import java.awt.Canvas;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsEnvironment;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.Transparency;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.awt.image.MemoryImageSource;
import java.net.URL;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;





//****************************************************************************
//
//
//
//****************************************************************************

class Constants 
{

	public static final double FIXED_TIME_STEP = 1.0 / 60.0;

	public final static int SCREEN_WIDTH = 640;
	public final static int SCREEN_HEIGHT = 480;

}


//****************************************************************************
//
//
//
//****************************************************************************

class Keyboard implements KeyListener
{
	private static Keyboard instance = new Keyboard();

	private boolean[] keysPressed = new boolean[256];
	private boolean[] keysReleased = new boolean[256];
	
	private boolean anyKeyPressed = false;
	
	private Keyboard()
	{
		
	}
	
	public static Keyboard getInstance()
	{
		return instance;
	}
	
	@Override
	public void keyPressed( KeyEvent e )
	{
		int keyId = (e.getKeyCode() & 255);
		keysPressed[keyId] = true;
		keysReleased[keyId] = false;
		anyKeyPressed = true;
	}

	@Override
	public void keyReleased( KeyEvent e )
	{
		int keyId = (e.getKeyCode() & 255);
		keysPressed[keyId] = false;
		keysReleased[keyId] = true;
		anyKeyPressed = false;
	}

	@Override
	public void keyTyped( KeyEvent e )
	{
		
	}
	
	public boolean isKeyPressed( int key ) 
	{
		return keysPressed[key];
	}
	
	public boolean isKeyReleased( int key ) 
	{
		return keysReleased[key];
	}
	
	public boolean isAnyKeyPressed()
	{
		return anyKeyPressed;
	}
	
	public void resetKeys() 
	{
		for( int i = 0; i < 256; i++ )
		{
			keysReleased[i]= false;
		}
	}
	
	
}


//****************************************************************************
//
//
//
//****************************************************************************

class Game
{

	private double accumulator = 0;

	private int fps = 0;
	private int framesPerSecond = 0;
	private double previousTime = 0;
	private double oldTime = 0;
	private double secondsElapsed = 0;

	int[] pixels = new int[ Constants.SCREEN_WIDTH * Constants.SCREEN_HEIGHT ];
	MemoryImageSource renderBufferSource = new MemoryImageSource( Constants.SCREEN_WIDTH, 
																  Constants.SCREEN_HEIGHT, 
																  pixels, 
																  0, 
																  Constants.SCREEN_WIDTH );

	Image renderBuffer;
	
	public Game()
	{
		
	}

	public void init( BufferStrategy strategy, Screen screen )
	{
		 
		Graphics2D g2D = (Graphics2D) strategy.getDrawGraphics();
		g2D.setColor(Color.BLACK);
		g2D.fillRect(0, 0, Constants.SCREEN_WIDTH, Constants.SCREEN_HEIGHT);

		Toolkit.getDefaultToolkit().sync();

		strategy.show();


		g2D.dispose();
		strategy.show();
		
		for( int y = 0; y < Constants.SCREEN_HEIGHT; y++ )
		{
			for( int x = 0; x < Constants.SCREEN_WIDTH; x++ )
			{
				pixels[x + y * Constants.SCREEN_WIDTH] = (x*x) ^ (y*y);
			}
			
		}
		
		
		renderBufferSource.setAnimated( true );
		renderBuffer = Toolkit.getDefaultToolkit().createImage(renderBufferSource);

		renderBufferSource.newPixels();
		
	}
	
	private void update() 
	{

		
		Keyboard.getInstance().resetKeys();
		
		
	}
	
	
	private void render( Graphics2D g2D, Screen screen ) 
	{

		for( int y = 0; y < Constants.SCREEN_HEIGHT; y++ )
		{
			for( int x = 0; x < Constants.SCREEN_WIDTH; x++ )
			{
				pixels[x + y * Constants.SCREEN_WIDTH] = (x*x*x) ^ (y*y*y);
			}
			
		}
		
		renderBufferSource.newPixels();
		
		g2D.drawImage( renderBuffer, 
				 	   0,
				 	   0,
				 	   screen );

		
	}


	public void run( BufferStrategy strategy, Screen screen ) 
	{

		double dt = getDeltaTime(getSystemTime());
		
		init( strategy, screen  );
		
		while (true) 
		{

			dt = getDeltaTime(getSystemTime());
			if( dt > Constants.FIXED_TIME_STEP ) dt = Constants.FIXED_TIME_STEP;
			
			accumulator += dt;
			secondsElapsed += dt;
			
			while( accumulator >= Constants.FIXED_TIME_STEP ) 
			{

				accumulator -= Constants.FIXED_TIME_STEP;
				update();
								
			}

			
			Graphics2D g2D = (Graphics2D) strategy.getDrawGraphics();
			g2D.setColor(Color.BLACK);
			g2D.fillRect(0, 0, Constants.SCREEN_WIDTH, Constants.SCREEN_HEIGHT);

			render( g2D, screen );
			g2D.dispose();
			strategy.show();
			Toolkit.getDefaultToolkit().sync();
			

			if( Keyboard.getInstance().isKeyPressed( KeyEvent.VK_ESCAPE ) )
			{
				System.exit(0);
			}
			
			try 
			{
				Thread.sleep(1);
			} 
			catch (InterruptedException e)
			{
				System.out.println("interrupted");
			}

		}

	}

	
	public Keyboard getKeyHandler()
	{
		return Keyboard.getInstance();
	}
	
	
	public double getSystemTime() 
	{
		return System.nanoTime() / 1000000000.0;
	}

	public double getDeltaTime( double timerInSeconds ) 
	{

		double currentTime = timerInSeconds;
		double elapsedTime = currentTime - oldTime;
		oldTime = currentTime;

		framesPerSecond++;

		if ((currentTime - previousTime) > 1.0) 
		{
			previousTime = currentTime;
			fps = framesPerSecond;
			framesPerSecond = 0;
		}

		return elapsedTime;
	}

		
}  // end class


//****************************************************************************
//
//
//
//****************************************************************************

class Screen extends Canvas 
{

	private static final long serialVersionUID = 1L;

	private BufferStrategy strategy;
	
	Game engine = new Game();
	
	public Screen() 
	{

		JFrame container = new JFrame("Java2D GFX Framework by Relminator");

		JPanel panel = (JPanel) container.getContentPane();
		panel.setPreferredSize(new Dimension(Constants.SCREEN_WIDTH,
				Constants.SCREEN_HEIGHT));
		panel.setLayout(null);

		setBounds(0, 0, Constants.SCREEN_WIDTH, Constants.SCREEN_HEIGHT);

		panel.add(this);

		setIgnoreRepaint(true);

		container.pack();
		container.setLocationRelativeTo(null);
		container.setResizable(false);
		container.setVisible(true);

		container.addWindowListener(new WindowAdapter() 
		{
			public void windowClosing(WindowEvent e) 
			{
				System.exit(0);
			}
		});

		addKeyListener( engine.getKeyHandler() );

		requestFocus();
		setFocusable(true);
		
		createBufferStrategy(2);
		strategy = getBufferStrategy();
		
		
	}

	public void playGame() 
	{

		engine.run( strategy, this );
		
	}

}


//****************************************************************************
//
// Main Entry Point
//
//****************************************************************************


public class XorTexture 
{

	public static void main(String[] args) 
	{

		Screen screen = new Screen();
		screen.playGame();
	
	}

}