canvas之五角星的绘制

<html>
<head>
<meta charset=utf-8>
<title>绘制简单图形线及矩形</title>
<style type="text/css">
canvas{
border: 1px solid #aaa;
display: block;
margin: 50px auto;
}
</style>
</head>
<body>
<canvas id="canvas"></canvas>
</body>
<script>
var c = document.querySelector("#canvas");
c.width = 800;
c.height = 800;
//画布
var context = c.getContext("2d");
//五角星的绘制
function drawstar(cxt,r,R,x,y,rot)
{
context.beginPath();
for( var i = 0; i <5 ;i++)
{
cxt.lineTo(Math.cos((18+i*72-rot)/180*Math.PI)*R+x,
-Math.sin((18+i*72-rot)/180*Math.PI)*R+y);
cxt.lineTo(Math.cos((54+i*72-rot)/180*Math.PI)*r+x,
-Math.sin((54+i*72-rot)/180*Math.PI)*r+y);

}
cxt.closePath();
cxt.fillStyle="pink";
cxt.lineWidth = 3;
cxt.fill();
cxt.stroke();

}
drawstar(context,130,200,400,400,60);
</script>
</html>

原文地址:https://www.cnblogs.com/angle-xiu/p/11197731.html