OpenSubdiv: Completely avoid possible access to non-existing CPU data

Make it so CCGDM reports 0 number of geometry when it uses GPU backend for
drawing. This screws up a bit statistics in info header and requires to have
some special handle of CCGDM in the drawing code, but makes it so non of the
areas will try to access non-existing geometry.

1 files changed, 10 insertions, 3 deletions

diff --git a/source/blender/editors/space_view3d/drawobject.c b/source/blender/editors/space_view3d/drawobject.c
index 82acc5863c4..f8af238de14 100644
--- a/source/blender/editors/space_view3d/drawobject.c
+++ b/source/blender/editors/space_view3d/drawobject.c
@@ -74,6 +74,7 @@
 #include "BKE_particle.h"
 #include "BKE_pointcache.h"
 #include "BKE_scene.h"
+#include "BKE_subsurf.h"
 #include "BKE_unit.h"
 #include "BKE_tracking.h"
 
@@ -4027,9 +4028,15 @@ static void draw_mesh_fancy(Scene *scene, ARegion *ar, View3D *v3d, RegionView3D
 	}
 	
 	/* check polys instead of tessfaces because of dyntopo where tessfaces don't exist */
-	no_edges = (dm->getNumEdges(dm) == 0);
-	no_faces = (dm->getNumPolys(dm) == 0);
-	
+	if (dm->type == DM_TYPE_CCGDM) {
+		no_edges = !subsurf_has_edges(dm);
+		no_faces = !subsurf_has_faces(dm);
+	}
+	else {
+		no_edges = (dm->getNumEdges(dm) == 0);
+		no_faces = (dm->getNumPolys(dm) == 0);
+	}
+
 	/* vertexpaint, faceselect wants this, but it doesnt work for shaded? */
 	glFrontFace((ob->transflag & OB_NEG_SCALE) ? GL_CW : GL_CCW);