/* 
 *  call-seq:
 *    draw_circle_a(center, radius, color)
 *
 *  Like #draw_circle, but the outline is anti-aliased.
 */
VALUE rbgm_draw_aacircle(VALUE target, VALUE center, VALUE radius, VALUE rgba)
{
  draw_circle(target,center,radius,rgba,1,0); /* aa, no fill */
  return target;
}