Android Open Source - libgdx-sample Desktop Camera Controller

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License

The source code is released under:

GNU Lesser General Public License

Java Source Code

package ch.epfl.chili.libgdx_sample.desktop;
//w  w  w .  j  a va2 s . c o m
import java.awt.Dimension;
import java.awt.image.DataBufferByte;
import java.nio.ByteBuffer;
import java.util.concurrent.locks.ReentrantLock;

import ch.epfl.chili.libgdx_sample.DeviceCameraController;
import ch.epfl.chili.libgdx_sample.util.Size2D;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.Pixmap.Format;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.github.sarxos.webcam.Webcam;

/**
 * The device camera interface object for desktop
 * @author Ayberk zgr
 */
public class DesktopCameraController implements DeviceCameraController {

  private long lastMillis = 0;
  private double fps = 0.0;
  
  private Webcam camera = null; //The device camera interface
  private Thread cameraThread; //The thread that will get the camera image
  private boolean running = false; //Indicator that we want the camera thread to abort
  
  private final int width = 640;
  private final int height = 480;
  
  private static byte[] image = null; //The image buffer that will hold the camera image when preview callback arrives
  private ReentrantLock imageLock = new ReentrantLock(); //Mutex to give exclusive access to image byte array
  private static ByteBuffer imageByteBuffer; //ByteBuffer to contain the byte array while it's passed to the texture

  private SpriteBatch spriteBatch; //Since we are not using a special shader for color space conversion, we can render the background with SpriteBatch's default shader
  private Texture background; //The background texture that holds the camera image
  
  @Override
  public void init() {
    
    //Initialize the libgdx objects
    spriteBatch = new SpriteBatch();
    background = new Texture(width,height,Format.RGB888);
    
    //Initialize the image buffers
    image = new byte[width*height*3];
    imageByteBuffer = ByteBuffer.allocateDirect(width*height*3);

    //Initialize the device camera interface
    camera = Webcam.getDefault();
    camera.setViewSize(new Dimension(width,height));
    camera.open();

    //Launch the device camera listener
    cameraThread = new Thread(){
      @Override
      public void run(){
        webcamRunner();
      }
    };
    running = true;
    cameraThread.start();
  }

  /**
   * Listens to the device camera interface and fills the image buffer
   */
  private void webcamRunner(){
    while(running){
      
      //Calculate the FPS
      long currentMillis = System.currentTimeMillis();
      try{
        double fpsNow = 1000/(currentMillis - lastMillis);
        fps = 0.8*fps + 0.2*fpsNow;
      }catch(Exception e){} //Guard against divide by zero
      lastMillis = currentMillis;
      
      //Get the image inside our byte array
      imageByteBuffer.position(0);
      imageByteBuffer.put(((DataBufferByte)camera.getImage().getRaster().getDataBuffer()).getData());
      imageByteBuffer.position(0);
      lockImage();
      imageByteBuffer.get(image);
      unlockImage();
    }
  }

  @Override
  public double getFPS() {
    return fps;
  }

  @Override
  public void renderBackground() {
    
    //Announce that we are rendering 2D images
    spriteBatch.begin();
    
    //Set the texture handle and bind our texture to it
    Gdx.gl.glActiveTexture(GL20.GL_TEXTURE0);
    background.bind();

    //Pass the camera image buffer's data to the texture
    //Y texture is (width*height) in size and each pixel is one byte; by setting GL_LUMINANCE, OpenGL puts this byte into R,G and B components of the texture
    imageByteBuffer.position(0);
    Gdx.gl.glTexImage2D(GL20.GL_TEXTURE_2D, 0, GL20.GL_RGB, width, height, 0, GL20.GL_RGB, GL20.GL_UNSIGNED_BYTE, imageByteBuffer);
    
    //Use linear interpolation when magnifying/minifying the texture to areas larger/smaller than the texture size
    Gdx.gl.glTexParameterf(GL20.GL_TEXTURE_2D, GL20.GL_TEXTURE_MIN_FILTER, GL20.GL_LINEAR);
    Gdx.gl.glTexParameterf(GL20.GL_TEXTURE_2D, GL20.GL_TEXTURE_MAG_FILTER, GL20.GL_LINEAR);
    Gdx.gl.glTexParameterf(GL20.GL_TEXTURE_2D, GL20.GL_TEXTURE_WRAP_S, GL20.GL_CLAMP_TO_EDGE);
    Gdx.gl.glTexParameterf(GL20.GL_TEXTURE_2D, GL20.GL_TEXTURE_WRAP_T, GL20.GL_CLAMP_TO_EDGE);
    
    //Draw the texture
    spriteBatch.draw(background, 0, 0);
    
    //Announce that we are done rendering 2D images
    spriteBatch.end();
  }

  @Override
  public void destroy() {
    running = false;
    camera.close();
  }

  @Override
  public Size2D getCameraSize() {
    return new Size2D(width,height);
  }

  @Override
  public Size2D getProcessingSize() {
    return new Size2D(width,height);
  }

  @Override
  public ImageFormat getImageFormat() {
    return ImageFormat.RGB888;
  }

  @Override
  public byte[] getImage(){
    return image;
  }

  @Override
  public void lockImage() {
    imageLock.lock();
  }

  @Override
  public void unlockImage() {
    imageLock.unlock();
  }
}

Java Source Code List

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