mjpg-streamer/www/jquery.rotate.js

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JavaScript
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2024-10-15 15:50:29 +08:00
// modified by mmikowski 20090803
// * Added semicolons after function declarations;
// their omission broke YUI compressor
// * Converted to Unix style line endings
// modified by mmikowski 20100114 for firefox 3.5 support
// * See http://code.google.com/p/jquery-rotate/issues/detail?id=3#c2 comment 1
// I had to rewrite this to resolve multiple rotations
//
jQuery.fn.rotate = function(angle,whence) {
var fnRotate = function(canvas,rotation){
var costheta = Math.cos(rotation);
var sintheta = Math.sin(rotation);
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();
};
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;
}
if (document.all && !window.opera) {
var canvas = document.createElement('img');
var costheta = Math.cos(rotation);
var sintheta = Math.sin(rotation);
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;
canvas.oImage.width = p.width;
canvas.oImage.height = p.height;
canvas.oImage.onload = function(){ fnRotate(canvas,rotation) };
} else {
canvas.oImage = p.oImage;
fnRotate(canvas,rotation);
}
}
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);
};