html5 canvas-绘制贝塞尔曲线

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <title>Document</title>

    <style>

    body{background: #131115;}

    #c1{background: #fbf7fe;}

    </style>

    <script>

    window.onload=function(){

        var oC=document.getElementById('c1');

        var oGC=oC.getContext('2d');

        oGC.moveTo(100,200);

        oGC.arcTo(100,100,300,200,50);

        oGC.stroke();

    }

   </script>

</head>

<body>

    <canvas id="c1" width="500" height="500"><!-- 默认宽300； 高150 -->

    <span>不支持camvas浏览器</span>

    </canvas>

</body>

</html>

html5 canvas-绘制贝塞尔曲线-LMLPHP

第2中写法

    window.onload=function(){

        var oC=document.getElementById('c1');

        var oGC=oC.getContext('2d');

        oGC.moveTo(100,200);

        /*oGC.arcTo(100,100,300,200,50);*/

        oGC.quadraticCurveTo(100,100,200,100);

        oGC.stroke();

    }

html5 canvas-绘制贝塞尔曲线-LMLPHP

第3中写法

    window.onload=function(){

        var oC=document.getElementById('c1');

        var oGC=oC.getContext('2d');

        oGC.moveTo(100,200);

        /*oGC.arcTo(100,100,300,200,50);*/

        /*oGC.quadraticCurveTo(100,100,200,100);*/

        oGC.bezierCurveTo(100,100,200,200,200,100);

        oGC.stroke();

    }

html5 canvas-绘制贝塞尔曲线-LMLPHP