VanillaQR.module.js

//https://github.com/chuckfairy/VanillaQR.js
//VanillaQR Function constructor
//pass an object with customizable options
//url, colorLight, colorDark, width, height
function VanillaQR ( customize ) {

    var scope = this;

    customize = typeof(customize) === "object" ? customize : {};

    /********************PUBLICS********************/

    scope.revision = 3;

    //canvas output types
    scope.imageTypes = {
        "bmp"    : "image/bmp",
        "gif"    : "image/gif",
        "jpeg"   : "image/jpeg",
        "jpg"    : "image/jpg",
        "png"    : "image/png",
        "svg+xml": "image/svg+xml",
        "tiff"   : "image/tiff",
        "webp"   : "image/webp",
        "x-icon" : "image/x-icon"
    };

    //toTable use will default if no canvas support
    scope.toTable = customize.toTable;

    //qr active domElement
    scope.domElement = (scope.toTable) ?
        document.createElement("div"):
        document.createElement("canvas");

    //QR url
    scope.url = customize.url || "";

    //Canvas and qr width and height
    scope.size  = (customize.size  || 280);

    //QR context
    scope.qrc = false;

    //QR colors
    scope.colorLight = customize.colorLight || '#fff';
    scope.colorDark = customize.colorDark || "#000";

    //Correction level
    scope.ecclevel = customize.ecclevel || 1;

    //Border related
    scope.noBorder = customize.noBorder;
    scope.borderSize = customize.borderSize || 4;


    /********************PRIVATES********************/

	// Set data values
	// Working buffers:
	var strinbuf = [];
	var eccbuf   = [];
	var qrframe  = [];
	var framask  = [];
	var rlens    = [];
	var genpoly  = [];

	// Control values - width is based on version, last 4 are from table.
	var ecclevel;
	var version;
	var width;
	var neccblk1;
	var neccblk2;
	var datablkw;
	var eccblkwid;


    /********************QR Creator API********************/

    // set bit to indicate cell in qrframe is immutable
    var setmask = function ( x, y ) {

        var bt;
        if (x > y) {
            bt = x;
            x = y;
            y = bt;
        }
        // y*y = 1+3+5...
        bt = y;
        bt *= y;
        bt += y;
        bt >>= 1;
        bt += x;
        framask[bt] = 1;

    };

    //black to qrframe, white to mask (later black frame merged to mask)
    var putalign = function ( x, y ) {

        var j;

        qrframe[x + width * y] = 1;
        for (j = -2; j < 2; j++) {
            qrframe[(x + j) + width * (y - 2)] = 1;
            qrframe[(x - 2) + width * (y + j + 1)] = 1;
            qrframe[(x + 2) + width * (y + j)] = 1;
            qrframe[(x + j + 1) + width * (y + 2)] = 1;
        }
        for (j = 0; j < 2; j++) {
            setmask(x - 1, y + j);
            setmask(x + 1, y - j);
            setmask(x - j, y - 1);
            setmask(x + j, y + 1);
        }
    }

    //Bit shift modnn
    var modnn = function(x) {

        while (x >= 255) {
            x -= 255;
            x = (x >> 8) + (x & 255);
        }

        return x;

    };

    // Calculate and append ECC data to data block.  Block is in strinbuf, indexes to buffers given.
    var appendrs = function ( data, dlen, ecbuf, eclen ) {

        var i, j, fb;
        var gexp = VanillaQR.gexp;
        var glog = VanillaQR.glog;

        for (i = 0; i < eclen; i++)
            strinbuf[ecbuf + i] = 0;
        for (i = 0; i < dlen; i++) {
            fb = glog[strinbuf[data + i] ^ strinbuf[ecbuf]];
            if (fb != 255)     /* fb term is non-zero */
                for (j = 1; j < eclen; j++)
                    strinbuf[ecbuf + j - 1] = strinbuf[ecbuf + j] ^ gexp[modnn(fb + genpoly[eclen - j])];
            else
                for( j = ecbuf ; j < ecbuf + eclen; j++ )
                    strinbuf[j] = strinbuf[j + 1];
            strinbuf[ ecbuf + eclen - 1] = fb == 255 ? 0 : gexp[modnn(fb + genpoly[0])];
        }

    };

    // check mask - since symmetrical use half.
    var ismasked = function(x, y) {

        var bt;
        if (x > y) {
            bt = x;
            x = y;
            y = bt;
        }
        bt = y;
        bt += y * y;
        bt >>= 1;
        bt += x;
        return framask[bt];

    };

