(function () {
    'use strict';

    function toString(obj) {
        if (!obj) {
            return obj
        }
        if (typeof obj === 'string') {
            return obj
        }
        return obj + '';
    }

    class ImageUtils {

        /**
         * Convert svg dataurl to canvas element
         * 
         * @private
         */
        async svg2canvas(svgDataURL, width, height) {
            const svgImage = await new Promise((resolve) => {
                var svgImage = new Image();
                svgImage.onload = function() {
                    resolve(svgImage);
                };
                svgImage.src = svgDataURL;
            });
            var canvas = document.createElement('canvas');
            canvas.width = width;
            canvas.height = height;
            const ctx = canvas.getContext('2d');
            ctx.drawImage(svgImage, 0, 0);
            return canvas;
        }
        
        toDataURL(svgNode, width, height, type, encoderOptions, options) {
            var xml = new XMLSerializer().serializeToString(svgNode);
        
            // documentMode is an IE-only property
            // http://msdn.microsoft.com/en-us/library/ie/cc196988(v=vs.85).aspx
            // http://stackoverflow.com/questions/10964966/detect-ie-version-prior-to-v9-in-javascript
            var isIE = document.documentMode;
        
            if (isIE) {
                // This is patch from canvas2svg
                // IE search for a duplicate xmnls because they didn't implement setAttributeNS correctly
                var xmlns = /xmlns="http:\/\/www\.w3\.org\/2000\/svg".+xmlns="http:\/\/www\.w3\.org\/2000\/svg/gi;
                if(xmlns.test(xml)) {
                    xml = xml.replace('xmlns="http://www.w3.org/2000/svg','xmlns:xlink="http://www.w3.org/1999/xlink');
                }
            }

            if (!options) {
                options = {};
            }
        
            var SVGDataURL = "data:image/svg+xml;charset=utf-8," + encodeURIComponent(xml);
            if (type === "image/svg+xml" || !type) {
                if (options.async) {
                    return Promise.resolve(SVGDataURL)
                }
                return SVGDataURL;
            }
            if (type === "image/jpeg" || type === "image/png") {
                if (!options.async) {
                    throw new Error('svgcanvas: options.async must be set to true if type is image/jpeg | image/png')
                }
                return (async () => {
                    const canvas = await this.svg2canvas(SVGDataURL, width, height);
                    const dataUrl = canvas.toDataURL(type, encoderOptions);
                    canvas.remove();
                    return dataUrl;
                })()
            }
            throw new Error('svgcanvas: Unknown type for toDataURL, please use image/jpeg | image/png | image/svg+xml.');
        }

        getImageData(svgNode, width, height, sx, sy, sw, sh, options) {
            if (!options) {
                options = {};
            }
            if (!options.async) {
                throw new Error('svgcanvas: options.async must be set to true for getImageData')
            }
            const svgDataURL = this.toDataURL(svgNode, width, height, 'image/svg+xml');
            return (async () => {
                const canvas = await this.svg2canvas(svgDataURL, width, height);
                const ctx = canvas.getContext('2d');
                const imageData = ctx.getImageData(sx, sy, sw, sh);
                canvas.remove();
                return imageData;
            })()
        }
    }

    const utils = new ImageUtils();

    /*!!
     *  SVGCanvas v2.0.3
     *  Draw on SVG using Canvas's 2D Context API.
     *
     *  Licensed under the MIT license:
     *  http://www.opensource.org/licenses/mit-license.php
     *
     *  Author:
     *  Kerry Liu
     *  Zeno Zeng
     *
     *  Copyright (c) 2014 Gliffy Inc.
     *  Copyright (c) 2021 Zeno Zeng
     */

    var Context = (function () {

        var STYLES, Context, CanvasGradient, CanvasPattern, namedEntities;

        //helper function to format a string
        function format(str, args) {
            var keys = Object.keys(args), i;
            for (i=0; i<keys.length; i++) {
                str = str.replace(new RegExp("\\{" + keys[i] + "\\}", "gi"), args[keys[i]]);
            }
            return str;
        }

        //helper function that generates a random string
        function randomString(holder) {
            var chars, randomstring, i;
            if (!holder) {
                throw new Error("cannot create a random attribute name for an undefined object");
            }
            chars = "ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz";
            randomstring = "";
            do {
                randomstring = "";
                for (i = 0; i < 12; i++) {
                    randomstring += chars[Math.floor(Math.random() * chars.length)];
                }
            } while (holder[randomstring]);
            return randomstring;
        }

        //helper function to map named to numbered entities
        function createNamedToNumberedLookup(items, radix) {
            var i, entity, lookup = {}, base10;
            items = items.split(',');
            radix = radix || 10;
            // Map from named to numbered entities.
            for (i = 0; i < items.length; i += 2) {
                entity = '&' + items[i + 1] + ';';
                base10 = parseInt(items[i], radix);
                lookup[entity] = '&#'+base10+';';
            }
            //FF and IE need to create a regex from hex values ie &nbsp; == \xa0
            lookup["\\xa0"] = '&#160;';
            return lookup;
        }

        //helper function to map canvas-textAlign to svg-textAnchor
        function getTextAnchor(textAlign) {
            //TODO: support rtl languages
            var mapping = {"left":"start", "right":"end", "center":"middle", "start":"start", "end":"end"};
            return mapping[textAlign] || mapping.start;
        }

        //helper function to map canvas-textBaseline to svg-dominantBaseline
        function getDominantBaseline(textBaseline) {
            //INFO: not supported in all browsers
            var mapping = {"alphabetic": "alphabetic", "hanging": "hanging", "top":"text-before-edge", "bottom":"text-after-edge", "middle":"central"};
            return mapping[textBaseline] || mapping.alphabetic;
        }

        // Unpack entities lookup where the numbers are in radix 32 to reduce the size
        // entity mapping courtesy of tinymce
        namedEntities = createNamedToNumberedLookup(
            '50,nbsp,51,iexcl,52,cent,53,pound,54,curren,55,yen,56,brvbar,57,sect,58,uml,59,copy,' +
                '5a,ordf,5b,laquo,5c,not,5d,shy,5e,reg,5f,macr,5g,deg,5h,plusmn,5i,sup2,5j,sup3,5k,acute,' +
                '5l,micro,5m,para,5n,middot,5o,cedil,5p,sup1,5q,ordm,5r,raquo,5s,frac14,5t,frac12,5u,frac34,' +
                '5v,iquest,60,Agrave,61,Aacute,62,Acirc,63,Atilde,64,Auml,65,Aring,66,AElig,67,Ccedil,' +
                '68,Egrave,69,Eacute,6a,Ecirc,6b,Euml,6c,Igrave,6d,Iacute,6e,Icirc,6f,Iuml,6g,ETH,6h,Ntilde,' +
                '6i,Ograve,6j,Oacute,6k,Ocirc,6l,Otilde,6m,Ouml,6n,times,6o,Oslash,6p,Ugrave,6q,Uacute,' +
                '6r,Ucirc,6s,Uuml,6t,Yacute,6u,THORN,6v,szlig,70,agrave,71,aacute,72,acirc,73,atilde,74,auml,' +
                '75,aring,76,aelig,77,ccedil,78,egrave,79,eacute,7a,ecirc,7b,euml,7c,igrave,7d,iacute,7e,icirc,' +
                '7f,iuml,7g,eth,7h,ntilde,7i,ograve,7j,oacute,7k,ocirc,7l,otilde,7m,ouml,7n,divide,7o,oslash,' +
                '7p,ugrave,7q,uacute,7r,ucirc,7s,uuml,7t,yacute,7u,thorn,7v,yuml,ci,fnof,sh,Alpha,si,Beta,' +
                'sj,Gamma,sk,Delta,sl,Epsilon,sm,Zeta,sn,Eta,so,Theta,sp,Iota,sq,Kappa,sr,Lambda,ss,Mu,' +
                'st,Nu,su,Xi,sv,Omicron,t0,Pi,t1,Rho,t3,Sigma,t4,Tau,t5,Upsilon,t6,Phi,t7,Chi,t8,Psi,' +
                't9,Omega,th,alpha,ti,beta,tj,gamma,tk,delta,tl,epsilon,tm,zeta,tn,eta,to,theta,tp,iota,' +
                'tq,kappa,tr,lambda,ts,mu,tt,nu,tu,xi,tv,omicron,u0,pi,u1,rho,u2,sigmaf,u3,sigma,u4,tau,' +
                'u5,upsilon,u6,phi,u7,chi,u8,psi,u9,omega,uh,thetasym,ui,upsih,um,piv,812,bull,816,hellip,' +
                '81i,prime,81j,Prime,81u,oline,824,frasl,88o,weierp,88h,image,88s,real,892,trade,89l,alefsym,' +
                '8cg,larr,8ch,uarr,8ci,rarr,8cj,darr,8ck,harr,8dl,crarr,8eg,lArr,8eh,uArr,8ei,rArr,8ej,dArr,' +
                '8ek,hArr,8g0,forall,8g2,part,8g3,exist,8g5,empty,8g7,nabla,8g8,isin,8g9,notin,8gb,ni,8gf,prod,' +
                '8gh,sum,8gi,minus,8gn,lowast,8gq,radic,8gt,prop,8gu,infin,8h0,ang,8h7,and,8h8,or,8h9,cap,8ha,cup,' +
                '8hb,int,8hk,there4,8hs,sim,8i5,cong,8i8,asymp,8j0,ne,8j1,equiv,8j4,le,8j5,ge,8k2,sub,8k3,sup,8k4,' +
                'nsub,8k6,sube,8k7,supe,8kl,oplus,8kn,otimes,8l5,perp,8m5,sdot,8o8,lceil,8o9,rceil,8oa,lfloor,8ob,' +
                'rfloor,8p9,lang,8pa,rang,9ea,loz,9j0,spades,9j3,clubs,9j5,hearts,9j6,diams,ai,OElig,aj,oelig,b0,' +
                'Scaron,b1,scaron,bo,Yuml,m6,circ,ms,tilde,802,ensp,803,emsp,809,thinsp,80c,zwnj,80d,zwj,80e,lrm,' +
                '80f,rlm,80j,ndash,80k,mdash,80o,lsquo,80p,rsquo,80q,sbquo,80s,ldquo,80t,rdquo,80u,bdquo,810,dagger,' +
                '811,Dagger,81g,permil,81p,lsaquo,81q,rsaquo,85c,euro', 32);


