[Bf-blender-cvs] SVN commit: /data/svn/bf-blender [45436] trunk/blender/source/blender/ editors/mesh/editmesh_knife.c: fix crash with stack memory usage for the knife tool.

[Campbell Barton]

Revision: 45436
          http://projects.blender.org/scm/viewvc.php?view=rev&root=bf-blender&revision=45436
Author:   campbellbarton
Date:     2012-04-06 06:17:52 +0000 (Fri, 06 Apr 2012)
Log Message:
-----------
fix crash with stack memory usage for the knife tool.
knife cutting ~25000 faces would crash with 8mb stack set.

fix by removing generic iterators in functions which do recursive calls.

Modified Paths:
--------------
    trunk/blender/source/blender/editors/mesh/editmesh_knife.c

Modified: trunk/blender/source/blender/editors/mesh/editmesh_knife.c
===================================================================
--- trunk/blender/source/blender/editors/mesh/editmesh_knife.c	2012-04-06 05:54:13 UTC (rev 45435)
+++ trunk/blender/source/blender/editors/mesh/editmesh_knife.c	2012-04-06 06:17:52 UTC (rev 45436)
@@ -270,13 +270,14 @@
 	return kfv;
 }
 
-/* get a KnifeEdge wrapper for an existing BMEdge */
+/**
+ * get a KnifeEdge wrapper for an existing BMEdge
+ * \note #knife_get_face_kedges / #get_bm_knife_edge are called recusively - KEEP STACK MEM USAGE LOW */
 static KnifeEdge *get_bm_knife_edge(knifetool_opdata *kcd, BMEdge *e)
 {
 	KnifeEdge *kfe = BLI_ghash_lookup(kcd->origedgemap, e);
 	if (!kfe) {
-		BMIter iter;
-		BMFace *f;
+		BMLoop *l_iter, *l_first;
 
 		kfe = new_knife_edge(kcd);
 		kfe->e = e;
@@ -287,13 +288,17 @@
 
 		BLI_ghash_insert(kcd->origedgemap, e, kfe);
 
-		BM_ITER(f, &iter, kcd->em->bm, BM_FACES_OF_EDGE, e) {
-			knife_append_list(kcd, &kfe->faces, f);
+		/* avoid BM_ITER because of stack memory usage
+		 * otherwise we could use BM_FACES_OF_EDGE */
+		l_iter = l_first = e->l;
+		do {
+			knife_append_list(kcd, &kfe->faces, l_iter->f);
 
 			/* ensures the kedges lst for this f is initialized,
 			 * it automatically adds kfe by itself */
-			knife_get_face_kedges(kcd, f);
-		}
+			knife_get_face_kedges(kcd, l_iter->f);
+
+		} while ((l_iter = l_iter->radial_next) != l_first);
 	}
 
 	return kfe;
@@ -323,19 +328,23 @@
 	}
 }
 
+/**
+ * \note #knife_get_face_kedges / #get_bm_knife_edge are called recusively - KEEP STACK MEM USAGE LOW */
 static ListBase *knife_get_face_kedges(knifetool_opdata *kcd, BMFace *f)
 {
 	ListBase *lst = BLI_ghash_lookup(kcd->kedgefacemap, f);
 
 	if (!lst) {
-		BMIter iter;
-		BMEdge *e;
+		BMLoop *l_iter, *l_first;
 
 		lst = knife_empty_list(kcd);
 
-		BM_ITER(e, &iter, kcd->em->bm, BM_EDGES_OF_FACE, f) {
-			knife_append_list(kcd, lst, get_bm_knife_edge(kcd, e));
-		}
+		/* avoid BM_ITER because of stack memory usage
+		 * otherwise we could use BM_EDGES_OF_FACE */
+		l_iter = l_first = BM_FACE_FIRST_LOOP(f);
+		do {
+			knife_append_list(kcd, lst, get_bm_knife_edge(kcd, l_iter->e));
+		} while ((l_iter = l_iter->next) != l_first);
 
 		BLI_ghash_insert(kcd->kedgefacemap, f, lst);
 	}