shaders/depth_compare.glsl

   1 uniform sampler2D uTexSceneDepth;
   2 uniform vec3 uInverseRatioDepth;
   3 uniform vec3 uInverseRatioMain;
   4 uniform int uDepthMode;
   5 uniform float uDitherCutoff;
   6
   7 float linear_depth( float depth, float near, float far ) {
   8    float z = depth * 2.0 - 1.0;
   9    return (2.0 * near * far) / (far + near - z * (far - near));
  10 }
  11
  12 void depth_compare_dither()
  13 {
  14    if( uDepthMode == 1 )
  15    {
  16       vec2 back_coord = gl_FragCoord.xy * uInverseRatioMain.xy
  17                                         * uInverseRatioDepth.xy;
  18       float back_depth = texture( uTexSceneDepth, back_coord ).r;
  19       float front_depth = gl_FragCoord.z/gl_FragCoord.w;
  20
  21       back_depth = linear_depth( back_depth, 0.1, 2100.0 );
  22       float diff = back_depth - front_depth;
  23
  24       vec2 ssuv = gl_FragCoord.xy;
  25       vec3 vDither = vec3( dot( vec2( 171.0, 231.0 ), ssuv) );
  26       float dither = fract( vDither.g / 71.0 ) - 0.5;
  27
  28       if( step(0.0,diff)+dither<0.3 )
  29          discard;
  30    }
  31
  32    if( uDepthMode == 2 )
  33    {
  34       vec2 ssuv = gl_FragCoord.xy;
  35       vec3 vDither = vec3( dot( vec2( 171.0, 231.0 ), ssuv) );
  36       float dither = fract( vDither.g / 71.0 );
  37       if( dither<uDitherCutoff ) discard;
  38    }
  39 }