这篇文章主要讲解了“Canvas如何实现坐标变换”，文中的讲解内容简单清晰，易于学习与理解，下面请大家跟着小编的思路慢慢深入，一起来研究和学习“Canvas如何实现坐标变换”吧！
代码如下:
<html>
<head>
</head>
<body>
<canvas id="myCanvas" width="600" height="300">你的浏览器还不支持哦</canvas>
<script type="text/javascript">
var c = document.getElementById("myCanvas");
var cxt = c.getContext("2d");
var slen = 60;
var mlen = 50;
var hlen = 40;
cxt.strokeRect(0, 0, c.width, c.height);
cxt.beginPath();
cxt.strokeStyle = "#00f";
cxt.fillStyle = "#00f";
cxt.arc(200, 150, 5, 0, 2 * Math.PI, true);
cxt.fill();
cxt.closePath();
cxt.beginPath();
cxt.strokeStyle = "#00f";
cxt.arc(200, 150, 100, 0, 2 * Math.PI, true);
cxt.stroke();
cxt.closePath();
cxt.beginPath();
cxt.translate(200, 150); //平移原点；
cxt.rotate(-Math.PI / 2);
cxt.save();
for (var i = 0; i < 60; i++) {
if (i % 5 == 0) {
// cxt.fillStyle = "#ff0000";
cxt.fillRect(80, 0, 20, 5);
cxt.fillText("" + (i / 5 == 0 ? 12 : i / 5), 70, 0);
} else {
// cxt.strokeStyle = "#00f";
cxt.fillRect(90, 0, 10, 2);
}
//document.getElementById("div1").innerText += " " + i;
cxt.rotate(Math.PI / 30);
}
cxt.closePath();
var ls = 0, lm = 0, lh = 0;
function Refresh() {
cxt.restore();
cxt.save();
cxt.rotate(ls * Math.PI / 30);
cxt.clearRect(5, -1, slen+1, 2+2);
cxt.restore(); cxt.save();
cxt.rotate(lm * Math.PI / 30);
cxt.clearRect(5, -1, mlen+1, 3+2);
cxt.restore(); cxt.save();
cxt.rotate(lh * Math.PI / 6);
cxt.clearRect(5, -3, hlen+1, 4+2);
var time = new Date();
var s = ls=time.getSeconds();
var m = lm=time.getMinutes();
var h = lh=time.getHours();
cxt.restore();
cxt.save();
cxt.rotate(s * Math.PI / 30);
cxt.fillRect(5, 0, slen, 2);
cxt.restore(); cxt.save();
cxt.rotate(m * Math.PI / 30);
cxt.fillRect(5, 0, mlen, 3);
cxt.restore(); cxt.save();
cxt.rotate(h * Math.PI / 6);
cxt.fillRect(5, -2, hlen, 4);
}
var MyInterval = setInterval("Refresh();", 1000);
</script>
<div id="div1" style=" background:#00f;"></div>
</body>
</html>
感谢各位的阅读，以上就是“Canvas如何实现坐标变换”的内容了，经过本文的学习后，相信大家对Canvas如何实现坐标变换这一问题有了更深刻的体会，具体使用情况还需要大家实践验证。这里是编程网，小编将为大家推送更多相关知识点的文章，欢迎关注！
