECCOPY(hit.co, co);
+	hit.dist = maxdist*5;
+	hit.index = -1;
+
+	tree->maxdist = maxdist;
+
+	BLI_bvhtree_find_nearest(tree->tree, co, &hit, vertsearchcallback, tree);
+	if (hit.dist != FLT_MAX && hit.index != -1) {
+		BMLoop **ls = tree->em->looptris[hit.index];
+		float dist, curdist = tree->maxdist, v[3];
+		int cur=0, i;
+
+		maxdist = tree->maxdist;
+
+		for (i=0; i<3; i++) {
+			sub_v3_v3v3(v, hit.co, ls[i]->v->co);
+
+			dist = sqrt(v[0]*v[0] + v[1]*v[1] + v[2]*v[2]);
+			if (dist < curdist) {
+				cur = i;
+				curdist = dist;
+			}
+		}
+
+		return ls[i]->v;
+	}
+
+	return NULL;
+}
+
+typedef struct walklist {
+	BMVert *v;
+	int valence;
+	int depth;
+	float w, r;
+	int totwalked;
+
+	/*state data*/
+	BMVert *lastv;
+	BMLoop *curl, *firstl;
+	BMEdge *cure;
+} walklist;
+
+
+static short winding(float *v1, float *v2, float *v3)
+/* is v3 to the right of v1-v2 ? With exception: v3==v1 || v3==v2 */
+{
+	double inp;
+
+	//inp= (v2[cox]-v1[cox])*(v1[coy]-v3[coy]) +(v1[coy]-v2[coy])*(v1[cox]-v3[cox]);
+	inp= (v2[0]-v1[0])*(v1[1]-v3[1]) +(v1[1]-v2[1])*(v1[0]-v3[0]);
+
+	if(inp<0.0) return 0;
+	else if(inp==0) {
+		if(v1[0]==v3[0] && v1[1]==v3[1]) return 0;
+		if(v2[0]==v3[0] && v2[1]==v3[1]) return 0;
+	}
+	return 1;
+}
+
+static float topo_compare(BMesh *bm, BMVert *v1, BMVert *v2, int tag)
+{
+	BMIter iter1, iter2;
+	BMEdge *e1, *e2, *cure1 = NULL, *cure2 = NULL;
+	BMLoop *l1, *l2;
+	BMVert *lastv1, *lastv2;
+	GHash *gh;
+	walklist *stack1=NULL, *stack2=NULL;
+	BLI_array_declare(stack1);
+	BLI_array_declare(stack2);
+	float vec1[3], vec2[3], minangle=FLT_MAX, w;
+	int lvl=1;
+	static int maxlevel = 8;
+
+	/*ok.  see how similar v is to v2, based on topological similaritys in the local
+	  topological neighborhood*/
+
+	/*step 1: find two edges, one that contains v and one that contains v2, with the
+	  smallest angle between the two edges*/
+
+	BM_ITER(e1, &iter1, bm, BM_EDGES_OF_VERT, v1) {
+		BM_ITER(e2, &iter2, bm, BM_EDGES_OF_VERT, v2) {
+			float angle;
+			
+			if (e1->v1 == e2->v1 || e1->v2 == e2->v2 || e1->v1 == e2->v2 || e1->v2 == e2->v1)
+				continue;
+
+			sub_v3_v3v3(vec1, BM_OtherEdgeVert(e1, v1)->co, v1->co);
+			sub_v3_v3v3(vec2, BM_OtherEdgeVert(e2, v2)->co, v2->co);
+
+			angle = fabs(angle_v3v3(vec1, vec2));
+
+			if (angle < minangle) {
+				minangle = angle;
+				cure1 = e1;
+				cure2 = e2;
+			}
+		}
+	}
+
+	if (!cure1 || !cure1->loop || !cure2->loop) {
+		/*just return 1.0 in this case*/
+		return 1.0f;
+	}
+
+	/*assumtions
+	
+	  we assume a 2-manifold mesh here.  if at any time this isn't the case,
+	  e.g. a hole or an edge with more then 2 faces around it, we um ignore
+	  that edge I guess, and try to make the algorithm go around as necassary.*/
+
+	l1 = cure1->loop;
+	l2 = cure2->loop;
+
+	lastv1 = l1->v == v1 ? ((BMLoop*)l1->head.next)->v : ((BMLoop*)l1->head.prev)->v;
+	lastv2 = l2->v == v2 ? ((BMLoop*)l2->head.next)->v : ((BMLoop*)l2->head.prev)->v;
+
+	/*we can only provide meaningful comparisons if v1 and v2 have the same valence*/
+	if (BM_Vert_EdgeCount(v1) != BM_Vert_EdgeCount(v2))
+		return 1.0f; /*full mismatch*/
+
+	gh = BLI_ghash_new(BLI_ghashutil_ptrhash, BLI_ghashutil_ptrcmp);
+
+#define SPUSH(s, d, vt, lv, e)\
