🔒 Locked

[java] origin for graphics context off screen

Started by xidis Apr 21, 2006 at 11:22 PM 2 replies 950+ views

Original Post

Apr 21, 2006 at 11:22 PM

I am writing a basic game in java. Every renderable object maintains its own coordinates and size. Each object assumes that the origin (0, 0) is where it should be, namely in the upper left corner of the screen. It seems that the origin is not in the upper left corner but rather somewhere in the negatives. Thus, if I try to draw in object at the origin, it does not appear on screen. Here is the code I use to obtain the Graphics object used for rendering.


private void renderObjects()
	{
		Graphics g = buffer.getDrawGraphics();
		g.setColor(frame.getBackground());
		
		g.fillRect(0, 0, frame.getWidth(), frame.getHeight());
		g.setColor(Color.black);
		g.setFont(new Font("Courier", Font.PLAIN, 28));
		g.drawString("Score: " + player.getScore() + "  Hits: " + player.getHits() + "  Misses: " + player.getMisses(), 100, 100);

		for(Creature creature: creatures)
		{
			creature.render(g);
		}
		
		buffer.show();
		g.dispose();
	}

The object "buffer" was obtained and stored in this code:


frame = new JFrame("Duck Hunt");
frame.setPreferredSize(new Dimension(800, 600));
frame.setBackground(Color.white);
frame.getContentPane().addMouseListener(new ClickHandler());

				frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
				
frame.createBufferStrategy(2);
buffer = frame.getBufferStrategy();
				
frame.setVisible(true);

Any help or suggetions is appreciated. Thanks.

CaptainJester

101

CaptainJester

Apr 22, 2006 at 6:15 AM

I can't tell what is wrong from the code shown, but the origin is in the upper-left corner. You will have to show more code to figure it out. Try a simple test.

import java.util.*;import java.awt.*;import javax.swing.*;public class Test extends JPanel {    public void paint(Graphics g) {        g.fillRect(10, 10, 100, 100);    }    public static void main(String args[]) {        JFrame f = new JFrame();        f.getContentPane().add(new Test());        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        f.setSize(300, 300);        f.show();    }}

This will show you where the origin is.

Aldacron

208

Aldacron

Apr 22, 2006 at 4:59 PM

Don't draw directly to the JFrame. Add a JPanel, or an AWT Canvas, to the frame and draw to that instead. Then you can keep the title bar on the frame and still use (0,0) as the origin.

Topic Locked

This topic has been locked by a moderator. New replies are not allowed.