        //Some basic mappings for attributes and default values.
        STYLES = {
            "strokeStyle":{
                svgAttr : "stroke", //corresponding svg attribute
                canvas : "#000000", //canvas default
                svg : "none",       //svg default
                apply : "stroke"    //apply on stroke() or fill()
            },
            "fillStyle":{
                svgAttr : "fill",
                canvas : "#000000",
                svg : null, //svg default is black, but we need to special case this to handle canvas stroke without fill
                apply : "fill"
            },
            "lineCap":{
                svgAttr : "stroke-linecap",
                canvas : "butt",
                svg : "butt",
                apply : "stroke"
            },
            "lineJoin":{
                svgAttr : "stroke-linejoin",
                canvas : "miter",
                svg : "miter",
                apply : "stroke"
            },
            "miterLimit":{
                svgAttr : "stroke-miterlimit",
                canvas : 10,
                svg : 4,
                apply : "stroke"
            },
            "lineWidth":{
                svgAttr : "stroke-width",
                canvas : 1,
                svg : 1,
                apply : "stroke"
            },
            "globalAlpha": {
                svgAttr : "opacity",
                canvas : 1,
                svg : 1,
                apply :  "fill stroke"
            },
            "font":{
                //font converts to multiple svg attributes, there is custom logic for this
                canvas : "10px sans-serif"
            },
            "shadowColor":{
                canvas : "#000000"
            },
            "shadowOffsetX":{
                canvas : 0
            },
            "shadowOffsetY":{
                canvas : 0
            },
            "shadowBlur":{
                canvas : 0
            },
            "textAlign":{
                canvas : "start"
            },
            "textBaseline":{
                canvas : "alphabetic"
            },
            "lineDash" : {
                svgAttr : "stroke-dasharray",
                canvas : [],
                svg : null,
                apply : "stroke"
            }
        };

        /**
         *
         * @param gradientNode - reference to the gradient
         * @constructor
         */
        CanvasGradient = function (gradientNode, ctx) {
            this.__root = gradientNode;
            this.__ctx = ctx;
        };

        /**
         * Adds a color stop to the gradient root
         */
        CanvasGradient.prototype.addColorStop = function (offset, color) {
            var stop = this.__ctx.__createElement("stop"), regex, matches;
            stop.setAttribute("offset", offset);
            if (toString(color).indexOf("rgba") !== -1) {
                //separate alpha value, since webkit can't handle it
                regex = /rgba\(\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d?\.?\d*)\s*\)/gi;
                matches = regex.exec(color);
                stop.setAttribute("stop-color", format("rgb({r},{g},{b})", {r:matches[1], g:matches[2], b:matches[3]}));
                stop.setAttribute("stop-opacity", matches[4]);
            } else {
                stop.setAttribute("stop-color", toString(color));
            }
            this.__root.appendChild(stop);
        };

        CanvasPattern = function (pattern, ctx) {
            this.__root = pattern;
            this.__ctx = ctx;
        };

        /**
         * The mock canvas context
         * @param o - options include:
         * ctx - existing Context2D to wrap around
         * width - width of your canvas (defaults to 500)
         * height - height of your canvas (defaults to 500)
         * enableMirroring - enables canvas mirroring (get image data) (defaults to false)
         * document - the document object (defaults to the current document)
         */
        Context = function (o) {

            var defaultOptions = { width:500, height:500, enableMirroring : false}, options;

            // keep support for this way of calling Context: new Context(width, height)
            if (arguments.length > 1) {
                options = defaultOptions;
                options.width = arguments[0];
                options.height = arguments[1];
            } else if ( !o ) {
                options = defaultOptions;
            } else {
                options = o;
            }

            if (!(this instanceof Context)) {
                //did someone call this without new?
                return new Context(options);
            }

            //setup options
            this.width = options.width || defaultOptions.width;
            this.height = options.height || defaultOptions.height;
            this.enableMirroring = options.enableMirroring !== undefined ? options.enableMirroring : defaultOptions.enableMirroring;

            this.canvas = this;   ///point back to this instance!
            this.__document = options.document || document;

            // allow passing in an existing context to wrap around
            // if a context is passed in, we know a canvas already exist
            if (options.ctx) {
                this.__ctx = options.ctx;
            } else {
                this.__canvas = this.__document.createElement("canvas");
                this.__ctx = this.__canvas.getContext("2d");
            }

            this.__setDefaultStyles();
            this.__styleStack = [this.__getStyleState()];
            this.__groupStack = [];

            //the root svg element
            this.__root = this.__document.createElementNS("http://www.w3.org/2000/svg", "svg");
            this.__root.setAttribute("version", 1.1);
            this.__root.setAttribute("xmlns", "http://www.w3.org/2000/svg");
            this.__root.setAttributeNS("http://www.w3.org/2000/xmlns/", "xmlns:xlink", "http://www.w3.org/1999/xlink");
            this.__root.setAttribute("width", this.width);
            this.__root.setAttribute("height", this.height);

            //make sure we don't generate the same ids in defs
            this.__ids = {};

            //defs tag
            this.__defs = this.__document.createElementNS("http://www.w3.org/2000/svg", "defs");
            this.__root.appendChild(this.__defs);

            //also add a group child. the svg element can't use the transform attribute
            this.__currentElement = this.__document.createElementNS("http://www.w3.org/2000/svg", "g");
            this.__root.appendChild(this.__currentElement);

            // init transformation matrix
            this.resetTransform();

            this.__options = options;
            this.__id = Math.random().toString(16).substring(2, 8);
            this.__debug(`new`, o);
        };

        /**
         * Log
         * 
         * @private
         */
        Context.prototype.__debug = function(...data) {
            if (!this.__options.debug) {
                return
            }
            console.debug(`svgcanvas#${this.__id}:`, ...data);
        };

        /**
         * Creates the specified svg element
         * @private
         */
        Context.prototype.__createElement = function (elementName, properties, resetFill) {
            if (typeof properties === "undefined") {
                properties = {};
            }

            var element = this.__document.createElementNS("http://www.w3.org/2000/svg", elementName),
                keys = Object.keys(properties), i, key;
            if (resetFill) {
                //if fill or stroke is not specified, the svg element should not display. By default SVG's fill is black.
                element.setAttribute("fill", "none");
                element.setAttribute("stroke", "none");
            }
            for (i=0; i<keys.length; i++) {
                key = keys[i];
                element.setAttribute(key, properties[key]);
            }
            return element;
        };

        /**
         * Applies default canvas styles to the context
         * @private
         */
        Context.prototype.__setDefaultStyles = function () {
            //default 2d canvas context properties see:http://www.w3.org/TR/2dcontext/
            var keys = Object.keys(STYLES), i, key;
            for (i=0; i<keys.length; i++) {
                key = keys[i];
                this[key] = STYLES[key].canvas;
            }
        };

        /**
         * Applies styles on restore
         * @param styleState
         * @private
         */
        Context.prototype.__applyStyleState = function (styleState) {
            var keys = Object.keys(styleState), i, key;
            for (i=0; i<keys.length; i++) {
                key = keys[i];
                this[key] = styleState[key];
            }
        };

        /**
         * Gets the current style state
         * @return {Object}
         * @private
         */
        Context.prototype.__getStyleState = function () {
            var i, styleState = {}, keys = Object.keys(STYLES), key;
            for (i=0; i<keys.length; i++) {
                key = keys[i];
                styleState[key] = this[key];
            }
            return styleState;
        };

        /**
         * @see https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/transform
         */
        Context.prototype.__applyTransformation = function (element, matrix) {
            const {a, b, c, d, e, f} = matrix || this.getTransform();
            element.setAttribute('transform', `matrix(${a} ${b} ${c} ${d} ${e} ${f})`);
        };

        /**
         * Apples the current styles to the current SVG element. On "ctx.fill" or "ctx.stroke"
         * @param type
         * @private
         */
        Context.prototype.__applyStyleToCurrentElement = function (type) {
        	var currentElement = this.__currentElement;
        	var currentStyleGroup = this.__currentElementsToStyle;
        	if (currentStyleGroup) {
        		currentElement.setAttribute(type, "");
        		currentElement = currentStyleGroup.element;
        		currentStyleGroup.children.forEach(function (node) {
        			node.setAttribute(type, "");
        		});
        	}

            var keys = Object.keys(STYLES), i, style, value, regex, matches, id, nodeIndex, node;
            for (i = 0; i < keys.length; i++) {
                style = STYLES[keys[i]];
                value = this[keys[i]];
                if (style.apply) {
                    //is this a gradient or pattern?
                    if (value instanceof CanvasPattern) {
                        //pattern
                        if (value.__ctx) {
                            //copy over defs
                            for(nodeIndex = 0; nodeIndex < value.__ctx.__defs.childNodes.length; nodeIndex++){
                              node = value.__ctx.__defs.childNodes[nodeIndex];
                              id = node.getAttribute("id");
                              this.__ids[id] = id;
                              this.__defs.appendChild(node);
                            }
                        }
                        currentElement.setAttribute(style.apply, format("url(#{id})", {id:value.__root.getAttribute("id")}));
                    }
                    else if (value instanceof CanvasGradient) {
                        //gradient
                        currentElement.setAttribute(style.apply, format("url(#{id})", {id:value.__root.getAttribute("id")}));
                    } else if (style.apply.indexOf(type)!==-1 && style.svg !== value) {
                        if ((style.svgAttr === "stroke" || style.svgAttr === "fill") && value.indexOf("rgba") !== -1) {
                            //separate alpha value, since illustrator can't handle it
                            regex = /rgba\(\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d?\.?\d*)\s*\)/gi;
                            matches = regex.exec(value);
                            currentElement.setAttribute(style.svgAttr, format("rgb({r},{g},{b})", {r:matches[1], g:matches[2], b:matches[3]}));
                            //should take globalAlpha here
                            var opacity = matches[4];
                            var globalAlpha = this.globalAlpha;
                            if (globalAlpha != null) {
                                opacity *= globalAlpha;
                            }
                            currentElement.setAttribute(style.svgAttr+"-opacity", opacity);
                        } else {
                            var attr = style.svgAttr;
                            if (keys[i] === 'globalAlpha') {
                                attr = type+'-'+style.svgAttr;
                                if (currentElement.getAttribute(attr)) {
                                     //fill-opacity or stroke-opacity has already been set by stroke or fill.
                                    continue;
                                }
                            }
                            //otherwise only update attribute if right type, and not svg default
                            currentElement.setAttribute(attr, value);
                        }
                    }
                }
            }
        };