    //  Apply the selected mask out of the 8.
    var applymask = function(m) {

        var x, y, r3x, r3y;

        switch (m) {
        case 0:
            for (y = 0; y < width; y++)
                for (x = 0; x < width; x++)
                    if (!((x + y) & 1) && !ismasked(x, y))
                        qrframe[x + y * width] ^= 1;
            break;
        case 1:
            for (y = 0; y < width; y++)
                for (x = 0; x < width; x++)
                    if (!(y & 1) && !ismasked(x, y))
                        qrframe[x + y * width] ^= 1;
            break;
        case 2:
            for (y = 0; y < width; y++)
                for (r3x = 0, x = 0; x < width; x++, r3x++) {
                    if (r3x == 3)
                        r3x = 0;
                    if (!r3x && !ismasked(x, y))
                        qrframe[x + y * width] ^= 1;
                }
            break;
        case 3:
            for (r3y = 0, y = 0; y < width; y++, r3y++) {
                if (r3y == 3)
                    r3y = 0;
                for (r3x = r3y, x = 0; x < width; x++, r3x++) {
                    if (r3x == 3)
                        r3x = 0;
                    if (!r3x && !ismasked(x, y))
                        qrframe[x + y * width] ^= 1;
                }
            }
            break;
        case 4:
            for (y = 0; y < width; y++)
                for (r3x = 0, r3y = ((y >> 1) & 1), x = 0; x < width; x++, r3x++) {
                    if (r3x == 3) {
                        r3x = 0;
                        r3y = !r3y;
                    }
                    if (!r3y && !ismasked(x, y))
                        qrframe[x + y * width] ^= 1;
                }
            break;
        case 5:
            for (r3y = 0, y = 0; y < width; y++, r3y++) {
                if (r3y == 3)
                    r3y = 0;
                for (r3x = 0, x = 0; x < width; x++, r3x++) {
                    if (r3x == 3)
                        r3x = 0;
                    if (!((x & y & 1) + !(!r3x | !r3y)) && !ismasked(x, y))
                        qrframe[x + y * width] ^= 1;
                }
            }
            break;
        case 6:
            for (r3y = 0, y = 0; y < width; y++, r3y++) {
                if (r3y == 3)
                    r3y = 0;
                for (r3x = 0, x = 0; x < width; x++, r3x++) {
                    if (r3x == 3)
                        r3x = 0;
                    if (!(((x & y & 1) + (r3x && (r3x == r3y))) & 1) && !ismasked(x, y))
                        qrframe[x + y * width] ^= 1;
                }
            }
            break;
        case 7:
            for (r3y = 0, y = 0; y < width; y++, r3y++) {
                if (r3y == 3)
                    r3y = 0;
                for (r3x = 0, x = 0; x < width; x++, r3x++) {
                    if (r3x == 3)
                        r3x = 0;
                    if (!(((r3x && (r3x == r3y)) + ((x + y) & 1)) & 1) && !ismasked(x, y))
                        qrframe[x + y * width] ^= 1;
                }
            }
            break;
        }

    };

    // Using the table of the length of each run, calculate the amount of bad image
    // - long runs or those that look like finders; called twice, once each for X and Y
    var badruns = function(length) {

        var i;
        var runsbad = 0;
        for (i = 0; i <= length; i++)
            if (rlens[i] >= 5)
                runsbad += VanillaQR.N1 + rlens[i] - 5;
        // BwBBBwB as in finder
        for (i = 3; i < length - 1; i += 2)
            if (rlens[i - 2] == rlens[i + 2]
                && rlens[i + 2] == rlens[i - 1]
                && rlens[i - 1] == rlens[i + 1]
                && rlens[i - 1] * 3 == rlens[i]
                // white around the black pattern? Not part of spec
                && (rlens[i - 3] == 0 // beginning
                    || i + 3 > length  // end
                    || rlens[i - 3] * 3 >= rlens[i] * 4 || rlens[i + 3] * 3 >= rlens[i] * 4)
               )
                runsbad += VanillaQR.N3;
        return runsbad;

    };

    // Calculate how bad the masked image is - blocks, imbalance, runs, or finders.
    var badcheck = function() {

        var x, y, h, b, b1;
        var thisbad = 0;
        var bw = 0;

        // blocks of same color.
        for (y = 0; y < width - 1; y++) {
            for (x = 0; x < width - 1; x++) {
                if ((qrframe[x + width * y] && qrframe[(x + 1) + width * y]
                     && qrframe[x + width * (y + 1)] && qrframe[(x + 1) + width * (y + 1)]) // all black
                    || !(qrframe[x + width * y] || qrframe[(x + 1) + width * y]
                         || qrframe[x + width * (y + 1)] || qrframe[(x + 1) + width * (y + 1)])) // all white
                    thisbad += VanillaQR.N2;
            }
        }

        // X runs
        for (y = 0; y < width; y++) {
            rlens[0] = 0;
            for (h = b = x = 0; x < width; x++) {
                if ((b1 = qrframe[x + width * y]) == b)
                    rlens[h]++;
                else
                    rlens[++h] = 1;
                b = b1;
                bw += b ? 1 : -1;
            }

            thisbad += badruns(h);

        }

        // black/white imbalance
        if (bw < 0)
            bw = -bw;

        var big = bw;
        var count = 0;
        big += big << 2;
        big <<= 1;
        while (big > width * width)
            big -= width * width, count++;
        thisbad += count * VanillaQR.N4;

