jquery 图片360度旋转
作者：chrispy
HTML：
<span id="rotLeft">向左转</span>
<span id="rotRight">向右转</span>
<div id="imgBox" class="image_box">
<img id="rotImg" src="http://image.zhangxinxu.com/image/study/s/s512/mm1.jpg" />
</div>
JS：
<script type="text/javascript">
$(function(){
var param = {
right: $("#rotRight"),
left: $("#rotLeft"),
box: $("#imgBox"),
rot: 0
};
var fun = {
right: function(){
param.rot += 90;
$("#rotImg").rotate(param.rot);
if(param.rot === 270){
param.rot = -90;
}
return false;
},
left: function(){
param.rot -= 90;
if(param.rot === -90){
param.rot = 270;
}
$("#rotImg").rotate(param.rot);
return false;
}
};
param.right.click(function(){
if(!$("img#rotImg").length){
param.box.html('<img id="rotImg" src="http://image.zhangxinxu.com/image/study/s/s512/mm1.jpg" />');
}
fun.right();
return false;
});
param.left.click(function(){
if(!$("img#rotImg").length){
param.box.html('<img id="rotImg" src="http://image.zhangxinxu.com/image/study/s/s512/mm1.jpg" />');
}
fun.left();
return false;
});
});
</script>
插件：
jQuery.fn.rotate = function(angle,whence) {
var p = this.get(0);
// we store the angle inside the image tag for persistence
if (!whence) {
p.angle = ((p.angle==undefined?0:p.angle) + angle) % 360;
} else {
p.angle = angle;
}
if (p.angle >= 0) {
var rotation = Math.PI * p.angle / 180;
} else {
var rotation = Math.PI * (360+p.angle) / 180;
}
var costheta = Math.round(Math.cos(rotation) * 1000) / 1000;
var sintheta = Math.round(Math.sin(rotation) * 1000) / 1000;
//alert(costheta+","+sintheta);
if (document.all && !window.opera) {
var canvas = document.createElement('img');
canvas.src = p.src;
canvas.height = p.height;
canvas.width = p.width;
canvas.style.filter = "progid:DXImageTransform.Microsoft.Matrix(M11="+costheta+",M12="+(-sintheta)+",M21="+sintheta+",M22="+costheta+",SizingMethod='auto expand')";
} else {
var canvas = document.createElement('canvas');
if (!p.oImage) {
canvas.oImage = new Image();
canvas.oImage.src = p.src;
} else {
canvas.oImage = p.oImage;
}
canvas.style.width = canvas.width = Math.abs(costheta*canvas.oImage.width) + Math.abs(sintheta*canvas.oImage.height);
canvas.style.height = canvas.height = Math.abs(costheta*canvas.oImage.height) + Math.abs(sintheta*canvas.oImage.width);
var context = canvas.getContext('2d');
context.save();
if (rotation <= Math.PI/2) {
context.translate(sintheta*canvas.oImage.height,0);
} else if (rotation <= Math.PI) {
context.translate(canvas.width,-costheta*canvas.oImage.height);
} else if (rotation <= 1.5*Math.PI) {
context.translate(-costheta*canvas.oImage.width,canvas.height);
} else {
context.translate(0,-sintheta*canvas.oImage.width);
}
context.rotate(rotation);
context.drawImage(canvas.oImage, 0, 0, canvas.oImage.width, canvas.oImage.height);
context.restore();
}
canvas.id = p.id;
canvas.angle = p.angle;
p.parentNode.replaceChild(canvas, p);
}
jQuery.fn.rotateRight = function(angle) {
this.rotate(angle==undefined?90:angle);
}
jQuery.fn.rotateLeft = function(angle) {
this.rotate(angle==undefined?-90:-angle);
}