data/vignette.glsl

   1 import postprocess;
   2
   3 uniform Vignette
   4 {
   5         vec2 coord_scale;
   6         vec4 optical;
   7         vec2 optical_range;
   8         float natural;
   9 };
  10
  11 #pragma MSP stage(fragment)
  12 void main()
  13 {
  14         vec4 incoming = texture(source, texcoord);
  15         vec2 r = vertex.xy*coord_scale;
  16         float r_sq = dot(r, r);
  17
  18         float vignette = 1.0;
  19         if(r_sq>=optical_range.y)
  20                 vignette = 0.0;
  21         else if(r_sq>=optical_range.x)
  22         {
  23                 float r = sqrt(r_sq)-optical.x;
  24                 float v = (optical.z*acos(r/optical.y)-sqrt(optical.z-r*r)*r);
  25                 vignette = v/optical.w;
  26         }
  27
  28         float c_sq = 1/(1+r_sq*natural);
  29         vignette *= c_sq*c_sq;
  30
  31         frag_color = vec4(incoming.rgb*vignette, incoming.a);
  32 }