        // Y runs
        for (x = 0; x < width; x++) {
            rlens[0] = 0;
            for (h = b = y = 0; y < width; y++) {
                if ((b1 = qrframe[x + width * y]) == b)
                    rlens[h]++;
                else
                    rlens[++h] = 1;
                b = b1;
            }
            thisbad += badruns(h);
        }

        return thisbad;

    };

    //Generate QR frame array
    scope.genframe = function(instring) {

        var eccblocks = VanillaQR.eccblocks;
        var gexp = VanillaQR.gexp;
        var glog = VanillaQR.glog;

        var x, y, k, t, v, i, j, m;

    // find the smallest version that fits the string
        t = instring.length;
        version = 0;
        do {
            version++;
            k = (ecclevel - 1) * 4 + (version - 1) * 16;
            neccblk1 = eccblocks[k++];
            neccblk2 = eccblocks[k++];
            datablkw = eccblocks[k++];
            eccblkwid = eccblocks[k];
            k = datablkw * (neccblk1 + neccblk2) + neccblk2 - 3 + (version <= 9);
            if (t <= k)
                break;
        } while (version < 40);

    // FIXME - insure that it fits insted of being truncated
        width = 17 + 4 * version;

    // allocate, clear and setup data structures
        v = datablkw + (datablkw + eccblkwid) * (neccblk1 + neccblk2) + neccblk2;
        for( t = 0; t < v; t++ )
            eccbuf[t] = 0;
        strinbuf = instring.slice(0);

        for( t = 0; t < width * width; t++ )
            qrframe[t] = 0;

        for( t = 0 ; t < (width * (width + 1) + 1) / 2; t++)
            framask[t] = 0;

    // insert finders - black to frame, white to mask

        for (t = 0; t < 3; t++) {
            k = 0;
            y = 0;
            if (t == 1)
                k = (width - 7);
            if (t == 2)
                y = (width - 7);
            qrframe[(y + 3) + width * (k + 3)] = 1;
            for (x = 0; x < 6; x++) {
                qrframe[(y + x) + width * k] = 1;
                qrframe[y + width * (k + x + 1)] = 1;
                qrframe[(y + 6) + width * (k + x)] = 1;
                qrframe[(y + x + 1) + width * (k + 6)] = 1;
            }
            for (x = 1; x < 5; x++) {
                setmask(y + x, k + 1);
                setmask(y + 1, k + x + 1);
                setmask(y + 5, k + x);
                setmask(y + x + 1, k + 5);
            }
            for (x = 2; x < 4; x++) {
                qrframe[(y + x) + width * (k + 2)] = 1;
                qrframe[(y + 2) + width * (k + x + 1)] = 1;
                qrframe[(y + 4) + width * (k + x)] = 1;
                qrframe[(y + x + 1) + width * (k + 4)] = 1;
            }
        }

    // alignment blocks
        if (version > 1) {

            t = VanillaQR.adelta[version];
            y = width - 7;
            for (;;) {
                x = width - 7;
                while (x > t - 3) {
                    putalign(x, y);
                    if (x < t)
                        break;
                    x -= t;
                }
                if (y <= t + 9)
                    break;
                y -= t;
                putalign(6, y);
                putalign(y, 6);
            }
        }

    // single black
        qrframe[8 + width * (width - 8)] = 1;

    // timing gap - mask only
        for (y = 0; y < 7; y++) {
            setmask(7, y);
            setmask(width - 8, y);
            setmask(7, y + width - 7);
        }
        for (x = 0; x < 8; x++) {
            setmask(x, 7);
            setmask(x + width - 8, 7);
            setmask(x, width - 8);
        }

    // reserve mask-format area
        for (x = 0; x < 9; x++)
            setmask(x, 8);
        for (x = 0; x < 8; x++) {
            setmask(x + width - 8, 8);
            setmask(8, x);
        }
        for (y = 0; y < 7; y++)
            setmask(8, y + width - 7);

    // timing row/col
        for (x = 0; x < width - 14; x++)
            if (x & 1) {
                setmask(8 + x, 6);
                setmask(6, 8 + x);
            }
            else {
                qrframe[(8 + x) + width * 6] = 1;
                qrframe[6 + width * (8 + x)] = 1;
            }

    // version block
        if (version > 6) {
            t = VanillaQR.vpat[version - 7];
            k = 17;
            for (x = 0; x < 6; x++)
                for (y = 0; y < 3; y++, k--)
                    if (1 & (k > 11 ? version >> (k - 12) : t >> k)) {
                        qrframe[(5 - x) + width * (2 - y + width - 11)] = 1;
                        qrframe[(2 - y + width - 11) + width * (5 - x)] = 1;
                    }
            else {
                setmask(5 - x, 2 - y + width - 11);
                setmask(2 - y + width - 11, 5 - x);
            }
        }

    // sync mask bits - only set above for white spaces, so add in black bits
        for (y = 0; y < width; y++)
            for (x = 0; x <= y; x++)
                if (qrframe[x + width * y])
                    setmask(x, y);

    // convert string to bitstream
    // 8 bit data to QR-coded 8 bit data (numeric or alphanum, or kanji not supported)
        v = strinbuf.length;

