[Bf-blender-cvs] [7c443ded1e2] blender2.8: Vertex Paint: multiply vertex paint overlay

[Jacques Lucke]

Commit: 7c443ded1e2b5b0b4cec940871cee9602004f17c
Author: Jacques Lucke
Date:   Fri Oct 5 14:03:22 2018 +0200
Branches: blender2.8
https://developer.blender.org/rB7c443ded1e2b5b0b4cec940871cee9602004f17c

Vertex Paint: multiply vertex paint overlay

Fixes the first part of T56999.

Reviewer: brecht

Differential Revision: https://developer.blender.org/D3768

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

M	source/blender/draw/modes/paint_vertex_mode.c
M	source/blender/draw/modes/shaders/paint_vertex_frag.glsl

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

diff --git a/source/blender/draw/modes/paint_vertex_mode.c b/source/blender/draw/modes/paint_vertex_mode.c
index 236f76367d4..d026e7a7924 100644
--- a/source/blender/draw/modes/paint_vertex_mode.c
+++ b/source/blender/draw/modes/paint_vertex_mode.c
@@ -115,10 +115,10 @@ static void PAINT_VERTEX_cache_init(void *vedata)
 		/* Create a pass */
 		psl->vcolor_faces = DRW_pass_create(
 		        "Vert Color Pass",
-		        DRW_STATE_WRITE_COLOR | DRW_STATE_DEPTH_EQUAL | DRW_STATE_BLEND);
+		        DRW_STATE_WRITE_COLOR | DRW_STATE_DEPTH_EQUAL | DRW_STATE_MULTIPLY);
 
 		stl->g_data->fvcolor_shgrp = DRW_shgroup_create(e_data.vcolor_face_shader, psl->vcolor_faces);
-		DRW_shgroup_uniform_float(stl->g_data->fvcolor_shgrp, "alpha", &v3d->overlay.vertex_paint_mode_opacity, 1);
+		DRW_shgroup_uniform_float_copy(stl->g_data->fvcolor_shgrp, "white_factor", 1.0f - v3d->overlay.vertex_paint_mode_opacity);
 	}
 
 	{
diff --git a/source/blender/draw/modes/shaders/paint_vertex_frag.glsl b/source/blender/draw/modes/shaders/paint_vertex_frag.glsl
index 2c968dafa69..3ff264a5e22 100644
--- a/source/blender/draw/modes/shaders/paint_vertex_frag.glsl
+++ b/source/blender/draw/modes/shaders/paint_vertex_frag.glsl
@@ -2,7 +2,8 @@
 in vec3 finalColor;
 
 out vec4 fragColor;
-uniform float alpha = 1.0;
+uniform float white_factor = 1.0;
+
 vec3 linear_to_srgb_attrib(vec3 c) {
 	c = max(c, vec3(0.0));
 	vec3 c1 = c * 12.92;
@@ -12,6 +13,6 @@ vec3 linear_to_srgb_attrib(vec3 c) {
 
 void main()
 {
-	fragColor.rgb = linear_to_srgb_attrib(finalColor);
-	fragColor.a = alpha;
+	fragColor.rgb = mix(linear_to_srgb_attrib(finalColor), vec3(1.0), white_factor);
+	fragColor.a = 1.0;
 }