epidemian · March 31, 2014 03:54 · epidemian · Mar 31, 2014
diff --git a/index.html b/index.html
 <!DOCTYPE html>
 <body>
 <script src="//cdnjs.cloudflare.com/ajax/libs/coffee-script/1.7.1/coffee-script.min.js"></script>
 <script src="owl.coffee" type="text/coffeescript"></script>
diff --git a/owl.coffee b/owl.coffee
 canvas = document.createElement 'canvas'
 canvas.style.backgroundColor = '#240202'
 canvas.style.transform = 'scale(0.5) translate(-480px,-570px)'
 W = canvas.width = 960
 H = canvas.height = 1140
 D = 50
 R = D / 2
 ctx = canvas.getContext '2d'
 imageData = ctx.getImageData 0, 0, W, H
 data = imageData.data
 owl = '''

 \ * * * * * * * * *
 \  *     * *     *
 \ *   *   *   *   *
 \    * *     * *
 \ *   *       *   *
 \  *     * *     *
 \ * *     *     * *
 \  * *         *
 \ * * * * * * *   *
 \  * * * *
 \ * * * * *       *
 \  * * * *
 \   * * * *       *
 \    * * * *
 \     * * * *     *
 \      * * * *
 \       * * * *   *
 \        *   * *
 \       *   *   * *
 \  * * * * * *   *
 \                 *
 '''.split '\n'

 insideDot = (x, y) ->
  w = 0
  for du in [-1..1] then for dv in [-1..1]
    u = x // D + du
    v = y // D + dv
    continue unless owl[v]?[u] is '*'
    dx = x - (u * D + R)
    dy = y - (v * D + R)
    d = dx * dx + dy * dy
    w += 1 / (d * d)
    return yes if w > 0.0000008
  no

 for y in [0...H] then for x in [0...W] when insideDot x, y
  i = (y * W + x) * 4
  data[i] = data[i+1] = data[i+3] = 255
  data[i+2] = 214

 ctx.putImageData imageData, 0, 0
 document.body.appendChild canvas
	<!DOCTYPE html>
	<body>
	<script src="//cdnjs.cloudflare.com/ajax/libs/coffee-script/1.7.1/coffee-script.min.js"></script>
	<script src="owl.coffee" type="text/coffeescript"></script>
	canvas = document.createElement 'canvas'
	canvas.style.backgroundColor = '#240202'
	canvas.style.transform = 'scale(0.5) translate(-480px,-570px)'
	W = canvas.width = 960
	H = canvas.height = 1140
	D = 50
	R = D / 2
	ctx = canvas.getContext '2d'
	imageData = ctx.getImageData 0, 0, W, H
	data = imageData.data
	owl = '''

	\ * * * * * * * * *
	\ * * * *
	\ * * * * *
	\ * * * *
	\ * * * *
	\ * * * *
	\ * * * * *
	\ * * *
	\ * * * * * * * *
	\ * * * *
	\ * * * * * *
	\ * * * *
	\ * * * * *
	\ * * * *
	\ * * * * *
	\ * * * *
	\ * * * * *
	\ * * *
	\ * * * *
	\ * * * * * * *
	\ *
	'''.split '\n'

	insideDot = (x, y) ->
	w = 0
	for du in [-1..1] then for dv in [-1..1]
	u = x // D + du
	v = y // D + dv
	continue unless owl[v]?[u] is '*'
	dx = x - (u * D + R)
	dy = y - (v * D + R)
	d = dx * dx + dy * dy
	w += 1 / (d * d)
	return yes if w > 0.0000008
	no

	for y in [0...H] then for x in [0...W] when insideDot x, y
	i = (y * W + x) * 4
	data[i] = data[i+1] = data[i+3] = 255
	data[i+2] = 214

	ctx.putImageData imageData, 0, 0
	document.body.appendChild canvas