    // string to array
        for( i = 0 ; i < v; i++ )
            eccbuf[i] = strinbuf.charCodeAt(i);
        strinbuf = eccbuf.slice(0);

    // calculate max string length
        x = datablkw * (neccblk1 + neccblk2) + neccblk2;
        if (v >= x - 2) {
            v = x - 2;
            if (version > 9)
                v--;
        }

    // shift and repack to insert length prefix
        i = v;
        if (version > 9) {
            strinbuf[i + 2] = 0;
            strinbuf[i + 3] = 0;
            while (i--) {
                t = strinbuf[i];
                strinbuf[i + 3] |= 255 & (t << 4);
                strinbuf[i + 2] = t >> 4;
            }
            strinbuf[2] |= 255 & (v << 4);
            strinbuf[1] = v >> 4;
            strinbuf[0] = 0x40 | (v >> 12);
        }
        else {
            strinbuf[i + 1] = 0;
            strinbuf[i + 2] = 0;
            while (i--) {
                t = strinbuf[i];
                strinbuf[i + 2] |= 255 & (t << 4);
                strinbuf[i + 1] = t >> 4;
            }
            strinbuf[1] |= 255 & (v << 4);
            strinbuf[0] = 0x40 | (v >> 4);
        }
    // fill to end with pad pattern
        i = v + 3 - (version < 10);
        while (i < x) {
            strinbuf[i++] = 0xec;
            // buffer has room    if (i == x)      break;
            strinbuf[i++] = 0x11;
        }

    // calculate and append ECC

    // calculate generator polynomial


        genpoly[0] = 1;
        for (i = 0; i < eccblkwid; i++) {
            genpoly[i + 1] = 1;
            for (j = i; j > 0; j--)
                genpoly[j] = genpoly[j]
                ? genpoly[j - 1] ^ gexp[modnn(glog[genpoly[j]] + i)] : genpoly[j - 1];
            genpoly[0] = gexp[modnn(glog[genpoly[0]] + i)];
        }
        for (i = 0; i <= eccblkwid; i++)
            genpoly[i] = glog[genpoly[i]]; // use logs for genpoly[] to save calc step

    // append ecc to data buffer
        k = x;
        y = 0;
        for (i = 0; i < neccblk1; i++) {
            appendrs(y, datablkw, k, eccblkwid);
            y += datablkw;
            k += eccblkwid;
        }
        for (i = 0; i < neccblk2; i++) {
            appendrs(y, datablkw + 1, k, eccblkwid);
            y += datablkw + 1;
            k += eccblkwid;
        }

    // interleave blocks
        y = 0;
        for (i = 0; i < datablkw; i++) {
            for (j = 0; j < neccblk1; j++)
                eccbuf[y++] = strinbuf[i + j * datablkw];
            for (j = 0; j < neccblk2; j++)
                eccbuf[y++] = strinbuf[(neccblk1 * datablkw) + i + (j * (datablkw + 1))];
        }
        for (j = 0; j < neccblk2; j++)
            eccbuf[y++] = strinbuf[(neccblk1 * datablkw) + i + (j * (datablkw + 1))];
        for (i = 0; i < eccblkwid; i++)
            for (j = 0; j < neccblk1 + neccblk2; j++)
                eccbuf[y++] = strinbuf[x + i + j * eccblkwid];
        strinbuf = eccbuf;

    // pack bits into frame avoiding masked area.
        x = y = width - 1;
        k = v = 1;         // up, minus
        /* inteleaved data and ecc codes */
        m = (datablkw + eccblkwid) * (neccblk1 + neccblk2) + neccblk2;
        for (i = 0; i < m; i++) {
            t = strinbuf[i];
            for (j = 0; j < 8; j++, t <<= 1) {
                if (0x80 & t)
                    qrframe[x + width * y] = 1;
                do {        // find next fill position
                    if (v)
                        x--;
                    else {
                        x++;
                        if (k) {
                            if (y != 0)
                                y--;
                            else {
                                x -= 2;
                                k = !k;
                                if (x == 6) {
                                    x--;
                                    y = 9;
                                }
                            }
                        }
                        else {
                            if (y != width - 1)
                                y++;
                            else {
                                x -= 2;
                                k = !k;
                                if (x == 6) {
                                    x--;
                                    y -= 8;
                                }
                            }
                        }
                    }
                    v = !v;
                } while (ismasked(x, y));
            }
        }

    // save pre-mask copy of frame
        strinbuf = qrframe.slice(0);
        t = 0;           // best
        y = 30000;         // demerit
    // for instead of while since in original arduino code
    // if an early mask was "good enough" it wouldn't try for a better one
    // since they get more complex and take longer.
        for (k = 0; k < 8; k++) {

            // returns black-white imbalance
            applymask(k);
            x = badcheck();

            if (x < y) { // current mask better than previous best?
                y = x;
                t = k;
            }
            if (t == 7)
                break;       // don't increment i to a void redoing mask
            qrframe = strinbuf.slice(0); // reset for next pass
        }
        if (t != k)         // redo best mask - none good enough, last wasn't t
            applymask(t);

