Scrolling Background in Java

gistfile1.txt

	public void drawBackground() {
	  // CIRCLE is a static var defined as MATH.PI * 2
	  // graphics() returns a Graphics2D context in this case from a BufferedImage createGraphics() method
		rotationOfBackground += 0.05;
		if(rotationOfBackground >= CIRCLE) {
			rotationOfBackground -= CIRCLE;
		}				
	
	  // In this case we're assuming that 300 is the height that we need
		int width = (int)(background.getWidth(this));		
    int left =(int)((rotationOfBackground / CIRCLE) * -width);
    graphics().drawImage(background, left, 0, width, 300, this);
    
    if (left < width - this.screenWidth) {
        graphics().drawImage(background, left + width, 0, width, 300, this);
    }
	}