import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
import java.util.List;

import javax.swing.JFrame;

/*
 * game template Aug 2014
 * @author	Forthx
 */

public class J2DTemplate extends JFrame implements Runnable, KeyListener {

	// resolution de la fenetre de jeu
	private final int W = 800;
	private final int H = 600;

	private static final long serialVersionUID = 1L;
	private final Color BLACK = new Color(0x0);
	private volatile List<Integer> keys = new ArrayList<Integer>();
	private long timer;
	private Graphics2D g, buffer_g;
	private BufferedImage buffer;

	private void gameloop(Graphics2D image) {
		// exemple de boucle de jeu
		image.setColor(Color.white);
		image.drawString("touche(s) clavier : " + keys.toString(), 320, 305);
		image.setColor(Color.green);
		image.drawRect(W / 3, H / 3, W / 3, H / 3);
	}

	public J2DTemplate() {
		this.setSize(W, H);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		this.setResizable(false);
		this.addKeyListener(this);
		this.setVisible(true);
		buffer = new BufferedImage(W, H, BufferedImage.TYPE_INT_ARGB);
		g = (Graphics2D) getGraphics();
		buffer_g = (Graphics2D) buffer.getGraphics();
	}

	public static void main(String[] args) {
		new Thread(new J2DTemplate()).start();
	}

	public void run() {
		while (true) {
			buffer_g.setColor(BLACK);
			buffer_g.fillRect(0, 0, 800, 600);
			timer = System.nanoTime();
			gameloop(buffer_g);
			g.drawImage(buffer, 0, 0, this);
			timer += 16000000; // 62 fps
			while (System.nanoTime() < timer)
				Thread.yield();
		}
	}

	@Override
	public void keyTyped(KeyEvent e) {
	}

	@Override
	public void keyPressed(KeyEvent e) {
		if (!keys.contains(e.getKeyCode()))
			keys.add(e.getKeyCode());
	}

	@Override
	public void keyReleased(KeyEvent e) {
		int index = keys.indexOf(e.getKeyCode());
		if (index >= 0)
			keys.remove(index);
	}
}