绘制星空

来源：互联网发布：武汉java培训机构排名编辑：程序博客网时间：2024/04/29 02:45

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
</head>
<body>
</body>
</html><!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
</head>
<body>
<canvas id="canvas" style="border:1px solid black;margin:0 auto;display:block;">
浏览器不支持
</canvas>
<script>
window.onload=function()
{
var canvas=document.getElementById("canvas");
var cxt=canvas.getContext("2d");

canvas.width=800;
canvas.height=800;

//drawStar(cxt,150,300,400,400,0);
cxt.fillStyle="black";
cxt.fillRect(0, 0, canvas.width,canvas.height);
//cxt.lineJoin="bevel";
//cxt.miterLimit=80;
//

cxt.fillStyle="pink";
cxt.lineJoin="round";
cxt.fill();
cxt.stroke();

for(var i=0;i<200;i++)
{
var r=Math.random()*10+10;
var x=Math.random()*canvas.width;
var y=Math.random()*canvas.height;
var a=Math.random()*360;
drawStar(cxt,r,r,x,y,a);
}
}
function drawStar(cxt,r,R,x,y,rot)
{
cxt.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);//横坐标前部分是角度转弧度，大圆半径暂定300，
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="rgba(0,236,0,0.5)";
cxt.lineJoin="round";
cxt.fill();
cxt.stroke();}
</script>
</body>
</html>

0 0