code: public void rotate(float rx, float ry, float ang) {
  		checkPush();
  
  		predraw();
  		translate(rx, ry);
  		GL.glRotatef(ang, 0, 0, 1);
  		translate(-rx, -ry);
  		postdraw();
  	}
docs: Apply a rotation to everything draw on the graphics context
  
  @param rx
  The x coordinate of the center of rotation
  @param ry
  The y coordinate of the center of rotation
  @param ang
  The angle (in degrees) to rotate by