/*! Picturefill - v3.0.2

* http://scottjehl.github.io/picturefill
* Copyright (c) 2015 https://github.com/scottjehl/picturefill/blob/master/Authors.txt;
*  License: MIT
*/

(function( window, document, undefined ) {

// Enable strict mode
"use strict";

// HTML shim|v it for old IE (IE9 will still need the HTML video tag workaround)
document.createElement( "picture" );

var warn, eminpx, alwaysCheckWDescriptor, evalId;
// local object for method references and testing exposure
var pf = {};
var isSupportTestReady = false;
var noop = function() {};
var image = document.createElement( "img" );
var getImgAttr = image.getAttribute;
var setImgAttr = image.setAttribute;
var removeImgAttr = image.removeAttribute;
var docElem = document.documentElement;
var types = {};
var cfg = {
        //resource selection:
        algorithm: ""
};
var srcAttr = "data-pfsrc";
var srcsetAttr = srcAttr + "set";
// ua sniffing is done for undetectable img loading features,
// to do some non crucial perf optimizations
var ua = navigator.userAgent;
var supportAbort = (/rident/).test(ua) || ((/ecko/).test(ua) && ua.match(/rv\:(\d+)/) && RegExp.$1 > 35 );
var curSrcProp = "currentSrc";
var regWDesc = /\s+\+?\d+(e\d+)?w/;
var regSize = /(\([^)]+\))?\s*(.+)/;
var setOptions = window.picturefillCFG;
/**
 * Shortcut property for https://w3c.github.io/webappsec/specs/mixedcontent/#restricts-mixed-content ( for easy overriding in tests )
 */
// baseStyle also used by getEmValue (i.e.: width: 1em is important)
var baseStyle = "position:absolute;left:0;visibility:hidden;display:block;padding:0;border:none;font-size:1em;width:1em;overflow:hidden;clip:rect(0px, 0px, 0px, 0px)";
var fsCss = "font-size:100%!important;";
var isVwDirty = true;

var cssCache = {};
var sizeLengthCache = {};
var DPR = window.devicePixelRatio;
var units = {
        px: 1,
        "in": 96
};
var anchor = document.createElement( "a" );
/**
 * alreadyRun flag used for setOptions. is it true setOptions will reevaluate
 * @type {boolean}
 */
var alreadyRun = false;

// Reusable, non-"g" Regexes

// (Don't use \s, to avoid matching non-breaking space.)
var regexLeadingSpaces = /^[ \t\n\r\u000c]+/,
    regexLeadingCommasOrSpaces = /^[, \t\n\r\u000c]+/,
    regexLeadingNotSpaces = /^[^ \t\n\r\u000c]+/,
    regexTrailingCommas = /[,]+$/,
    regexNonNegativeInteger = /^\d+$/,

    // ( Positive or negative or unsigned integers or decimals, without or without exponents.
    // Must include at least one digit.
    // According to spec tests any decimal point must be followed by a digit.
    // No leading plus sign is allowed.)
    // https://html.spec.whatwg.org/multipage/infrastructure.html#valid-floating-point-number
    regexFloatingPoint = /^-?(?:[0-9]+|[0-9]*\.[0-9]+)(?:[eE][+-]?[0-9]+)?$/;

var on = function(obj, evt, fn, capture) {
        if ( obj.addEventListener ) {
                obj.addEventListener(evt, fn, capture || false);
        } else if ( obj.attachEvent ) {
                obj.attachEvent( "on" + evt, fn);
        }
};

/**
 * simple memoize function:
 */

var memoize = function(fn) {
        var cache = {};
        return function(input) {
                if ( !(input in cache) ) {
                        cache[ input ] = fn(input);
                }
                return cache[ input ];
        };
};

// UTILITY FUNCTIONS

// Manual is faster than RegEx
// http://jsperf.com/whitespace-character/5
function isSpace(c) {
        return (c === "\u0020" || // space
                c === "\u0009" || // horizontal tab
                c === "\u000A" || // new line
                c === "\u000C" || // form feed
                c === "\u000D");  // carriage return
}

/**
 * gets a mediaquery and returns a boolean or gets a css length and returns a number
 * @param css mediaqueries or css length
 * @returns {boolean|number}
 *
 * based on: https://gist.github.com/jonathantneal/db4f77009b155f083738
 */
var evalCSS = (function() {

        var regLength = /^([\d\.]+)(em|vw|px)$/;
        var replace = function() {
                var args = arguments, index = 0, string = args[0];
                while (++index in args) {
                        string = string.replace(args[index], args[++index]);
                }
                return string;
        };

        var buildStr = memoize(function(css) {

                return "return " + replace((css || "").toLowerCase(),
                        // interpret `and`
                        /\band\b/g, "&&",

                        // interpret `,`
                        /,/g, "||",

                        // interpret `min-` as >=
                        /min-([a-z-\s]+):/g, "e.$1>=",

                        // interpret `max-` as <=
                        /max-([a-z-\s]+):/g, "e.$1<=",

                        //calc value
                        /calc([^)]+)/g, "($1)",

                        // interpret css values
                        /(\d+[\.]*[\d]*)([a-z]+)/g, "($1 * e.$2)",
                        //make eval less evil
                        /^(?!(e.[a-z]|[0-9\.&=|><\+\-\*\(\)\/])).*/ig, ""
                ) + ";";
        });

        return function(css, length) {
                var parsedLength;
                if (!(css in cssCache)) {
                        cssCache[css] = false;
                        if (length && (parsedLength = css.match( regLength ))) {
                                cssCache[css] = parsedLength[ 1 ] * units[parsedLength[ 2 ]];
                        } else {
                                /*jshint evil:true */
                                try{
                                        cssCache[css] = new Function("e", buildStr(css))(units);
                                } catch(e) {}
                                /*jshint evil:false */
                        }
                }
                return cssCache[css];
        };
})();

var setResolution = function( candidate, sizesattr ) {
        if ( candidate.w ) { // h = means height: || descriptor.type === 'h' do not handle yet...
                candidate.cWidth = pf.calcListLength( sizesattr || "100vw" );
                candidate.res = candidate.w / candidate.cWidth ;
        } else {
                candidate.res = candidate.d;
        }
        return candidate;
};

/**
 *
 * @param opt
 */
var picturefill = function( opt ) {

        if (!isSupportTestReady) {return;}

        var elements, i, plen;

        var options = opt || {};

        if ( options.elements && options.elements.nodeType === 1 ) {
                if ( options.elements.nodeName.toUpperCase() === "IMG" ) {
                        options.elements =  [ options.elements ];
                } else {
                        options.context = options.elements;
                        options.elements =  null;
                }
        }

        elements = options.elements || pf.qsa( (options.context || document), ( options.reevaluate || options.reselect ) ? pf.sel : pf.selShort );

        if ( (plen = elements.length) ) {

                pf.setupRun( options );
                alreadyRun = true;

                // Loop through all elements
                for ( i = 0; i < plen; i++ ) {
                        pf.fillImg(elements[ i ], options);
                }

                pf.teardownRun( options );
        }
};

/**
 * outputs a warning for the developer
 * @param {message}
 * @type {Function}
 */
warn = ( window.console && console.warn ) ?
        function( message ) {
                console.warn( message );
        } :
        noop
;

if ( !(curSrcProp in image) ) {
        curSrcProp = "src";
}

// Add support for standard mime types.
types[ "image/jpeg" ] = true;
types[ "image/gif" ] = true;
types[ "image/png" ] = true;

function detectTypeSupport( type, typeUri ) {
        // based on Modernizr's lossless img-webp test
        // note: asynchronous
        var image = new window.Image();
        image.onerror = function() {
                types[ type ] = false;
                picturefill();
        };
        image.onload = function() {
                types[ type ] = image.width === 1;
                picturefill();
        };
        image.src = typeUri;
        return "pending";
}

// test svg support
types[ "image/svg+xml" ] = document.implementation.hasFeature( "http://www.w3.org/TR/SVG11/feature#Image", "1.1" );

/**
 * updates the internal vW property with the current viewport width in px
 */
function updateMetrics() {

        isVwDirty = false;
        DPR = window.devicePixelRatio;
        cssCache = {};
        sizeLengthCache = {};

        pf.DPR = DPR || 1;

        units.width = Math.max(window.innerWidth || 0, docElem.clientWidth);
        units.height = Math.max(window.innerHeight || 0, docElem.clientHeight);

        units.vw = units.width / 100;
        units.vh = units.height / 100;

        evalId = [ units.height, units.width, DPR ].join("-");

        units.em = pf.getEmValue();
        units.rem = units.em;
}

function chooseLowRes( lowerValue, higherValue, dprValue, isCached ) {
        var bonusFactor, tooMuch, bonus, meanDensity;

        //experimental
        if (cfg.algorithm === "saveData" ){
                if ( lowerValue > 2.7 ) {
                        meanDensity = dprValue + 1;
                } else {
                        tooMuch = higherValue - dprValue;
                        bonusFactor = Math.pow(lowerValue - 0.6, 1.5);

                        bonus = tooMuch * bonusFactor;

                        if (isCached) {
                                bonus += 0.1 * bonusFactor;
                        }

                        meanDensity = lowerValue + bonus;
                }
        } else {
                meanDensity = (dprValue > 1) ?
                        Math.sqrt(lowerValue * higherValue) :
                        lowerValue;
        }

        return meanDensity > dprValue;
}

function applyBestCandidate( img ) {
        var srcSetCandidates;
        var matchingSet = pf.getSet( img );
        var evaluated = false;
        if ( matchingSet !== "pending" ) {
                evaluated = evalId;
                if ( matchingSet ) {
                        srcSetCandidates = pf.setRes( matchingSet );
                        pf.applySetCandidate( srcSetCandidates, img );
                }
        }
        img[ pf.ns ].evaled = evaluated;
}

function ascendingSort( a, b ) {
        return a.res - b.res;
}

function setSrcToCur( img, src, set ) {
        var candidate;
        if ( !set && src ) {
                set = img[ pf.ns ].sets;
                set = set && set[set.length - 1];
        }

        candidate = getCandidateForSrc(src, set);

        if ( candidate ) {
                src = pf.makeUrl(src);
                img[ pf.ns ].curSrc = src;
                img[ pf.ns ].curCan = candidate;

                if ( !candidate.res ) {
                        setResolution( candidate, candidate.set.sizes );
                }
        }
        return candidate;
}

function getCandidateForSrc( src, set ) {
        var i, candidate, candidates;
        if ( src && set ) {
                candidates = pf.parseSet( set );
                src = pf.makeUrl(src);
                for ( i = 0; i < candidates.length; i++ ) {
                        if ( src === pf.makeUrl(candidates[ i ].url) ) {
                                candidate = candidates[ i ];
                                break;
                        }
                }
        }
        return candidate;
}

function getAllSourceElements( picture, candidates ) {
        var i, len, source, srcset;

        // SPEC mismatch intended for size and perf:
        // actually only source elements preceding the img should be used
        // also note: don't use qsa here, because IE8 sometimes doesn't like source as the key part in a selector
        var sources = picture.getElementsByTagName( "source" );

        for ( i = 0, len = sources.length; i < len; i++ ) {
                source = sources[ i ];
                source[ pf.ns ] = true;
                srcset = source.getAttribute( "srcset" );

                // if source does not have a srcset attribute, skip
                if ( srcset ) {
                        candidates.push( {
                                srcset: srcset,
                                media: source.getAttribute( "media" ),
                                type: source.getAttribute( "type" ),
                                sizes: source.getAttribute( "sizes" )
                        } );
                }
        }
}

/**
 * Srcset Parser
 * By Alex Bell |  MIT License
 *
 * @returns Array [{url: _, d: _, w: _, h:_, set:_(????)}, ...]
 *
 * Based super duper closely on the reference algorithm at:
 * https://html.spec.whatwg.org/multipage/embedded-content.html#parse-a-srcset-attribute
 */

// 1. Let input be the value passed to this algorithm.
// (TO-DO : Explain what "set" argument is here. Maybe choose a more
// descriptive & more searchable name.  Since passing the "set" in really has
// nothing to do with parsing proper, I would prefer this assignment eventually
// go in an external fn.)
function parseSrcset(input, set) {

        function collectCharacters(regEx) {
                var chars,
                    match = regEx.exec(input.substring(pos));
                if (match) {
                        chars = match[ 0 ];
                        pos += chars.length;
                        return chars;
                }
        }

        var inputLength = input.length,
            url,
            descriptors,
            currentDescriptor,
            state,
            c,

            // 2. Let position be a pointer into input, initially pointing at the start
            //    of the string.
            pos = 0,

            // 3. Let candidates be an initially empty source set.
            candidates = [];

        /**
        * Adds descriptor properties to a candidate, pushes to the candidates array
        * @return undefined
        */
        // (Declared outside of the while loop so that it's only created once.
        // (This fn is defined before it is used, in order to pass JSHINT.
        // Unfortunately this breaks the sequencing of the spec comments. :/ )
        function parseDescriptors() {

                // 9. Descriptor parser: Let error be no.
                var pError = false,

                // 10. Let width be absent.
                // 11. Let density be absent.
                // 12. Let future-compat-h be absent. (We're implementing it now as h)
                    w, d, h, i,
                    candidate = {},
                    desc, lastChar, value, intVal, floatVal;

                // 13. For each descriptor in descriptors, run the appropriate set of steps
                // from the following list:
                for (i = 0 ; i < descriptors.length; i++) {
                        desc = descriptors[ i ];

                        lastChar = desc[ desc.length - 1 ];
                        value = desc.substring(0, desc.length - 1);
                        intVal = parseInt(value, 10);
                        floatVal = parseFloat(value);

                        // If the descriptor consists of a valid non-negative integer followed by
                        // a U+0077 LATIN SMALL LETTER W character
                        if (regexNonNegativeInteger.test(value) && (lastChar === "w")) {

                                // If width and density are not both absent, then let error be yes.
                                if (w || d) {pError = true;}

                                // Apply the rules for parsing non-negative integers to the descriptor.
                                // If the result is zero, let error be yes.
                                // Otherwise, let width be the result.
                                if (intVal === 0) {pError = true;} else {w = intVal;}

                        // If the descriptor consists of a valid floating-point number followed by
                        // a U+0078 LATIN SMALL LETTER X character
                        } else if (regexFloatingPoint.test(value) && (lastChar === "x")) {

                                // If width, density and future-compat-h are not all absent, then let error
                                // be yes.
                                if (w || d || h) {pError = true;}

                                // Apply the rules for parsing floating-point number values to the descriptor.
                                // If the result is less than zero, let error be yes. Otherwise, let density
                                // be the result.
                                if (floatVal < 0) {pError = true;} else {d = floatVal;}

                        // If the descriptor consists of a valid non-negative integer followed by
                        // a U+0068 LATIN SMALL LETTER H character
                        } else if (regexNonNegativeInteger.test(value) && (lastChar === "h")) {

                                // If height and density are not both absent, then let error be yes.
                                if (h || d) {pError = true;}

                                // Apply the rules for parsing non-negative integers to the descriptor.
                                // If the result is zero, let error be yes. Otherwise, let future-compat-h
                                // be the result.
                                if (intVal === 0) {pError = true;} else {h = intVal;}

                        // Anything else, Let error be yes.
                        } else {pError = true;}
                } // (close step 13 for loop)

                // 15. If error is still no, then append a new image source to candidates whose
                // URL is url, associated with a width width if not absent and a pixel
                // density density if not absent. Otherwise, there is a parse error.
                if (!pError) {
                        candidate.url = url;

                        if (w) { candidate.w = w;}
                        if (d) { candidate.d = d;}
                        if (h) { candidate.h = h;}
                        if (!h && !d && !w) {candidate.d = 1;}
                        if (candidate.d === 1) {set.has1x = true;}
                        candidate.set = set;

                        candidates.push(candidate);
                }
        } // (close parseDescriptors fn)

        /**
        * Tokenizes descriptor properties prior to parsing
        * Returns undefined.
        * (Again, this fn is defined before it is used, in order to pass JSHINT.
        * Unfortunately this breaks the logical sequencing of the spec comments. :/ )
        */
        function tokenize() {

                // 8.1. Descriptor tokeniser: Skip whitespace
                collectCharacters(regexLeadingSpaces);

                // 8.2. Let current descriptor be the empty string.
                currentDescriptor = "";

                // 8.3. Let state be in descriptor.
                state = "in descriptor";

                while (true) {

                        // 8.4. Let c be the character at position.
                        c = input.charAt(pos);

                        //  Do the following depending on the value of state.
                        //  For the purpose of this step, "EOF" is a special character representing
                        //  that position is past the end of input.

