/* 
 *  call-seq:
 *     zoom_to(width, height, smooth=false)  ->  Surface
 *
 *  Return a zoomed version of the Surface.
 *
 *  This method takes these arguments:
 *  width::   the width to scale to. If nil is given, will keep x axis unscaled.
 *  height::  the height to scale to. If nil is given, will keep x axis
 *            unscaled.
 *  smooth::  whether to anti-alias the new surface. This option can be
 *            omitted, in which case the surface will not be anti-aliased.
 *            If true, the new surface will be 32bit RGBA.
 */
VALUE rbgm_transform_zoom_to(int argc, VALUE *argv, VALUE self)
{
  SDL_Surface *src, *dst;
  VALUE v_width, v_height, v_smooth;
  double zoomx, zoomy;
  int smooth;

  rb_scan_args(argc, argv, "21", &v_width, &v_height, &v_smooth);

  Data_Get_Struct(self,SDL_Surface,src);
  smooth = RTEST(v_smooth) ? 1 : 0;
  zoomx  = NIL_P(v_width) ? 1.0 : NUM2DBL(v_width)/src->w;
  zoomy  = NIL_P(v_height) ? 1.0 : NUM2DBL(v_height)/src->h;
  dst    = zoomSurface(src,zoomx,zoomy,smooth);

  if(dst == NULL)
    rb_raise(eSDLError,"Could not rotozoom surface: %s",SDL_GetError());

  return Data_Wrap_Struct(cSurface,0,SDL_FreeSurface,dst);
}