My game gives me a white screen when I run it with tiles moving enabled

Newbie & Debugging Questions
#1

When I try to run my game with x++ and y++ enabled after update(), I get a white screen.

(Somewhat) working code:

package com.jr.tm.graphics;

import java.awt.Canvas;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferInt;

import javax.swing.JFrame;

import com.jr.tm.Input.Keyboard;

public class Game extends Canvas implements Runnable {

/**
 * 
 */
private static final long serialVersionUID = 1L;
public static int width = 300;
public static int height = width / 16 * 9; 
public static int scale = 3; 
public static String title = "The Struggle";

private Thread thread;
private JFrame frame;
private Keyboard key;
private boolean running = false;

private Screen screen; 

private BufferedImage image= new BufferedImage (width, height, BufferedImage.TYPE_INT_RGB);
private int[] pixels = ((DataBufferInt)image.getRaster().getDataBuffer()).getData(); 

public Game () {
	Dimension size = new Dimension( width * scale , height * scale); 
	setPreferredSize(size); 
	
	screen = new Screen(width, height); 
	frame = new JFrame(); 
	key = new Keyboard();
	
	addKeyListener(key);
}

public synchronized void start () {
	running = true;
	thread = new Thread (this, "Display") ;
	thread.start () ; 
}
public synchronized void stop () {
	running = false;
	try {
	thread.join () ;
	} catch (InterruptedException e) {
	e.printStackTrace(); 
	}

}	

public void run() {
	long lastTime = System.nanoTime();
	long timer = System.currentTimeMillis();
	final double ns = 1000000000.0 / 60.0;
	double delta = 0;
	int frames = 0;
	int updates = 0;
	while (running = true) {
		long now = System.nanoTime();
		delta += (now - lastTime) / ns;
		lastTime = now;
		while (delta >= 1) {
			update();
			updates++;
			delta--;
		}
		render();
		frames++;
		
		if (System.currentTimeMillis() - timer > 10000)
			timer += 1000;
		System.out.println(updates+ "ups, " + frames + "fps");
		frame.setTitle( title + " | " + updates+ "ups, " + frames + "fps");
		updates = 0;
		frames = 0;
	}
	stop();
}
int x = 0; int y = 0;

public void update() {
	//x++;
	//y++;
}

public void render() {
	BufferStrategy bs = getBufferStrategy();
	if (bs == null) {
		createBufferStrategy(3); 
		return;
	}
	
	screen.clear();
	screen.render(x , y);
	
	for(int i = 0; i < pixels.length; i++) {
		pixels [i] = screen.pixels[i];
	}
	
	Graphics g = bs.getDrawGraphics();
	g.drawImage(image, 0, 0, getWidth() , getHeight(), null);
	g.dispose();
	bs.show(); }

public static void main(String[] args) {
Game game = new Game();
game.frame.setResizable(false);
game.frame.setTitle(Game.title);
game.frame.add(game);
game.frame.pack();
game.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
game.frame.setLocationRelativeTo(null);
game.frame.setVisible(true);

game.start();

}

}

Not working code:

package com.jr.tm.graphics;

import java.awt.Canvas;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferInt;

import javax.swing.JFrame;

import com.jr.tm.Input.Keyboard;

public class Game extends Canvas implements Runnable {

/**
 * 
 */
private static final long serialVersionUID = 1L;
public static int width = 300;
public static int height = width / 16 * 9; 
public static int scale = 3; 
public static String title = "The Struggle";

private Thread thread;
private JFrame frame;
private Keyboard key;
private boolean running = false;

private Screen screen; 

private BufferedImage image= new BufferedImage (width, height, BufferedImage.TYPE_INT_RGB);
private int[] pixels = ((DataBufferInt)image.getRaster().getDataBuffer()).getData(); 

public Game () {
	Dimension size = new Dimension( width * scale , height * scale); 
	setPreferredSize(size); 
	
	screen = new Screen(width, height); 
	frame = new JFrame(); 
	key = new Keyboard();
	
	addKeyListener(key);
}

public synchronized void start () {
	running = true;
	thread = new Thread (this, "Display") ;
	thread.start () ; 
}
public synchronized void stop () {
	running = false;
	try {
	thread.join () ;
	} catch (InterruptedException e) {
	e.printStackTrace(); 
	}