                        // In descriptor
                        if (state === "in descriptor") {
                                // Do the following, depending on the value of c:

                          // Space character
                          // If current descriptor is not empty, append current descriptor to
                          // descriptors and let current descriptor be the empty string.
                          // Set state to after descriptor.
                                if (isSpace(c)) {
                                        if (currentDescriptor) {
                                                descriptors.push(currentDescriptor);
                                                currentDescriptor = "";
                                                state = "after descriptor";
                                        }

                                // U+002C COMMA (,)
                                // Advance position to the next character in input. If current descriptor
                                // is not empty, append current descriptor to descriptors. Jump to the step
                                // labeled descriptor parser.
                                } else if (c === ",") {
                                        pos += 1;
                                        if (currentDescriptor) {
                                                descriptors.push(currentDescriptor);
                                        }
                                        parseDescriptors();
                                        return;

                                // U+0028 LEFT PARENTHESIS (()
                                // Append c to current descriptor. Set state to in parens.
                                } else if (c === "\u0028") {
                                        currentDescriptor = currentDescriptor + c;
                                        state = "in parens";

                                // EOF
                                // If current descriptor is not empty, append current descriptor to
                                // descriptors. Jump to the step labeled descriptor parser.
                                } else if (c === "") {
                                        if (currentDescriptor) {
                                                descriptors.push(currentDescriptor);
                                        }
                                        parseDescriptors();
                                        return;

                                // Anything else
                                // Append c to current descriptor.
                                } else {
                                        currentDescriptor = currentDescriptor + c;
                                }
                        // (end "in descriptor"

                        // In parens
                        } else if (state === "in parens") {

                                // U+0029 RIGHT PARENTHESIS ())
                                // Append c to current descriptor. Set state to in descriptor.
                                if (c === ")") {
                                        currentDescriptor = currentDescriptor + c;
                                        state = "in descriptor";

                                // EOF
                                // Append current descriptor to descriptors. Jump to the step labeled
                                // descriptor parser.
                                } else if (c === "") {
                                        descriptors.push(currentDescriptor);
                                        parseDescriptors();
                                        return;

                                // Anything else
                                // Append c to current descriptor.
                                } else {
                                        currentDescriptor = currentDescriptor + c;
                                }

                        // After descriptor
                        } else if (state === "after descriptor") {

                                // Do the following, depending on the value of c:
                                // Space character: Stay in this state.
                                if (isSpace(c)) {

                                // EOF: Jump to the step labeled descriptor parser.
                                } else if (c === "") {
                                        parseDescriptors();
                                        return;

                                // Anything else
                                // Set state to in descriptor. Set position to the previous character in input.
                                } else {
                                        state = "in descriptor";
                                        pos -= 1;

                                }
                        }

                        // Advance position to the next character in input.
                        pos += 1;

                // Repeat this step.
                } // (close while true loop)
        }

        // 4. Splitting loop: Collect a sequence of characters that are space
        //    characters or U+002C COMMA characters. If any U+002C COMMA characters
        //    were collected, that is a parse error.
        while (true) {
                collectCharacters(regexLeadingCommasOrSpaces);

                // 5. If position is past the end of input, return candidates and abort these steps.
                if (pos >= inputLength) {
                        return candidates; // (we're done, this is the sole return path)
                }

                // 6. Collect a sequence of characters that are not space characters,
                //    and let that be url.
                url = collectCharacters(regexLeadingNotSpaces);

                // 7. Let descriptors be a new empty list.
                descriptors = [];

                // 8. If url ends with a U+002C COMMA character (,), follow these substeps:
                //              (1). Remove all trailing U+002C COMMA characters from url. If this removed
                //         more than one character, that is a parse error.
                if (url.slice(-1) === ",") {
                        url = url.replace(regexTrailingCommas, "");
                        // (Jump ahead to step 9 to skip tokenization and just push the candidate).
                        parseDescriptors();

                //      Otherwise, follow these substeps:
                } else {
                        tokenize();
                } // (close else of step 8)

        // 16. Return to the step labeled splitting loop.
        } // (Close of big while loop.)
}

/*
 * Sizes Parser
 *
 * By Alex Bell |  MIT License
 *
 * Non-strict but accurate and lightweight JS Parser for the string value <img sizes="here">
 *
 * Reference algorithm at:
 * https://html.spec.whatwg.org/multipage/embedded-content.html#parse-a-sizes-attribute
 *
 * Most comments are copied in directly from the spec
 * (except for comments in parens).
 *
 * Grammar is:
 * <source-size-list> = <source-size># [ , <source-size-value> ]? | <source-size-value>
 * <source-size> = <media-condition> <source-size-value>
 * <source-size-value> = <length>
 * http://www.w3.org/html/wg/drafts/html/master/embedded-content.html#attr-img-sizes
 *
 * E.g. "(max-width: 30em) 100vw, (max-width: 50em) 70vw, 100vw"
 * or "(min-width: 30em), calc(30vw - 15px)" or just "30vw"
 *
 * Returns the first valid <css-length> with a media condition that evaluates to true,
 * or "100vw" if all valid media conditions evaluate to false.
 *
 */

function parseSizes(strValue) {

        // (Percentage CSS lengths are not allowed in this case, to avoid confusion:
        // https://html.spec.whatwg.org/multipage/embedded-content.html#valid-source-size-list
        // CSS allows a single optional plus or minus sign:
        // http://www.w3.org/TR/CSS2/syndata.html#numbers
        // CSS is ASCII case-insensitive:
        // http://www.w3.org/TR/CSS2/syndata.html#characters )
        // Spec allows exponential notation for <number> type:
        // http://dev.w3.org/csswg/css-values/#numbers
        var regexCssLengthWithUnits = /^(?:[+-]?[0-9]+|[0-9]*\.[0-9]+)(?:[eE][+-]?[0-9]+)?(?:ch|cm|em|ex|in|mm|pc|pt|px|rem|vh|vmin|vmax|vw)$/i;

