Fix T39517,

Issue here is that "show diffuse" option does not respect its intended
purpose which is to be used only for masking.

There are a couple of caveats here:

Dyntopo and multires -always- have mask data enabled, and thus as soon
as one goes to dyntopo mode or adds a multires modifier he would get the
default grey color instead.

Matcaps would break when nodes asked for a diffuse material color (this
was broken before too). Solved by adding global material state for when
matcaps are enabled. Also matcaps don't always played well with VBOs
off.

Added a few more missing updates for mask operators to notify
show_diffuse property as changed. This was also needed on rebuilding
dyntopo pbvh.

Also make zero mask color duller again after artist feedback.

1 files changed, 1 insertions, 0 deletions

diff --git a/source/blender/gpu/GPU_draw.h b/source/blender/gpu/GPU_draw.h
index 7e2f4655cb1..ee1eabc2a15 100644
--- a/source/blender/gpu/GPU_draw.h
+++ b/source/blender/gpu/GPU_draw.h
@@ -76,6 +76,7 @@ int GPU_enable_material(int nr, void *attribs);
 void GPU_disable_material(void);
 
 void GPU_material_diffuse_get(int nr, float diff[4]);
+bool GPU_material_use_matcaps_get(void);
 
 void GPU_set_material_alpha_blend(int alphablend);
 int GPU_get_material_alpha_blend(void);