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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 
     18 package android.filterpacks.imageproc;
     19 
     20 import android.filterfw.core.FilterContext;
     21 import android.filterfw.core.FrameFormat;
     22 import android.filterfw.core.GenerateFieldPort;
     23 import android.filterfw.core.MutableFrameFormat;
     24 import android.filterfw.core.Program;
     25 import android.filterfw.core.ShaderProgram;
     26 import android.filterfw.format.ImageFormat;
     27 
     28 /**
     29  * @hide
     30  */
     31 public class ToGrayFilter extends SimpleImageFilter {
     32 
     33     @GenerateFieldPort(name = "invertSource", hasDefault = true)
     34     private boolean mInvertSource = false;
     35 
     36     @GenerateFieldPort(name = "tile_size", hasDefault = true)
     37     private int mTileSize = 640;
     38 
     39     private MutableFrameFormat mOutputFormat;
     40 
     41     private static final String mColorToGray4Shader =
     42             "precision mediump float;\n" +
     43             "uniform sampler2D tex_sampler_0;\n" +
     44             "varying vec2 v_texcoord;\n" +
     45             "void main() {\n" +
     46             "  vec4 color = texture2D(tex_sampler_0, v_texcoord);\n" +
     47             "  float y = dot(color, vec4(0.299, 0.587, 0.114, 0));\n" +
     48             "  gl_FragColor = vec4(y, y, y, color.a);\n" +
     49             "}\n";
     50 
     51     public ToGrayFilter(String name) {
     52         super(name, null);
     53     }
     54 
     55     @Override
     56     public void setupPorts() {
     57         addMaskedInputPort("image", ImageFormat.create(ImageFormat.COLORSPACE_RGBA,
     58                                                        FrameFormat.TARGET_GPU));
     59         addOutputBasedOnInput("image", "image");
     60     }
     61 
     62     @Override
     63     protected Program getNativeProgram(FilterContext context) {
     64         throw new RuntimeException("Native toGray not implemented yet!");
     65     }
     66 
     67     @Override
     68     protected Program getShaderProgram(FilterContext context) {
     69         int inputChannels = getInputFormat("image").getBytesPerSample();
     70         if (inputChannels != 4) {
     71             throw new RuntimeException("Unsupported GL input channels: " +
     72                                        inputChannels + "! Channels must be 4!");
     73         }
     74         ShaderProgram program = new ShaderProgram(context, mColorToGray4Shader);
     75         program.setMaximumTileSize(mTileSize);
     76         if (mInvertSource)
     77             program.setSourceRect(0.0f, 1.0f, 1.0f, -1.0f);
     78         return program;
     79     }
     80 
     81 }
     82