        /**
         * Will return the closest group or svg node. May return the current element.
         * @private
         */
        Context.prototype.__closestGroupOrSvg = function (node) {
            node = node || this.__currentElement;
            if (node.nodeName === "g" || node.nodeName === "svg") {
                return node;
            } else {
                return this.__closestGroupOrSvg(node.parentNode);
            }
        };

        /**
         * Returns the serialized value of the svg so far
         * @param fixNamedEntities - Standalone SVG doesn't support named entities, which document.createTextNode encodes.
         *                           If true, we attempt to find all named entities and encode it as a numeric entity.
         * @return serialized svg
         */
        Context.prototype.getSerializedSvg = function (fixNamedEntities) {
            var serialized = new XMLSerializer().serializeToString(this.__root),
                keys, i, key, value, regexp, xmlns;

            //IE search for a duplicate xmnls because they didn't implement setAttributeNS correctly
            xmlns = /xmlns="http:\/\/www\.w3\.org\/2000\/svg".+xmlns="http:\/\/www\.w3\.org\/2000\/svg/gi;
            if (xmlns.test(serialized)) {
                serialized = serialized.replace('xmlns="http://www.w3.org/2000/svg','xmlns:xlink="http://www.w3.org/1999/xlink');
            }

            if (fixNamedEntities) {
                keys = Object.keys(namedEntities);
                //loop over each named entity and replace with the proper equivalent.
                for (i=0; i<keys.length; i++) {
                    key = keys[i];
                    value = namedEntities[key];
                    regexp = new RegExp(key, "gi");
                    if (regexp.test(serialized)) {
                        serialized = serialized.replace(regexp, value);
                    }
                }
            }

            return serialized;
        };


        /**
         * Returns the root svg
         * @return
         */
        Context.prototype.getSvg = function () {
            return this.__root;
        };

        /**
         * Will generate a group tag.
         */
        Context.prototype.save = function () {
            var group = this.__createElement("g");
            var parent = this.__closestGroupOrSvg();
            this.__groupStack.push(parent);
            parent.appendChild(group);
            this.__currentElement = group;
            const style = this.__getStyleState();

            this.__debug('save style', style);
            this.__styleStack.push(style);
            if (!this.__transformMatrixStack) {
                this.__transformMatrixStack = [];
            }
            this.__transformMatrixStack.push(this.getTransform());
        };

        /**
         * Sets current element to parent, or just root if already root
         */
        Context.prototype.restore = function () {
            this.__currentElement = this.__groupStack.pop();
            this.__currentElementsToStyle = null;
            //Clearing canvas will make the poped group invalid, currentElement is set to the root group node.
            if (!this.__currentElement) {
                this.__currentElement = this.__root.childNodes[1];
            }
            var state = this.__styleStack.pop();
            this.__debug('restore style', state);
            this.__applyStyleState(state);
            if (this.__transformMatrixStack && this.__transformMatrixStack.length > 0) {
                this.setTransform(this.__transformMatrixStack.pop());
            }
           
        };

        /**
         * Create a new Path Element
         */
        Context.prototype.beginPath = function () {
            var path, parent;

            // Note that there is only one current default path, it is not part of the drawing state.
            // See also: https://html.spec.whatwg.org/multipage/scripting.html#current-default-path
            this.__currentDefaultPath = "";
            this.__currentPosition = {};

            path = this.__createElement("path", {}, true);
            parent = this.__closestGroupOrSvg();
            parent.appendChild(path);
            this.__currentElement = path;
        };

        /**
         * Helper function to apply currentDefaultPath to current path element
         * @private
         */
        Context.prototype.__applyCurrentDefaultPath = function () {
        	var currentElement = this.__currentElement;
            if (currentElement.nodeName === "path") {
    			currentElement.setAttribute("d", this.__currentDefaultPath);
            } else {
    			console.error("Attempted to apply path command to node", currentElement.nodeName);
            }
        };

        /**
         * Helper function to add path command
         * @private
         */
        Context.prototype.__addPathCommand = function (command) {
            this.__currentDefaultPath += " ";
            this.__currentDefaultPath += command;
        };

        /**
         * Adds the move command to the current path element,
         * if the currentPathElement is not empty create a new path element
         */
        Context.prototype.moveTo = function (x,y) {
            if (this.__currentElement.nodeName !== "path") {
                this.beginPath();
            }

            // creates a new subpath with the given point
            this.__currentPosition = {x: x, y: y};
            this.__addPathCommand(format("M {x} {y}", {
                x: this.__matrixTransform(x, y).x, 
                y: this.__matrixTransform(x, y).y
            }));
        };

        /**
         * Closes the current path
         */
        Context.prototype.closePath = function () {
            if (this.__currentDefaultPath) {
                this.__addPathCommand("Z");
            }
        };

        /**
         * Adds a line to command
         */
        Context.prototype.lineTo = function (x, y) {
            this.__currentPosition = {x: x, y: y};
            if (this.__currentDefaultPath.indexOf('M') > -1) {
                this.__addPathCommand(format("L {x} {y}", {
                    x: this.__matrixTransform(x, y).x, 
                    y: this.__matrixTransform(x, y).y
                }));
            } else {
                this.__addPathCommand(format("M {x} {y}", {
                    x: this.__matrixTransform(x, y).x, 
                    y: this.__matrixTransform(x, y).y
                }));
            }
        };

        /**
         * Add a bezier command
         */
        Context.prototype.bezierCurveTo = function (cp1x, cp1y, cp2x, cp2y, x, y) {
            this.__currentPosition = {x: x, y: y};
            this.__addPathCommand(format("C {cp1x} {cp1y} {cp2x} {cp2y} {x} {y}",
                {
                    cp1x: this.__matrixTransform(cp1x, cp1y).x,
                    cp1y: this.__matrixTransform(cp1x, cp1y).y,
                    cp2x: this.__matrixTransform(cp2x, cp2y).x,
                    cp2y: this.__matrixTransform(cp2x, cp2y).y,
                    x: this.__matrixTransform(x, y).x, 
                    y: this.__matrixTransform(x, y).y
                }));
        };

        /**
         * Adds a quadratic curve to command
         */
        Context.prototype.quadraticCurveTo = function (cpx, cpy, x, y) {
            this.__currentPosition = {x: x, y: y};
            this.__addPathCommand(format("Q {cpx} {cpy} {x} {y}", {
                cpx: this.__matrixTransform(cpx, cpy).x, 
                cpy: this.__matrixTransform(cpx, cpy).y,
                x: this.__matrixTransform(x, y).x, 
                y: this.__matrixTransform(x, y).y
            }));
        };


        /**
         * Return a new normalized vector of given vector
         */
        var normalize = function (vector) {
            var len = Math.sqrt(vector[0] * vector[0] + vector[1] * vector[1]);
            return [vector[0] / len, vector[1] / len];
        };

        /**
         * Adds the arcTo to the current path
         *
         * @see http://www.w3.org/TR/2015/WD-2dcontext-20150514/#dom-context-2d-arcto
         */
        Context.prototype.arcTo = function (x1, y1, x2, y2, radius) {
            // Let the point (x0, y0) be the last point in the subpath.
            var x0 = this.__currentPosition && this.__currentPosition.x;
            var y0 = this.__currentPosition && this.__currentPosition.y;

            // First ensure there is a subpath for (x1, y1).
            if (typeof x0 == "undefined" || typeof y0 == "undefined") {
                return;
            }

            // Negative values for radius must cause the implementation to throw an IndexSizeError exception.
            if (radius < 0) {
                throw new Error("IndexSizeError: The radius provided (" + radius + ") is negative.");
            }

            // If the point (x0, y0) is equal to the point (x1, y1),
            // or if the point (x1, y1) is equal to the point (x2, y2),
            // or if the radius radius is zero,
            // then the method must add the point (x1, y1) to the subpath,
            // and connect that point to the previous point (x0, y0) by a straight line.
            if (((x0 === x1) && (y0 === y1))
                || ((x1 === x2) && (y1 === y2))
                || (radius === 0)) {
                this.lineTo(x1, y1);
                return;
            }

            // Otherwise, if the points (x0, y0), (x1, y1), and (x2, y2) all lie on a single straight line,
            // then the method must add the point (x1, y1) to the subpath,
            // and connect that point to the previous point (x0, y0) by a straight line.
            var unit_vec_p1_p0 = normalize([x0 - x1, y0 - y1]);
            var unit_vec_p1_p2 = normalize([x2 - x1, y2 - y1]);
            if (unit_vec_p1_p0[0] * unit_vec_p1_p2[1] === unit_vec_p1_p0[1] * unit_vec_p1_p2[0]) {
                this.lineTo(x1, y1);
                return;
            }

            // Otherwise, let The Arc be the shortest arc given by circumference of the circle that has radius radius,
            // and that has one point tangent to the half-infinite line that crosses the point (x0, y0) and ends at the point (x1, y1),
            // and that has a different point tangent to the half-infinite line that ends at the point (x1, y1), and crosses the point (x2, y2).
            // The points at which this circle touches these two lines are called the start and end tangent points respectively.

