content: /*
   * Copyright (C) 2012 CyberAgent
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package jp.co.cyberagent.android.gpuimage;
  
  import android.opengl.GLES20;
  
  /**
   * Reduces the color range of the image. <br>
   * <br>
   * colorLevels: ranges from 1 to 256, with a default of 10
   */
  public class GPUImagePosterizeFilter extends GPUImageFilter {
      public static final String POSTERIZE_FRAGMENT_SHADER = "" +
              "varying highp vec2 textureCoordinate;\n" +
              "\n" +
              "uniform sampler2D inputImageTexture;\n" +
              "uniform highp float colorLevels;\n" +
              "\n" +
              "void main()\n" +
              "{\n" +
              "   highp vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);\n" +
              "   \n" +
              "   gl_FragColor = floor((textureColor * colorLevels) + vec4(0.5)) / colorLevels;\n" +
              "}";
  
      private int mGLUniformColorLevels;
      private int mColorLevels;
  
      public GPUImagePosterizeFilter() {
          this(10);
      }
  
      public GPUImagePosterizeFilter(final int colorLevels) {
          super(GPUImageFilter.NO_FILTER_VERTEX_SHADER, POSTERIZE_FRAGMENT_SHADER);
          mColorLevels = colorLevels;
      }
  
      @Override
      public void onInit() {
          super.onInit();
          mGLUniformColorLevels = GLES20.glGetUniformLocation(getProgram(), "colorLevels");
          setColorLevels(mColorLevels);
      }
  
      public void setColorLevels(final int colorLevels) {
          mColorLevels = colorLevels;
          setFloat(mGLUniformColorLevels, colorLevels);
      }
  }
  