canvas 3D运动球效果多球

<!DOCTYPE html>

<html>

<head>

    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">

    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">

    <title>canvas</title>

    <style type="text/css">

    #canvas{

        background-color: #eeeeee;

    }

    </style>

</head>

<body>

<canvas id="canvas" width="500" height="500"></canvas>

<script type="text/javascript">

    window.onload = function(){

        var canvas = document.getElementById("canvas");

        var cobj = canvas.getContext("2d");

        var arr = [];

        for(var i=0; i<8; i++){

            var arrObj = {

                r: 15+5*Math.random(),

                x_3d: -200+i*30,

                y_3d: -100+200*Math.random(),

                z_3d: i*10,

                z_speed: 5+10*Math.random()

            }

            arr.push(arrObj);

        }

        var focusLen = 300;

        cobj.translate(250,250);

        setInterval(function(){

            cobj.clearRect(-250,-250,500,500);

            var newarr = arr.sort(function(a,b){

                return a.z_3d<b.z_3d;

            });

            for(var i=0; i<newarr.length; i++){

                arr[i].z_3d += arr[i].z_speed;

                if(arr[i].z_3d>600 || arr[i].z_3d<=-50){

                    arr[i].z_speed*=-1;

                }

                var scales = focusLen/(focusLen+arr[i].z_3d);

                var x = arr[i].x_3d*scales;

                var y = arr[i].y_3d*scales;

                cobj.save();

                cobj.translate(x,y);

                cobj.scale(scales,scales);

                cobj.beginPath();

                var colorObj = cobj.createRadialGradient(3,3,0,0,0,15);

                colorObj.addColorStop(0,"#cbc0f3");

                colorObj.addColorStop(1,"#06198b");

                cobj.fillStyle = colorObj;

                cobj.arc(0,0,15,0,2*Math.PI);

                cobj.fill();

                cobj.restore();

            }

        },50);

    }

</script>

</body>

</html>
canvas 3D运动球效果 多球

canvas 3D运动球效果多球
