public void run(ReentrantLock physicsLock) {
		while (!Display.isCloseRequested() && !quit){
			// update 1 frame of display
			GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT);
			GL11.glMatrixMode(GL11.GL_MODELVIEW);
			GL11.glLoadIdentity();
			GL11.glTranslated(0, 0, -centerDistance);
			GL11.glRotated(pitch, 1, 0, 0);
			GL11.glRotated(yaw, 0, 0, 1);
			GL11.glScaled(1E-7, 1E-7, 1E-7);	
	
			
			physicsLock.lock(); // keeps physics from updating at the same time
			focus();
			for (Body b : bodies) {
				b.draw(centerDistance);
			}
			for (Craft c : ships) {
				c.draw(centerDistance);
			}
			physicsLock.unlock();
	
			pollInput();
	
			Display.update();
			Display.sync(60);
		}
	}