Question

I’m planning on making a game and want the window to have 3 different modes: a small 800 x 500 window, a maximized window, and a fullscreen window. I plan on using active rendering to draw graphics into the jframe and to paint the components in the layeredpane. I am using a bufferstrategy with 2 buffers. In order to deal with the problem of setting an already visible screen to fullscreen, each time the window has it’s dimensions changed (it isnt resizeable by the window itself, only by buttons within the program) a new jframe is created, given the proper size, and a jpanel containing the components to paint is added to the frame. for some reason, every time I paint something with the graphics from the bufferstrategy, there is an offset (painting something at 0,0, would show up around -3, -20, and I’m not sure why. This happens when I either just draw with the graphics or call paint components with the graphics (on the current jframe’s layered panel). Any help you can give would be appreciated.enter code here

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class ScreenManager {

private GraphicsDevice device;
private JFrame window;
private int sizeState;
private JPanel contentPane;
private String title;
private Rectangle maxBounds;    

public static final int SMALL_WINDOW = 1;
public static final int MAXIMIZED_WINDOW = 2;
public static final int FULLSCREEN_WINDOW = 3;

private static final int SMALL_WIDTH = 800;
private static final int SMALL_HEIGHT = 500;

public ScreenManager(String s){     
    NullRepaintManager.install();
    title = s;      
    GraphicsEnvironment environment = GraphicsEnvironment.getLocalGraphicsEnvironment();        
    maxBounds = environment.getMaximumWindowBounds();
    device = environment.getDefaultScreenDevice();  
    contentPane = new JPanel();             
    resetJFrame();      
    setSmallWindow();       
}

public JPanel getPanel(){
    return contentPane;
}

public Graphics2D getGraphics(){
    while(true){
        if(window != null){     
    try{
    return (Graphics2D) window.getBufferStrategy().getDrawGraphics();
    }catch(Exception e){}
    }       
}
}
public void update(){
    if(window != null && !window.getBufferStrategy().contentsLost()){
        window.getBufferStrategy().show();
    }

    Toolkit.getDefaultToolkit().sync();
}

public int getWidth(){
    if(window != null){
        return contentPane.getWidth();
    }
    return 0;
}

public int getHeight(){
    if(window != null){
        return contentPane.getHeight();
    }
    return 0;
}

public void paintComponents(Graphics2D g){      
        if(window != null){
            contentPane.paintComponents(g);
                }
        }

public void closeWindow(){          
    System.exit(0);
}

public void setSmallWindow(){
    if(window != null && sizeState != ScreenManager.SMALL_WINDOW){
    resetJFrame();      
    window.setSize(ScreenManager.SMALL_WIDTH, ScreenManager.SMALL_HEIGHT);      
    contentPane.setSize(ScreenManager.SMALL_WIDTH, ScreenManager.SMALL_HEIGHT);
    window.setLocationRelativeTo(null);         
    window.setVisible(true);        
    window.createBufferStrategy(2);         
    sizeState = ScreenManager.SMALL_WINDOW;     
}
}

public void setMaximizedWindow(){
    if(window != null && sizeState != ScreenManager.MAXIMIZED_WINDOW){
    resetJFrame();
    window.setSize((int) maxBounds.getWidth(), (int) maxBounds.getHeight());    
    contentPane.setSize(window.getWidth(), window.getHeight());
    window.setLocation(0,0);
    window.setVisible(true);        
    window.createBufferStrategy(2);     
    sizeState = ScreenManager.MAXIMIZED_WINDOW;     
}
}

public void setFullScreenWindow(){
    if(window != null && sizeState != ScreenManager.FULLSCREEN_WINDOW){
        resetJFrame();      
        window.setUndecorated(true);
        device.setFullScreenWindow(window);
        contentPane.setSize(window.getWidth(), window.getHeight());
        window.createBufferStrategy(2);
        sizeState = ScreenManager.FULLSCREEN_WINDOW;            
    }
}

private void resetJFrame(){
    if(sizeState == ScreenManager.FULLSCREEN_WINDOW){
        device.setFullScreenWindow(null);
    }

    if(window != null){
        window.dispose();
        window = null;
    }

    window = new JFrame(title);         
    window.setResizable(false);         
    window.setIgnoreRepaint(true);
    window.addWindowListener(new WindowExitAdapter());
    window.add(contentPane);            
    contentPane.setOpaque(false);       
}

private class WindowExitAdapter extends WindowAdapter{

    public void windowClosing(WindowEvent 
e){                     
        closeWindow();
    }               
}
 }

