1 files changed, 33 insertions, 10 deletions
diff --git a/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl b/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl
index 31b2a32f7f..520b3bbd47 100755
--- a/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl
+++ b/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl
@@ -78,16 +78,39 @@ vec3 vary_AtmosAttenuation;
 uniform mat4 inv_proj;
 uniform vec2 screen_res;
 
-vec3 decode_normal (vec2 enc)
-{
-    vec2 fenc = enc*4-2;
-    float f = dot(fenc,fenc);
-    float g = sqrt(1-f/4);
-    vec3 n;
-    n.xy = fenc*g;
-    n.z = 1-f/2;
-    return n;
-}
+#ifdef SINGLE_FP_ONLY
+vec2 encode_normal(vec3 n)
+{
+	vec2 sn;
+	sn.xy = (n.xy * vec2(0.5f,0.5f)) + vec2(0.5f,0.5f);
+	return sn;
+}
+
+vec3 decode_normal (vec2 enc)
+{
+	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)
+{
+	float f = sqrt(8 * n.z + 8);
+	return n.xy / f + 0.5;
+}
+
+vec3 decode_normal (vec2 enc)
+{
+    vec2 fenc = enc*4-2;
+    float f = dot(fenc,fenc);
+    float g = sqrt(1-f/4);
+    vec3 n;
+    n.xy = fenc*g;
+    n.z = 1-f/2;
+    return n;
+}
+#endif
 
 vec4 getPosition_d(vec2 pos_screen, float depth)
 {