[mixer] Merged fixed from 2.0 where contrast adjustment incorrectly worked on premult...

[casparcg] / accelerator / ogl / image / blending_glsl.h

diff --git a/accelerator/ogl/image/blending_glsl.h b/accelerator/ogl/image/blending_glsl.h
index 7d82f7c6d383aca7aa7e1f90035f6cb103065b0a..326e6f7153044b4afaaf84e67882ea2a89592107 100644 (file)
--- a/accelerator/ogl/image/blending_glsl.h
+++ b/accelerator/ogl/image/blending_glsl.h
@@ -30,7 +30,7 @@ static std::string get_adjustement_glsl()
                        ** http://irrlicht.sourceforge.net/phpBB2/viewtopic.php?t=21057
                        */
 
-                       vec3 ContrastSaturationBrightness(vec3 color, float brt, float sat, float con)
+                       vec3 ContrastSaturationBrightness(vec4 color, float brt, float sat, float con)
                        {
                                const float AvgLumR = 0.5;
                                const float AvgLumG = 0.5;
@@ -40,11 +40,17 @@ static std::string get_adjustement_glsl()
                                                ? vec3(0.0722, 0.7152, 0.2126)
                                                : vec3(0.114, 0.587, 0.299);
 
+                               if (color.a > 0.0)
+                                       color.rgb /= color.a;
+
                                vec3 AvgLumin = vec3(AvgLumR, AvgLumG, AvgLumB);
-                               vec3 brtColor = color * brt;
+                               vec3 brtColor = color.rgb * brt;
                                vec3 intensity = vec3(dot(brtColor, LumCoeff));
                                vec3 satColor = mix(intensity, brtColor, sat);
                                vec3 conColor = mix(AvgLumin, satColor, con);
+
+                               conColor.rgb *= color.a;
+
                                return conColor;
                        }