content: /*
   * Copyright (C) 2011 The Android Open Source Project
   *
   * 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 android.filterpacks.imageproc;
  
  import android.filterfw.core.Filter;
  import android.filterfw.core.FilterContext;
  import android.filterfw.core.Frame;
  import android.filterfw.core.FrameFormat;
  import android.filterfw.core.GenerateFieldPort;
  import android.filterfw.core.MutableFrameFormat;
  import android.filterfw.core.Program;
  import android.filterfw.core.ShaderProgram;
  import android.filterfw.format.ImageFormat;
  
  public class ImageSlicer extends Filter {
  
      @GenerateFieldPort(name = "xSlices")
      private int mXSlices;
  
      @GenerateFieldPort(name = "ySlices")
      private int mYSlices;
  
      @GenerateFieldPort(name = "padSize")
      private int mPadSize;
  
      // The current slice index from 0 to xSlices * ySlices
      private int mSliceIndex;
  
      private Frame mOriginalFrame;
  
      private Program mProgram;
  
      private int mInputWidth;
      private int mInputHeight;
  
      private int mSliceWidth;
      private int mSliceHeight;
  
      private int mOutputWidth;
      private int mOutputHeight;
  
      public ImageSlicer(String name) {
          super(name);
          mSliceIndex = 0;
      }
  
      @Override
      public void setupPorts() {
          addMaskedInputPort("image", ImageFormat.create(ImageFormat.COLORSPACE_RGBA,
                                                         FrameFormat.TARGET_GPU));
          addOutputBasedOnInput("image", "image");
      }
  
      @Override
      public FrameFormat getOutputFormat(String portName, FrameFormat inputFormat) {
          return inputFormat;
      }
  
      private void calcOutputFormatForInput(Frame frame) {
  
          // calculate the output size based on input size, xSlices, and ySlices
          mInputWidth = frame.getFormat().getWidth();
          mInputHeight = frame.getFormat().getHeight();
  
          mSliceWidth = (mInputWidth + mXSlices - 1) / mXSlices;
          mSliceHeight = (mInputHeight + mYSlices - 1)/ mYSlices;
  
          mOutputWidth = mSliceWidth + mPadSize * 2;
          mOutputHeight = mSliceHeight + mPadSize * 2;
      }
  
  
      @Override
      public void process(FilterContext context) {
  
          // Get input frame
          if (mSliceIndex == 0) {
              mOriginalFrame = pullInput("image");
              calcOutputFormatForInput(mOriginalFrame);
          }
  
          FrameFormat inputFormat = mOriginalFrame.getFormat();
          MutableFrameFormat outputFormat = inputFormat.mutableCopy();
          outputFormat.setDimensions(mOutputWidth, mOutputHeight);
  
          // Create output frame
          Frame output = context.getFrameManager().newFrame(outputFormat);
  
          // Create the program if not created already
          if (mProgram == null) {
              mProgram = ShaderProgram.createIdentity(context);
          }
  
          // Calculate the four corner of the source region
          int xSliceIndex = mSliceIndex % mXSlices;
          int ySliceIndex = mSliceIndex / mXSlices;
  
          // TODO(rslin) : not sure shifting by 0.5 is needed.
          float x0 = (xSliceIndex * mSliceWidth - mPadSize) / ((float) mInputWidth);
          float y0 = (ySliceIndex * mSliceHeight - mPadSize) / ((float) mInputHeight);
  
          ((ShaderProgram) mProgram).setSourceRect(x0, y0,
                                                   ((float) mOutputWidth) / mInputWidth,
                                                   ((float) mOutputHeight) / mInputHeight);
  
          // Process
          mProgram.process(mOriginalFrame, output);
          mSliceIndex++;
  
          if (mSliceIndex == mXSlices * mYSlices) {
              mSliceIndex = 0;
              mOriginalFrame.release();
              setWaitsOnInputPort("image", true);
          } else {
              // Retain the original frame so it can be used next time.
              mOriginalFrame.retain();
              setWaitsOnInputPort("image", false);
          }
  
          // Push output
          pushOutput("image", output);
  
          // Release pushed frame
          output.release();
      }
  }
  