+	if (BLI_array_count(s) <= lvl) BLI_array_growone(s);\
+	memset((s+lvl), 0, sizeof(*s));\
+	s[lvl].depth = d;\
+	s[lvl].v = vt;\
+	s[lvl].cure = e;\
+	s[lvl].lastv = lv;\
+	s[lvl].valence = BM_Vert_EdgeCount(vt);\
+
+	lvl = 0;
+
+	SPUSH(stack1, 0, v1, lastv1, cure1);
+	SPUSH(stack2, 0, v2, lastv2, cure2);
+
+	BLI_srand( BLI_rand() ); /* random seed */
+
+	lvl = 1;
+	while (lvl) {
+		int term = 0;
+		walklist *s1 = stack1 + lvl - 1, *s2 = stack2 + lvl - 1;
+
+		/*pop from the stack*/
+		lvl--;
+
+		if (s1->curl && s1->curl->e == s1->cure)
+			term = 1;
+		if (s2->curl && s2->curl->e == s2->cure)
+			term = 1;
+
+		/*find next case to do*/
+		if (!s1->curl)
+			s1->curl = s1->cure->loop;
+		if (!s2->curl) {
+			int wind1, wind2;
+			
+			s2->curl = s2->cure->loop;
+
+			/*find which of two possible faces to use*/
+			wind1 = winding(s1->v->co, s1->lastv->co, 
+				s1->v == s1->curl->v ? ((BMLoop*)s1->curl->head.prev->prev)->v->co : ((BMLoop*)s1->curl->head.next->next)->v->co);
+
+			wind2 = winding(s2->v->co, s2->lastv->co, 
+				s2->v == s2->curl->v ? ((BMLoop*)s2->curl->head.prev->prev)->v->co : ((BMLoop*)s2->curl->head.next->next)->v->co);
+			
+			if (wind1 == wind2)
+				s2->curl = s2->curl->radial.next->data;
+		}
+
+		/*handle termination cases of having already looped through all child
+		  nodes, or the valence mismatching between v1 and v2, or we hit max
+		  recursion depth*/
+		term |= s1->valence != s2->valence || lvl+1 > maxlevel;
+		term |= s1->curl->radial.next->data == (BMLoop*)l1;
+		term |= s2->curl->radial.next->data == (BMLoop*)l2;
+
+		if (!term) {
+			lastv1 = s1->v;
+			lastv2 = s2->v;
+			v1 = BM_OtherEdgeVert(s1->curl->e, lastv1);
+			v2 = BM_OtherEdgeVert(s2->curl->e, lastv2);
+			
+			e1 = s1->curl->e;
+			e2 = s2->curl->e;
+
+			if (!BLI_ghash_haskey(gh, v1) && !BLI_ghash_haskey(gh, v2)) {
+				/*repush the current stack item*/
+				lvl++;
+				
+				if (maxlevel % 2 == 0) {
+					BLI_ghash_insert(gh, v1, NULL);
+					BLI_ghash_insert(gh, v2, NULL);
+				}
+
+				/*now push the child node*/
+				SPUSH(stack1, lvl, v1, lastv1, e1);
+				SPUSH(stack2, lvl, v2, lastv2, e2);
+
+				lvl++;
+
+				s1 = stack1 + lvl - 2;
+				s2 = stack2 + lvl - 2;
+			}
+
+			s1->curl = s1->curl->v == s1->v ? (BMLoop*) s1->curl->head.prev : (BMLoop*) s1->curl->head.next;
+			s2->curl = s2->curl->v == s2->v ? (BMLoop*) s2->curl->head.prev : (BMLoop*) s2->curl->head.next;
+		
+			s1->curl = (BMLoop*) s1->curl->radial.next->data;
+			s2->curl = (BMLoop*) s2->curl->radial.next->data;
+		}
+
+#define WADD(stack, s)\
+		if (lvl) {/*silly attempt to make this non-commutative: randomize\
+			      how much this particular weight adds to the total*/\
+			stack[lvl-1].r += r;\
+			s->w *= r;\
+			stack[lvl-1].totwalked++;\
+			stack[lvl-1].w += s->w;\
+		}
+
+		/*if no next case to do, update parent weight*/
+		if (term) {
+			float r = 0.8f + BLI_frand()*0.2f - FLT_EPSILON;
+
+			if (s1->totwalked) {
+				s1->w /= s1->r;
+			} else
+				s1->w = s1->valence == s2->valence ? 1.0f : 0.0f;
+
+			WADD(stack1, s1);
+
+			if (s2->totwalked) {
+				s2->w /= s2->r;
+			} else
+				s2->w = s1->valence == s2->valence ? 1.0f : 0.0f;
+			
+			WADD(stack2, s2);
+
