//////////////////////////////////////////////////


  //  fisheye
  //
  //        author            : frank reitberger
  //        blog            : http://www.prinzipiell.com
  //  copyright 2008
  //
  
//////////////////////////////s
/////////////////



  
  <languageVersion: 1.0;>
  
  kernel fisheye
  
  <   
      namespace:          "fisheye";
      vendor:             "Frank Reitberger";
      version:            1;
      description:        "so what might a fisheye filter do?";
  >
  
   {
  
      parameter float center_x
      <
          minValue:float(-200.0);
          maxValue:float(2048.0);
          defaultValue:float(210.0);
          description: "center point x";
      >;
      
      parameter float center_y
      <
          minValue:float(-200.0);
          maxValue:float(2048.0);
          defaultValue:float(160.0);
          description: "center point y";
      >;  
      
       parameter float radius
      <
          minValue:float(0.1);
          maxValue:float(400.0);
          defaultValue:float(200.0);
          description: "radius";
      >;    
      
      input image4 src;
      output pixel4 pxl; 
      
      void
      evaluatePixel() {
      
          float2 center;
          center.x = center_x;
          center.y = center_y;
      
      
          float2 pos  = outCoord() - center;
          float step  = length(pos) / radius;
  
          step *= 1.0;
          pos *= step;
      
          pxl = sampleLinear( src, center + pos );
    
      }    
      
  }