bmesh - python api

- bm.*.layers.*.verify()
- bm.*.layers.*.is_singleton
- bm.*.layers.*.copy_from(other)


also added api functons
- BM_data_layer_copy(...)
- CustomData_layertype_is_singleton(type)

2 files changed, 16 insertions, 1 deletions

diff --git a/source/blender/blenkernel/BKE_customdata.h b/source/blender/blenkernel/BKE_customdata.h
index 6a3625e2133..4b52189d8b7 100644
--- a/source/blender/blenkernel/BKE_customdata.h
+++ b/source/blender/blenkernel/BKE_customdata.h
@@ -305,6 +305,7 @@ int CustomData_sizeof(int type);
 
 /* get the name of a layer type */
 const char *CustomData_layertype_name(int type);
+int         CustomData_layertype_is_singleton(int type);
 
 /* make sure the name of layer at index is unique */
 void CustomData_set_layer_unique_name(struct CustomData *data, int index);
diff --git a/source/blender/blenkernel/intern/customdata.c b/source/blender/blenkernel/intern/customdata.c
index 4666aa6a456..4cf48ff6005 100644
--- a/source/blender/blenkernel/intern/customdata.c
+++ b/source/blender/blenkernel/intern/customdata.c
@@ -71,7 +71,11 @@ typedef struct LayerTypeInfo {
 	int size;          /* the memory size of one element of this layer's data */
 	const char *structname;  /* name of the struct used, for file writing */
 	int structnum;     /* number of structs per element, for file writing */
-	const char *defaultname; /* default layer name */
+
+	/* default layer name.
+	 * note! when NULL this is a way to ensure there is only ever one item
+	 * see: CustomData_layertype_is_singleton() */
+	const char *defaultname;
 
 	/* a function to copy count elements of this layer's data
 	 * (deep copy if appropriate)
@@ -2601,6 +2605,16 @@ const char *CustomData_layertype_name(int type)
 	return layerType_getName(type);
 }
 
+
+/**
+ * Can only ever be one of these.
+ */
+int CustomData_layertype_is_singleton(int type)
+{
+	const LayerTypeInfo *typeInfo = layerType_getInfo(type);
+	return typeInfo->defaultname != NULL;
+}
+
 static int  CustomData_is_property_layer(int type)
 {
 	if ((type == CD_PROP_FLT) || (type == CD_PROP_INT) || (type == CD_PROP_STR))