/* 
 *  call-seq:
 *    draw_ellipse(center, radius, color)
 *
 *  Draw a non-solid ellipse (oval) on the Surface, given the 
 *  coordinates of its center and its horizontal and vertical radii.
 *  See also #draw_ellipse_a and #draw_ellipse_s
 *
 *  This method takes these arguments:
 *  center::  the coordinates of ellipse's center, [x,y].
 *  radii::   the x and y radii (pixels), [rx,ry].
 *  color::   the color of the shape, [r,g,b,a]. If alpha
 *            is omitted, it is drawn at full opacity.
 */
VALUE rbgm_draw_ellipse(VALUE target, VALUE center, VALUE radii, VALUE rgba)
{
  draw_ellipse(target,center,radii,rgba,0,0); /* no aa, no fill */
  return target;
}