            // note that both vectors are unit vectors, so the length is 1
            var cos = (unit_vec_p1_p0[0] * unit_vec_p1_p2[0] + unit_vec_p1_p0[1] * unit_vec_p1_p2[1]);
            var theta = Math.acos(Math.abs(cos));

            // Calculate origin
            var unit_vec_p1_origin = normalize([
                unit_vec_p1_p0[0] + unit_vec_p1_p2[0],
                unit_vec_p1_p0[1] + unit_vec_p1_p2[1]
            ]);
            var len_p1_origin = radius / Math.sin(theta / 2);
            var x = x1 + len_p1_origin * unit_vec_p1_origin[0];
            var y = y1 + len_p1_origin * unit_vec_p1_origin[1];

            // Calculate start angle and end angle
            // rotate 90deg clockwise (note that y axis points to its down)
            var unit_vec_origin_start_tangent = [
                -unit_vec_p1_p0[1],
                unit_vec_p1_p0[0]
            ];
            // rotate 90deg counter clockwise (note that y axis points to its down)
            var unit_vec_origin_end_tangent = [
                unit_vec_p1_p2[1],
                -unit_vec_p1_p2[0]
            ];
            var getAngle = function (vector) {
                // get angle (clockwise) between vector and (1, 0)
                var x = vector[0];
                var y = vector[1];
                if (y >= 0) { // note that y axis points to its down
                    return Math.acos(x);
                } else {
                    return -Math.acos(x);
                }
            };
            var startAngle = getAngle(unit_vec_origin_start_tangent);
            var endAngle = getAngle(unit_vec_origin_end_tangent);

            // Connect the point (x0, y0) to the start tangent point by a straight line
            this.lineTo(x + unit_vec_origin_start_tangent[0] * radius,
                        y + unit_vec_origin_start_tangent[1] * radius);

            // Connect the start tangent point to the end tangent point by arc
            // and adding the end tangent point to the subpath.
            this.arc(x, y, radius, startAngle, endAngle);
        };

        /**
         * Sets the stroke property on the current element
         */
        Context.prototype.stroke = function () {
            if (this.__currentElement.nodeName === "path") {
                this.__currentElement.setAttribute("paint-order", "fill stroke markers");
            }
            this.__applyCurrentDefaultPath();
            this.__applyStyleToCurrentElement("stroke");
        };

        /**
         * Sets fill properties on the current element
         */
        Context.prototype.fill = function () {
            if (this.__currentElement.nodeName === "path") {
                this.__currentElement.setAttribute("paint-order", "stroke fill markers");
            }
            this.__applyCurrentDefaultPath();
            this.__applyStyleToCurrentElement("fill");
        };

        /**
         *  Adds a rectangle to the path.
         */
        Context.prototype.rect = function (x, y, width, height) {
            if (this.__currentElement.nodeName !== "path") {
                this.beginPath();
            }
            this.moveTo(x, y);
            this.lineTo(x+width, y);
            this.lineTo(x+width, y+height);
            this.lineTo(x, y+height);
            this.lineTo(x, y);
            this.closePath();
        };


        /**
         * adds a rectangle element
         */
        Context.prototype.fillRect = function (x, y, width, height) {
            let {a, b, c, d, e, f} = this.getTransform();
            if (JSON.stringify([a, b, c, d, e, f]) === JSON.stringify([1, 0, 0, 1, 0, 0])) {
                //clear entire canvas
                if (x === 0 && y === 0 && width === this.width && height === this.height) {
                    this.__clearCanvas();
                }
            }
            var rect, parent;
            rect = this.__createElement("rect", {
                x : x,
                y : y,
                width : width,
                height : height
            }, true);
            parent = this.__closestGroupOrSvg();
            parent.appendChild(rect);
            this.__currentElement = rect;
            this.__applyTransformation(rect);
            this.__applyStyleToCurrentElement("fill");
        };

        /**
         * Draws a rectangle with no fill
         * @param x
         * @param y
         * @param width
         * @param height
         */
        Context.prototype.strokeRect = function (x, y, width, height) {
            var rect, parent;
            rect = this.__createElement("rect", {
                x : x,
                y : y,
                width : width,
                height : height
            }, true);
            parent = this.__closestGroupOrSvg();
            parent.appendChild(rect);
            this.__currentElement = rect;
            this.__applyTransformation(rect);
            this.__applyStyleToCurrentElement("stroke");
        };


        /**
         * Clear entire canvas:
         * 1. save current transforms
         * 2. remove all the childNodes of the root g element
         */
        Context.prototype.__clearCanvas = function () {
            var rootGroup = this.__root.childNodes[1];
            this.__root.removeChild(rootGroup);
            this.__currentElement = this.__document.createElementNS("http://www.w3.org/2000/svg", "g");
            this.__root.appendChild(this.__currentElement);
            //reset __groupStack as all the child group nodes are all removed.
            this.__groupStack = [];
        };

        /**
         * "Clears" a canvas by just drawing a white rectangle in the current group.
         */
        Context.prototype.clearRect = function (x, y, width, height) {
            let {a, b, c, d, e, f} = this.getTransform();
            if (JSON.stringify([a, b, c, d, e, f]) === JSON.stringify([1, 0, 0, 1, 0, 0])) {
                //clear entire canvas
                if (x === 0 && y === 0 && width === this.width && height === this.height) {
                    this.__clearCanvas();
                    return;
                }
            }
            var rect, parent = this.__closestGroupOrSvg();
            rect = this.__createElement("rect", {
                x : x,
                y : y,
                width : width,
                height : height,
                fill : "#FFFFFF"
            }, true);
            this.__applyTransformation(rect);
            parent.appendChild(rect);
        };

        /**
         * Adds a linear gradient to a defs tag.
         * Returns a canvas gradient object that has a reference to it's parent def
         */
        Context.prototype.createLinearGradient = function (x1, y1, x2, y2) {
            var grad = this.__createElement("linearGradient", {
                id : randomString(this.__ids),
                x1 : x1+"px",
                x2 : x2+"px",
                y1 : y1+"px",
                y2 : y2+"px",
                "gradientUnits" : "userSpaceOnUse"
            }, false);
            this.__defs.appendChild(grad);
            return new CanvasGradient(grad, this);
        };

        /**
         * Adds a radial gradient to a defs tag.
         * Returns a canvas gradient object that has a reference to it's parent def
         */
        Context.prototype.createRadialGradient = function (x0, y0, r0, x1, y1, r1) {
            var grad = this.__createElement("radialGradient", {
                id : randomString(this.__ids),
                cx : x1+"px",
                cy : y1+"px",
                r  : r1+"px",
                fx : x0+"px",
                fy : y0+"px",
                "gradientUnits" : "userSpaceOnUse"
            }, false);
            this.__defs.appendChild(grad);
            return new CanvasGradient(grad, this);

        };

        /**
         * Parses the font string and returns svg mapping
         * @private
         */
        Context.prototype.__parseFont = function () {
            var regex = /^\s*(?=(?:(?:[-a-z]+\s*){0,2}(italic|oblique))?)(?=(?:(?:[-a-z]+\s*){0,2}(small-caps))?)(?=(?:(?:[-a-z]+\s*){0,2}(bold(?:er)?|lighter|[1-9]00))?)(?:(?:normal|\1|\2|\3)\s*){0,3}((?:xx?-)?(?:small|large)|medium|smaller|larger|[.\d]+(?:\%|in|[cem]m|ex|p[ctx]))(?:\s*\/\s*(normal|[.\d]+(?:\%|in|[cem]m|ex|p[ctx])))?\s*([-,\'\"\sa-z0-9]+?)\s*$/i;
            var fontPart = regex.exec( this.font );
            var data = {
                style : fontPart[1] || 'normal',
                size : fontPart[4] || '10px',
                family : fontPart[6] || 'sans-serif',
                weight: fontPart[3] || 'normal',
                decoration : fontPart[2] || 'normal',
                href : null
            };

            //canvas doesn't support underline natively, but we can pass this attribute
            if (this.__fontUnderline === "underline") {
                data.decoration = "underline";
            }

            //canvas also doesn't support linking, but we can pass this as well
            if (this.__fontHref) {
                data.href = this.__fontHref;
            }

            return data;
        };

        /**
         * Helper to link text fragments
         * @param font
         * @param element
         * @return {*}
         * @private
         */
        Context.prototype.__wrapTextLink = function (font, element) {
            if (font.href) {
                var a = this.__createElement("a");
                a.setAttributeNS("http://www.w3.org/1999/xlink", "xlink:href", font.href);
                a.appendChild(element);
                return a;
            }
            return element;
        };

        /**
         * Fills or strokes text
         * @param text
         * @param x
         * @param y
         * @param action - stroke or fill
         * @private
         */
        Context.prototype.__applyText = function (text, x, y, action) {
            var font = this.__parseFont(),
                parent = this.__closestGroupOrSvg(),
                textElement = this.__createElement("text", {
                    "font-family" : font.family,
                    "font-size" : font.size,
                    "font-style" : font.style,
                    "font-weight" : font.weight,
                    "text-decoration" : font.decoration,
                    "x" : x,
                    "y" : y,
                    "text-anchor": getTextAnchor(this.textAlign),
                    "dominant-baseline": getDominantBaseline(this.textBaseline)
                }, true);

            textElement.appendChild(this.__document.createTextNode(text));
            this.__currentElement = textElement;
            this.__applyTransformation(textElement);
            this.__applyStyleToCurrentElement(action);
            parent.appendChild(this.__wrapTextLink(font,textElement));
        };

        /**
         * Creates a text element
         * @param text
         * @param x
         * @param y
         */
        Context.prototype.fillText = function (text, x, y) {
            this.__applyText(text, x, y, "fill");
        };

        /**
         * Strokes text
         * @param text
         * @param x
         * @param y
         */
        Context.prototype.strokeText = function (text, x, y) {
            this.__applyText(text, x, y, "stroke");
        };

        /**
         * No need to implement this for svg.
         * @param text
         * @return {TextMetrics}
         */
        Context.prototype.measureText = function (text) {
            this.__ctx.font = this.font;
            return this.__ctx.measureText(text);
        };

        /**
         *  Arc command!
         */
        Context.prototype.arc = function (x, y, radius, startAngle, endAngle, counterClockwise) {
            // in canvas no circle is drawn if no angle is provided.
            if (startAngle === endAngle) {
                return;
            }
            startAngle = startAngle % (2*Math.PI);
            endAngle = endAngle % (2*Math.PI);
            if (startAngle === endAngle) {
                //circle time! subtract some of the angle so svg is happy (svg elliptical arc can't draw a full circle)
                endAngle = ((endAngle + (2*Math.PI)) - 0.001 * (counterClockwise ? -1 : 1)) % (2*Math.PI);
            }
            var endX = x+radius*Math.cos(endAngle),
                endY = y+radius*Math.sin(endAngle),
                startX = x+radius*Math.cos(startAngle),
                startY = y+radius*Math.sin(startAngle),
                sweepFlag = counterClockwise ? 0 : 1,
                largeArcFlag = 0,
                diff = endAngle - startAngle;

            // https://github.com/gliffy/canvas2svg/issues/4
            if (diff < 0) {
                diff += 2*Math.PI;
            }

            if (counterClockwise) {
                largeArcFlag = diff > Math.PI ? 0 : 1;
            } else {
                largeArcFlag = diff > Math.PI ? 1 : 0;
            }

            this.lineTo(startX, startY);
            this.__addPathCommand(format("A {rx} {ry} {xAxisRotation} {largeArcFlag} {sweepFlag} {endX} {endY}",
                {
                    rx:radius,
                    ry:radius,
                    xAxisRotation:0,
                    largeArcFlag:largeArcFlag,
                    sweepFlag:sweepFlag,
                    endX: this.__matrixTransform(endX, endY).x, 
                    endY: this.__matrixTransform(endX, endY).y
                }));

            this.__currentPosition = {x: endX, y: endY};
        };