    // add in final mask/ecclevel bytes
        y = VanillaQR.fmtword[t + ((ecclevel - 1) << 3)];
        // low byte
        for (k = 0; k < 8; k++, y >>= 1)
            if (y & 1) {
                qrframe[(width - 1 - k) + width * 8] = 1;
                if (k < 6)
                    qrframe[8 + width * k] = 1;
                else
                    qrframe[8 + width * (k + 1)] = 1;
            }
        // high byte
        for (k = 0; k < 7; k++, y >>= 1)
            if (y & 1) {
                qrframe[8 + width * (width - 7 + k)] = 1;
                if (k)
                    qrframe[(6 - k) + width * 8] = 1;
                else
                    qrframe[7 + width * 8] = 1;
            }

    // return image
        return qrframe;
    };

    //Initialize QR Code
    scope.init = function() {

        ecclevel = scope.ecclevel;
        var qf = scope.genframe(scope.url);

        if(scope.toTable) {

            scope.tableWrite(qf, width);

        } else {

            scope.canvasWrite(qf, width);

        }

    };

    //Auto initialize
    scope.init();

}

//Get canvas 2D Context
VanillaQR.prototype = {

    //Canvas create
    canvasWrite: function(qf, width) {

        var scope = this;

        //Get context and proceed if it is allowed
        if(!scope.qrc) {

            scope.qrc = scope.getContext(scope.domElement);

            //No canvas support default to Table
            if(!scope.qrc) {
                scope.toTable = true;
                scope.domElement = document.createElement("div");
                scope.tableWrite(qf, width);
                return;
            }

        }

        //Setup canvas context
        var size = scope.size;
        var qrc = scope.qrc;

        qrc.lineWidth=1;

        var px = size;
        px /= width + 10;
        px=Math.round(px - 0.5);

        var offset = 4;

        if (scope.noBorder) {
            qrc.canvas.width = qrc.canvas.height = px * width;
            offset = 0;
        }
        else {
            qrc.canvas.width = qrc.canvas.height = size;
        }

        //Fill canvas with set colors
        qrc.clearRect( 0, 0, size, size );
        qrc.fillStyle = scope.colorLight;
        qrc.fillRect(0, 0, px*(width+8), px*(width+8));
        qrc.fillStyle = scope.colorDark;

        //Write boxes per row
        for( var i = 0; i < width; i++ ) {

            for( var j = 0; j < width; j++ ) {
                if( qf[j*width+i] ) {
                    qrc.fillRect(px*(offset+i),px*(offset+j),px,px);
                }
             }

         }

    },

    //Table write qr code
    tableWrite: function(qf, width) {

        var scope = this;

        //Table style
        var collapseStyle = "border:0;border-collapse:collapse;";
        var tdWidth = Math.round((this.size / width) - 3.5) + "px";
        var borderWidth = width + ( ( scope.noBorder ) ? 0 : ( scope.borderSize * 2 ) );
        var sideBorderWidth = scope.borderSize;
        var tdStyle = "width:" + tdWidth + ";height:" + tdWidth + ";";

        var colorLight = scope.colorLight;
        var colorDark = scope.colorDark;

        //Table elements
        var table = document.createElement("table");
        table.style.cssText = collapseStyle;

        var tr = document.createElement("tr");
        var td = document.createElement("td");

        //Cloning and creating table Elements
        var cloneTD = function() { return td.cloneNode(); };

        var createTDDark = function() {
            var elem = cloneTD();
            elem.style.cssText = tdStyle + "background:" + colorDark;
            return elem;
        };

        var createTDLight = function() {
            var elem = cloneTD();
            elem.style.cssText = tdStyle + "background:" + colorLight;
            return elem;
        }


        //Regular borders appending
        var appendBorders = function( table ) {

            var insertNode = table.firstChild;

            for( var i = 0; i < scope.borderSize; i ++ ) {

                var row = tr.cloneNode();

                for( var t = 0; t < borderWidth; t++ ) {
                    var lightTD = createTDLight();
                    row.appendChild(lightTD);
                }

                table.appendChild( row );
                table.insertBefore( row.cloneNode( true ), insertNode );

            }

        }


        //Create side border
        var appendSideBorders = function( row ) {

            var insertNode = row.firstChild;

            for( var i = 0; i < sideBorderWidth; i ++ ) {

                row.insertBefore( createTDLight(), insertNode );

                row.appendChild(createTDLight());

            }

        };

        //Write boxes per row
        for( var i = 0; i < width; i++ ) {

            var currentRow = tr.cloneNode();
            table.appendChild(currentRow);

            for( var j = 0; j < width; j++ ) {

                //Is a dark color
                if( qf[ (i*width) + j ] === 1 ) {
                    var darkTd = createTDDark();
                    currentRow.appendChild(darkTd);
                }

                //Light color
                else {
                    var lightTD = createTDLight();
                    currentRow.appendChild(lightTD);
                }

