[Bf-blender-cvs] [fd34e3e] strand_editmode: Fix for verts-of-strand iterator: This requires a second pointer in addition to the edge, otherwise the last point is omitted.

[Lukas Tönne]

Commit: fd34e3efbc1587de14718a0d7706cfa3fb6bc870
Author: Lukas Tönne
Date:   Fri Nov 28 14:02:06 2014 +0100
Branches: strand_editmode
https://developer.blender.org/rBfd34e3efbc1587de14718a0d7706cfa3fb6bc870

Fix for verts-of-strand iterator: This requires a second pointer in
addition to the edge, otherwise the last point is omitted.

===================================================================

M	source/blender/bmesh/intern/bmesh_strands.c
M	source/blender/bmesh/intern/bmesh_strands.h

===================================================================

diff --git a/source/blender/bmesh/intern/bmesh_strands.c b/source/blender/bmesh/intern/bmesh_strands.c
index 1fdd880..09bc574 100644
--- a/source/blender/bmesh/intern/bmesh_strands.c
+++ b/source/blender/bmesh/intern/bmesh_strands.c
@@ -56,27 +56,33 @@ void *bmstranditer__strands_of_mesh_step(struct BMIter__elem_of_mesh *iter)
  * VERTS OF STRAND CALLBACKS
  */
 
-void  bmstranditer__verts_of_strand_begin(struct BMIter__vert_of_edge *UNUSED(iter))
+/* BMIter__vert_of_strand is not included in the union in BMIter, just make sure it is big enough */
+BLI_STATIC_ASSERT(sizeof(BMIter__vert_of_strand) <= sizeof(BMIter), "BMIter must be at least as large as BMIter__vert_of_strand")
+
+void  bmstranditer__verts_of_strand_begin(struct BMIter__vert_of_strand *iter)
 {
+	iter->e_next = iter->v_next->e;
 }
 
-void *bmstranditer__verts_of_strand_step(struct BMIter__vert_of_edge *iter)
+void *bmstranditer__verts_of_strand_step(struct BMIter__vert_of_strand *iter)
 {
-	if (iter->edata) {
-		/* by definition the all strand edges run in the same direction,
-		 * with the root being v1 of the first edge.
-		 */
-		BMVert *v_curr = iter->edata->v1;
-		BMEdge *e_first = iter->edata;
+	BMVert *v_curr = iter->v_next;
+	
+	if (iter->e_next) {
+		BMEdge *e_first = iter->e_next;
+		
+		/* select the other vertex of the current edge */
+		iter->v_next = (iter->v_next == iter->e_next->v1 ? iter->e_next->v2 : iter->e_next->v1);
 		
-		iter->edata = bmesh_disk_edge_next(iter->edata, iter->edata->v2);
-		if (iter->edata == e_first) {
+		/* select the next edge of the current vertex */
+		iter->e_next = bmesh_disk_edge_next(iter->e_next, iter->v_next);
+		if (iter->e_next == e_first) {
 			/* only one edge means the last segment, terminate */
-			iter->edata = NULL;
+			iter->e_next = NULL;
 		}
-		
-		return v_curr;
 	}
 	else
-		return NULL;
+		iter->v_next = NULL; /* last vertex, terminate */
+	
+	return v_curr;
 }
diff --git a/source/blender/bmesh/intern/bmesh_strands.h b/source/blender/bmesh/intern/bmesh_strands.h
index a912c4f..f2c8bf5 100644
--- a/source/blender/bmesh/intern/bmesh_strands.h
+++ b/source/blender/bmesh/intern/bmesh_strands.h
@@ -64,11 +64,16 @@ typedef enum BMStrandsIterType {
 #define BM_ITER_STRANDS_ELEM(ele, iter, data, itype) \
 	for (ele = BM_strand_iter_new(iter, NULL, itype, data); ele; ele = BM_iter_step(iter))
 
+typedef struct BMIter__vert_of_strand {
+	BMVert *v_next;
+	BMEdge *e_next;
+} BMIter__vert_of_strand;
+
 void  bmstranditer__strands_of_mesh_begin(struct BMIter__elem_of_mesh *iter);
 void *bmstranditer__strands_of_mesh_step(struct BMIter__elem_of_mesh *iter);
 
-void  bmstranditer__verts_of_strand_begin(struct BMIter__vert_of_edge *iter);
-void *bmstranditer__verts_of_strand_step(struct BMIter__vert_of_edge *iter);
+void  bmstranditer__verts_of_strand_begin(struct BMIter__vert_of_strand *iter);
+void *bmstranditer__verts_of_strand_step(struct BMIter__vert_of_strand *iter);
 
 BLI_INLINE bool BM_strand_iter_init(BMIter *iter, BMesh *bm, const char itype, void *data)
 {
@@ -93,10 +98,7 @@ BLI_INLINE bool BM_strand_iter_init(BMIter *iter, BMesh *bm, const char itype, v
 			BLI_assert(BM_strands_vert_is_root(root));
 			iter->begin = (BMIter__begin_cb)bmstranditer__verts_of_strand_begin;
 			iter->step  = (BMIter__step_cb)bmstranditer__verts_of_strand_step;
-			/* Note: Iterating over a strand is in fact more like a vertices-of-vertex iterator,
-			 * but due to strand topology we can start with the first edge as well.
-			 */
-			iter->data.vert_of_edge.edata = root->e;
+			((BMIter__vert_of_strand *)(&iter->data))->v_next = root;
 			break;
 		}
 		default: