raphael.dropshadow.filter.js

/*!
* Raphael Drop Shadow Plugin 0.1
*
* by Daniel Hoffmann
* 
* Based on Raphael Blur Plugin 0.1 by Dmitry Baranovskiy (http://raphaeljs.com)
* https://github.com/DmitryBaranovskiy/raphael/blob/master/plugins/raphael.blur.js
* Licensed under the MIT (http://www.opensource.org/licenses/mit-license.php) license.
* 
*/

(function () {
    if (!Raphael.vml) {
        var $ = function (el, attr) {
            if (attr) {
                for (var key in attr) if (attr.hasOwnProperty(key)) {
                    el.setAttribute(key, attr[key]);
                }
            } else {
                return document.createElementNS("http://www.w3.org/2000/svg", el);
            }
        };
        Raphael.fn.addDropShadowFilter = function (size, offsetX, offsetY, opacity) {
	    opacity = opacity || 1;
            if (size != "none") {
                var fltr = $("filter"),
                    blur = $("feGaussianBlur"),
                    colorMatrix = $("feColorMatrix"),
                    offset = $("feOffset"),
                    merge = $("feMerge"),
                    mergeNodeShadow = $("feMergeNode"),
                    mergeNodeSource = $("feMergeNode");
                fltr.id = "dropshadow";
                $(fltr, {height: "130%", width: "130%"});
                $(blur, {stdDeviation: +size});
                $(blur, {in: "SourceAlpha"});
                $(colorMatrix, {result: "bluralpha", type: "bluralpha", values: "1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 "+opacity+" 0 "});
                $(offset, {dx: offsetX, dy: offsetY, result: "offsetblur"});
                $(mergeNodeShadow, {in: "offsetblur"});
                $(mergeNodeSource, {in: "SourceGraphic"});
                fltr.appendChild(blur);
                fltr.appendChild(colorMatrix);
                fltr.appendChild(offset);
                fltr.appendChild(merge);
                merge.appendChild(mergeNodeShadow);
                merge.appendChild(mergeNodeSource);
                this.defs.appendChild(fltr);
                this._blur = fltr;
            } else {
                if (this._blur) {
                    this._blur.parentNode.removeChild(this._blur);
                    delete this._blur;
                }
            }
        };
    }
})();