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();

    }

}