画布旋转——HTML5之特效
translate.html内容如下：
[html]
<!doctype html>
<html>
<head>
<script type="text/javascript" src="jquery-1.7.2.min.js"></script>
<script type="text/javascript" src="translate.js"></script>
<script type="text/javascript">
$(document).ready(function(){
});
</script>
</head>
<body>
<canvas id="simple"></canvas>
</body>
</html>
<!doctype html>
<html>
<head>
<script type="text/javascript" src="jquery-1.7.2.min.js"></script>
<script type="text/javascript" src="translate.js"></script>
<script type="text/javascript">
$(document).ready(function(){
});
</script>
</head>
<body>
<canvas id="simple"></canvas>
</body>
</html>
translate.js代码如下：
[javascript]
(function(){
var canvas=null,
context=null,
angle=0;
function resetcanvas(){
canvas=document.getelementbyid("simple");
canvas.width=window.innerwidth;
canvas.height=window.innerheight;
context=canvas.getcontext("2d");
}
function animate(){
context.save();
try{
//清除画布
context.clearrect(0, 0, canvas.width, canvas.height);
//设置原点
context.translate(canvas.width * 0.5, canvas.height * 0.5);
//旋转角度
context.rotate(angle);
//设置填充颜色
context.fillstyle = "#ff0000";
//绘制矩形
context.fillrect(-30, -30, 60, 60);
angle += 0.05 * math.pi;
}
finally{
context.restore();
}
}
$(window).bind("resize",resetcanvas).bind("reorient",resetcanvas);
$(document).ready(function(){
window.scrollto(0,1);
resetcanvas();
setinterval(animate,40);
});
})();
(function(){
var canvas=null,
context=null,
angle=0;
function resetcanvas(){
canvas=document.getelementbyid("simple");
canvas.width=window.innerwidth;
canvas.height=window.innerheight;
context=canvas.getcontext("2d");
}
function animate(){
context.save();
try{
//清除画布
context.clearrect(0, 0, canvas.width, canvas.height);
//设置原点
context.translate(canvas.width * 0.5, canvas.height * 0.5);
//旋转角度
context.rotate(angle);
//设置填充颜色
context.fillstyle = "#ff0000";
//绘制矩形
context.fillrect(-30, -30, 60, 60);
angle += 0.05 * math.pi;
}
finally{
context.restore();
}
}
$(window).bind("resize",resetcanvas).bind("reorient",resetcanvas);
$(document).ready(function(){
window.scrollto(0,1);
resetcanvas();
setinterval(animate,40);
});
})();
用支持hmtl5的打开translate.html就可以看到一个旋转的红色方块
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