        // (This is a quick and lenient test. Because of optional unlimited-depth internal
        // grouping parens and strict spacing rules, this could get very complicated.)
        var regexCssCalc = /^calc\((?:[0-9a-z \.\+\-\*\/\(\)]+)\)$/i;

        var i;
        var unparsedSizesList;
        var unparsedSizesListLength;
        var unparsedSize;
        var lastComponentValue;
        var size;

        // UTILITY FUNCTIONS

        //  (Toy CSS parser. The goals here are:
        //  1) expansive test coverage without the weight of a full CSS parser.
        //  2) Avoiding regex wherever convenient.
        //  Quick tests: http://jsfiddle.net/gtntL4gr/3/
        //  Returns an array of arrays.)
        function parseComponentValues(str) {
                var chrctr;
                var component = "";
                var componentArray = [];
                var listArray = [];
                var parenDepth = 0;
                var pos = 0;
                var inComment = false;

                function pushComponent() {
                        if (component) {
                                componentArray.push(component);
                                component = "";
                        }
                }

                function pushComponentArray() {
                        if (componentArray[0]) {
                                listArray.push(componentArray);
                                componentArray = [];
                        }
                }

                // (Loop forwards from the beginning of the string.)
                while (true) {
                        chrctr = str.charAt(pos);

                        if (chrctr === "") { // ( End of string reached.)
                                pushComponent();
                                pushComponentArray();
                                return listArray;
                        } else if (inComment) {
                                if ((chrctr === "*") && (str[pos + 1] === "/")) { // (At end of a comment.)
                                        inComment = false;
                                        pos += 2;
                                        pushComponent();
                                        continue;
                                } else {
                                        pos += 1; // (Skip all characters inside comments.)
                                        continue;
                                }
                        } else if (isSpace(chrctr)) {
                                // (If previous character in loop was also a space, or if
                                // at the beginning of the string, do not add space char to
                                // component.)
                                if ( (str.charAt(pos - 1) && isSpace( str.charAt(pos - 1) ) ) || !component ) {
                                        pos += 1;
                                        continue;
                                } else if (parenDepth === 0) {
                                        pushComponent();
                                        pos +=1;
                                        continue;
                                } else {
                                        // (Replace any space character with a plain space for legibility.)
                                        chrctr = " ";
                                }
                        } else if (chrctr === "(") {
                                parenDepth += 1;
                        } else if (chrctr === ")") {
                                parenDepth -= 1;
                        } else if (chrctr === ",") {
                                pushComponent();
                                pushComponentArray();
                                pos += 1;
                                continue;
                        } else if ( (chrctr === "/") && (str.charAt(pos + 1) === "*") ) {
                                inComment = true;
                                pos += 2;
                                continue;
                        }

                        component = component + chrctr;
                        pos += 1;
                }
        }

        function isValidNonNegativeSourceSizeValue(s) {
                if (regexCssLengthWithUnits.test(s) && (parseFloat(s) >= 0)) {return true;}
                if (regexCssCalc.test(s)) {return true;}
                // ( http://www.w3.org/TR/CSS2/syndata.html#numbers says:
                // "-0 is equivalent to 0 and is not a negative number." which means that
                // unitless zero and unitless negative zero must be accepted as special cases.)
                if ((s === "0") || (s === "-0") || (s === "+0")) {return true;}
                return false;
        }

        // When asked to parse a sizes attribute from an element, parse a
        // comma-separated list of component values from the value of the element's
        // sizes attribute (or the empty string, if the attribute is absent), and let
        // unparsed sizes list be the result.
        // http://dev.w3.org/csswg/css-syntax/#parse-comma-separated-list-of-component-values

        unparsedSizesList = parseComponentValues(strValue);
        unparsedSizesListLength = unparsedSizesList.length;

        // For each unparsed size in unparsed sizes list:
        for (i = 0; i < unparsedSizesListLength; i++) {
                unparsedSize = unparsedSizesList[i];

                // 1. Remove all consecutive <whitespace-token>s from the end of unparsed size.
                // ( parseComponentValues() already omits spaces outside of parens. )

                // If unparsed size is now empty, that is a parse error; continue to the next
                // iteration of this algorithm.
                // ( parseComponentValues() won't push an empty array. )

                // 2. If the last component value in unparsed size is a valid non-negative
                // <source-size-value>, let size be its value and remove the component value
                // from unparsed size. Any CSS function other than the calc() function is
                // invalid. Otherwise, there is a parse error; continue to the next iteration
                // of this algorithm.
                // http://dev.w3.org/csswg/css-syntax/#parse-component-value
                lastComponentValue = unparsedSize[unparsedSize.length - 1];

                if (isValidNonNegativeSourceSizeValue(lastComponentValue)) {
                        size = lastComponentValue;
                        unparsedSize.pop();
                } else {
                        continue;
                }

                // 3. Remove all consecutive <whitespace-token>s from the end of unparsed
                // size. If unparsed size is now empty, return size and exit this algorithm.
                // If this was not the last item in unparsed sizes list, that is a parse error.
                if (unparsedSize.length === 0) {
                        return size;
                }

                // 4. Parse the remaining component values in unparsed size as a
                // <media-condition>. If it does not parse correctly, or it does parse
                // correctly but the <media-condition> evaluates to false, continue to the
                // next iteration of this algorithm.
                // (Parsing all possible compound media conditions in JS is heavy, complicated,
                // and the payoff is unclear. Is there ever an situation where the
                // media condition parses incorrectly but still somehow evaluates to true?
                // Can we just rely on the browser/polyfill to do it?)
                unparsedSize = unparsedSize.join(" ");
                if (!(pf.matchesMedia( unparsedSize ) ) ) {
                        continue;
                }

                // 5. Return size and exit this algorithm.
                return size;
        }

        // If the above algorithm exhausts unparsed sizes list without returning a
        // size value, return 100vw.
        return "100vw";
}

