//This file is automatically rebuilt by the Cesium build process.
export default "uniform sampler2D colorTexture;\n\
uniform float avgLuminance;\n\
uniform float threshold;\n\
uniform float offset;\n\
varying vec2 v_textureCoordinates;\n\
float key(float avg)\n\
{\n\
float guess = 1.5 - (1.5 / (avg * 0.1 + 1.0));\n\
return max(0.0, guess) + 0.1;\n\
}\n\
void main()\n\
{\n\
vec4 color = texture2D(colorTexture, v_textureCoordinates);\n\
vec3 xyz = czm_RGBToXYZ(color.rgb);\n\
float luminance = xyz.r;\n\
float scaledLum = key(avgLuminance) * luminance / avgLuminance;\n\
float brightLum = max(scaledLum - threshold, 0.0);\n\
float brightness = brightLum / (offset + brightLum);\n\
xyz.r = brightness;\n\
gl_FragColor = vec4(czm_XYZToRGB(xyz), 1.0);\n\
}\n\
";