shaders/depth_compare.glsl

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