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.GLFrame;
  import android.filterfw.core.ShaderProgram;
  import android.filterfw.geometry.Quad;
  import android.filterfw.format.ImageFormat;
  import android.filterfw.format.ObjectFormat;
  
  import android.opengl.GLES20;
  
  /**
   * @hide
   */
  public class DrawRectFilter extends Filter {
  
      @GenerateFieldPort(name = "colorRed",  hasDefault = true)
      private float mColorRed = 0.8f;
  
      @GenerateFieldPort(name = "colorGreen", hasDefault = true)
      private float mColorGreen = 0.8f;
  
      @GenerateFieldPort(name = "colorBlue", hasDefault = true)
      private float mColorBlue = 0.0f;
  
      private final String mVertexShader =
          "attribute vec4 aPosition;\n" +
          "void main() {\n" +
          "  gl_Position = aPosition;\n" +
          "}\n";
  
      private final String mFixedColorFragmentShader =
          "precision mediump float;\n" +
          "uniform vec4 color;\n" +
          "void main() {\n" +
          "  gl_FragColor = color;\n" +
          "}\n";
  
      private ShaderProgram mProgram;
  
  
      public DrawRectFilter(String name) {
          super(name);
      }
  
      @Override
      public void setupPorts() {
          addMaskedInputPort("image", ImageFormat.create(ImageFormat.COLORSPACE_RGBA,
                                                         FrameFormat.TARGET_GPU));
          addMaskedInputPort("box", ObjectFormat.fromClass(Quad.class, FrameFormat.TARGET_SIMPLE));
          addOutputBasedOnInput("image", "image");
      }
  
      @Override
      public FrameFormat getOutputFormat(String portName, FrameFormat inputFormat) {
          return inputFormat;
      }
  
      @Override
      public void prepare(FilterContext context) {
          mProgram = new ShaderProgram(context, mVertexShader, mFixedColorFragmentShader);
      }
  
      @Override
      public void process(FilterContext env) {
          // Get input frame
          Frame imageFrame = pullInput("image");
          Frame boxFrame = pullInput("box");
  
          // Get the box
          Quad box = (Quad)boxFrame.getObjectValue();
          box = box.scaled(2.0f).translated(-1.0f, -1.0f);
  
          // Create output frame with copy of input
          GLFrame output = (GLFrame)env.getFrameManager().duplicateFrame(imageFrame);
  
          // Draw onto output
          output.focus();
          renderBox(box);
  
          // Push output
          pushOutput("image", output);
  
          // Release pushed frame
          output.release();
      }
  
      private void renderBox(Quad box) {
          final int FLOAT_SIZE = 4;
  
          // Get current values
          float[] color = {mColorRed, mColorGreen, mColorBlue, 1f};
          float[] vertexValues = { box.p0.x, box.p0.y,
                                   box.p1.x, box.p1.y,
                                   box.p3.x, box.p3.y,
                                   box.p2.x, box.p2.y };
  
          // Set the program variables
          mProgram.setHostValue("color", color);
          mProgram.setAttributeValues("aPosition", vertexValues, 2);
          mProgram.setVertexCount(4);
  
          // Draw
          mProgram.beginDrawing();
          GLES20.glLineWidth(1.0f);
          GLES20.glDrawArrays(GLES20.GL_LINE_LOOP, 0, 4);
      }
  }
  