}	

public void run() {
	long lastTime = System.nanoTime();
	long timer = System.currentTimeMillis();
	final double ns = 1000000000.0 / 60.0;
	double delta = 0;
	int frames = 0;
	int updates = 0;
	while (running = true) {
		long now = System.nanoTime();
		delta += (now - lastTime) / ns;
		lastTime = now;
		while (delta >= 1) {
			update();
			updates++;
			delta--;
		}
		render();
		frames++;
		
		if (System.currentTimeMillis() - timer > 10000)
			timer += 1000;
		System.out.println(updates+ "ups, " + frames + "fps");
		frame.setTitle( title + " | " + updates+ "ups, " + frames + "fps");
		updates = 0;
		frames = 0;
	}
	stop();
}
int x = 0; int y = 0;

public void update() {
	x++;
	y++;
}

public void render() {
	BufferStrategy bs = getBufferStrategy();
	if (bs == null) {
		createBufferStrategy(3); 
		return;
	}
	
	screen.clear();
	screen.render(x , y);
	
	for(int i = 0; i < pixels.length; i++) {
		pixels [i] = screen.pixels[i];
	}
	
	Graphics g = bs.getDrawGraphics();
	g.drawImage(image, 0, 0, getWidth() , getHeight(), null);
	g.dispose();
	bs.show(); }

public static void main(String[] args) {
Game game = new Game();
game.frame.setResizable(false);
game.frame.setTitle(Game.title);
game.frame.add(game);
game.frame.pack();
game.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
game.frame.setLocationRelativeTo(null);
game.frame.setVisible(true);

game.start();

}

}
package com.jr.tm.graphics;

import java.awt.Canvas;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferInt;

import javax.swing.JFrame;

import com.jr.tm.Input.Keyboard;

public class Game extends Canvas implements Runnable {

/**
 * 
 */
private static final long serialVersionUID = 1L;
public static int width = 300;
public static int height = width / 16 * 9; 
public static int scale = 3; 
public static String title = "The Struggle";

private Thread thread;
private JFrame frame;
private Keyboard key;
private boolean running = false;

private Screen screen; 

private BufferedImage image= new BufferedImage (width, height, BufferedImage.TYPE_INT_RGB);
private int[] pixels = ((DataBufferInt)image.getRaster().getDataBuffer()).getData(); 

public Game () {
	Dimension size = new Dimension( width * scale , height * scale); 
	setPreferredSize(size); 
	
	screen = new Screen(width, height); 
	frame = new JFrame(); 
	key = new Keyboard();
	
	addKeyListener(key);
}

public synchronized void start () {
	running = true;
	thread = new Thread (this, "Display") ;
	thread.start () ; 
}
public synchronized void stop () {
	running = false;
	try {
	thread.join () ;
	} catch (InterruptedException e) {
	e.printStackTrace(); 
	}

}	

public void run() {
	long lastTime = System.nanoTime();
	long timer = System.currentTimeMillis();
	final double ns = 1000000000.0 / 60.0;
	double delta = 0;
	int frames = 0;
	int updates = 0;
	while (running = true) {
		long now = System.nanoTime();
		delta += (now - lastTime) / ns;
		lastTime = now;
		while (delta >= 1) {
			update();
			updates++;
			delta--;
		}
		render();
		frames++;
		
		if (System.currentTimeMillis() - timer > 10000)
			timer += 1000;
		System.out.println(updates+ "ups, " + frames + "fps");
		frame.setTitle( title + " | " + updates+ "ups, " + frames + "fps");
		updates = 0;
		frames = 0;
	}
	stop();
}
int x = 0; int y = 0;

public void update() {
	x++;
	y++;
}

public void render() {
	BufferStrategy bs = getBufferStrategy();
	if (bs == null) {
		createBufferStrategy(3); 
		return;
	}
	
	screen.clear();
	screen.render(x , y);
	
	for(int i = 0; i < pixels.length; i++) {
		pixels [i] = screen.pixels[i];
	}
	
	Graphics g = bs.getDrawGraphics();
	g.drawImage(image, 0, 0, getWidth() , getHeight(), null);
	g.dispose();
	bs.show(); }

public static void main(String[] args) {
Game game = new Game();
game.frame.setResizable(false);
game.frame.setTitle(Game.title);
game.frame.add(game);
game.frame.pack();
game.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
game.frame.setLocationRelativeTo(null);
game.frame.setVisible(true);

game.start();

