ÿþjQuery.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.cos(rotation);

	var sintheta = Math.sin(rotation);



	if (document.all && !window.opera) {

		var canvas = document.createElement('img');



		canvas.src = p.src;

		canvas.height = p.height;

		canvas.width = 50;



		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);

}



/**

*   Xoay £nh có thêm các tham sÑ 
Ù rÙng , 
Ù dài cça £nh

*/

jQuery.fn.rotateWithCus = function(angle,scalewidth, scaleheight) {

	var p = this.get(0);



	// we store the angle inside the image tag for persistence

	p.angle = ((p.angle==undefined?0:p.angle) + angle) % 360;



    // rotation là góc tính theo radian

	if (p.angle >= 0) {

		var rotation = Math.PI * p.angle / 180;

	} else {

		var rotation = Math.PI * (360+p.angle) / 180;

	}

	var costheta = Math.cos(rotation);

	var sintheta = Math.sin(rotation);



	if (document.all && !window.opera) {

	// ---- trình duyÇt IE

		var canvas = document.createElement('img');



		canvas.src = p.src;

		canvas.height = scaleheight;

		canvas.width = scalewidth;

		

		// chÉnh vË trí cho £nh sinh ra - m·c 
Ënh ko có

		canvas.style.margin = "2px 0 0 0";

		

		canvas.style.filter = "progid:DXImageTransform.Microsoft.Matrix(M11="+costheta+",M12="+(-sintheta)+",M21="+sintheta+",M22="+costheta+",SizingMethod='auto expand')";

	} else {

	// ---- trình duyÇt fire fox

		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) {

		    // n¿u 0 < góc <= 90o

			context.translate(sintheta*canvas.oImage.height,0);

		} else if (rotation <= Math.PI) {

		    // n¿u 90o < góc <= 180o

			context.translate(canvas.width,-costheta*canvas.oImage.height);

		} else if (rotation <= 1.5*Math.PI) {

		    // n¿u 180o < góc <= 270o

			context.translate(-costheta*canvas.oImage.width,canvas.height);

		} else {

		    // n¿u 270o < góc <= 360o

			context.translate(2,-sintheta*canvas.oImage.width-7);

		}

		context.rotate(rotation);

		//context.drawImage(canvas.oImage, 0, 0, canvas.oImage.width, canvas.oImage.height);

		context.drawImage(canvas.oImage, 0, 0, scalewidth, scaleheight);

		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);

}