/*
 *  call-seq:
 *    runtime  ->  Integer
 *
 *  Return the number of milliseconds since the Rubygame timer system
 *  was initialized.
 *
 *  The Rubygame timer system will be initialized when you call this function,
 *  if it has not been already.
 */
VALUE rbgm_clock_runtime( VALUE module )
{
  rg_init_sdl_timer();

  return UINT2NUM(SDL_GetTicks());
}