Skip hidden faces in PBVH BMesh ray intersection test

Moved the GPU function gpu_bmesh_face_visible() to BKE_paint and
inverted the test to match equivalent tests for other mesh types:
paint_is_bmesh_face_hidden().

Changed BKE_pbvh_bmesh_node_save_orig() to not save hidden faces into
the triangle array.

Modified the non-use-original branch of pbvh_bmesh_node_raycast() to
skip hidden faces.

Fixes bug #33914:
projects.blender.org/tracker/index.php?func=detail&aid=33914&group_id=9&atid=498

1 files changed, 18 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/paint.c b/source/blender/blenkernel/intern/paint.c
index 5847e7508f0..dc8aed91c00 100644
--- a/source/blender/blenkernel/intern/paint.c
+++ b/source/blender/blenkernel/intern/paint.c
@@ -47,6 +47,8 @@
 #include "BKE_paint.h"
 #include "BKE_subsurf.h"
 
+#include "bmesh.h"
+
 #include <stdlib.h>
 #include <string.h>
 
@@ -224,6 +226,22 @@ int paint_is_grid_face_hidden(const unsigned int *grid_hidden,
 	        BLI_BITMAP_GET(grid_hidden, (y + 1) * gridsize + x));
 }
 
+/* Return TRUE if all vertices in the face are visible, FALSE otherwise */
+int paint_is_bmesh_face_hidden(BMFace *f)
+{
+	BMLoop *l_iter;
+	BMLoop *l_first;
+
+	l_iter = l_first = BM_FACE_FIRST_LOOP(f);
+	do {
+		if (BM_elem_flag_test(l_iter->v, BM_ELEM_HIDDEN)) {
+			return true;
+		}
+	} while ((l_iter = l_iter->next) != l_first);
+
+	return false;
+}
+
 float paint_grid_paint_mask(const GridPaintMask *gpm, unsigned level,
                             unsigned x, unsigned y)
 {