        /**
         * Generates a ClipPath from the clip command.
         */
        Context.prototype.clip = function () {
            var group = this.__closestGroupOrSvg(),
                clipPath = this.__createElement("clipPath"),
                id =  randomString(this.__ids),
                newGroup = this.__createElement("g");

            this.__applyCurrentDefaultPath();
            group.removeChild(this.__currentElement);
            clipPath.setAttribute("id", id);
            clipPath.appendChild(this.__currentElement);

            this.__defs.appendChild(clipPath);

            //set the clip path to this group
            group.setAttribute("clip-path", format("url(#{id})", {id:id}));

            //clip paths can be scaled and transformed, we need to add another wrapper group to avoid later transformations
            // to this path
            group.appendChild(newGroup);

            this.__currentElement = newGroup;

        };

        /**
         * Draws a canvas, image or mock context to this canvas.
         * Note that all svg dom manipulation uses node.childNodes rather than node.children for IE support.
         * http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#dom-context-2d-drawimage
         */
        Context.prototype.drawImage = function () {
            //convert arguments to a real array
            var args = Array.prototype.slice.call(arguments),
                image=args[0],
                dx, dy, dw, dh, sx=0, sy=0, sw, sh, parent, svg, defs, group,
                svgImage, canvas, context, id;

            if (args.length === 3) {
                dx = args[1];
                dy = args[2];
                sw = image.width;
                sh = image.height;
                dw = sw;
                dh = sh;
            } else if (args.length === 5) {
                dx = args[1];
                dy = args[2];
                dw = args[3];
                dh = args[4];
                sw = image.width;
                sh = image.height;
            } else if (args.length === 9) {
                sx = args[1];
                sy = args[2];
                sw = args[3];
                sh = args[4];
                dx = args[5];
                dy = args[6];
                dw = args[7];
                dh = args[8];
            } else {
                throw new Error("Invalid number of arguments passed to drawImage: " + arguments.length);
            }

            parent = this.__closestGroupOrSvg();
            const matrix = this.getTransform().translate(dx, dy);
            if (image instanceof Context) {
                //canvas2svg mock canvas context. In the future we may want to clone nodes instead.
                //also I'm currently ignoring dw, dh, sw, sh, sx, sy for a mock context.
                svg = image.getSvg().cloneNode(true);
                if (svg.childNodes && svg.childNodes.length > 1) {
                    defs = svg.childNodes[0];
                    while(defs.childNodes.length) {
                        id = defs.childNodes[0].getAttribute("id");
                        this.__ids[id] = id;
                        this.__defs.appendChild(defs.childNodes[0]);
                    }
                    group = svg.childNodes[1];
                    if (group) {
                        this.__applyTransformation(group, matrix);
                        parent.appendChild(group);
                    }
                }
            } else if (image.nodeName === "CANVAS" || image.nodeName === "IMG") {
                //canvas or image
                svgImage = this.__createElement("image");
                svgImage.setAttribute("width", dw);
                svgImage.setAttribute("height", dh);
                svgImage.setAttribute("preserveAspectRatio", "none");

                if (sx || sy || sw !== image.width || sh !== image.height) {
                    //crop the image using a temporary canvas
                    canvas = this.__document.createElement("canvas");
                    canvas.width = dw;
                    canvas.height = dh;
                    context = canvas.getContext("2d");
                    context.drawImage(image, sx, sy, sw, sh, 0, 0, dw, dh);
                    image = canvas;
                }
                this.__applyTransformation(svgImage, matrix);
                svgImage.setAttributeNS("http://www.w3.org/1999/xlink", "xlink:href",
                    image.nodeName === "CANVAS" ? image.toDataURL() : image.getAttribute("src"));
                parent.appendChild(svgImage);
            }
        };

        /**
         * Generates a pattern tag
         */
        Context.prototype.createPattern = function (image, repetition) {
            var pattern = this.__document.createElementNS("http://www.w3.org/2000/svg", "pattern"), id = randomString(this.__ids),
                img;
            pattern.setAttribute("id", id);
            pattern.setAttribute("width", image.width);
            pattern.setAttribute("height", image.height);
            // We want the pattern sizing to be absolute, and not relative
            // https://developer.mozilla.org/en-US/docs/Web/SVG/Tutorial/Patterns
            // https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/patternUnits
            pattern.setAttribute("patternUnits", "userSpaceOnUse");

            if (image.nodeName === "CANVAS" || image.nodeName === "IMG") {
                img = this.__document.createElementNS("http://www.w3.org/2000/svg", "image");
                img.setAttribute("width", image.width);
                img.setAttribute("height", image.height);
                img.setAttributeNS("http://www.w3.org/1999/xlink", "xlink:href",
                    image.nodeName === "CANVAS" ? image.toDataURL() : image.getAttribute("src"));
                pattern.appendChild(img);
                this.__defs.appendChild(pattern);
            } else if (image instanceof Context) {
                pattern.appendChild(image.__root.childNodes[1]);
                this.__defs.appendChild(pattern);
            }
            return new CanvasPattern(pattern, this);
        };

        Context.prototype.setLineDash = function (dashArray) {
            if (dashArray && dashArray.length > 0) {
                this.lineDash = dashArray.join(",");
            } else {
                this.lineDash = null;
            }
        };

        /**
         * SetTransform changes the current transformation matrix to 
         * the matrix given by the arguments as described below.
         * 
         * @see https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/setTransform
         */
        Context.prototype.setTransform = function (a, b, c, d, e, f) {
            if (a instanceof DOMMatrix) {
                this.__transformMatrix = new DOMMatrix([a.a, a.b, a.c, a.d, a.e, a.f]);
            } else {
                this.__transformMatrix = new DOMMatrix([a, b, c, d, e, f]);
            }
        };

        /**
         * GetTransform Returns a copy of the current transformation matrix,
         * as a newly created DOMMAtrix Object
         * 
         * @returns A DOMMatrix Object
         */
        Context.prototype.getTransform = function () {
            let {a, b, c, d, e, f} = this.__transformMatrix;
            return new DOMMatrix([a, b, c, d, e, f]);
        };

        /**
         * ResetTransform resets the current transformation matrix to the identity matrix
         * 
         * @see https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/resetTransform
         */
        Context.prototype.resetTransform = function () {
            this.setTransform(1, 0, 0, 1, 0, 0);
        };

        /**
         * Add the scaling transformation described by the arguments to the current transformation matrix. 
         * 
         * @param x The x argument represents the scale factor in the horizontal direction 
         * @param y The y argument represents the scale factor in the vertical direction.
         * @see https://html.spec.whatwg.org/multipage/canvas.html#dom-context-2d-scale
         */
        Context.prototype.scale = function (x, y) {        
            if (y === undefined) {
                y = x;
            }
            // If either of the arguments are infinite or NaN, then return.
            if (isNaN(x) || isNaN(y) || !isFinite(x) || !isFinite(y)) {
                return
            }
            let matrix = this.getTransform().scale(x, y);
            this.setTransform(matrix);
        };

        /**
         * Rotate adds a rotation to the transformation matrix.
         * 
         * @param angle The rotation angle, clockwise in radians. You can use degree * Math.PI / 180 to calculate a radian from a degree.
         * @see https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/rotate
         * @see https://www.w3.org/TR/css-transforms-1
         */
        Context.prototype.rotate = function (angle) {
            let matrix = this.getTransform().multiply(new DOMMatrix([
                Math.cos(angle),
                Math.sin(angle),
                -Math.sin(angle),
                Math.cos(angle),
                0,
                0
            ]));
            this.setTransform(matrix);
        };

        /**
         * Translate adds a translation transformation to the current matrix.
         * 
         * @param x Distance to move in the horizontal direction. Positive values are to the right, and negative to the left.
         * @param y Distance to move in the vertical direction. Positive values are down, and negative are up.
         * @see https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/translate
         */
        Context.prototype.translate = function (x, y) {
            const matrix = this.getTransform().translate(x, y);
            this.setTransform(matrix);
        };

        /**
         * Transform multiplies the current transformation with the matrix described by the arguments of this method. 
         * This lets you scale, rotate, translate (move), and skew the context.
         * 
         * @see https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/transform
         */
        Context.prototype.transform = function (a, b, c, d, e, f) {
            const matrix = this.getTransform().multiply(new DOMMatrix([a, b, c, d, e, f]));
            this.setTransform(matrix);
        };

        Context.prototype.__matrixTransform = function(x, y) {
            return new DOMPoint(x, y).matrixTransform(this.__transformMatrix)
        };

        /**
         * 
         * @param {*} sx The x-axis coordinate of the top-left corner of the rectangle from which the ImageData will be extracted.
         * @param {*} sy The y-axis coordinate of the top-left corner of the rectangle from which the ImageData will be extracted.
         * @param {*} sw The width of the rectangle from which the ImageData will be extracted. Positive values are to the right, and negative to the left.
         * @param {*} sh The height of the rectangle from which the ImageData will be extracted. Positive values are down, and negative are up.
         * @param {Boolean} options.async Will return a Promise<ImageData> if true, must be set to true
         * @returns An ImageData object containing the image data for the rectangle of the canvas specified. The coordinates of the rectangle's top-left corner are (sx, sy), while the coordinates of the bottom corner are (sx + sw, sy + sh).
         */
        Context.prototype.getImageData = function(sx, sy, sw, sh, options) {
            return utils.getImageData(this.getSvg(), this.width, this.height, sx, sy, sw, sh, options);
        };

        /**
         * Not yet implemented
         */
        Context.prototype.drawFocusRing = function () {};
        Context.prototype.createImageData = function () {};
        Context.prototype.putImageData = function () {};
        Context.prototype.globalCompositeOperation = function () {};

        return Context;
    }());

    function SVGCanvasElement(options) {

        this.ctx = new Context(options);
        this.svg = this.ctx.__root;

        // sync attributes to svg
        var svg = this.svg;
        var _this = this;

        var wrapper = document.createElement('div');
        wrapper.style.display = 'inline-block';
        wrapper.appendChild(svg);
        this.wrapper = wrapper;

        Object.defineProperty(this, 'className', {
            get: function() {
                return wrapper.getAttribute('class') || '';
            },
            set: function(val) {
                return wrapper.setAttribute('class', val);
            }
        });

        ["width", "height"].forEach(function(prop) {
            Object.defineProperty(_this, prop, {
                get: function() {
                    return svg.getAttribute(prop) | 0;
                },
                set: function(val) {
                    if (isNaN(val) || (typeof val === "undefined")) {
                        return;
                    }
                    _this.ctx[prop] = val;
                    svg.setAttribute(prop, val);
                    return wrapper[prop] = val;
                }
            });
        });

