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 ImageStitcher extends Filter {
  
      @GenerateFieldPort(name = "xSlices")
      private int mXSlices;
  
      @GenerateFieldPort(name = "ySlices")
      private int mYSlices;
  
      @GenerateFieldPort(name = "padSize")
      private int mPadSize;
  
      private Program mProgram;
      private Frame mOutputFrame;
  
      private int mInputWidth;
      private int mInputHeight;
  
      private int mImageWidth;
      private int mImageHeight;
  
      private int mSliceWidth;
      private int mSliceHeight;
  
      private int mSliceIndex;
  
      public ImageStitcher(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 FrameFormat calcOutputFormatForInput(FrameFormat format) {
          MutableFrameFormat outputFormat = format.mutableCopy();
  
          mInputWidth = format.getWidth();
          mInputHeight = format.getHeight();
  
          mSliceWidth = mInputWidth - 2 * mPadSize;
          mSliceHeight = mInputHeight - 2 * mPadSize;
  
          mImageWidth =  mSliceWidth * mXSlices;
          mImageHeight = mSliceHeight * mYSlices;
  
          outputFormat.setDimensions(mImageWidth, mImageHeight);
          return outputFormat;
      }
  
      @Override
      public void process(FilterContext context) {
          // Get input frame
          Frame input = pullInput("image");
          FrameFormat format = input.getFormat();
  
          // Create output frame
          if (mSliceIndex == 0) {
              mOutputFrame = context.getFrameManager().newFrame(calcOutputFormatForInput(format));
          } else {
              if ((format.getWidth() != mInputWidth) ||
                  (format.getHeight() != mInputHeight)) {
                  // CHECK input format here
                  throw new RuntimeException("Image size should not change.");
              }
          }
  
          // Create the program if not created already
          if (mProgram == null) {
              mProgram = ShaderProgram.createIdentity(context);
          }
  
          // TODO(rslin) : not sure shifting by 0.5 is needed.
          float x0 = ((float) mPadSize) / mInputWidth;
          float y0 = ((float) mPadSize) / mInputHeight;
  
          int outputOffsetX = (mSliceIndex % mXSlices) * mSliceWidth;
          int outputOffsetY = (mSliceIndex / mXSlices) * mSliceHeight;
  
          float outputWidth = (float) Math.min(mSliceWidth, mImageWidth - outputOffsetX);
          float outputHeight = (float) Math.min(mSliceHeight, mImageHeight - outputOffsetY);
  
          // We need to set the source rect as well because the input are padded images.
          ((ShaderProgram) mProgram).setSourceRect(x0, y0,
                                                   outputWidth / mInputWidth,
                                                   outputHeight / mInputHeight);
  
          ((ShaderProgram) mProgram).setTargetRect(((float) outputOffsetX)/ mImageWidth,
                                                   ((float) outputOffsetY) / mImageHeight,
                                                   outputWidth / mImageWidth,
                                                   outputHeight / mImageHeight);
  
          // Process this tile
          mProgram.process(input, mOutputFrame);
          mSliceIndex++;
  
          // Push output
          if (mSliceIndex == mXSlices * mYSlices) {
              pushOutput("image", mOutputFrame);
              mOutputFrame.release();
              mSliceIndex = 0;
          }
      }
  }
  