// namespace
pf.ns = ("pf" + new Date().getTime()).substr(0, 9);

// srcset support test
pf.supSrcset = "srcset" in image;
pf.supSizes = "sizes" in image;
pf.supPicture = !!window.HTMLPictureElement;

// UC browser does claim to support srcset and picture, but not sizes,
// this extended test reveals the browser does support nothing
if (pf.supSrcset && pf.supPicture && !pf.supSizes) {
        (function(image2) {
                image.srcset = "data:,a";
                image2.src = "data:,a";
                pf.supSrcset = image.complete === image2.complete;
                pf.supPicture = pf.supSrcset && pf.supPicture;
        })(document.createElement("img"));
}

// Safari9 has basic support for sizes, but does't expose the `sizes` idl attribute
if (pf.supSrcset && !pf.supSizes) {

        (function() {
                var width2 = "data:image/gif;base64,R0lGODlhAgABAPAAAP///wAAACH5BAAAAAAALAAAAAACAAEAAAICBAoAOw==";
                var width1 = "data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==";
                var img = document.createElement("img");
                var test = function() {
                        var width = img.width;

                        if (width === 2) {
                                pf.supSizes = true;
                        }

                        alwaysCheckWDescriptor = pf.supSrcset && !pf.supSizes;

                        isSupportTestReady = true;
                        // force async
                        setTimeout(picturefill);
                };

                img.onload = test;
                img.onerror = test;
                img.setAttribute("sizes", "9px");

                img.srcset = width1 + " 1w," + width2 + " 9w";
                img.src = width1;
        })();

} else {
        isSupportTestReady = true;
}

// using pf.qsa instead of dom traversing does scale much better,
// especially on sites mixing responsive and non-responsive images
pf.selShort = "picture>img,img[srcset]";
pf.sel = pf.selShort;
pf.cfg = cfg;

/**
 * Shortcut property for `devicePixelRatio` ( for easy overriding in tests )
 */
pf.DPR = (DPR  || 1 );
pf.u = units;

// container of supported mime types that one might need to qualify before using
pf.types =  types;

pf.setSize = noop;

/**
 * Gets a string and returns the absolute URL
 * @param src
 * @returns {String} absolute URL
 */

pf.makeUrl = memoize(function(src) {
        anchor.href = src;
        return anchor.href;
});

/**
 * Gets a DOM element or document and a selctor and returns the found matches
 * Can be extended with jQuery/Sizzle for IE7 support
 * @param context
 * @param sel
 * @returns {NodeList|Array}
 */
pf.qsa = function(context, sel) {
        return ( "querySelector" in context ) ? context.querySelectorAll(sel) : [];
};

/**
 * Shortcut method for matchMedia ( for easy overriding in tests )
 * wether native or pf.mMQ is used will be decided lazy on first call
 * @returns {boolean}
 */
pf.matchesMedia = function() {
        if ( window.matchMedia && (matchMedia( "(min-width: 0.1em)" ) || {}).matches ) {
                pf.matchesMedia = function( media ) {
                        return !media || ( matchMedia( media ).matches );
                };
        } else {
                pf.matchesMedia = pf.mMQ;
        }

        return pf.matchesMedia.apply( this, arguments );
};

/**
 * A simplified matchMedia implementation for IE8 and IE9
 * handles only min-width/max-width with px or em values
 * @param media
 * @returns {boolean}
 */
pf.mMQ = function( media ) {
        return media ? evalCSS(media) : true;
};

/**
 * Returns the calculated length in css pixel from the given sourceSizeValue
 * http://dev.w3.org/csswg/css-values-3/#length-value
 * intended Spec mismatches:
 * * Does not check for invalid use of CSS functions
 * * Does handle a computed length of 0 the same as a negative and therefore invalid value
 * @param sourceSizeValue
 * @returns {Number}
 */
pf.calcLength = function( sourceSizeValue ) {

        var value = evalCSS(sourceSizeValue, true) || false;
        if (value < 0) {
                value = false;
        }

        return value;
};

/**
 * Takes a type string and checks if its supported
 */

pf.supportsType = function( type ) {
        return ( type ) ? types[ type ] : true;
};

/**
 * Parses a sourceSize into mediaCondition (media) and sourceSizeValue (length)
 * @param sourceSizeStr
 * @returns {*}
 */
pf.parseSize = memoize(function( sourceSizeStr ) {
        var match = ( sourceSizeStr || "" ).match(regSize);
        return {
                media: match && match[1],
                length: match && match[2]
        };
});

pf.parseSet = function( set ) {
        if ( !set.cands ) {
                set.cands = parseSrcset(set.srcset, set);
        }
        return set.cands;
};

/**
 * returns 1em in css px for html/body default size
 * function taken from respondjs
 * @returns {*|number}
 */
pf.getEmValue = function() {
        var body;
        if ( !eminpx && (body = document.body) ) {
                var div = document.createElement( "div" ),
                        originalHTMLCSS = docElem.style.cssText,
                        originalBodyCSS = body.style.cssText;

                div.style.cssText = baseStyle;

                // 1em in a media query is the value of the default font size of the browser
                // reset docElem and body to ensure the correct value is returned
                docElem.style.cssText = fsCss;
                body.style.cssText = fsCss;

                body.appendChild( div );
                eminpx = div.offsetWidth;
                body.removeChild( div );

                //also update eminpx before returning
                eminpx = parseFloat( eminpx, 10 );

                // restore the original values
                docElem.style.cssText = originalHTMLCSS;
                body.style.cssText = originalBodyCSS;

        }
        return eminpx || 16;
};

