NORSPEC-287 Make alpha sRGB correction curves match OpenGL spec.

1 files changed, 22 insertions, 2 deletions

diff --git a/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl b/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl
index 6e05091b57..06447261b4 100755
--- a/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl
+++ b/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl
@@ -78,6 +78,26 @@ vec3 vary_AtmosAttenuation;
 uniform mat4 inv_proj;
 uniform vec2 screen_res;
 
+vec3 srgb_to_linear(vec3 cs)
+{
+	
+/*        {  cs / 12.92,                 cs <= 0.04045
+    cl = {
+        {  ((cs + 0.055)/1.055)^2.4,   cs >  0.04045*/
+
+	return pow((cs+vec3(0.055))/vec3(1.055), vec3(2.4));
+}
+
+vec3 linear_to_srgb(vec3 cl)
+{
+	    /*{  0.0,                          0         <= cl
+            {  12.92 * c,                    0         <  cl < 0.0031308
+    cs = {  1.055 * cl^0.41666 - 0.055,   0.0031308 <= cl < 1
+            {  1.0,                                       cl >= 1*/
+
+	return 1.055 * pow(cl, vec3(0.41666)) - 0.055;
+}
+
 vec2 encode_normal(vec3 n)
 {
 	float f = sqrt(8 * n.z + 8);
@@ -326,7 +346,7 @@ void main()
 	vec4 diffuse = texture2DRect(diffuseRect, tc);
 
 	//convert to gamma space
-	diffuse.rgb = pow(diffuse.rgb, vec3(1.0/2.2));
+	diffuse.rgb = linear_to_srgb(diffuse.rgb);
 	
 	vec3 col;
 	float bloom = 0.0;
@@ -392,7 +412,7 @@ void main()
 			col = mix(scaleSoftClip(col), fullbrightScaleSoftClip(col), diffuse.a);
 		}
 
-		col = pow(col, vec3(2.2));
+		col = srgb_to_linear(col);
 
 		//col = vec3(1,0,1);
 		//col.g = envIntensity;