        ["style", "id"].forEach(function(prop) {
            Object.defineProperty(_this, prop, {
                get: function() {
                    return wrapper[prop];
                },
                set: function(val) {
                    if (typeof val !== "undefined") {
                        return wrapper[prop] = val;
                    }
                }
            });
        });

        ["getBoundingClientRect"].forEach(function(fn) {
            _this[fn] = function() {
                return svg[fn]();
            };
        });
    }

    SVGCanvasElement.prototype.getContext = function(type) {
        if (type !== '2d') {
            throw new Error('Unsupported type of context for SVGCanvas');
        }

        return this.ctx;
    };

    // you should always use URL.revokeObjectURL after your work done
    SVGCanvasElement.prototype.toObjectURL = function() {
        var data = new XMLSerializer().serializeToString(this.svg);
        var svg = new Blob([data], {type: 'image/svg+xml;charset=utf-8'});
        return URL.createObjectURL(svg);
    };

    /**
     * toDataURL returns a data URI containing a representation of the image in the format specified by the type parameter.
     * 
     * @param {String} type A DOMString indicating the image format. The default type is image/svg+xml; this image format will be also used if the specified type is not supported.
     * @param {Number} encoderOptions A Number between 0 and 1 indicating the image quality to be used when creating images using file formats that support lossy compression (such as image/jpeg or image/webp). A user agent will use its default quality value if this option is not specified, or if the number is outside the allowed range.
     * @param {Boolean} options.async Will return a Promise<String> if true, must be set to true if type is not image/svg+xml
     */
    SVGCanvasElement.prototype.toDataURL = function(type, encoderOptions, options) {
        return utils.toDataURL(this.svg, this.width, this.height, type, encoderOptions, options)
    };

    SVGCanvasElement.prototype.addEventListener = function() {
        return this.svg.addEventListener.apply(this.svg, arguments);
    };

    // will return wrapper element: <div><svg></svg></div>
    SVGCanvasElement.prototype.getElement = function() {
        return this.wrapper;
    };
    var Element$1 = SVGCanvasElement;

    const DEBUG = false;

    function RendererSVG(p5) {
        /**
         * @namespace RendererSVG
         * @constructor
         * @param {Element} elt canvas element to be replaced
         * @param {p5} pInst p5 Instance
         * @param {Bool} isMainCanvas
         */
        function RendererSVG(elt, pInst, isMainCanvas) {
            var svgCanvas = new Element$1({debug: DEBUG});
            var svg = svgCanvas.svg;

            // replace <canvas> with <svg> and copy id, className
            var parent = elt.parentNode;
            var id = elt.id;
            var className = elt.className;
            parent.replaceChild(svgCanvas.getElement(), elt);
            svgCanvas.id = id;
            svgCanvas.className = className;
            elt = svgCanvas; // our fake <canvas>

            elt.parentNode = {
                // fake parentNode.removeChild so that noCanvas will work
                removeChild: function(element) {
                    if (element === elt) {
                        var wrapper = svgCanvas.getElement();
                        wrapper.parentNode.removeChild(wrapper);
                    }
                }
            };

            const pInstProxy = new Proxy(pInst, {
                get: function(target, prop) {
                    if (prop === '_pixelDensity') {
                        // 1 is OK for SVG
                        return 1;
                    }
                    return target[prop];
                }
            });

            p5.Renderer2D.call(this, elt, pInstProxy, isMainCanvas);

            this.isSVG = true;
            this.svg = svg;

            return this;
        }

        RendererSVG.prototype = Object.create(p5.Renderer2D.prototype);

        RendererSVG.prototype._applyDefaults = function() {
            p5.Renderer2D.prototype._applyDefaults.call(this);
            this.drawingContext.lineWidth = 1;
        };

        RendererSVG.prototype.resize = function(w, h) {
            if (!w || !h) {
                return;
            }
            if (this.width !== w || this.height !== h) {
                // canvas will be cleared if its size changed
                // so, we do same thing for SVG
                // note that at first this.width and this.height is undefined
                this.drawingContext.__clearCanvas();
            }

            p5.Renderer2D.prototype.resize.call(this, w, h);

            // For scale, crop
            // see also: http://sarasoueidan.com/blog/svg-coordinate-systems/
            this.svg.setAttribute('viewBox', [0, 0, w, h].join(' '));
        };

        /**
         * Append a element to current SVG Graphics
         *
         * @function appendChild
         * @memberof RendererSVG.prototype
         * @param {SVGElement|Element} element
         */
        RendererSVG.prototype.appendChild = function(element) {
            if (element && element.elt) {
                element = element.elt;
            }
            var g = this.drawingContext.__closestGroupOrSvg();
            g.appendChild(element);
        };

        /**
         * Draw an image or SVG to current SVG Graphics
         *
         * FIXME: sx, sy, sWidth, sHeight
         *
         * @function image
         * @memberof RendererSVG.prototype
         * @param {p5.Graphics|SVGGraphics|SVGElement|Element} image
         * @param {Number} x
         * @param {Number} y
         * @param {Number} width
         * @param {Number} height
         */
        RendererSVG.prototype.image = function(img, sx, sy, sWidth, sHeight, x, y, w, h) {
            if (!img) {
                throw new Error('Invalid image: ' + img);
            }
            var elt = img._renderer && img._renderer.svg; // handle SVG Graphics
            elt = elt || (img.elt && img.elt.nodeName && (img.elt.nodeName.toLowerCase() === 'svg') && img.elt); // SVGElement
            elt = elt || (img.nodeName && (img.nodeName.toLowerCase() == 'svg') && img); // <svg>
            if (elt) {
                // it's <svg> element, let's handle it
                elt = elt.cloneNode(true);
                elt.setAttribute('width', w);
                elt.setAttribute('height', h);
                elt.setAttribute('x', x);
                elt.setAttribute('y', y);
                if (sx || sy || sWidth || sHeight) {
                    sWidth /= this._pInst._pixelDensity;
                    sHeight /= this._pInst._pixelDensity;
                    elt.setAttribute('viewBox', [sx, sy, sWidth, sHeight].join(', '));
                }
                this.appendChild(elt);
            } else {
                p5.Renderer2D.prototype.image.apply(this, arguments);
            }
        };

        /**
         * @method parent
         * @return {p5.Element}
         *
         * @see https://github.com/zenozeng/p5.js-svg/issues/187
         */
        RendererSVG.prototype.parent = function() {
            const $this = {
                elt: this.elt.getElement()
            };
            return p5.Element.prototype.parent.apply($this, arguments);
        };


        RendererSVG.prototype.loadPixels = async function() {
            const pixelsState = this._pixelsState; // if called by p5.Image
            const pd = pixelsState._pixelDensity;
            const w = this.width * pd;
            const h = this.height * pd;
            const imageData = await this.drawingContext.getImageData(0, 0, w, h, {async: true});
            pixelsState._setProperty('imageData', imageData);
            pixelsState._setProperty('pixels', imageData.data);
        };

        p5.RendererSVG = RendererSVG;
    }

    var constants = {
        SVG: 'svg'
    };

    function Rendering(p5) {
        // patch p5.Graphics for SVG
        var _graphics = p5.Graphics;
        p5.Graphics = function(w, h, renderer, pInst) {
            const isSVG = renderer === constants.SVG;
            _graphics.apply(this, [w, h, isSVG ? p5.P2D : renderer, pInst]);
            if (isSVG) {
                // replace <canvas> with <svg>
                var c = this._renderer.elt;
                this._renderer = new p5.RendererSVG(c, this, false); // replace renderer
                c = this._renderer.elt;
                this.elt = c; // replace this.elt
                // do default again
                this._renderer.resize(w, h);
                this._renderer._applyDefaults();
            }
            return this;
        };
        p5.Graphics.prototype = _graphics.prototype;

        /**
         * Patched version of createCanvas
         *
         * use createCanvas(100, 100, SVG) to create SVG canvas.
         *
         * Creates a SVG element in the document, and sets its width and
         * height in pixels. This method should be called only once at
         * the start of setup.
         * @function createCanvas
         * @memberof p5.prototype
         * @param {Number} width - Width (in px) for SVG Element
         * @param {Number} height - Height (in px) for SVG Element
         * @return {Graphics}
         */
        var _createCanvas = p5.prototype.createCanvas;
        p5.prototype.createCanvas = function(w, h, renderer) {
            var graphics = _createCanvas.apply(this, arguments);
            if (renderer === constants.SVG) {
                var c = graphics.canvas;
                this._setProperty('_renderer', new p5.RendererSVG(c, this, true));
                this._isdefaultGraphics = true;
                this._renderer.resize(w, h);
                this._renderer._applyDefaults();
            }
            return this._renderer;
        };

        p5.prototype.createGraphics = function(w, h, renderer) {
            return new p5.Graphics(w, h, renderer, this);
        };

    }

    function IO(p5) {
        /**
         * Convert SVG Element to jpeg / png data url
         *
         * @private
         * @param {SVGElement} svg SVG Element
         * @param {String} mine Mine
         * @param {Function} callback
         */
        var svg2img = function(svg, mine, callback) {
            svg = (new XMLSerializer()).serializeToString(svg);
            svg = 'data:image/svg+xml;charset=utf-8,' + encodeURIComponent(svg);
            if (mine == 'image/svg+xml') {
                callback(null, svg);
                return;
            }
            var img = new Image();
            var canvas = document.createElement('canvas');
            var ctx = canvas.getContext('2d');
            img.onload = function() {
                canvas.width = img.width;
                canvas.height = img.height;
                ctx.drawImage(img, 0, 0);
                var dataURL = canvas.toDataURL(mine);
                callback(null, dataURL);
            };
            img.src = svg;
        };