/**
 * Takes a string of sizes and returns the width in pixels as a number
 */
pf.calcListLength = function( sourceSizeListStr ) {
        // Split up source size list, ie ( max-width: 30em ) 100%, ( max-width: 50em ) 50%, 33%
        //
        //                           or (min-width:30em) calc(30% - 15px)
        if ( !(sourceSizeListStr in sizeLengthCache) || cfg.uT ) {
                var winningLength = pf.calcLength( parseSizes( sourceSizeListStr ) );

                sizeLengthCache[ sourceSizeListStr ] = !winningLength ? units.width : winningLength;
        }

        return sizeLengthCache[ sourceSizeListStr ];
};

/**
 * Takes a candidate object with a srcset property in the form of url/
 * ex. "images/pic-medium.png 1x, images/pic-medium-2x.png 2x" or
 *     "images/pic-medium.png 400w, images/pic-medium-2x.png 800w" or
 *     "images/pic-small.png"
 * Get an array of image candidates in the form of
 *      {url: "/foo/bar.png", resolution: 1}
 * where resolution is http://dev.w3.org/csswg/css-values-3/#resolution-value
 * If sizes is specified, res is calculated
 */
pf.setRes = function( set ) {
        var candidates;
        if ( set ) {

                candidates = pf.parseSet( set );

                for ( var i = 0, len = candidates.length; i < len; i++ ) {
                        setResolution( candidates[ i ], set.sizes );
                }
        }
        return candidates;
};

pf.setRes.res = setResolution;

pf.applySetCandidate = function( candidates, img ) {
        if ( !candidates.length ) {return;}
        var candidate,
                i,
                j,
                length,
                bestCandidate,
                curSrc,
                curCan,
                candidateSrc,
                abortCurSrc;

        var imageData = img[ pf.ns ];
        var dpr = pf.DPR;

        curSrc = imageData.curSrc || img[curSrcProp];

        curCan = imageData.curCan || setSrcToCur(img, curSrc, candidates[0].set);

        // if we have a current source, we might either become lazy or give this source some advantage
        if ( curCan && curCan.set === candidates[ 0 ].set ) {

                // if browser can abort image request and the image has a higher pixel density than needed
                // and this image isn't downloaded yet, we skip next part and try to save bandwidth
                abortCurSrc = (supportAbort && !img.complete && curCan.res - 0.1 > dpr);

                if ( !abortCurSrc ) {
                        curCan.cached = true;

                        // if current candidate is "best", "better" or "okay",
                        // set it to bestCandidate
                        if ( curCan.res >= dpr ) {
                                bestCandidate = curCan;
                        }
                }
        }

        if ( !bestCandidate ) {

                candidates.sort( ascendingSort );

                length = candidates.length;
                bestCandidate = candidates[ length - 1 ];

                for ( i = 0; i < length; i++ ) {
                        candidate = candidates[ i ];
                        if ( candidate.res >= dpr ) {
                                j = i - 1;

                                // we have found the perfect candidate,
                                // but let's improve this a little bit with some assumptions ;-)
                                if (candidates[ j ] &&
                                        (abortCurSrc || curSrc !== pf.makeUrl( candidate.url )) &&
                                        chooseLowRes(candidates[ j ].res, candidate.res, dpr, candidates[ j ].cached)) {

                                        bestCandidate = candidates[ j ];

                                } else {
                                        bestCandidate = candidate;
                                }
                                break;
                        }
                }
        }

        if ( bestCandidate ) {

                candidateSrc = pf.makeUrl( bestCandidate.url );

                imageData.curSrc = candidateSrc;
                imageData.curCan = bestCandidate;

                if ( candidateSrc !== curSrc ) {
                        pf.setSrc( img, bestCandidate );
                }
                pf.setSize( img );
        }
};

pf.setSrc = function( img, bestCandidate ) {
        var origWidth;
        img.src = bestCandidate.url;

        // although this is a specific Safari issue, we don't want to take too much different code paths
        if ( bestCandidate.set.type === "image/svg+xml" ) {
                origWidth = img.style.width;
                img.style.width = (img.offsetWidth + 1) + "px";

                // next line only should trigger a repaint
                // if... is only done to trick dead code removal
                if ( img.offsetWidth + 1 ) {
                        img.style.width = origWidth;
                }
        }
};

pf.getSet = function( img ) {
        var i, set, supportsType;
        var match = false;
        var sets = img [ pf.ns ].sets;

        for ( i = 0; i < sets.length && !match; i++ ) {
                set = sets[i];

                if ( !set.srcset || !pf.matchesMedia( set.media ) || !(supportsType = pf.supportsType( set.type )) ) {
                        continue;
                }

                if ( supportsType === "pending" ) {
                        set = supportsType;
                }

                match = set;
                break;
        }

        return match;
};

pf.parseSets = function( element, parent, options ) {
        var srcsetAttribute, imageSet, isWDescripor, srcsetParsed;

        var hasPicture = parent && parent.nodeName.toUpperCase() === "PICTURE";
        var imageData = element[ pf.ns ];

        if ( imageData.src === undefined || options.src ) {
                imageData.src = getImgAttr.call( element, "src" );
                if ( imageData.src ) {
                        setImgAttr.call( element, srcAttr, imageData.src );
                } else {
                        removeImgAttr.call( element, srcAttr );
                }
        }

        if ( imageData.srcset === undefined || options.srcset || !pf.supSrcset || element.srcset ) {
                srcsetAttribute = getImgAttr.call( element, "srcset" );
                imageData.srcset = srcsetAttribute;
                srcsetParsed = true;
        }

        imageData.sets = [];

        if ( hasPicture ) {
                imageData.pic = true;
                getAllSourceElements( parent, imageData.sets );
        }

        if ( imageData.srcset ) {
                imageSet = {
                        srcset: imageData.srcset,
                        sizes: getImgAttr.call( element, "sizes" )
                };

                imageData.sets.push( imageSet );

                isWDescripor = (alwaysCheckWDescriptor || imageData.src) && regWDesc.test(imageData.srcset || "");

