ProjectArcade

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// AA-Color shader, Modified to use in PPSSPP. Grabbed from:
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// http://forums.ngemu.com/showthread.php?t=76098
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// by guest(r) (guest.r@gmail.com)
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// license: GNU-GPL
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// Color variables
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#ifdef GL_ES
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precision mediump float;
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precision mediump int;
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#endif
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const vec3 c_ch = vec3(1.0,1.0,1.0);  //  rgb color channel intensity
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const float   a = 1.20 ;              //  saturation 
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const float   b = 1.00 ;              //  brightness 
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const float   c = 1.25 ;              //  contrast   
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// you can use contrast1,contrast2...contrast4 (or contrast0 for speedup)
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float contrast0(float x)
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{ return x; }
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float contrast1(float x)
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{ x = x*1.1547-1.0;
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  return sign(x)*pow(abs(x),1.0/c)*0.86 +  0.86;}
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float contrast2(float x) 
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{ return normalize(vec2(pow(x,c),pow(0.86,c))).x*1.72;}
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float contrast3(float x)
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{ return 1.73*pow(0.57735*x,c); }
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float contrast4(float x)
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{ return clamp(0.866 + c*(x-0.866),0.05, 1.73); }
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uniform sampler2D sampler0;
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varying vec4 v_texcoord0;
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varying vec4 v_texcoord1;
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varying vec4 v_texcoord2;
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varying vec4 v_texcoord3;
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varying vec4 v_texcoord4;
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varying vec4 v_texcoord5;
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varying vec4 v_texcoord6;
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void main()
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{
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  vec3 c10 = texture2D(sampler0, v_texcoord1.xy).xyz; 
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  vec3 c01 = texture2D(sampler0, v_texcoord4.xy).xyz; 
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  vec3 c11 = texture2D(sampler0, v_texcoord0.xy).xyz; 
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  vec3 c21 = texture2D(sampler0, v_texcoord5.xy).xyz; 
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  vec3 c12 = texture2D(sampler0, v_texcoord2.xy).xyz; 
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  vec3 dt = vec3(1.0,1.0,1.0);
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  float k1=dot(abs(c01-c21),dt);
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  float k2=dot(abs(c10-c12),dt);
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  vec3 color = (k1*(c10+c12)+k2*(c01+c21)+0.001*c11)/(2.0*(k1+k2)+0.001);
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  float x = sqrt(dot(color,color));
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  color.r = pow(color.r+0.001,a);
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  color.g = pow(color.g+0.001,a);
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  color.b = pow(color.b+0.001,a);
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  gl_FragColor.rgb = contrast4(x)*normalize(color*c_ch)*b;
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  gl_FragColor.a = 1.0;
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}
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