Workbench: make normal packing optional

1 files changed, 10 insertions, 4 deletions

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 8b03b058301..008ab90d7a3 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_common_lib.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_common_lib.glsl
@@ -15,21 +15,27 @@ float bayer_dither_noise() {
 
 /* From http://aras-p.info/texts/CompactNormalStorage.html
  * Using Method #4: Spheremap Transform */
-vec3 normal_decode(vec2 enc)
+vec3 normal_decode(vec3 enc)
 {
-	vec2 fenc = enc * 4.0 - 2.0;
+	vec2 fenc = enc.xy * 4.0 - 2.0;
 	float f = dot(fenc, fenc);
 	float g = sqrt(1.0 - f / 4.0);
 	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 */
-vec2 normal_encode(vec3 n)
+vec3 normal_encode(vec3 n)
 {
 	float p = sqrt(n.z * 8.0 + 8.0);
-	return n.xy / p + 0.5;
+	vec3 result = vec3(n.xyz / p + 0.5);
+	result.z = (gl_FrontFacing)? 0.0: 1.0;
+	return result;
 }