Add CCGKey/CCGElem for accessing CCGSubSurf elements.

CCGKey caches information about the CCGSubSurf element layout. This
data, along with the CCG_* inline functions, allows access to
CCGSubSurf elements with an arbitrary number of layers (as opposed to
the hardcoded DMGridData structure which assumes xyz coordinates
followed by three normal components.)

The CCGElem structure is declared but not defined anywhere, just used
as a convenient type.

1 files changed, 28 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/CCGSubSurf.c b/source/blender/blenkernel/intern/CCGSubSurf.c
index db2f41aca3e..a15d5938641 100644
--- a/source/blender/blenkernel/intern/CCGSubSurf.c
+++ b/source/blender/blenkernel/intern/CCGSubSurf.c
@@ -7,6 +7,7 @@
 #include <string.h>
 #include <math.h>
 
+#include "BKE_ccg.h"
 #include "CCGSubSurf.h"
 #include "BKE_subsurf.h"
 
@@ -3101,3 +3102,30 @@ int ccgSubSurf_getNumFinalFaces(const CCGSubSurf *ss)
 	int numFinalFaces = ss->numGrids * ((gridSize - 1) * (gridSize - 1));
 	return numFinalFaces;
 }
+
+/***/
+
+void CCG_key(CCGKey *key, const CCGSubSurf *ss, int level)
+{
+	key->level = level;
+	
+	key->elem_size = ss->meshIFC.vertDataSize;
+	key->has_normals = ss->calcVertNormals;
+	key->num_layers = ss->meshIFC.numLayers;
+	
+	/* if normals are present, always the last three floats of an
+	   element */
+	if (key->has_normals)
+		key->normal_offset = key->elem_size - sizeof(float) * 3;
+	else
+		key->normal_offset = -1;
+
+	key->grid_size = ccgSubSurf_getGridLevelSize(ss, level);
+	key->grid_area = key->grid_size * key->grid_size;
+	key->grid_bytes = key->elem_size * key->grid_area;
+}
+
+void CCG_key_top_level(CCGKey *key, const CCGSubSurf *ss)
+{
+	CCG_key(key, ss, ccgSubSurf_getSubdivisionLevels(ss));
+}