BM_iter_as_arrayN() can now take an optional existing array argument, useful to avoid many small malloc's by passing a fixes size stack variable instead.

Will give some speedup to edge-split modifier and bevel.

1 files changed, 8 insertions, 2 deletions

diff --git a/source/blender/bmesh/intern/bmesh_iterators.c b/source/blender/bmesh/intern/bmesh_iterators.c
index 1cb95d94e9b..51a3776c21d 100644
--- a/source/blender/bmesh/intern/bmesh_iterators.c
+++ b/source/blender/bmesh/intern/bmesh_iterators.c
@@ -116,10 +116,14 @@ int BM_iter_as_array(BMesh *bm, const char itype, void *data, void **array, cons
  *
  * Caller needs to free the array.
  */
-void *BM_iter_as_arrayN(BMesh *bm, const char itype, void *data, int *r_len)
+void *BM_iter_as_arrayN(BMesh *bm, const char itype, void *data, int *r_len,
+                        /* optional static vars to avoid an alloc */
+                        void **stack_array, int stack_array_size)
 {
 	BMIter iter;
 
+	BLI_assert(stack_array_size == 0 || (stack_array_size && stack_array));
+
 	/* we can't rely on coun't being set */
 	switch (itype) {
 		case BM_VERTS_OF_MESH:
@@ -137,7 +141,9 @@ void *BM_iter_as_arrayN(BMesh *bm, const char itype, void *data, int *r_len)
 
 	if (BM_iter_init(&iter, bm, itype, data) && iter.count > 0) {
 		BMElem *ele;
-		BMElem **array = MEM_mallocN(sizeof(ele) * iter.count, __func__);
+		BMElem **array = iter.count > stack_array_size ?
+		                 MEM_mallocN(sizeof(ele) * iter.count, __func__) :
+		                 stack_array;
 		int i = 0;
 
 		*r_len = iter.count;  /* set before iterating */