            }

            if( !scope.noBorder ) {

                appendSideBorders(currentRow);

            }

        }

        if( !scope.noBorder ) {

            appendBorders( table );

        }

         scope.domElement.innerHTML = "";
         scope.domElement.appendChild(table);

    },

    //get domElement 2D  Context
    getContext: function(domElement) {

        //try to get 2d context error
        if(!(domElement.getContext && domElement.getContext('2d'))) {

            console.log("Browser does not have 2d Canvas support");
            return false;

        }

        return domElement.getContext('2d');

    },

    //QR frame to image type
    toImage: function(type) {

        if(!this.qrc) {return;}

        //Check image output type
        var dataType = this.imageTypes[type];
        if(!dataType) {
            throw new Error(type + " is not a valid image type ");
        }

        //create image with src of QR code
    	var image = new Image;
    	image.src = this.domElement.toDataURL(dataType);
    	return image;

    }

};


// Private variables
// alignment pattern
VanillaQR.adelta = [
  0, 11, 15, 19, 23, 27, 31, // force 1 pat
  16, 18, 20, 22, 24, 26, 28, 20, 22, 24, 24, 26, 28, 28, 22, 24, 24,
  26, 26, 28, 28, 24, 24, 26, 26, 26, 28, 28, 24, 26, 26, 26, 28, 28
];

// version block
VanillaQR.vpat = [
    0xc94, 0x5bc, 0xa99, 0x4d3, 0xbf6, 0x762, 0x847, 0x60d,
    0x928, 0xb78, 0x45d, 0xa17, 0x532, 0x9a6, 0x683, 0x8c9,
    0x7ec, 0xec4, 0x1e1, 0xfab, 0x08e, 0xc1a, 0x33f, 0xd75,
    0x250, 0x9d5, 0x6f0, 0x8ba, 0x79f, 0xb0b, 0x42e, 0xa64,
    0x541, 0xc69
];

// final format bits with mask: level << 3 | mask
VanillaQR.fmtword = [
    0x77c4, 0x72f3, 0x7daa, 0x789d, 0x662f, 0x6318, 0x6c41, 0x6976,    //L
    0x5412, 0x5125, 0x5e7c, 0x5b4b, 0x45f9, 0x40ce, 0x4f97, 0x4aa0,    //M
    0x355f, 0x3068, 0x3f31, 0x3a06, 0x24b4, 0x2183, 0x2eda, 0x2bed,    //Q
    0x1689, 0x13be, 0x1ce7, 0x19d0, 0x0762, 0x0255, 0x0d0c, 0x083b    //H
];

