Workbench: Cleanups and reduce shader variations

Also optimize deferred engine by only outputing material data if needed.
This make the bare flat shading mode (no effects) only a depth prepass.

1 files changed, 39 insertions, 38 deletions

diff --git a/source/blender/draw/engines/workbench/shaders/workbench_prepass_frag.glsl b/source/blender/draw/engines/workbench/shaders/workbench_prepass_frag.glsl
index 93170037c4b..722add22a89 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_prepass_frag.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_prepass_frag.glsl
@@ -4,69 +4,70 @@ uniform vec3 materialDiffuseColor;
 uniform float materialMetallic;
 uniform float materialRoughness;
 
-#ifdef V3D_SHADING_TEXTURE_COLOR
 uniform sampler2D image;
 uniform float ImageTransparencyCutoff = 0.1;
 
-#endif
-
 #ifdef NORMAL_VIEWPORT_PASS_ENABLED
 in vec3 normal_viewport;
-#endif /* NORMAL_VIEWPORT_PASS_ENABLED */
+#endif
 
 #ifdef V3D_SHADING_TEXTURE_COLOR
 in vec2 uv_interp;
-#endif /* V3D_SHADING_TEXTURE_COLOR */
+#endif
 
 #ifdef HAIR_SHADER
 flat in float hair_rand;
 #endif
 
-layout(location=0) out uint objectId;
-layout(location=1) out vec4 materialData;
+#ifdef MATDATA_PASS_ENABLED
+layout(location=0) out vec4 materialData;
+#endif
+#ifdef OBJECT_ID_PASS_ENABLED
+layout(location=1) out uint objectId;
+#endif
 #ifdef NORMAL_VIEWPORT_PASS_ENABLED
-#  ifdef WORKBENCH_ENCODE_NORMALS
-layout(location=2) out vec2 normalViewport;
-#  else /* WORKBENCH_ENCODE_NORMALS */
-layout(location=2) out vec3 normalViewport;
-#  endif /* WORKBENCH_ENCODE_NORMALS */
-#endif /* NORMAL_VIEWPORT_PASS_ENABLED */
+layout(location=2) out WB_Normal normalViewport;
+#endif
 
 void main()
 {
-	objectId = uint(object_id);
+#ifdef MATDATA_PASS_ENABLED
+	float metallic, roughness;
+	vec4 color;
 
-	vec4 color_roughness;
-#ifdef V3D_SHADING_TEXTURE_COLOR
-	color_roughness = texture(image, uv_interp);
-	if (color_roughness.a < ImageTransparencyCutoff) {
+#  ifdef V3D_SHADING_TEXTURE_COLOR
+	color = texture(image, uv_interp);
+	if (color.a < ImageTransparencyCutoff) {
 		discard;
 	}
-	color_roughness.a = materialRoughness;
-#else
-	color_roughness = vec4(materialDiffuseColor, materialRoughness);
-#endif /* V3D_SHADING_TEXTURE_COLOR */
-
-#ifdef HAIR_SHADER
-	float hair_color_variation = hair_rand * 0.1;
-	color_roughness = clamp(color_roughness - hair_color_variation, 0.0, 1.0);
-#endif
-
-	float metallic;
-#ifdef V3D_SHADING_SPECULAR_HIGHLIGHT
-#  ifdef HAIR_SHADER
-	metallic = clamp(materialMetallic - hair_color_variation, 0.0, 1.0);
 #  else
-	metallic = materialMetallic;
+	color.rgb = materialDiffuseColor;
 #  endif
-#elif defined(V3D_LIGHTING_MATCAP)
+
+#  ifdef V3D_LIGHTING_MATCAP
 	/* Encode front facing in metallic channel. */
 	metallic = float(gl_FrontFacing);
-	color_roughness.a = 0.0;
-#endif
+	roughness = 0.0;
+#  else
+	metallic = materialMetallic;
+	roughness = materialRoughness;
+#  endif
 
-	materialData.rgb = color_roughness.rgb;
-	materialData.a   = workbench_float_pair_encode(color_roughness.a, metallic);
+#  ifdef HAIR_SHADER
+	/* Add some variation to the hairs to avoid uniform look. */
+	float hair_variation = hair_rand * 0.1;
+	color = clamp(color - hair_variation, 0.0, 1.0);
+	metallic = clamp(materialMetallic - hair_variation, 0.0, 1.0);
+	roughness = clamp(materialRoughness - hair_variation, 0.0, 1.0);
+#  endif
+
+	materialData.rgb = color.rgb;
+	materialData.a   = workbench_float_pair_encode(roughness, metallic);
+#endif /* MATDATA_PASS_ENABLED */
+
+#ifdef OBJECT_ID_PASS_ENABLED
+	objectId = uint(object_id);
+#endif
 
 #ifdef NORMAL_VIEWPORT_PASS_ENABLED
 	vec3 n = (gl_FrontFacing) ? normal_viewport : -normal_viewport;