threshold.shader

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Shader "Custom/threshold" {  
    Properties
    {        
              //_webcamTex ("Base (RGB)", 2D) = "" {}
              _MainTex ("Texture Image", 2D) = "white" {} 
//              _SobelKernel ("_SobelKernel", 2D) = "white" {} 
//              _GaussKernel ("_GaussKernel", 2D) = "white" {} 
//              _PrevTex ("Previous Frame", 2D) = "white" {} 
////              _TexSize ("Texture Size", Vector) = (0,0,0,0)
//              _TexSizeX ("Texture Width", Float) = 0.0
//              _TexSizeY ("Texture Height", Float) = 0.0
           _Thresholds ("_Thresholds", Vector) = (0.0,0.0,0.0,0.0)
           _Thresholds2 ("_Thresholds2", Vector) = (0.0,0.0,0.0,0.0)
           _BinaryMode ("_BinaryMode", Float) = 0
           _ThresholdMode ("_ThresholdMode", Float) = 1

    }
    SubShader
    {
        //Tags { "Queue" = "Geometry" }
        //Tags { "RenderType" = "Transparent" }
        Pass
            {      
               //Blend SrcAlpha OneMinusSrcAlpha      
                GLSLPROGRAM       
//                #pragma only_renderers gles    

               
                uniform sampler2D _MainTex;
//                uniform sampler2D _SobelKernel;
//                uniform sampler2D _GaussKernel;
                uniform vec4 _Thresholds;
                uniform vec4 _Thresholds2;
                uniform int _BinaryMode;
                uniform int _ThresholdMode;
                
                varying vec4 textureCoordinates; 
                                       
                #ifdef VERTEX   
                
                void main()
                {          
                   
                   
                    gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
                    
                    
                    //desktop
//                    textureCoordinates = gl_Position;
                    textureCoordinates = vec4( gl_Vertex.y * 2.0, gl_Vertex.x * 2.0, gl_Vertex.z, gl_Vertex.w);
//                    textureCoordinates = vec4(gl_Position.x * -1.0, gl_Position.y, gl_Position.z, gl_Position.w);
                   textureCoordinates = (textureCoordinates + 1.0) * 0.5;
//                 textureCoordinates.x = textureCoordinates.x * 0.5 + 0.25;
                   
                   
                   //mobile
                   
//                 textureCoordinates = (gl_Position + 1.0) * 0.5;
//                 textureCoordinates = textureCoordinates.yxzw;
                }
                #endif  
           
                #ifdef FRAGMENT
                
                vec3 rgb2hsv(vec3 c){
                
                   vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
                   vec4 p = mix(vec4(c.bg, K.wz), vec4(c.gb, K.xy), step(c.b, c.g));
                   vec4 q = mix(vec4(p.xyw, c.r), vec4(c.r, p.yzx), step(p.x, c.r));

                   float d = q.x - min(q.w, q.y);
                   float e = 1.0e-10;
                   return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
               }

               vec3 hsv2rgb(vec3 c){
               
                   vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
                   vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
                   return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
               }
               
                
                void setColor(vec4 c1, vec4 c2){
                   if(_BinaryMode == 1.0){
                       gl_FragColor = c2;
                   }else{
                       
                       gl_FragColor = c1;
                   }
                }
                
                void main()
                {           
                   
                   
                   vec4 c = texture2D(_MainTex,  vec2(textureCoordinates));
               
                   vec3 c1 = rgb2hsv(c);
                   c1.g *= 1.7;
                   c = vec4(hsv2rgb(c1), 1.0);
                   
                   if(_ThresholdMode == 1.0){
                   

//                 http://link.springer.com/chapter/10.1007%2F978-3-540-74472-6_85?LI=true#page-1
                       
                       float y = 16.0 + 65.481 * c.r + 128.553 * c.g + 24.966 * c.b;
                       float cb = 128.0 - 37.797 * c.r - 74.203 * c.g + 112.0 * c.b;
//                     float cr = 128.0 + 112.0 * c.r - 93.786 * c.g - 18.214 * c.b;
                       float cr = 128.0 + 112.0 * c.r - 93.786 * c.g - 18.214 * c.b;
                       
                       if((_Thresholds.z < cr && cr < _Thresholds.w  && _Thresholds.x < cb  && cb < _Thresholds.y) || ( _Thresholds2.x < y  && y < _Thresholds2.y)){

//                     if(_Thresholds.x < c.r  && c.r < _Thresholds.y && _Thresholds.z < c.g && c.g < _Thresholds.w && _Thresholds2.x < c.b  && c.b < _Thresholds2.y){
                               
                           
                           setColor(c, vec4(1.0, 1.0, 1.0, 1.0));
                           
//                         if(_BinaryMode == 1)
//                             gl_FragColor = vec4(1.0, 1.0, 1.0, 1.0);
//                         else
//                             gl_FragColor = c;
                       }else{
                       
                           setColor(c * 0.5, vec4(0.0, 0.0, 0.0, 1.0));
                           
                       }
                   
                   }
                   else{
                   
                       gl_FragColor = c;
                   
                   }
                   
                   
                }
                #endif                          
                ENDGLSL        
            }
     }

}