                // add normal src as candidate, if source has no w descriptor
                if ( !isWDescripor && imageData.src && !getCandidateForSrc(imageData.src, imageSet) && !imageSet.has1x ) {
                        imageSet.srcset += ", " + imageData.src;
                        imageSet.cands.push({
                                url: imageData.src,
                                d: 1,
                                set: imageSet
                        });
                }

        } else if ( imageData.src ) {
                imageData.sets.push( {
                        srcset: imageData.src,
                        sizes: null
                } );
        }

        imageData.curCan = null;
        imageData.curSrc = undefined;

        // if img has picture or the srcset was removed or has a srcset and does not support srcset at all
        // or has a w descriptor (and does not support sizes) set support to false to evaluate
        imageData.supported = !( hasPicture || ( imageSet && !pf.supSrcset ) || (isWDescripor && !pf.supSizes) );

        if ( srcsetParsed && pf.supSrcset && !imageData.supported ) {
                if ( srcsetAttribute ) {
                        setImgAttr.call( element, srcsetAttr, srcsetAttribute );
                        element.srcset = "";
                } else {
                        removeImgAttr.call( element, srcsetAttr );
                }
        }

        if (imageData.supported && !imageData.srcset && ((!imageData.src && element.src) ||  element.src !== pf.makeUrl(imageData.src))) {
                if (imageData.src === null) {
                        element.removeAttribute("src");
                } else {
                        element.src = imageData.src;
                }
        }

        imageData.parsed = true;
};

pf.fillImg = function(element, options) {
        var imageData;
        var extreme = options.reselect || options.reevaluate;

        // expando for caching data on the img
        if ( !element[ pf.ns ] ) {
                element[ pf.ns ] = {};
        }

        imageData = element[ pf.ns ];

        // if the element has already been evaluated, skip it
        // unless `options.reevaluate` is set to true ( this, for example,
        // is set to true when running `picturefill` on `resize` ).
        if ( !extreme && imageData.evaled === evalId ) {
                return;
        }

        if ( !imageData.parsed || options.reevaluate ) {
                pf.parseSets( element, element.parentNode, options );
        }

        if ( !imageData.supported ) {
                applyBestCandidate( element );
        } else {
                imageData.evaled = evalId;
        }
};

pf.setupRun = function() {
        if ( !alreadyRun || isVwDirty || (DPR !== window.devicePixelRatio) ) {
                updateMetrics();
        }
};

// If picture is supported, well, that's awesome.
if ( pf.supPicture ) {
        picturefill = noop;
        pf.fillImg = noop;
} else {

         // Set up picture polyfill by polling the document
        (function() {
                var isDomReady;
                var regReady = window.attachEvent ? /d$|^c/ : /d$|^c|^i/;

                var run = function() {
                        var readyState = document.readyState || "";

                        timerId = setTimeout(run, readyState === "loading" ? 200 :  999);
                        if ( document.body ) {
                                pf.fillImgs();
                                isDomReady = isDomReady || regReady.test(readyState);
                                if ( isDomReady ) {
                                        clearTimeout( timerId );
                                }

                        }
                };

                var timerId = setTimeout(run, document.body ? 9 : 99);

                // Also attach picturefill on resize and readystatechange
                // http://modernjavascript.blogspot.com/2013/08/building-better-debounce.html
                var debounce = function(func, wait) {
                        var timeout, timestamp;
                        var later = function() {
                                var last = (new Date()) - timestamp;

                                if (last < wait) {
                                        timeout = setTimeout(later, wait - last);
                                } else {
                                        timeout = null;
                                        func();
                                }
                        };

                        return function() {
                                timestamp = new Date();

                                if (!timeout) {
                                        timeout = setTimeout(later, wait);
                                }
                        };
                };
                var lastClientWidth = docElem.clientHeight;
                var onResize = function() {
                        isVwDirty = Math.max(window.innerWidth || 0, docElem.clientWidth) !== units.width || docElem.clientHeight !== lastClientWidth;
                        lastClientWidth = docElem.clientHeight;
                        if ( isVwDirty ) {
                                pf.fillImgs();
                        }
                };

                on( window, "resize", debounce(onResize, 99 ) );
                on( document, "readystatechange", run );
        })();
}

pf.picturefill = picturefill;
//use this internally for easy monkey patching/performance testing
pf.fillImgs = picturefill;
pf.teardownRun = noop;

/* expose methods for testing */
picturefill._ = pf;

window.picturefillCFG = {
        pf: pf,
        push: function(args) {
                var name = args.shift();
                if (typeof pf[name] === "function") {
                        pf[name].apply(pf, args);
                } else {
                        cfg[name] = args[0];
                        if (alreadyRun) {
                                pf.fillImgs( { reselect: true } );
                        }
                }
        }
};

while (setOptions && setOptions.length) {
        window.picturefillCFG.push(setOptions.shift());
}

/* expose picturefill */
window.picturefill = picturefill;

/* expose picturefill */
if ( typeof module === "object" && typeof module.exports === "object" ) {
        // CommonJS, just export
        module.exports = picturefill;
} else if ( typeof define === "function" && define.amd ) {
        // AMD support
        define( "picturefill", function() { return picturefill; } );
}

// IE8 evals this sync, so it must be the last thing we do
if ( !pf.supPicture ) {
        types[ "image/webp" ] = detectTypeSupport("image/webp", "data:image/webp;base64,UklGRkoAAABXRUJQVlA4WAoAAAAQAAAAAAAAAAAAQUxQSAwAAAABBxAR/Q9ERP8DAABWUDggGAAAADABAJ0BKgEAAQADADQlpAADcAD++/1QAA==" );
}

} )( window, document );