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, 9 insertions, 1 deletions

diff --git a/source/blender/gpu/intern/gpu_draw.c b/source/blender/gpu/intern/gpu_draw.c
index fba7e028830..64ab701acba 100644
--- a/source/blender/gpu/intern/gpu_draw.c
+++ b/source/blender/gpu/intern/gpu_draw.c
@@ -1342,6 +1342,7 @@ static struct GPUMaterialState {
 	GPUBlendMode *alphablend;
 	GPUBlendMode alphablend_fixed[FIXEDMAT];
 	bool use_alpha_pass, is_alpha_pass;
+	bool use_matcaps;
 
 	int lastmatnr, lastretval;
 	GPUBlendMode lastalphablend;
@@ -1409,6 +1410,7 @@ void GPU_begin_object_materials(View3D *v3d, RegionView3D *rv3d, Scene *scene, O
 	GMS.lastmatnr = -1;
 	GMS.lastretval = -1;
 	GMS.lastalphablend = GPU_BLEND_SOLID;
+	GMS.use_matcaps = use_matcap;
 
 	GMS.backface_culling = (v3d->flag2 & V3D_BACKFACE_CULLING) != 0;
 
@@ -1444,7 +1446,7 @@ void GPU_begin_object_materials(View3D *v3d, RegionView3D *rv3d, Scene *scene, O
 	if (use_matcap) {
 		GMS.gmatbuf[0] = v3d->defmaterial;
 		GPU_material_matcap(scene, v3d->defmaterial);
-		
+
 		/* do material 1 too, for displists! */
 		memcpy(&GMS.matbuf[1], &GMS.matbuf[0], sizeof(GPUMaterialFixed));
 	
@@ -1656,6 +1658,12 @@ void GPU_material_diffuse_get(int nr, float diff[4])
 	}
 }
 
+bool GPU_material_use_matcaps_get(void)
+{
+	return GMS.use_matcaps;
+}
+
+
 void GPU_end_object_materials(void)
 {
 	GPU_disable_material();