module.exports =
  arrow: do ->
    getPoints = (x, y, angle, width, length) -> [
      {
        x: x + Math.cos(angle + Math.PI / 2) * width / 2,
        y: y + Math.sin(angle + Math.PI / 2) * width / 2,
      },
      {
        x: x + Math.cos(angle) * length,
        y: y + Math.sin(angle) * length,
      },
      {
        x: x + Math.cos(angle - Math.PI / 2) * width / 2,
        y: y + Math.sin(angle - Math.PI / 2) * width / 2,
      }
    ]

    drawToCanvas: (ctx, x, y, angle, width, color, length=0) ->
      length = length or width

      ctx.fillStyle = color
      ctx.lineWidth = 0
      ctx.strokeStyle = 'transparent'
      ctx.beginPath()
      points = getPoints(x, y, angle, width, length)

      ctx.moveTo(points[0].x, points[0].y)
      ctx.lineTo(points[1].x, points[1].y)
      ctx.lineTo(points[2].x, points[2].y)
      ctx.fill()

    svg: (x, y, angle, width, color, length=0) ->
      length = length or width
      points = getPoints(x, y, angle, width, length)

      "
        <polygon
          fill='#{color}' stroke='none'
          points='#{points.map((p) -> "#{p.x},#{p.y}")}' />
      "