Simple2DGameEngine.java

// A simple Demo for creating a Java 2D Game Engine
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsEnvironment;
import java.awt.Transparency;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.image.BufferedImage;
import java.util.Random;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.WindowConstants;

public class Test extends Thread {
	
	// Graphics Stuff
	private boolean isRunning = true;
	private JPanel canvasPanel;
	private BufferedImage background;
	private Graphics2D backgroundGraphics;
	private JFrame frame;
	private int width = 800;
	private int height = 600;
	private int scale = 1;
	private int fps = 30;
	private GraphicsConfiguration config =
			GraphicsEnvironment.getLocalGraphicsEnvironment()
				.getDefaultScreenDevice()
				.getDefaultConfiguration();

	// Create a hardware accelerated image
	public final BufferedImage create(final int width, final int height,
			final boolean alpha) {
		return config.createCompatibleImage(width, height, alpha
				? Transparency.TRANSLUCENT : Transparency.OPAQUE);
	}
	
	// Setup
	public Test() {
		// JFrame
		frame = new JFrame();
		frame.addWindowListener(new FrameClose());
		frame.setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE);
		frame.setSize(width * scale, height * scale);
		frame.setVisible(true);

		// Canvas
		canvasPanel = new JPanel(false);
		canvasPanel.setPreferredSize(new Dimension(width * scale, height * scale));
		frame.add(canvasPanel, 0);

		// Background & Buffer
		background = create(width, height, false);
		start();
	}

	private class FrameClose extends WindowAdapter {
		@Override
		public void windowClosing(final WindowEvent e) {
			isRunning = false;
		}
	}

	
	// MainLoop ----------------------------------------------------------------
	public void run() {
		// Using a Background Image instead of drawing directly to the buffer 
		// has three advantages: 1. You're able to scale the output and 2. 
		// it's actually faster and last but not least it eliminates the need of
		// double buffering
		backgroundGraphics = (Graphics2D) background.getGraphics();
		
		long fpsWait = (long) (1.0 / fps * 1000);
		while (isRunning) {
			long renderStart = System.nanoTime();
			updateGame();

			// Update Graphics
			Graphics2D bg = (Graphics2D) canvasPanel.getGraphics();
			renderGame(backgroundGraphics);
			if (scale != 1) {
				bg.drawImage(background, 0, 0, width * scale, height
							* scale, 0, 0, width, height, null);
			} else {
				bg.drawImage(background, 0, 0, null);
			}
			bg.dispose();

			// FPS Limiting
			long renderTime = (System.nanoTime() - renderStart) / 1000000;
			try {
				Thread.sleep(Math.max(0, fpsWait - renderTime));
			} catch (InterruptedException e) {
				Thread.interrupted();
				break;
			}
			renderTime = (System.nanoTime() - renderStart) / 1000000;
		}
		frame.dispose();
	}

	
	// Game Methods ------------------------------------------------------------
	public void updateGame() {
		// update game logic here
	}

	private Random rand = new Random();
	public void renderGame(Graphics2D g) {
		g.setColor(Color.BLACK);
		g.fillRect(0, 0, width, height);
		
		g.setColor(Color.ORANGE);
		
		g.fillRect(rand.nextInt(width), rand.nextInt(height), 20, 20);
	}

	public static void main(final String args[]) {
		new Test();
	}
}

Could you please indicate why do you say that using a BufferedImage is faster? (I think by that you mean "faster than direct buffer drawing", please correct me if I'm wrong). Thank you.