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.Program;
  import android.filterfw.core.ShaderProgram;
  import android.filterfw.format.ImageFormat;
  import android.filterfw.geometry.Quad;
  import android.filterfw.geometry.Point;
  
  /**
   * @hide
   */
  public class StraightenFilter extends Filter {
  
      @GenerateFieldPort(name = "angle", hasDefault = true)
      private float mAngle = 0f;
  
      @GenerateFieldPort(name = "maxAngle", hasDefault = true)
      private float mMaxAngle = 45f;
  
      @GenerateFieldPort(name = "tile_size", hasDefault = true)
      private int mTileSize = 640;
  
      private Program mProgram;
  
      private int mWidth = 0;
      private int mHeight = 0;
      private int mTarget = FrameFormat.TARGET_UNSPECIFIED;
  
      private static final float DEGREE_TO_RADIAN = (float) Math.PI / 180.0f;
  
      public StraightenFilter(String name) {
          super(name);
      }
  
      @Override
      public void setupPorts() {
          addMaskedInputPort("image", ImageFormat.create(ImageFormat.COLORSPACE_RGBA));
          addOutputBasedOnInput("image", "image");
      }
  
      public void initProgram(FilterContext context, int target) {
          switch (target) {
              case FrameFormat.TARGET_GPU:
                  ShaderProgram shaderProgram = ShaderProgram.createIdentity(context);
                  shaderProgram.setMaximumTileSize(mTileSize);
                  mProgram = shaderProgram;
                  break;
  
              default:
                  throw new RuntimeException("Filter Sharpen does not support frames of " +
                      "target " + target + "!");
          }
          mTarget = target;
      }
  
      @Override
      public void fieldPortValueUpdated(String name, FilterContext context) {
          if (mProgram != null) {
              updateParameters();
          }
      }
  
      @Override
      public void process(FilterContext context) {
          // Get input frame
          Frame input = pullInput("image");
          FrameFormat inputFormat = input.getFormat();
  
          // Create program if not created already
          if (mProgram == null || inputFormat.getTarget() != mTarget) {
              initProgram(context, inputFormat.getTarget());
          }
  
          // Create output frame
          if (inputFormat.getWidth() != mWidth || inputFormat.getHeight() != mHeight) {
              mWidth = inputFormat.getWidth();
              mHeight = inputFormat.getHeight();
              updateParameters();
          }
  
          Frame output = context.getFrameManager().newFrame(inputFormat);
  
          // Process
          mProgram.process(input, output);
  
          // Push output
          pushOutput("image", output);
  
          // Release pushed frame
          output.release();
      }
  
      private void updateParameters() {
          float cosTheta = (float) Math.cos(mAngle * DEGREE_TO_RADIAN);
          float sinTheta = (float) Math.sin(mAngle * DEGREE_TO_RADIAN);
  
          if (mMaxAngle <= 0)
              throw new RuntimeException("Max angle is out of range (0-180).");
          mMaxAngle = (mMaxAngle > 90) ? 90 : mMaxAngle;
  
          Point p0 = new Point(-cosTheta * mWidth + sinTheta * mHeight,
                               -sinTheta * mWidth - cosTheta * mHeight);
  
          Point p1 = new Point(cosTheta * mWidth + sinTheta * mHeight,
                               sinTheta * mWidth - cosTheta * mHeight);
  
          Point p2 = new Point(-cosTheta * mWidth - sinTheta * mHeight,
                               -sinTheta * mWidth + cosTheta * mHeight);
  
          Point p3 = new Point(cosTheta * mWidth - sinTheta * mHeight,
                               sinTheta * mWidth + cosTheta * mHeight);
  
          float maxWidth = (float) Math.max(Math.abs(p0.x), Math.abs(p1.x));
          float maxHeight = (float) Math.max(Math.abs(p0.y), Math.abs(p1.y));
  
          float scale = 0.5f * Math.min( mWidth / maxWidth,
                                         mHeight / maxHeight);
  
          p0.set(scale * p0.x / mWidth + 0.5f, scale * p0.y / mHeight + 0.5f);
          p1.set(scale * p1.x / mWidth + 0.5f, scale * p1.y / mHeight + 0.5f);
          p2.set(scale * p2.x / mWidth + 0.5f, scale * p2.y / mHeight + 0.5f);
          p3.set(scale * p3.x / mWidth + 0.5f, scale * p3.y / mHeight + 0.5f);
  
          Quad quad = new Quad(p0, p1, p2, p3);
          ((ShaderProgram) mProgram).setSourceRegion(quad);
      }
  }
  