+			/*apply additional penalty to weight mismatch*/
+			if (s2->w != s1->w)
+				s2->w *= 0.8f;
+		}
+	}
+
+	w = (stack1[0].w + stack2[0].w)*0.5f;
+
+	BLI_array_free(stack1);
+	BLI_array_free(stack2);
+
+	BLI_ghash_free(gh, NULL, NULL);
+
+	return 1.0f - w;
+}
+
+static void vertsearchcallback_topo(void *userdata, int index, const float *co, BVHTreeNearest *hit)
+{
+	BMBVHTree *tree = userdata;
+	BMLoop **ls = tree->em->looptris[index];
+	int i;
+	float dist, maxdist, vec[3], w;
+
+	maxdist = tree->maxdist;
+
+	for (i=0; i<3; i++) {
+		float dis;
+
+		if (BLI_ghash_haskey(tree->gh, ls[i]->v))
+			continue;
+
+		sub_v3_v3v3(vec, tree->co, ls[i]->v->co);
+		dis = dot_v3v3(vec, vec);
+
+		w = topo_compare(tree->em->bm, tree->v, ls[i]->v, tree->curtag++);
+		
+		if (w < tree->curw-FLT_EPSILON*4) {
+			tree->curw = w;
+			tree->curv = ls[i]->v;
+		   
+			sub_v3_v3v3(vec, tree->co, ls[i]->v->co);
+			tree->curd = dot_v3v3(vec, vec);
+
+			/*we deliberately check for equality using (smallest possible float)*4 
+			  comparison factor, to always prefer distance in cases of verts really
+			  close to each other*/
+		} else if (fabs(tree->curw - w) < FLT_EPSILON*4) {
+			/*if w is equal to hitex->curw, sort by distance*/
+			sub_v3_v3v3(vec, tree->co, ls[i]->v->co);
+			dis = dot_v3v3(vec, vec);
+
+			if (dis < tree->curd) {
+				tree->curd = dis;
+				tree->curv = ls[i]->v;
+			}
+		}
+
+		BLI_ghash_insert(tree->gh, ls[i]->v, NULL);
+	}
+}
+
+BMVert *BMBVH_FindClosestVertTopo(BMBVHTree *tree, float *co, float maxdist, BMVert *sourcev)
+{
+	BVHTreeNearest hit;
+	BMVert *v;
+	BMIter iter;
+
+	memset(&hit, 0, sizeof(hit));
+
+	VECCOPY(hit.co, co);
+	VECCOPY(tree->co, co);
+	hit.index = -1;
+	hit.dist = 10.0f;
+
+	tree->curw = FLT_MAX;
+	tree->curd = FLT_MAX;
+	tree->curv = NULL;
+	tree->curtag = 1;
+
+	BM_ITER(v, &iter, tree->bm, BM_VERTS_OF_MESH, NULL) {
+		BMINDEX_SET(v, 0);
+	}
+
+	tree->gh = BLI_ghash_new(BLI_ghashutil_ptrhash, BLI_ghashutil_ptrcmp);
+
+	tree->maxdist = maxdist;
+	tree->v = sourcev;
+
+	BLI_bvhtree_find_nearest(tree->tree, co, &hit, vertsearchcallback_topo, tree);
+	
+	BLI_ghash_free(tree->gh, NULL, NULL);
+	tree->gh = NULL;
+
+	return tree->curv;
+}
+
+
 #if 0 //BMESH_TODO: not implemented yet
 int BMBVH_VertVisible(BMBVHTree *tree, BMEdge *e, RegionView3D *r3d)
 {
diff --git a/source/blender/editors/mesh/editbmesh_bvh.h b/source/blender/editors/mesh/editbmesh_bvh.h
index 5bc403828a9..f188d616978 100644
--- a/source/blender/editors/mesh/editbmesh_bvh.h
+++ b/source/blender/editors/mesh/editbmesh_bvh.h
@@ -13,5 +13,11 @@ struct BMBVHTree *BMBVH_NewBVH(struct BMEditMesh *em);
 void BMBVH_FreeBVH(struct BMBVHTree *tree);
 
 struct BMFace *BMBVH_RayCast(struct BMBVHTree *tree, float *co, float *dir, float *hitout);
+
 int BMBVH_EdgeVisible(struct BMBVHTree *tree, struct BMEdge *e, 
                       struct RegionView3D *r3d, struct Object *obedit);
+
+/*find a vert closest to co in a sphere of radius maxdist*/
+struct BMVert *BMBVH_FindClosestVert(struct BMBVHTree *tree, float *co, float maxdist);
+struct BMVert *BMBVH_FindClosestVertTopo(struct BMBVHTree *tree, float *co,
+                                         float maxdist, struct BMVert *sourcev);