_window = 1
_width  = 600
_height = 500

local fn SierpinskyTriangle( level as NSUInteger, x as NSUInteger, y as NSUInteger, w as NSUInteger, h as NSUInteger )
  NSUInteger w2 = w/2, w4 = w/4, h2 = h/2

  if ( level == 1 )
    pen -1.0
    line to x,    y
    pen 1.0, fn ColorYellow
    line to x+w2, y+h
    line to x+w,  y
    line to x,    y
  else
    fn SierpinskyTriangle( level-1, x,    y,    w2, h2 )
    fn SierpinskyTriangle( level-1, x+w4, y+h2, w2, h2 )
    fn SierpinskyTriangle( level-1, x+w2, y,    w2, h2 )
  end if
end fn

window _window, @"Sierpinsky Triangle", ( 0, 0, _width, _height )
WindowSetBackgroundColor( 1, fn ColorBlack )

fn SierpinskyTriangle( 9, _width * 0.05, _height * 0.05, _width * 0.9, _height * 0.9 )

HandleEvents