[Bf-blender-cvs] [9c12ca2] mesh-transfer-data: Mesh loop-island api: reuse the memory arena

[Campbell Barton]

Commit: 9c12ca22a5c1f9d5fd35b51c5f1b3f8f530e2547
Author: Campbell Barton
Date:   Mon Nov 17 14:48:42 2014 +0100
Branches: mesh-transfer-data
https://developer.blender.org/rB9c12ca22a5c1f9d5fd35b51c5f1b3f8f530e2547

Mesh loop-island api: reuse the memory arena

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

M	source/blender/blenkernel/BKE_mesh_mapping.h
M	source/blender/blenkernel/intern/mesh_mapping.c

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

diff --git a/source/blender/blenkernel/BKE_mesh_mapping.h b/source/blender/blenkernel/BKE_mesh_mapping.h
index 0ae740a..41cb270 100644
--- a/source/blender/blenkernel/BKE_mesh_mapping.h
+++ b/source/blender/blenkernel/BKE_mesh_mapping.h
@@ -155,6 +155,7 @@ typedef struct MeshIslands {
 void BKE_mesh_loop_islands_init(
         MeshIslands *islands,
         const short item_type, const int num_items, const short island_type);
+void BKE_mesh_loop_islands_clear(MeshIslands *islands);
 void BKE_mesh_loop_islands_free(MeshIslands *islands);
 void BKE_mesh_loop_islands_add(
         MeshIslands *islands, const int num_items, int *item_indices,
diff --git a/source/blender/blenkernel/intern/mesh_mapping.c b/source/blender/blenkernel/intern/mesh_mapping.c
index 928d300..dee02c2 100644
--- a/source/blender/blenkernel/intern/mesh_mapping.c
+++ b/source/blender/blenkernel/intern/mesh_mapping.c
@@ -574,13 +574,16 @@ void BKE_mesh_loop_islands_init(
         MeshIslands *islands,
         const short item_type, const int num_items, const short island_type)
 {
-	MemArena *mem = BLI_memarena_new(BLI_MEMARENA_STD_BUFSIZE, __func__);
+	MemArena *mem = islands->mem;
+
+	if (mem == NULL) {
+		mem = BLI_memarena_new(BLI_MEMARENA_STD_BUFSIZE, __func__);
+	}
+	/* else memarena should be cleared */
 
 	BLI_assert(ELEM(item_type, MISLAND_TYPE_VERT, MISLAND_TYPE_EDGE, MISLAND_TYPE_POLY, MISLAND_TYPE_LOOP));
 	BLI_assert(ELEM(island_type, MISLAND_TYPE_VERT, MISLAND_TYPE_EDGE, MISLAND_TYPE_POLY, MISLAND_TYPE_LOOP));
 
-	BKE_mesh_loop_islands_free(islands);
-
 	islands->item_type = item_type;
 	islands->nbr_items = num_items;
 	islands->items_to_islands_idx = BLI_memarena_alloc(mem, sizeof(*islands->items_to_islands_idx) * (size_t)num_items);
@@ -592,14 +595,8 @@ void BKE_mesh_loop_islands_init(
 	islands->mem = mem;
 }
 
-void BKE_mesh_loop_islands_free(MeshIslands *islands)
+void BKE_mesh_loop_islands_clear(MeshIslands *islands)
 {
-	MemArena *mem = islands->mem;
-
-	if (mem) {
-		BLI_memarena_free(mem);
-	}
-
 	islands->item_type = 0;
 	islands->nbr_items = 0;
 	islands->items_to_islands_idx = NULL;
@@ -608,10 +605,21 @@ void BKE_mesh_loop_islands_free(MeshIslands *islands)
 	islands->nbr_islands = 0;
 	islands->islands = NULL;
 
-	islands->mem = NULL;
+	if (islands->mem) {
+		BLI_memarena_clear(islands->mem);
+		islands->mem = NULL;
+	}
+
 	islands->allocated_islands = 0;
 }
 
+void BKE_mesh_loop_islands_free(MeshIslands *islands)
+{
+	if (islands->mem) {
+		BLI_memarena_free(islands->mem);
+	}
+}
+
 void BKE_mesh_loop_islands_add(
         MeshIslands *islands, const int num_items, int *items_indices,
         const int num_island_items, int *island_item_indices)
@@ -679,7 +687,7 @@ bool BKE_mesh_calc_islands_loop_poly_uv(
 
 	int grp_idx, p_idx, pl_idx, l_idx;
 
-	BKE_mesh_loop_islands_free(r_islands);
+	BKE_mesh_loop_islands_clear(r_islands);
 	BKE_mesh_loop_islands_init(r_islands, MISLAND_TYPE_LOOP, totloop, MISLAND_TYPE_POLY);
 
 	poly_loop_islands_calc(