今天,我们来介绍一下,如何基于JavaScript绘制太极图。
<html>
  <head>
    <title>Canvas tutorial</title>
    <style type="text/css">
      canvas { border: 1px solid black; }
    </style>
    <script type="text/javascript" src="./draw.js" />
  </head>
  <body onload="draw();">
    <canvas id="tutorial" width="150" height="150"></canvas>
  </body>
</html>
draw.js
      function draw(){
        var canvas = document.getElementById('tutorial');
        if (canvas.getContext){
          var ctx = canvas.getContext('2d');
			
			ctx.beginPath();
			ctx.arc(150, 50, 50, Math.PI*(1/2), Math.PI*(3/2), true);
			ctx.stroke();
			ctx.beginPath();
			ctx.arc(150, 150, 50, Math.PI*(3/2), Math.PI*(1/2), true);
			ctx.stroke();
			ctx.beginPath();
			ctx.arc(150, 100, 100, 0, Math.PI*2, true);
			ctx.stroke();
        }
      }
来源:oschina
链接:https://my.oschina.net/qwfys200/blog/4258743