// 4 per version: number of blocks 1,2; data width; ecc width
VanillaQR.eccblocks = [
    1, 0, 19, 7, 1, 0, 16, 10, 1, 0, 13, 13, 1, 0, 9, 17,
    1, 0, 34, 10, 1, 0, 28, 16, 1, 0, 22, 22, 1, 0, 16, 28,
    1, 0, 55, 15, 1, 0, 44, 26, 2, 0, 17, 18, 2, 0, 13, 22,
    1, 0, 80, 20, 2, 0, 32, 18, 2, 0, 24, 26, 4, 0, 9, 16,
    1, 0, 108, 26, 2, 0, 43, 24, 2, 2, 15, 18, 2, 2, 11, 22,
    2, 0, 68, 18, 4, 0, 27, 16, 4, 0, 19, 24, 4, 0, 15, 28,
    2, 0, 78, 20, 4, 0, 31, 18, 2, 4, 14, 18, 4, 1, 13, 26,
    2, 0, 97, 24, 2, 2, 38, 22, 4, 2, 18, 22, 4, 2, 14, 26,
    2, 0, 116, 30, 3, 2, 36, 22, 4, 4, 16, 20, 4, 4, 12, 24,
    2, 2, 68, 18, 4, 1, 43, 26, 6, 2, 19, 24, 6, 2, 15, 28,
    4, 0, 81, 20, 1, 4, 50, 30, 4, 4, 22, 28, 3, 8, 12, 24,
    2, 2, 92, 24, 6, 2, 36, 22, 4, 6, 20, 26, 7, 4, 14, 28,
    4, 0, 107, 26, 8, 1, 37, 22, 8, 4, 20, 24, 12, 4, 11, 22,
    3, 1, 115, 30, 4, 5, 40, 24, 11, 5, 16, 20, 11, 5, 12, 24,
    5, 1, 87, 22, 5, 5, 41, 24, 5, 7, 24, 30, 11, 7, 12, 24,
    5, 1, 98, 24, 7, 3, 45, 28, 15, 2, 19, 24, 3, 13, 15, 30,
    1, 5, 107, 28, 10, 1, 46, 28, 1, 15, 22, 28, 2, 17, 14, 28,
    5, 1, 120, 30, 9, 4, 43, 26, 17, 1, 22, 28, 2, 19, 14, 28,
    3, 4, 113, 28, 3, 11, 44, 26, 17, 4, 21, 26, 9, 16, 13, 26,
    3, 5, 107, 28, 3, 13, 41, 26, 15, 5, 24, 30, 15, 10, 15, 28,
    4, 4, 116, 28, 17, 0, 42, 26, 17, 6, 22, 28, 19, 6, 16, 30,
    2, 7, 111, 28, 17, 0, 46, 28, 7, 16, 24, 30, 34, 0, 13, 24,
    4, 5, 121, 30, 4, 14, 47, 28, 11, 14, 24, 30, 16, 14, 15, 30,
    6, 4, 117, 30, 6, 14, 45, 28, 11, 16, 24, 30, 30, 2, 16, 30,
    8, 4, 106, 26, 8, 13, 47, 28, 7, 22, 24, 30, 22, 13, 15, 30,
    10, 2, 114, 28, 19, 4, 46, 28, 28, 6, 22, 28, 33, 4, 16, 30,
    8, 4, 122, 30, 22, 3, 45, 28, 8, 26, 23, 30, 12, 28, 15, 30,
    3, 10, 117, 30, 3, 23, 45, 28, 4, 31, 24, 30, 11, 31, 15, 30,
    7, 7, 116, 30, 21, 7, 45, 28, 1, 37, 23, 30, 19, 26, 15, 30,
    5, 10, 115, 30, 19, 10, 47, 28, 15, 25, 24, 30, 23, 25, 15, 30,
    13, 3, 115, 30, 2, 29, 46, 28, 42, 1, 24, 30, 23, 28, 15, 30,
    17, 0, 115, 30, 10, 23, 46, 28, 10, 35, 24, 30, 19, 35, 15, 30,
    17, 1, 115, 30, 14, 21, 46, 28, 29, 19, 24, 30, 11, 46, 15, 30,
    13, 6, 115, 30, 14, 23, 46, 28, 44, 7, 24, 30, 59, 1, 16, 30,
    12, 7, 121, 30, 12, 26, 47, 28, 39, 14, 24, 30, 22, 41, 15, 30,
    6, 14, 121, 30, 6, 34, 47, 28, 46, 10, 24, 30, 2, 64, 15, 30,
    17, 4, 122, 30, 29, 14, 46, 28, 49, 10, 24, 30, 24, 46, 15, 30,
    4, 18, 122, 30, 13, 32, 46, 28, 48, 14, 24, 30, 42, 32, 15, 30,
    20, 4, 117, 30, 40, 7, 47, 28, 43, 22, 24, 30, 10, 67, 15, 30,
    19, 6, 118, 30, 18, 31, 47, 28, 34, 34, 24, 30, 20, 61, 15, 30
];

// Galois field log table
VanillaQR.glog = [
    0xff, 0x00, 0x01, 0x19, 0x02, 0x32, 0x1a, 0xc6, 0x03, 0xdf, 0x33, 0xee, 0x1b, 0x68, 0xc7, 0x4b,
    0x04, 0x64, 0xe0, 0x0e, 0x34, 0x8d, 0xef, 0x81, 0x1c, 0xc1, 0x69, 0xf8, 0xc8, 0x08, 0x4c, 0x71,
    0x05, 0x8a, 0x65, 0x2f, 0xe1, 0x24, 0x0f, 0x21, 0x35, 0x93, 0x8e, 0xda, 0xf0, 0x12, 0x82, 0x45,
    0x1d, 0xb5, 0xc2, 0x7d, 0x6a, 0x27, 0xf9, 0xb9, 0xc9, 0x9a, 0x09, 0x78, 0x4d, 0xe4, 0x72, 0xa6,
    0x06, 0xbf, 0x8b, 0x62, 0x66, 0xdd, 0x30, 0xfd, 0xe2, 0x98, 0x25, 0xb3, 0x10, 0x91, 0x22, 0x88,
    0x36, 0xd0, 0x94, 0xce, 0x8f, 0x96, 0xdb, 0xbd, 0xf1, 0xd2, 0x13, 0x5c, 0x83, 0x38, 0x46, 0x40,
    0x1e, 0x42, 0xb6, 0xa3, 0xc3, 0x48, 0x7e, 0x6e, 0x6b, 0x3a, 0x28, 0x54, 0xfa, 0x85, 0xba, 0x3d,
    0xca, 0x5e, 0x9b, 0x9f, 0x0a, 0x15, 0x79, 0x2b, 0x4e, 0xd4, 0xe5, 0xac, 0x73, 0xf3, 0xa7, 0x57,
    0x07, 0x70, 0xc0, 0xf7, 0x8c, 0x80, 0x63, 0x0d, 0x67, 0x4a, 0xde, 0xed, 0x31, 0xc5, 0xfe, 0x18,
    0xe3, 0xa5, 0x99, 0x77, 0x26, 0xb8, 0xb4, 0x7c, 0x11, 0x44, 0x92, 0xd9, 0x23, 0x20, 0x89, 0x2e,
    0x37, 0x3f, 0xd1, 0x5b, 0x95, 0xbc, 0xcf, 0xcd, 0x90, 0x87, 0x97, 0xb2, 0xdc, 0xfc, 0xbe, 0x61,
    0xf2, 0x56, 0xd3, 0xab, 0x14, 0x2a, 0x5d, 0x9e, 0x84, 0x3c, 0x39, 0x53, 0x47, 0x6d, 0x41, 0xa2,
    0x1f, 0x2d, 0x43, 0xd8, 0xb7, 0x7b, 0xa4, 0x76, 0xc4, 0x17, 0x49, 0xec, 0x7f, 0x0c, 0x6f, 0xf6,
    0x6c, 0xa1, 0x3b, 0x52, 0x29, 0x9d, 0x55, 0xaa, 0xfb, 0x60, 0x86, 0xb1, 0xbb, 0xcc, 0x3e, 0x5a,
    0xcb, 0x59, 0x5f, 0xb0, 0x9c, 0xa9, 0xa0, 0x51, 0x0b, 0xf5, 0x16, 0xeb, 0x7a, 0x75, 0x2c, 0xd7,
    0x4f, 0xae, 0xd5, 0xe9, 0xe6, 0xe7, 0xad, 0xe8, 0x74, 0xd6, 0xf4, 0xea, 0xa8, 0x50, 0x58, 0xaf
];

