Workbench: Add transparency support for materials

This adds the posibility of having certain materials transparent in solid
mode. The option is (for now) per material only and thus only shows in
material color mode.

This uses the same rendering technique as Xray mode.

Note that objects are not considered transparent for selection with this.

1 files changed, 11 insertions, 4 deletions

diff --git a/source/blender/draw/engines/workbench/shaders/workbench_forward_composite_frag.glsl b/source/blender/draw/engines/workbench/shaders/workbench_forward_composite_frag.glsl
index cb5516ca34f..b1f08cfef15 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_forward_composite_frag.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_forward_composite_frag.glsl
@@ -5,10 +5,13 @@ uniform sampler2D transparentAccum;
 uniform sampler2D transparentRevealage;
 uniform vec2 invertedViewportSize;
 
+#ifndef ALPHA_COMPOSITE
 layout(std140) uniform world_block {
 	WorldData world_data;
 };
+#endif
 
+/* TODO: Bypass the whole shader if there is no xray pass and no outline pass. */
 void main()
 {
 	ivec2 texel = ivec2(gl_FragCoord.xy);
@@ -19,17 +22,21 @@ void main()
 	float trans_revealage = trans_accum.a;
 	trans_accum.a = texelFetch(transparentRevealage, texel, 0).r;
 
+	vec3 trans_color = trans_accum.rgb / clamp(trans_accum.a, 1e-4, 5e4);
+
+#ifndef ALPHA_COMPOSITE
 	vec3 bg_color = background_color(world_data, uv_viewport.y);
 
-	/* TODO: Bypass the whole shader if there is no xray pass and no outline pass. */
-	vec3 trans_color = trans_accum.rgb / clamp(trans_accum.a, 1e-4, 5e4);
 	vec3 color = mix(trans_color, bg_color, trans_revealage);
 
-#ifdef V3D_SHADING_OBJECT_OUTLINE
+#  ifdef V3D_SHADING_OBJECT_OUTLINE
 	uint object_id = texelFetch(objectId, texel, 0).r;
 	float outline = calculate_object_outline(objectId, texel, object_id);
 	color = mix(world_data.object_outline_color.rgb, color, outline);
-#endif
+#  endif
 
 	fragColor = vec4(color, 1.0);
+#else
+	fragColor = vec4(trans_color, 1.0 - trans_revealage);
+#endif
 }