1 files changed, 6 insertions, 10 deletions
diff --git a/indra/newview/app_settings/shaders/class2/deferred/spotLightF.glsl b/indra/newview/app_settings/shaders/class2/deferred/spotLightF.glsl
index 0436c80710..4fc9a6ad87 100755
--- a/indra/newview/app_settings/shaders/class2/deferred/spotLightF.glsl
+++ b/indra/newview/app_settings/shaders/class2/deferred/spotLightF.glsl
@@ -71,20 +71,16 @@ uniform mat4 inv_proj;
 #ifdef SINGLE_FP_ONLY
 vec2 encode_normal(vec3 n)
 {
-	float f = sqrt(2 * n.z + 2);
-	return (n.xy / vec2(f)) + vec2(0.5f);
+	vec2 sn;
+	sn.xy = (n.xy * vec2(0.5f,0.5f)) + vec2(0.5f,0.5f);
 }
 
 vec3 decode_normal (vec2 enc)
 {
-    vec2 fenc = enc - 0.5f;
-    float f = dot(fenc,fenc);
-    f = clamp(f,0.0f,1.0f);
-    float g = sqrt(1-f);
-    vec3 n;
-    n.xy = fenc*g;
-    n.z = 1.0f - (f * 0.5f);
-    return normalize(n);
+	vec3 n;
+	n.xy = (enc.xy * vec2(2.0f,2.0f)) - vec2(1.0f,1.0f);
+	n.z = sqrt(1.0f - dot(n.xy,n.xy));
+	return n;
 }
 #else
 vec2 encode_normal(vec3 n)