TexturePaint: Missing Texture Depth Test

Depth testing was off as it used the precomputed ModelView matrix. As
draw engines currently use a different approach the depth was sometimes
a bit off making the color disappear.

This change will use a different vertex shader that will write the
correct depth. I expected the same change to be needed in the bone
selection overlay but was not able to reproduce it.

Reviewed By: fclem

Maniphest Tasks: T64615

Differential Revision: https://developer.blender.org/D5006

2 files changed, 21 insertions, 10 deletions

diff --git a/source/blender/draw/modes/shaders/paint_face_selection_vert.glsl b/source/blender/draw/modes/shaders/paint_face_selection_vert.glsl
new file mode 100644
index 00000000000..4b5191ead07
--- /dev/null
+++ b/source/blender/draw/modes/shaders/paint_face_selection_vert.glsl
@@ -0,0 +1,19 @@
+
+in vec3 pos;
+in vec4 nor; /* select flag on the 4th component */
+
+void main()
+{
+  vec3 world_pos = point_object_to_world(pos);
+  gl_Position = point_world_to_ndc(world_pos);
+
+  /* Don't draw faces that are selected. */
+  if (nor.w > 0.0) {
+    gl_Position = vec4(0.0, 0.0, 0.0, 1.0);
+  }
+  else {
+#ifdef USE_WORLD_CLIP_PLANES
+    world_clip_planes_calc_clip_distance(world_pos);
+#endif
+  }
+}
diff --git a/source/blender/draw/modes/shaders/paint_face_vert.glsl b/source/blender/draw/modes/shaders/paint_face_vert.glsl
index 4b5191ead07..d135071c15c 100644
--- a/source/blender/draw/modes/shaders/paint_face_vert.glsl
+++ b/source/blender/draw/modes/shaders/paint_face_vert.glsl
@@ -1,19 +1,11 @@
-
 in vec3 pos;
-in vec4 nor; /* select flag on the 4th component */
 
 void main()
 {
   vec3 world_pos = point_object_to_world(pos);
   gl_Position = point_world_to_ndc(world_pos);
 
-  /* Don't draw faces that are selected. */
-  if (nor.w > 0.0) {
-    gl_Position = vec4(0.0, 0.0, 0.0, 1.0);
-  }
-  else {
 #ifdef USE_WORLD_CLIP_PLANES
-    world_clip_planes_calc_clip_distance(world_pos);
+  world_clip_planes_calc_clip_distance(world_pos);
 #endif
-  }
-}
+}
\ No newline at end of file