Merge pull request cats-oss#166 from badjano/master

Fixing GPUImageChromaKeyBlendFilter

Author: wasabeef

library/src/jp/co/cyberagent/android/gpuimage/GPUImageChromaKeyBlendFilter.java

@@ -22,47 +22,32 @@
  * Selectively replaces a color in the first image with the second image
  */
 public class GPUImageChromaKeyBlendFilter extends GPUImageTwoInputFilter {
-    public static final String CHROMA_KEY_BLEND_FRAGMENT_SHADER = "varying highp vec2 textureCoordinate;\n" +
-            " varying highp vec2 textureCoordinate2;\n" +
+    public static final String CHROMA_KEY_BLEND_FRAGMENT_SHADER = " precision highp float;\n" +
             " \n" +
+            " varying highp vec2 textureCoordinate;\n" +
+            " varying highp vec2 textureCoordinate2;\n" +
+            "\n" +
+            " uniform float thresholdSensitivity;\n" +
+            " uniform float smoothing;\n" +
+            " uniform vec3 colorToReplace;\n" +
             " uniform sampler2D inputImageTexture;\n" +
             " uniform sampler2D inputImageTexture2;\n" +
             " \n" +
-            " highp float lum(lowp vec3 c) {\n" +
-            "     return dot(c, vec3(0.3, 0.59, 0.11));\n" +
-            " }\n" +
-            " \n" +
-            " lowp vec3 clipcolor(lowp vec3 c) {\n" +
-            "     highp float l = lum(c);\n" +
-            "     lowp float n = min(min(c.r, c.g), c.b);\n" +
-            "     lowp float x = max(max(c.r, c.g), c.b);\n" +
-            "     \n" +
-            "     if (n < 0.0) {\n" +
-            "         c.r = l + ((c.r - l) * l) / (l - n);\n" +
-            "         c.g = l + ((c.g - l) * l) / (l - n);\n" +
-            "         c.b = l + ((c.b - l) * l) / (l - n);\n" +
-            "     }\n" +
-            "     if (x > 1.0) {\n" +
-            "         c.r = l + ((c.r - l) * (1.0 - l)) / (x - l);\n" +
-            "         c.g = l + ((c.g - l) * (1.0 - l)) / (x - l);\n" +
-            "         c.b = l + ((c.b - l) * (1.0 - l)) / (x - l);\n" +
-            "     }\n" +
-            "     \n" +
-            "     return c;\n" +
-            " }\n" +
-            "\n" +
-            " lowp vec3 setlum(lowp vec3 c, highp float l) {\n" +
-            "     highp float d = l - lum(c);\n" +
-            "     c = c + vec3(d);\n" +
-            "     return clipcolor(c);\n" +
-            " }\n" +
-            " \n" +
             " void main()\n" +
             " {\n" +
-            "   highp vec4 baseColor = texture2D(inputImageTexture, textureCoordinate);\n" +
-            "   highp vec4 overlayColor = texture2D(inputImageTexture2, textureCoordinate2);\n" +
-            "\n" +
-            "     gl_FragColor = vec4(baseColor.rgb * (1.0 - overlayColor.a) + setlum(overlayColor.rgb, lum(baseColor.rgb)) * overlayColor.a, baseColor.a);\n" +
+            "     vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);\n" +
+            "     vec4 textureColor2 = texture2D(inputImageTexture2, textureCoordinate2);\n" +
+            "     \n" +
+            "     float maskY = 0.2989 * colorToReplace.r + 0.5866 * colorToReplace.g + 0.1145 * colorToReplace.b;\n" +
+            "     float maskCr = 0.7132 * (colorToReplace.r - maskY);\n" +
+            "     float maskCb = 0.5647 * (colorToReplace.b - maskY);\n" +
+            "     \n" +
+            "     float Y = 0.2989 * textureColor.r + 0.5866 * textureColor.g + 0.1145 * textureColor.b;\n" +
+            "     float Cr = 0.7132 * (textureColor.r - Y);\n" +
+            "     float Cb = 0.5647 * (textureColor.b - Y);\n" +
+            "     \n" +
+            "     float blendValue = 1.0 - smoothstep(thresholdSensitivity, thresholdSensitivity + smoothing, distance(vec2(Cr, Cb), vec2(maskCr, maskCb)));\n" +
+            "     gl_FragColor = mix(textureColor, textureColor2, blendValue);\n" +
             " }";
 
     private int mThresholdSensitivityLocation;