private void update(int delta) {
		rotation += 0.15f * delta;
		if (Keyboard.isKeyDown(Keyboard.KEY_LEFT))
			xpos -= 0.35f * delta;
		if (Keyboard.isKeyDown(Keyboard.KEY_RIGHT))
			xpos += 0.35f * delta;

		if (Keyboard.isKeyDown(Keyboard.KEY_UP))
			ypos -= 0.35f * delta;
		if (Keyboard.isKeyDown(Keyboard.KEY_DOWN))
			ypos += 0.35f * delta;

		// Keep quad on screen
		if (xpos < 0)
			xpos = 0;
		if (xpos > x_res)
			xpos = x_res;
		if (ypos > y_res)
			ypos = y_res;
		if (ypos < 0)
			ypos = 0;

		updateFPS();
	}