// Galios field exponent table
VanillaQR.gexp = [
    0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1d, 0x3a, 0x74, 0xe8, 0xcd, 0x87, 0x13, 0x26,
    0x4c, 0x98, 0x2d, 0x5a, 0xb4, 0x75, 0xea, 0xc9, 0x8f, 0x03, 0x06, 0x0c, 0x18, 0x30, 0x60, 0xc0,
    0x9d, 0x27, 0x4e, 0x9c, 0x25, 0x4a, 0x94, 0x35, 0x6a, 0xd4, 0xb5, 0x77, 0xee, 0xc1, 0x9f, 0x23,
    0x46, 0x8c, 0x05, 0x0a, 0x14, 0x28, 0x50, 0xa0, 0x5d, 0xba, 0x69, 0xd2, 0xb9, 0x6f, 0xde, 0xa1,
    0x5f, 0xbe, 0x61, 0xc2, 0x99, 0x2f, 0x5e, 0xbc, 0x65, 0xca, 0x89, 0x0f, 0x1e, 0x3c, 0x78, 0xf0,
    0xfd, 0xe7, 0xd3, 0xbb, 0x6b, 0xd6, 0xb1, 0x7f, 0xfe, 0xe1, 0xdf, 0xa3, 0x5b, 0xb6, 0x71, 0xe2,
    0xd9, 0xaf, 0x43, 0x86, 0x11, 0x22, 0x44, 0x88, 0x0d, 0x1a, 0x34, 0x68, 0xd0, 0xbd, 0x67, 0xce,
    0x81, 0x1f, 0x3e, 0x7c, 0xf8, 0xed, 0xc7, 0x93, 0x3b, 0x76, 0xec, 0xc5, 0x97, 0x33, 0x66, 0xcc,
    0x85, 0x17, 0x2e, 0x5c, 0xb8, 0x6d, 0xda, 0xa9, 0x4f, 0x9e, 0x21, 0x42, 0x84, 0x15, 0x2a, 0x54,
    0xa8, 0x4d, 0x9a, 0x29, 0x52, 0xa4, 0x55, 0xaa, 0x49, 0x92, 0x39, 0x72, 0xe4, 0xd5, 0xb7, 0x73,
    0xe6, 0xd1, 0xbf, 0x63, 0xc6, 0x91, 0x3f, 0x7e, 0xfc, 0xe5, 0xd7, 0xb3, 0x7b, 0xf6, 0xf1, 0xff,
    0xe3, 0xdb, 0xab, 0x4b, 0x96, 0x31, 0x62, 0xc4, 0x95, 0x37, 0x6e, 0xdc, 0xa5, 0x57, 0xae, 0x41,
    0x82, 0x19, 0x32, 0x64, 0xc8, 0x8d, 0x07, 0x0e, 0x1c, 0x38, 0x70, 0xe0, 0xdd, 0xa7, 0x53, 0xa6,
    0x51, 0xa2, 0x59, 0xb2, 0x79, 0xf2, 0xf9, 0xef, 0xc3, 0x9b, 0x2b, 0x56, 0xac, 0x45, 0x8a, 0x09,
    0x12, 0x24, 0x48, 0x90, 0x3d, 0x7a, 0xf4, 0xf5, 0xf7, 0xf3, 0xfb, 0xeb, 0xcb, 0x8b, 0x0b, 0x16,
    0x2c, 0x58, 0xb0, 0x7d, 0xfa, 0xe9, 0xcf, 0x83, 0x1b, 0x36, 0x6c, 0xd8, 0xad, 0x47, 0x8e, 0x00
];

// Badness coefficients.
VanillaQR.N1 = 3;
VanillaQR.N2 = 3;
VanillaQR.N3 = 40;
VanillaQR.N4 = 10;

/**
 * Module loading footer
 */

export default VanillaQR;