}

}
package com.jr.tm.graphics;

import java.awt.Canvas;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferInt;

import javax.swing.JFrame;

import com.jr.tm.Input.Keyboard;

public class Game extends Canvas implements Runnable {

/**
 * 
 */
private static final long serialVersionUID = 1L;
public static int width = 300;
public static int height = width / 16 * 9; 
public static int scale = 3; 
public static String title = "The Struggle";

private Thread thread;
private JFrame frame;
private Keyboard key;
private boolean running = false;

private Screen screen; 

private BufferedImage image= new BufferedImage (width, height, BufferedImage.TYPE_INT_RGB);
private int[] pixels = ((DataBufferInt)image.getRaster().getDataBuffer()).getData(); 

public Game () {
	Dimension size = new Dimension( width * scale , height * scale); 
	setPreferredSize(size); 
	
	screen = new Screen(width, height); 
	frame = new JFrame(); 
	key = new Keyboard();
	
	addKeyListener(key);
}

public synchronized void start () {
	running = true;
	thread = new Thread (this, "Display") ;
	thread.start () ; 
}
public synchronized void stop () {
	running = false;
	try {
	thread.join () ;
	} catch (InterruptedException e) {
	e.printStackTrace(); 
	}

}	

public void run() {
	long lastTime = System.nanoTime();
	long timer = System.currentTimeMillis();
	final double ns = 1000000000.0 / 60.0;
	double delta = 0;
	int frames = 0;
	int updates = 0;
	while (running = true) {
		long now = System.nanoTime();
		delta += (now - lastTime) / ns;
		lastTime = now;
		while (delta >= 1) {
			update();
			updates++;
			delta--;
		}
		render();
		frames++;
		
		if (System.currentTimeMillis() - timer > 10000)
			timer += 1000;
		System.out.println(updates+ "ups, " + frames + "fps");
		frame.setTitle( title + " | " + updates+ "ups, " + frames + "fps");
		updates = 0;
		frames = 0;
	}
	stop();
}
int x = 0; int y = 0;

public void update() {
	x++;
	y++;
}

public void render() {
	BufferStrategy bs = getBufferStrategy();
	if (bs == null) {
		createBufferStrategy(3); 
		return;
	}
	
	screen.clear();
	screen.render(x , y);
	
	for(int i = 0; i < pixels.length; i++) {
		pixels [i] = screen.pixels[i];
	}
	
	Graphics g = bs.getDrawGraphics();
	g.drawImage(image, 0, 0, getWidth() , getHeight(), null);
	g.dispose();
	bs.show(); }

public static void main(String[] args) {
Game game = new Game();
game.frame.setResizable(false);
game.frame.setTitle(Game.title);
game.frame.add(game);
game.frame.pack();
game.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
game.frame.setLocationRelativeTo(null);
game.frame.setVisible(true);

game.start();

}

}
package com.jr.tm.graphics;

import java.awt.Canvas;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferInt;

import javax.swing.JFrame;

import com.jr.tm.Input.Keyboard;

public class Game extends Canvas implements Runnable {

/**
 * 
 */
private static final long serialVersionUID = 1L;
public static int width = 300;
public static int height = width / 16 * 9; 
public static int scale = 3; 
public static String title = "The Struggle";

private Thread thread;
private JFrame frame;
private Keyboard key;
private boolean running = false;

private Screen screen; 

private BufferedImage image= new BufferedImage (width, height, BufferedImage.TYPE_INT_RGB);
private int[] pixels = ((DataBufferInt)image.getRaster().getDataBuffer()).getData(); 

public Game () {
	Dimension size = new Dimension( width * scale , height * scale); 
	setPreferredSize(size); 
	
	screen = new Screen(width, height); 
	frame = new JFrame(); 
	key = new Keyboard();
	
	addKeyListener(key);
}

public synchronized void start () {
	running = true;
	thread = new Thread (this, "Display") ;
	thread.start () ; 
}
public synchronized void stop () {
	running = false;
	try {
	thread.join () ;
	} catch (InterruptedException e) {
	e.printStackTrace(); 
	}

