Android GPUImage-10: Pixelation

1.效果图

2.fragment shader

public static final String PIXELATION_FRAGMENT_SHADER = "" +
            "precision highp float;\n" +

            "varying vec2 textureCoordinate;\n" +

            "uniform float imageWidthFactor;\n" +
            "uniform float imageHeightFactor;\n" +
            "uniform sampler2D inputImageTexture;\n" +
            "uniform float pixel;\n" +

            "void main()\n" +
            "{\n" +
            "  vec2 uv  = textureCoordinate.xy;\n" +
            "  float dx = pixel * imageWidthFactor;\n" +
            "  float dy = pixel * imageHeightFactor;\n" +
            "  vec2 coord = vec2(dx * floor(uv.x / dx), dy * floor(uv.y / dy));\n" +
            "  vec3 tc = texture2D(inputImageTexture, coord).xyz;\n" +
            "  gl_FragColor = vec4(tc, 1.0);\n" +
            "}";

3.原理

透过floor，限制像素的块的大小。