        /**
         * Get SVG frame, and convert to target type
         *
         * @private
         * @param {Object} options
         * @param {SVGElement} options.svg SVG Element, defaults to current svg element
         * @param {String} options.filename
         * @param {String} options.ext Extension: 'svg' or 'jpg' or 'jpeg' or 'png'
         * @param {Function} options.callback
         */
        p5.prototype._makeSVGFrame = function(options) {
            var filename = options.filename || 'untitled';
            var ext = options.extension;
            ext = ext || this._checkFileExtension(filename, ext)[1];
            var regexp = new RegExp('\\.' + ext + '$');
            filename = filename.replace(regexp, '');
            if (ext === '') {
                ext = 'svg';
            }
            var mine = {
                png: 'image/png',
                jpeg: 'image/jpeg',
                jpg: 'image/jpeg',
                svg: 'image/svg+xml'
            }[ext];
            if (!mine) {
                throw new Error('Fail to getFrame, invalid extension: ' + ext + ', please use png | jpeg | jpg | svg.');
            }

            var svg = options.svg || this._renderer.svg;
            svg2img(svg, mine, function(err, dataURL) {
                var downloadMime = 'image/octet-stream';
                dataURL = dataURL.replace(mine, downloadMime);
                options.callback(err, {
                    imageData: dataURL,
                    filename: filename,
                    ext: ext
                });
            });
        };

        /**
         * Save the current SVG as an image. In Safari, will open the
         * image in the window and the user must provide their own
         * filename on save-as. Other browsers will either save the
         * file immediately, or prompt the user with a dialogue window.
         *
         * @function saveSVG
         * @memberof p5.prototype
         * @param {Graphics|Element|SVGElement} [svg] Source to save
         * @param {String} [filename]
         * @param {String} [extension] Extension: 'svg' or 'jpg' or 'jpeg' or 'png'
         */
        p5.prototype.saveSVG = function() {
            // don't use slice on arguments because it prevents optimizations
            var args = arguments;
            args = [args[0], args[1], args[2]];

            var svg;

            if (args[0] instanceof p5.Graphics) {
                svg = args[0]._renderer.svg;
                args.shift();
            }

            if (args[0] && args[0].elt) {
                svg = args[0].elt;
                args.shift();
            }

            if (typeof args[0] == 'object') {
                svg = args[0];
                args.shift();
            }

            var filename = args[0];
            var ext = args[1];

            var p = this;
            this._makeSVGFrame({
                svg: svg,
                filename: filename,
                extension: ext,
                callback: function(err, frame) {
                    p.downloadFile(frame.imageData, frame.filename, frame.ext);
                }
            });
        };

        /**
         * Extends p5's saveFrames with SVG support
         *
         * @function saveFrames
         * @memberof p5.prototype
         * @param {String} filename filename
         * @param {String} extension Extension: 'svg' or 'jpg' or 'jpeg' or 'png'
         * @param {Number} duration duration
         * @param {Number} fps fps
         * @param {Function} callback callback
         */
        var _saveFrames = p5.prototype.saveFrames;
        p5.prototype.saveFrames = function(filename, extension, duration, fps, callback) {
            var args = arguments;

            if (!this._renderer.svg) {
                _saveFrames.apply(this, args);
                return;
            }

            duration = duration || 3;
            duration = p5.prototype.constrain(duration, 0, 15);
            duration = duration * 1000;
            fps = fps || 15;
            fps = p5.prototype.constrain(fps, 0, 22);
            var count = 0;

            var frames = [];
            var pending = 0;

            var p = this;
            var frameFactory = setInterval(function () {
                (function(count) {
                    pending++;
                    p._makeSVGFrame({
                        filename: filename + count,
                        extension: extension,
                        callback: function(err, frame) {
                            frames[count] = frame;
                            pending--;
                        }
                    });
                })(count);
                count++;
            }, 1000 / fps);

            var done = function() {
                if (pending > 0) {
                    setTimeout(function() {
                        done();
                    }, 10);
                    return;
                }
                if (callback) {
                    callback(frames);
                } else {
                    frames.forEach(function(f) {
                        p.downloadFile(f.imageData, f.filename, f.ext);
                    });
                }
            };

            setTimeout(function () {
                clearInterval(frameFactory);
                done();
            }, duration + 0.01);
        };

        /**
         * Extends p5's save method with SVG support
         *
         * @function save
         * @memberof p5.prototype
         * @param {Graphics|Element|SVGElement} [source] Source to save
         * @param {String} [filename] filename
         */
        var _save = p5.prototype.save;
        p5.prototype.save = function() {
            var args = arguments;
            args = [args[0], args[1]];

            var svg;

            if (args[0] instanceof p5.Graphics) {
                var svgcanvas = args[0].elt;
                svg = svgcanvas.svg;
                args.shift();
            }

            if (args[0] && args[0].elt) {
                svg = args[0].elt;
                args.shift();
            }

            if (typeof args[0] == 'object') {
                svg = args[0];
                args.shift();
            }

            svg = svg || (this._renderer && this._renderer.svg);

            var filename = args[0];
            var supportedExtensions = ['jpeg', 'png', 'jpg', 'svg', ''];
            var ext = this._checkFileExtension(filename, '')[1];

            var useSVG = svg && svg.nodeName && svg.nodeName.toLowerCase() === 'svg' && supportedExtensions.indexOf(ext) > -1;

            if (useSVG) {
                this.saveSVG(svg, filename);
            } else {
                return _save.apply(this, arguments);
            }
        };

        /**
         * Custom get in p5.svg (handles http and dataurl)
         * @private
         */
        p5.prototype._svg_get = function(path, successCallback, failureCallback) {
            if (path.indexOf('data:') === 0) {
                if (path.indexOf(',') === -1) {
                    failureCallback(new Error('Fail to parse dataurl: ' + path));
                    return;
                }
                var svg = path.split(',').pop();
                // force request to dataurl to be async
                // so that it won't make preload mess
                setTimeout(function() {
                    if (path.indexOf(';base64,') > -1) {
                        svg = atob(svg);
                    } else {
                        svg = decodeURIComponent(svg);
                    }
                    successCallback(svg);
                }, 1);
                return svg;
            } else {
                this.httpGet(path, successCallback);
                return null;
            }
        };

        /**
         * loadSVG (like loadImage, but will return SVGElement)
         *
         * @function loadSVG
         * @memberof p5.prototype
         * @returns {p5.SVGElement}
         */
        p5.prototype.loadSVG = function(path, successCallback, failureCallback) {
            var div = document.createElement('div');
            var element = new p5.SVGElement(div);
            this._incrementPreload();
            new Promise((resolve, reject) => {
                this._svg_get(path, function(svg) {
                    div.innerHTML = svg;
                    svg = div.querySelector('svg');
                    if (!svg) {
                        reject('Fail to create <svg>.');
                        return;
                    }
                    element.elt = svg;
                    resolve(element);
                }, reject);
            }).then((v) => {
                successCallback && successCallback(v);
            }).catch((e) => {
                failureCallback && failureCallback(e);
            }).finally(() => {
                this._decrementPreload();
            });
            return element;
        };

        p5.prototype.getDataURL = function() {
            return this._renderer.elt.toDataURL('image/svg+xml');
        };
    }

    function Element(p5) {
        /**
         * Returns an Array of SVGElements of current SVG Graphics matching given selector
         *
         * @function querySVG
         * @memberof p5.prototype
         * @param {String} selector CSS selector for query
         * @returns {SVGElement[]}
         */
        p5.prototype.querySVG = function(selector) {
            var svg = this._renderer && this._renderer.svg;
            if (!svg) {
                return null;
            }
            return p5.SVGElement.prototype.query.call({elt: svg}, selector);
        };

        /**
         * @namespace SVGElement
         * @constructor
         * @param {Element} element
         */
        function SVGElement(element) {
            if (!element) {
                return null;
            }
            return p5.Element.apply(this, arguments);
        }

        SVGElement.prototype = Object.create(p5.Element.prototype);

        /**
         * Returns an Array of children of current SVG Element matching given selector
         *
         * @function query
         * @memberof SVGElement.prototype
         * @param {String} selector CSS selector for query
         * @returns {SVGElement[]}
         */
        SVGElement.prototype.query = function(selector) {
            var elements = this.elt.querySelectorAll(selector);
            var objects = [];
            for (var i = 0; i < elements.length; i++) {
                objects[i] = new SVGElement(elements[i]);
            }
            return objects;
        };

        /**
         * Append a new child to current element.
         *
         * @function append
         * @memberof SVGElement.prototype
         * @param {SVGElement|Element} element
         */
        SVGElement.prototype.append = function(element) {
            var elt = element.elt || element;
            this.elt.appendChild(elt);
            return this;
        };

        /**
         * Apply different attribute operation based on arguments.length
         * <ul>
         *     <li>setAttribute(name, value)</li>
         *     <li>setAttributeNS(namespace, name, value)</li>
         *     <li>getAttribute(name)</li>
         * </ul>
         *
         * @function attribute
         * @memberof SVGElement.prototype
         */
        SVGElement.prototype.attribute = function() {
            var args = arguments;
            if (args.length === 3) {
                this.elt.setAttributeNS.apply(this.elt, args);
            }
            if (args.length === 2) {
                this.elt.setAttribute.apply(this.elt, args);
            }
            if (args.length === 1) {
                return this.elt.getAttribute.apply(this.elt, args);
            }
            return this;
        };

        /**
         * Apply filter on current element.
         * If called multiple times,
         * these filters will be chained together and combine to a bigger SVG filter.
         *
         * @function filter
         * @memberof SVGElement.prototype
         * @param {String} filter BLUR, GRAY, INVERT, THRESHOLD, OPAQUE, ERODE, DILATE (defined in p5's constants)
         * @param {Any} argument Argument for that filter
         */
        SVGElement.prototype._filter = function(filter, arg, defs) {
            p5.SVGFilters.apply(this, filter, arg, defs);
            return this;
        };

        /**
         * Create SVGElement
         *
         * @function create
         * @memberof SVGElement
         * @param {String} nodeName
         * @param {Object} [attributes] Attributes for the element
         * @return {SVGElement}
         */
        SVGElement.create = function(nodeName, attributes) {
            attributes = attributes || {};
            var elt = document.createElementNS('http://www.w3.org/2000/svg', nodeName);
            Object.keys(attributes).forEach(function(k) {
                elt.setAttribute(k, attributes[k]);
            });
            return new SVGElement(elt);
        };


        /**
         * Get parentNode.
         * If selector not given, returns parentNode.
         * Otherwise, will look up all ancestors,
         * and return closest element matching given selector,
         * or return null if not found.
         *
         * @function parentNode
         * @memberof SVGElement.prototype
         * @param {String} [selector] CSS Selector
         * @return {SVGElement}
         */
        SVGElement.prototype.parentNode = function(selector) {
            if (!selector) {
                return new SVGElement(this.elt.parentNode);
            }
            var elt = this;
            while (elt) {
                elt = this.parentNode();
                if (elt && elt.matches(selector)) {
                    return elt;
                }
            }
            return null;
        };

        p5.SVGElement = SVGElement;
    }

    function P5SVGFilters(p5) {
        var SVGFilters = function() {};

        var SVGElement = p5.SVGElement;

        var generateID = function() {
            return Date.now().toString() + Math.random().toString().replace(/0\./, '');
        };

