[Bf-blender-cvs] [4723644e7f5] master: Fix T67587 Overlay: WeightPaint color blends with background in wireframe mode

[Clément Foucault]

Commit: 4723644e7f5b9ac607844fb9c43fafda7360e606
Author: Clément Foucault
Date:   Wed Jul 1 19:11:22 2020 +0200
Branches: master
https://developer.blender.org/rB4723644e7f5b9ac607844fb9c43fafda7360e606

Fix T67587 Overlay: WeightPaint color blends with background in wireframe mode

Fix this by rendering to the overlay framebuffer when using alpha blend
mode.

===================================================================

M	source/blender/draw/engines/overlay/overlay_paint.c

===================================================================

diff --git a/source/blender/draw/engines/overlay/overlay_paint.c b/source/blender/draw/engines/overlay/overlay_paint.c
index 456c56f9c03..652d6af54a2 100644
--- a/source/blender/draw/engines/overlay/overlay_paint.c
+++ b/source/blender/draw/engines/overlay/overlay_paint.c
@@ -254,11 +254,18 @@ void OVERLAY_paint_draw(OVERLAY_Data *vedata)
   OVERLAY_PrivateData *pd = stl->pd;
 
   OVERLAY_PassList *psl = vedata->psl;
+  OVERLAY_FramebufferList *fbl = vedata->fbl;
   DefaultFramebufferList *dfbl = DRW_viewport_framebuffer_list_get();
 
   if (DRW_state_is_fbo()) {
-    /* Paint overlay needs final color because of multiply blend mode. */
-    GPU_framebuffer_bind(pd->painting.in_front ? dfbl->in_front_fb : dfbl->default_fb);
+    if (pd->painting.alpha_blending) {
+      GPU_framebuffer_bind(pd->painting.in_front ? fbl->overlay_in_front_fb :
+                                                   fbl->overlay_default_fb);
+    }
+    else {
+      /* Paint overlay needs final color because of multiply blend mode. */
+      GPU_framebuffer_bind(pd->painting.in_front ? dfbl->in_front_fb : dfbl->default_fb);
+    }
   }
 
   if (psl->paint_depth_ps) {