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mobile-query-three-vendor-three.js-shaders-HueSaturationShader.js / js



  

author: tapio / tapio.github.com/ Hue and saturation adjustment github.com/evanw/glfx.js hue: -1 to 1 (-1 is 180 degrees in the negative direction, 0 is no change, etc. saturation: -1 to 1 (-1 is solid gray, 0 is no change, and 1 is maximum contrast)

  
  
  THREE.HueSaturationShader = {
  
          uniforms: {
  
                  "tDiffuse":   { type: "t", value: null },
                  "hue":        { type: "f", value: 0 },
                  "saturation": { type: "f", value: 0 }
  
          },
  
          vertexShader: [
  
                  "varying vec2 vUv;",
  
                  "void main() {",
  
                          "vUv = uv;",
  
                          "gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );",
  
                  "}"
  
          ].join("\n"),
  
          fragmentShader: [
  
                  "uniform sampler2D tDiffuse;",
                  "uniform float hue;",
                  "uniform float saturation;",
  
                  "varying vec2 vUv;",
  
                  "void main() {",
  
                          "gl_FragColor = texture2D( tDiffuse, vUv );",
  
                          // hue
                          "float angle = hue * 3.14159265;",
                          "float s = sin(angle), c = cos(angle);",
                          "vec3 weights = (vec3(2.0 * c, -sqrt(3.0) * s - c, sqrt(3.0) * s - c) + 1.0) / 3.0;",
                          "float len = length(gl_FragColor.rgb);",
                          "gl_FragColor.rgb = vec3(",
                                  "dot(gl_FragColor.rgb, weights.xyz),",
                                  "dot(gl_FragColor.rgb, weights.zxy),",
                                  "dot(gl_FragColor.rgb, weights.yzx)",
                          ");",
  
                          // saturation
                          "float average = (gl_FragColor.r + gl_FragColor.g + gl_FragColor.b) / 3.0;",
                          "if (saturation > 0.0) {",
                                  "gl_FragColor.rgb += (average - gl_FragColor.rgb) * (1.0 - 1.0 / (1.001 - saturation));",
                          "} else {",
                                  "gl_FragColor.rgb += (average - gl_FragColor.rgb) * (-saturation);",
                          "}",
  
                  "}"
  
          ].join("\n")
  
  };
  


(C) Æliens 04/09/2009

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