javascript - Coffeescript 中的 beginPath() ？

Question

希望使用 CoffeeScript 操作 html5 Canvas 。

正在寻找 jQuery beginPath() 的类似方法，但我在互联网上找不到。

如何在coffeescript中使用beginPath()？感谢您的任何想法!

Answer 1

这是来自 ( http://autotelicum.github.io/Smooth-CoffeeScript/interactive/interactive-coffeescript.html ) 的“生命种子”示例

webdesign = -> 
  doctype 5
  html ->
    head ->
      meta charset: 'utf-8'
      title 'My drawing | My awesome website'
      style '''
        body {font-family: sans-serif}
        header, nav, section, footer {display: block}
      '''
      coffeescript ->
        draw = (ctx, x, y) ->
          circle = (ctx, x, y) ->
            ctx.beginPath()
            ctx.arc x, y, 100, 0, 2*Math.PI, false
            ctx.stroke()
          ctx.strokeStyle = 'rgba(255,40,20,0.7)'
          circle ctx, x, y
          for angle in [0...2*Math.PI] by 1/3*Math.PI
            circle ctx, x+100*Math.cos(angle),
                        y+100*Math.sin(angle)
        window.onload = ->
          canvas = document.getElementById 'drawCanvas'
          context = canvas.getContext '2d'
          draw context, 300, 200
    body ->
      header -> h1 'Seed of Life'
      canvas id: 'drawCanvas', width: 550, height: 400