<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>使用bezierCurveTo绘制贝塞尔曲线</title>
<script>
function draw(id){
var canvas=document.getElementById(id);
if(canvas==null)
{
return false;
}
var context=canvas.getContest("2d");
context.fillRect(0,0,300,400);
var dx=150;
var dy=150;
var s=100;
context.beginPath();
context.fillStyle="rgb(100,255,100)";
var x=Math.sin(0);
var y=Math.cos(0);
var dig=Math.PI/15*11;
context.moveTo(dx,dy);//设置原点位置,开始点
for(var i=0;i<30;i++)
{
var x=Math.sin(i*dig);
var y=Math.cos(i*dig);
//moveTo(dx,dy);//设置原点位置,开始点
//控制点1:dx+x*s,dy+y*s-100
//控制点2:dx+x*s+100,dy+y*s
//结束点:dx+x*s,dy+y*s
context.bezierVurveTo(dx+x*s,dy+y*s-100,dx+x*s+100,dy+y*s,dx+x*s,dy+y*s);
}
context.closePath();
context.fill();
context.stroke();
}
</script>
</head>
<body onload="draw("canvas");">
<canvas id="canvas" width="300" height="400"></canvas>
</body>
</html>