[Bf-blender-cvs] [6c1a121aef0] blender2.8-workbench: Workbench: normal packing

[Jeroen Bakker]

Commit: 6c1a121aef0e2a1fb06121a44d3d57eca20a003e
Author: Jeroen Bakker
Date:   Wed Apr 25 21:33:59 2018 +0200
Branches: blender2.8-workbench
https://developer.blender.org/rB6c1a121aef0e2a1fb06121a44d3d57eca20a003e

Workbench: normal packing

Normal packing. The sign is stored in the A of the color buffer.
if the A == 1.0 the normal should be inverted. before use.

The reason is that packing has more precision for frontfaces, than for
backfaces

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

M	source/blender/draw/engines/workbench/shaders/workbench_common_lib.glsl
M	source/blender/draw/engines/workbench/shaders/workbench_composite_frag.glsl
M	source/blender/draw/engines/workbench/shaders/workbench_prepass_frag.glsl
M	source/blender/draw/engines/workbench/workbench_materials.c

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

diff --git a/source/blender/draw/engines/workbench/shaders/workbench_common_lib.glsl b/source/blender/draw/engines/workbench/shaders/workbench_common_lib.glsl
index 008ab90d7a3..e9d9b8c02e8 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_common_lib.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_common_lib.glsl
@@ -15,7 +15,7 @@ float bayer_dither_noise() {
 
 /* From http://aras-p.info/texts/CompactNormalStorage.html
  * Using Method #4: Spheremap Transform */
-vec3 normal_decode(vec3 enc)
+vec3 normal_decode(vec2 enc)
 {
 	vec2 fenc = enc.xy * 4.0 - 2.0;
 	float f = dot(fenc, fenc);
@@ -23,19 +23,13 @@ vec3 normal_decode(vec3 enc)
 	vec3 n;
 	n.xy = fenc*g;
 	n.z = 1 - f / 2;
-
-	if (enc.z > 0.5) {
-		n = -n;
-	}
 	return n;
 }
 
 /* From http://aras-p.info/texts/CompactNormalStorage.html
  * Using Method #4: Spheremap Transform */
-vec3 normal_encode(vec3 n)
+vec2 normal_encode(vec3 n)
 {
 	float p = sqrt(n.z * 8.0 + 8.0);
-	vec3 result = vec3(n.xyz / p + 0.5);
-	result.z = (gl_FrontFacing)? 0.0: 1.0;
-	return result;
+	return vec2(n.xy / p + 0.5);
 }
diff --git a/source/blender/draw/engines/workbench/shaders/workbench_composite_frag.glsl b/source/blender/draw/engines/workbench/shaders/workbench_composite_frag.glsl
index 89e5b882536..6a5d6c71aba 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_composite_frag.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_composite_frag.glsl
@@ -40,18 +40,22 @@ void main()
 	}
 #endif /* !V3D_DRAWOPTION_OBJECT_OVERLAP */
 
-	vec3 diffuse_color = texelFetch(colorBuffer, texel, 0).rgb;
 
 #ifdef V3D_LIGHTING_STUDIO
+	vec4 diffuse_color = texelFetch(colorBuffer, texel, 0);
 #ifdef WORKBENCH_ENCODE_NORMALS
-	vec3 normal_viewport = normal_decode(texelFetch(normalBuffer, texel, 0).rgb);
-#else
+	vec3 normal_viewport = normal_decode(texelFetch(normalBuffer, texel, 0).rg);
+	if (diffuse_color.a == 1.0) {
+		normal_viewport = - normal_viewport;
+	}
+#else /* WORKBENCH_ENCODE_NORMALS */
 	vec3 normal_viewport = texelFetch(normalBuffer, texel, 0).rgb;
-#endif
+#endif /* WORKBENCH_ENCODE_NORMALS */
 	vec3 diffuse_light = get_world_diffuse_light(world_data, normal_viewport);
-	vec3 shaded_color = diffuse_light * diffuse_color;
+	vec3 shaded_color = diffuse_light * diffuse_color.rgb;
 
 #else /* V3D_LIGHTING_STUDIO */
+	vec3 diffuse_color = texelFetch(colorBuffer, texel, 0).rgb;
 	vec3 shaded_color = diffuse_color;
 #endif /* V3D_LIGHTING_STUDIO */
 
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 32133914e65..1535ab2e36f 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_prepass_frag.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_prepass_frag.glsl
@@ -4,17 +4,25 @@ uniform vec3 object_color = vec3(1.0, 0.0, 1.0);
 in vec3 normal_viewport;
 
 out uint objectId;
-out vec3 diffuseColor;
+out vec4 diffuseColor;
+#ifdef WORKBENCH_ENCODE_NORMALS
+out vec2 normalViewport;
+#else
 out vec3 normalViewport;
-
+#endif
 
 void main()
 {
 	objectId = uint(object_id);
-	diffuseColor = object_color;
+	diffuseColor = vec4(object_color, 0.0);
 #ifdef WORKBENCH_ENCODE_NORMALS
-	normalViewport = normal_encode(normal_viewport);
-#else
+	if (!gl_FrontFacing) {
+		normalViewport = normal_encode(-normal_viewport);
+		diffuseColor.a = 1.0;
+	} else {
+		normalViewport = normal_encode(normal_viewport);
+	}
+#else /* WORKBENCH_ENCODE_NORMALS */
 	normalViewport = normal_viewport;
-#endif
+#endif /* WORKBENCH_ENCODE_NORMALS */
 }
diff --git a/source/blender/draw/engines/workbench/workbench_materials.c b/source/blender/draw/engines/workbench/workbench_materials.c
index 6fc416c068e..2ee87c9f2ce 100644
--- a/source/blender/draw/engines/workbench/workbench_materials.c
+++ b/source/blender/draw/engines/workbench/workbench_materials.c
@@ -206,7 +206,7 @@ void workbench_materials_engine_init(WORKBENCH_Data *vedata)
 		e_data.object_id_tx = DRW_texture_pool_query_2D(size[0], size[1], DRW_TEX_R_32U, &draw_engine_workbench_solid);
 		e_data.color_buffer_tx = DRW_texture_pool_query_2D(size[0], size[1], DRW_TEX_RGBA_8, &draw_engine_workbench_solid);
 #ifdef WORKBENCH_ENCODE_NORMALS
-		e_data.normal_buffer_tx = DRW_texture_pool_query_2D(size[0], size[1], DRW_TEX_RGBA_8, &draw_engine_workbench_solid);
+		e_data.normal_buffer_tx = DRW_texture_pool_query_2D(size[0], size[1], DRW_TEX_RG_8, &draw_engine_workbench_solid);
 #else
 		e_data.normal_buffer_tx = DRW_texture_pool_query_2D(size[0], size[1], DRW_TEX_RGBA_32, &draw_engine_workbench_solid);
 #endif