canvas曲线的绘制 

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        canvas {
            border: 1px solid #ccc;
        }
    </style>
</head>
<body>
<canvas width="600" height="400"></canvas>
<script>
    var myCanvas = document.querySelector('canvas');
    var ctx = myCanvas.getContext('2d');
    /*1.体验曲线的绘制*/
    /*2.线是由点构成的*/
    /*3.曲线可以由数学公式得来*/
    /*公式：y = x/2 */
    /*公式：y = (x + 2) ^2  */
    /*公式：y = sin(x) */
    for(var i = 1 ; i < 600 ; i ++){
        var x = i;
        //var y = x/2;
        //var y = Math.pow(x/10-30,2);
        var y = 50*Math.sin(x/10) + 100;
        ctx.lineTo(x,y);
    }
    ctx.stroke();
</script>
</body>
</html>

运行结果如下:

posted @ 2020-02-15 16:59  阳神  阅读(183)  评论(0)  编辑  收藏  举报