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class ScreenManagerTest implements ActionListener{

private ScreenManager sm;
private JButton fullscreenButton;
private JButton smallScreenButton;
private JButton maxScreenButton;
private JButton quitButton;
private boolean isRunning = true;

private int sizeState = 1;


public static void main(String[] args) {
    new ScreenManagerTest().go();       
}

public void go(){
    sm = new ScreenManager("Nertz! Solitaire");
    sm.getPanel().setLayout(new BorderLayout());
    fullscreenButton = new JButton("Set Fullscreen");       
    sm.getPanel().add(fullscreenButton, BorderLayout.CENTER);
    smallScreenButton = new JButton("Set Small Screen");        
    sm.getPanel().add(smallScreenButton, BorderLayout.WEST);
    maxScreenButton = new JButton("Set Max Screen");        
    sm.getPanel().add(maxScreenButton, BorderLayout.EAST);
    quitButton = new JButton("Exit Program");       
    sm.getPanel().add(quitButton, BorderLayout.SOUTH);
    fullscreenButton.addActionListener(this);
    smallScreenButton.addActionListener(this);
    maxScreenButton.addActionListener(this);
    quitButton.addActionListener(this);

    while(isRunning == true){           
        switch(sizeState){

        case ScreenManager.FULLSCREEN_WINDOW:
            sm.setFullScreenWindow();
            break;
        case ScreenManager.MAXIMIZED_WINDOW:
            sm.setMaximizedWindow();
            break;
        case ScreenManager.SMALL_WINDOW:
            sm.setSmallWindow();
            break;
        }
        draw(sm.getGraphics());         
        try{
            Thread.sleep(20);
        }catch(Exception e){}
    }
    sm.closeWindow();
}

public void draw(Graphics2D g){ 
    sm.paintComponents(g);
    sm.update();

    g.dispose();
}

public void actionPerformed(ActionEvent event){
    if(event.getSource() == fullscreenButton){
        sm.setFullScreenWindow();
        sizeState = ScreenManager.FULLSCREEN_WINDOW;
    }
    if(event.getSource() == smallScreenButton){
        sm.setSmallWindow();
        sizeState = ScreenManager.SMALL_WINDOW;
    }
    if(event.getSource() == maxScreenButton){
        sm.setMaximizedWindow();    
        sizeState = ScreenManager.MAXIMIZED_WINDOW;
    }
    if(event.getSource() == quitButton){
        isRunning = false;  
    }
}
}

Answer 1

for some reason, every time I paint something with the graphics from
the bufferstrategy, there is an offset (painting something at 0,0,
would show up around -3, -20, and I’m not sure why.

Just a wild guess… Maybe you are painting not from (0,0) but by frame bounds zero, since (-3, -20) point seems to be window zero coordinate (small border @ left and ~20px window header)?

In case you are actually drawing from (0,0) but coordinates getting moved to (-3, -20) and this is actually a window border – you can add a small patch @ the start of paint method:

protected void paintComponent ( Graphics g )
{
    Point wl = SwingUtilities.getWindowAncestor ( this ).getLocationOnScreen ();
    Point los = this.getLocationOnScreen ();
    Point zero = new Point ( los.x-wl.x, los.y-wl.y );
    g.translate ( zero.x, zero.y );

    // ...
}

But still i can’t explain why that could happen. Maybe you are saving the zero coordinate when switching between window and fullscreen modes and that causes such problem…