        // @private
        // We have to build a filter for each element
        // the `filter: f1 f2` and svg param is not supported by many browsers
        // so we can just modify the filter def to do so
        SVGFilters.apply = function(svgElement, func, arg, defs) {
            // get filters
            var filters = svgElement.attribute('data-p5-svg-filters') || '[]';
            filters = JSON.parse(filters);
            if (func) {
                filters.push([func, arg]);
            }
            svgElement.attribute('data-p5-svg-filters', JSON.stringify(filters));

            if (filters.length === 0) {
                svgElement.attribute('filter', null);
                return;
            }

            // generate filters chain
            filters = filters.map(function(filter, index) {
                var inGraphics = index === 0 ? 'SourceGraphic' : ('result-' + (index - 1));
                var resultGraphics = 'result-' + index;
                return SVGFilters[filter[0]].call(null, inGraphics, resultGraphics, filter[1]);
            });

            // get filter id for this element or create one
            var filterid = svgElement.attribute('data-p5-svg-filter-id');
            if (!filterid) {
                filterid = 'p5-svg-' + generateID();
                svgElement.attribute('data-p5-svg-filter-id', filterid);
            }
            // Note that when filters is [], we will remove filter attr
            // So, here, we write this attr every time
            svgElement.attribute('filter', 'url(#' + filterid + ')');

            // create <filter>
            var filter = SVGElement.create('filter', {id: filterid});
            filters.forEach(function(elt) {
                if (!Array.isArray(elt)) {
                    elt = [elt];
                }
                elt.forEach(function(elt) {
                    filter.append(elt);
                });
            });

            // get defs
            var oldfilter = defs.querySelectorAll('#' + filterid)[0];
            if (!oldfilter) {
                defs.appendChild(filter.elt);
            } else {
                oldfilter.elt.parentNode.replaceChild(filter.elt, oldfilter);
            }
        };

        SVGFilters.blur = function(inGraphics, resultGraphics, val) {
            return SVGElement.create('feGaussianBlur', {
                stdDeviation: val,
                in: inGraphics,
                result: resultGraphics,
                'color-interpolation-filters': 'sRGB'
            });
        };

        // See also: http://www.w3.org/TR/SVG11/filters.html#feColorMatrixElement
        // See also: http://stackoverflow.com/questions/21977929/match-colors-in-fecolormatrix-filter
        SVGFilters.colorMatrix = function(inGraphics, resultGraphics, matrix) {
            return SVGElement.create('feColorMatrix', {
                type: 'matrix',
                values: matrix.join(' '),
                'color-interpolation-filters': 'sRGB',
                in: inGraphics,
                result: resultGraphics
            });
        };

        // Here we use CIE luminance for RGB
        SVGFilters.gray = function(inGraphics, resultGraphics) {
            var matrix = [
                0.2126, 0.7152, 0.0722, 0, 0, // R'
                0.2126, 0.7152, 0.0722, 0, 0, // G'
                0.2126, 0.7152, 0.0722, 0, 0, // B'
                0, 0, 0, 1, 0 // A'
            ];
            return SVGFilters.colorMatrix(inGraphics, resultGraphics, matrix);
        };

        SVGFilters.threshold = function(inGraphics, resultGraphics, val) {
            var elements = [];
            elements.push(SVGFilters.gray(inGraphics, resultGraphics + '-tmp'));
            var componentTransfer = SVGElement.create('feComponentTransfer', {
                'in': resultGraphics + '-tmp',
                result: resultGraphics
            });
            var thresh = Math.floor(val * 255);
            ['R', 'G', 'B'].forEach(function(channel) {
                // Note that original value is from 0 to 1
                var func = SVGElement.create('feFunc' + channel, {
                    type: 'linear',
                    slope: 255, // all non-zero * 255
                    intercept: (thresh - 1) * -1
                });
                componentTransfer.append(func);
            });
            elements.push(componentTransfer);
            return elements;
        };

        SVGFilters.invert = function(inGraphics, resultGraphics) {
            var matrix = [
                -1, 0, 0, 0, 1,
                0, -1, 0, 0, 1,
                0, 0, -1, 0, 1,
                0, 0, 0, 1, 0
            ];
            return SVGFilters.colorMatrix(inGraphics, resultGraphics, matrix);
        };

        SVGFilters.opaque = function(inGraphics, resultGraphics) {
            var matrix = [
                1, 0, 0, 0, 0, // original R
                0, 1, 0, 0, 0, // original G
                0, 0, 1, 0, 0, // original B
                0, 0, 0, 0, 1 // set A to 1
            ];
            return SVGFilters.colorMatrix(inGraphics, resultGraphics, matrix);
        };

        /**
         * Generate discrete table values based on the given color map function
         *
         * @private
         * @param {Function} fn - Function to map channel values (val ∈ [0, 255])
         * @see http://www.w3.org/TR/SVG/filters.html#feComponentTransferElement
         */
        SVGFilters._discreteTableValues = function(fn) {
            var table = [];
            for (var val = 0; val < 256; val++) {
                var newval = fn(val);
                table.push(newval / 255); // map to ∈ [0, 1]
            }
            return table;
        };

        /**
         * Limits each channel of the image to the number of colors specified as
         * the parameter. The parameter can be set to values between 2 and 255, but
         * results are most noticeable in the lower ranges.
         *
         * Adapted from p5's Filters.posterize
         */
        SVGFilters.posterize = function(inGraphics, resultGraphics, level) {
            level = parseInt(level, 10);
            if ((level < 2) || (level > 255)) {
                throw new Error(
                    'Level must be greater than 2 and less than 255 for posterize'
                );
            }

            var tableValues = SVGFilters._discreteTableValues(function(val) {
                return (((val * level) >> 8) * 255) / (level - 1);
            });

            var componentTransfer = SVGElement.create('feComponentTransfer', {
                'in': inGraphics,
                result: resultGraphics,
                'color-interpolation-filters': 'sRGB'
            });
            ['R', 'G', 'B'].forEach(function(channel) {
                var func = SVGElement.create('feFunc' + channel, {
                    type: 'discrete',
                    tableValues: tableValues.join(' ')
                });
                componentTransfer.append(func);
            });

            return componentTransfer;
        };

        SVGFilters._blendOffset = function(inGraphics, resultGraphics, mode) {
            var elements = [];
            [
                ['left', -1, 0],
                ['right', 1, 0],
                ['up', 0, -1],
                ['down', 0, 1]
            ].forEach(function(neighbor) {
                elements.push(SVGElement.create('feOffset', {
                    'in': inGraphics,
                    result: resultGraphics + '-' + neighbor[0],
                    dx: neighbor[1],
                    dy: neighbor[2]
                }));
            });
            [
                [null, inGraphics],
                [resultGraphics + '-left', resultGraphics + '-tmp-0'],
                [resultGraphics + '-right', resultGraphics + '-tmp-1'],
                [resultGraphics + '-up', resultGraphics + '-tmp-2'],
                [resultGraphics + '-down', resultGraphics + '-tmp-3']
            ].forEach(function(layer, i, layers) {
                if (i === 0) {
                    return;
                }
                elements.push(SVGElement.create('feBlend', {
                    'in': layers[i - 1][1],
                    in2: layer[0],
                    result: layer[1],
                    mode: mode
                }));
            });
            return elements;
        };

        /**
         * Increases the bright areas in an image
         *
         * Will create 4 offset layer and blend them using darken mode
         */
        SVGFilters.erode = function(inGraphics, resultGraphics) {
            return SVGFilters._blendOffset(inGraphics, resultGraphics, 'darken');
        };

        SVGFilters.dilate = function(inGraphics, resultGraphics) {
            return SVGFilters._blendOffset(inGraphics, resultGraphics, 'lighten');
        };

        p5.SVGFilters = SVGFilters;

        return SVGFilters;
    }

    // SVG Filter

    function Filters(p5) {
        var _filter = p5.prototype.filter;

        var SVGFilters = P5SVGFilters(p5);

        /**
         * Register a custom SVG Filter
         *
         * @function registerSVGFilter
         * @memberof p5.prototype
         * @param {String} name Name for Custom SVG filter
         * @param {Function} filterFunction filterFunction(inGraphicsName, resultGraphicsName, value)
         *                                  should return SVGElement or Array of SVGElement.
         * @example
         * registerSVGFilter('myblur', function(inGraphicsName, resultGraphicsName, value) {
         *     return SVGElement.create('feGaussianBlur', {
         *         stdDeviation: val,
         *         in: inGraphics,
         *         result: resultGraphics,
         *         'color-interpolation-filters': 'sRGB'
         *     });
         * });
         * filter('myblur', 5);
         */
        p5.prototype.registerSVGFilter = function(name, fn) {
            SVGFilters[name] = fn;
        };

        p5.prototype.filter = function(operation, value) {
            var svg = this._renderer.svg;
            if (svg) {
                const ctx = this._renderer.drawingContext;
                const defs = ctx.__root.querySelectorAll('defs')[0];
                const rootGroup = ctx.__root.childNodes[1];
                // move nodes to a new <g>
                let g = p5.SVGElement.create('g');
                while (rootGroup.childNodes.length > 0) {
                    g.elt.appendChild(rootGroup.childNodes[0]);
                }
                rootGroup.appendChild(g.elt);

                // apply filter
                g._filter(operation, value, defs);

                // create new <g> so that new element won't be influenced by the filter
                g = p5.SVGElement.create('g');
                rootGroup.appendChild(g.elt);
                ctx.__currentElement = g.elt;
            } else {
                _filter.apply(this, arguments);
            }
        };
    }

    function Image$1(p5) {
        p5.prototype.loadPixels = function(...args) {
            p5._validateParameters('loadPixels', args);
            return this._renderer.loadPixels();
        };
    }

    function init(p5) {
        /**
         * @namespace p5
         */
        RendererSVG(p5);
        Rendering(p5);
        IO(p5);
        Element(p5);
        Filters(p5);
        Image$1(p5);

        // attach constants to p5 instance
        Object.keys(constants).forEach(function(k) {
            p5.prototype[k] = constants[k];
        });
    }

    if (typeof window.p5 !== 'undefined') {
        init(window.p5);
    }

    return init;

}());
//# sourceMappingURL=p5.svg.js.map