DrawNGon.coffee

  # http://svg-whiz.com/svg/starPrimative.svg
  drawNGon: (cx, cy, r, rCorner, arms, shift = 0) ->
    polyPoints = ''

    if arms in [1,3,5,7,9]
      orient = 'point'
    else
      orient = 'edge'

    for s in [0..arms]
      angle = 2.0 * pi * (s / arms)

      if orient == 'point'
        angle -= pi/2
      else
        angle = (angle + (pi/arms)) - (pi/2)

      x = (r * cos(angle)) + cx
      y = (r * sin(angle)) + cy

      polyPoints += x + ',' + y + ' '

    $ngon = svg 'polygon', canvas.$drawing
    $ngon.setAttributeNS null, 'points', polyPoints
    $ngon.setAttributeNS null, 'fill', 'blue'
    $ngon.setAttributeNS(null, 'stroke', 'red')
    $ngon.setAttributeNS(null, 'stroke-width', '2')