Imported existing code

indra/newview/app_settings/shaders/class2/effects/extractF.glsl

@@ -0,0 +1,22 @@
+/**
+ * @file extractF.glsl
+ *
+ * Copyright (c) 2007-$CurrentYear$, Linden Research, Inc.
+ * $License$
+ */
+
+uniform sampler2DRect RenderTexture;
+uniform float extractLow;
+uniform float extractHigh;
+uniform vec3 lumWeights;
+
+void main(void) 
+{
+	/// Get scene color
+	vec3 color = vec3(texture2DRect(RenderTexture, gl_TexCoord[0].st));
+	
+	/// Extract luminance and scale up by night vision brightness
+	float lum = smoothstep(extractLow, extractHigh, dot(color, lumWeights));
+
+	gl_FragColor = vec4(vec3(lum), 1.0);
+}