Canvas实现太极图案并旋转

来源：互联网发布：linux 系统编程delay 编辑：程序博客网时间：2024/05/16 06:19

效果如下：

<!DOCTYPE HTML>

<html>
<body>
<canvas id="myCanvas" width="500" height="500" >your browser does not support the canvas tag </canvas>
<script type="text/javascript">
var canvas = document.getElementById('myCanvas');
var ctx = canvas.getContext("2d");
var angle = 0;
var count = 360;
var clrA = '#000';
var clrB = 'red';

function taiji(x, y, radius, angle, wise) {
angleangle = angle || 0;
wisewise = wise ? 1 : -1;
ctx.save();
ctx.translate(x, y);
ctx.rotate(angle);
ctx.fillStyle = clrA;
ctx.beginPath();
ctx.arc(0, 0, radius, 0, Math.PI, true);
ctx.fill();
ctx.beginPath();
ctx.fillStyle = clrB;
ctx.arc(0, 0, radius, 0, Math.PI, false);
ctx.fill();
ctx.fillStyle = clrB;
ctx.beginPath();
ctx.arc(wise * -0.5 * radius, 0, radius / 2, 0, Math.PI * 2, true);
ctx.fill();
ctx.beginPath();
ctx.fillStyle = clrA;
ctx.arc(wise * +0.5 * radius, 0, radius / 2, 0, Math.PI * 2, false);
ctx.arc(wise * -0.5 * radius, 0, radius / 10, 0, Math.PI * 2, true);
ctx.fill();
ctx.beginPath();
ctx.fillStyle = clrB;
ctx.arc(wise * +0.5 * radius, 0, radius / 10, 0, Math.PI * 2, true);
ctx.fill();
ctx.restore();
}

loop = setInterval(function () {
beginTag = true;
ctx.clearRect(0, 0, canvas.width, canvas.height);
taiji(200, 200, 50, Math.PI * (angle / count) * 2, true);
//taiji(350, 350, 50, Math.PI * ((count - angle) / count) * 2, false);
angle = (angle + 5) % count;
}, 50);
</script> </p> <p></body>
</html>

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