shaders/Curvature.shader

   1 <?xml version="1.0" encoding="UTF-8"?>
   2 <!--
   3    Curvature shader from the bsnes project.
   4    Author unknown.
   5 -->
   6 <shader language="GLSL">
   7   <fragment filter="linear"><![CDATA[
   8     uniform sampler2D rubyTexture;
   9     uniform vec2 rubyInputSize;
  10     uniform vec2 rubyTextureSize;
  11
  12     // Tweak this parameter for more / less distortion
  13     #define distortion 0.15
  14
  15     vec2 radialDistortion(vec2 coord) {
  16       coord *= rubyTextureSize / rubyInputSize;
  17       vec2 cc = coord - vec2(0.5);
  18       float dist = dot(cc, cc) * distortion;
  19       return (coord + cc * (1.0 + dist) * dist) * rubyInputSize / rubyTextureSize;
  20     }
  21
  22     void main(void) {
  23       gl_FragColor = texture2D(rubyTexture, radialDistortion(gl_TexCoord[0].xy));
  24     }
  25   ]]></fragment>
  26 </shader>