}	

public void run() {
	long lastTime = System.nanoTime();
	long timer = System.currentTimeMillis();
	final double ns = 1000000000.0 / 60.0;
	double delta = 0;
	int frames = 0;
	int updates = 0;
	while (running = true) {
		long now = System.nanoTime();
		delta += (now - lastTime) / ns;
		lastTime = now;
		while (delta >= 1) {
			update();
			updates++;
			delta--;
		}
		render();
		frames++;
		
		if (System.currentTimeMillis() - timer > 10000)
			timer += 1000;
		System.out.println(updates+ "ups, " + frames + "fps");
		frame.setTitle( title + " | " + updates+ "ups, " + frames + "fps");
		updates = 0;
		frames = 0;
	}
	stop();
}
int x = 0; int y = 0;

public void update() {
	x++;
	y++;
}

public void render() {
	BufferStrategy bs = getBufferStrategy();
	if (bs == null) {
		createBufferStrategy(3); 
		return;
	}
	
	screen.clear();
	screen.render(x , y);
	
	for(int i = 0; i < pixels.length; i++) {
		pixels [i] = screen.pixels[i];
	}
	
	Graphics g = bs.getDrawGraphics();
	g.drawImage(image, 0, 0, getWidth() , getHeight(), null);
	g.dispose();
	bs.show(); }

public static void main(String[] args) {
Game game = new Game();
game.frame.setResizable(false);
game.frame.setTitle(Game.title);
game.frame.add(game);
game.frame.pack();
game.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
game.frame.setLocationRelativeTo(null);
game.frame.setVisible(true);

game.start();

}

}
Please, help!

#2

If you would like to see my other classes as well, just let me know.

#3

Welcome to the JGO. :slight_smile:
We generally like to help, but please don’t expect us to read through something like 500+ lines of code.
Use the [ code ] and [ /code ] tags (without spaces) and only share the part of your code that is relevant to your issue.
If you have to share really long code use JGO’s Pastebin feature.

After a quick look at your code I would say that your issue should be inside your Screen class but I can’t help any more then this because you haven’t shared that class with us.

#4

Sorry man, I wasn’t sure where the error was and didn’t want to take any chances.
Here is my Screen class:

 package com.jr.tm.graphics;

import java.util.Random;

public class Screen {
	
	private int width , height;
	public int[] pixels; 
	public final int MAP_SIZE = 8;
	public final int MAP_SIZE_MASK = MAP_SIZE - 1;
	public int[] tiles = new int [MAP_SIZE * MAP_SIZE];
	
	private Random random = new Random();
	
	public Screen (int width, int height) {
		this.width = width; 
		this.height = height;
		pixels = new int[width * height];
		
		for (int i = 0; i < MAP_SIZE*MAP_SIZE; i++)
			tiles[i] = random.nextInt(0xffffff);
			tiles[0] = 0;
	}
	
	public void clear() {
		for (int i= 0; i < pixels.length; i++) {
			pixels[i]=0;
		}
	}
	
	
	public void render(int xOffset, int yOffset) {
		for (int y= 0; y < height ; y++) {
			int yy = y + yOffset;
			//if (yy < 0 || yy >= height) break;
			for (int x= 0; x < width; x++) {
				int xx = x + xOffset;
				//if (xx < 0 || xx  >= width) break;
				int tileIndex = ((xx >> 4) & MAP_SIZE_MASK) + ((yy >> 4) & MAP_SIZE_MASK) * MAP_SIZE;//// x/y >> 4 = x/y / 16
				pixels[xx + yy * width] = tiles[tileIndex];
			} 
				
		}
	}

}

See anything wrong here???

#5

Maybe it’s moving to fast and you don’t see it, try moving it just 10 pixels and stop!

#6

Honestly just keep watching the tutorial (theCherno) and rewrite the code. I’ve watched his tutorials too, they work fine. You made a mistake copying his code somewhere.

#7

By the way, the game is only running at 0 ups and 1 fps :-\ … Would this have anything to do with it? If so, how can I fix this?

#8

How would you recommend that I do this?