src/liquidity/bloom-filter.vala

   1 /*
   2  *  liquidity/bloom-filter.vala
   3  *
   4  *  Copyright (c) 2008 Patrick Walton <pcwalton@uchicago.edu>
   5  *  GLSL filter code by Romain Guy <http://www.curious-creature.org/
   6  *      2007/02/20/fast-image-processing-with-jogl/>
   7  */
   8
   9 using GLib;
  10 using Gee;
  11
  12 namespace Liquidity {
  13     public class BloomFilter : Filter {
  14         protected override string# glsl_source {
  15             get {
  16                 return
  17 "uniform sampler2DRect rectTexture; "                                       +
  18 "uniform float brightPassThreshold;"                                        +
  19 "void main(void) {"                                                         +
  20 "    vec3 luminanceVector = vec3(0.2125, 0.7154, 0.0721);"                  +
  21 "    vec4 sample = texture2DRect(rectTexture, gl_TexCoord[0].st);"          +
  22 "    float luminance = dot(luminanceVector, sample.rgb);"                   +
  23 "    luminance = max(0.0, luminance - brightPassThreshold);"                +
  24 "    sample.rgb *= sign(luminance);"                                        +
  25 "    sample.a = 1.0;"                                                       +
  26 "    gl_FragColor = sample;"                                                +
  27 "}"                                                                         ;
  28             }
  29         }
  30
  31         private HashMap<string, weak Float> _glsl_params = null;
  32         protected override HashMap<string, weak Float> glsl_params {
  33             get {
  34                 if (_glsl_params == null) {
  35                     _glsl_params = new HashMap<string, weak Float>(str_hash,
  36                             str_equal);
  37
  38                     /*
  39                      *  Ugh... awful hack. When will Gee support real hash maps
  40                      *  that manage memory properly? :(
  41                      */
  42
  43                     Float *fp = new Float(0.75F);
  44                     _glsl_params.set("brightPassThreshold", fp);
  45                 }
  46
  47                 return _glsl_params;
  48             }
  49         }
  50     }
  51 }
  52