qrcode.js

//---------------------------------------------------------------------
// QRCode for JavaScript
//
// Copyright (c) 2009 Kazuhiko Arase
//
// URL: http://www.d-project.com/
//
// Licensed under the MIT license:
//   http://www.opensource.org/licenses/mit-license.php
//
// The word "QR Code" is registered trademark of 
// DENSO WAVE INCORPORATED
//   http://www.denso-wave.com/qrcode/faqpatent-e.html
//
//---------------------------------------------------------------------

// modified by hanquan.csf@taobao.com

//---------------------------------------------------------------------
// QR8bitByte
//---------------------------------------------------------------------
function QR8bitByte(data) {
    this.mode = QRMode.MODE_8BIT_BYTE;
    this.data = data;
}

QR8bitByte.prototype = {

    getLength : function(buffer) {
        return this.data.length;
    },

    write : function(buffer) {
        for (var i = 0; i < this.data.length; i++) {
            // not JIS ...
            buffer.put(this.data.charCodeAt(i), 8);
        }
    }
};

//---------------------------------------------------------------------
// QRCode
//---------------------------------------------------------------------

function QRCode(typeNumber, errorCorrectLevel) {
    this.typeNumber = typeNumber;
    this.errorCorrectLevel = errorCorrectLevel;
    this.modules = null;
    this.moduleCount = 0;
    this.dataCache = null;
    this.dataList = new Array();
}

QRCode.prototype = {

    addData : function(data) {
        var newData = new QR8bitByte(data);
        this.dataList.push(newData);
        this.dataCache = null;
    },

    isDark : function(row, col) {
        if (row < 0 || this.moduleCount <= row || col < 0 || this.moduleCount <= col) {
            throw new Error(row + "," + col);
        }
        return this.modules[row][col];
    },

    getModuleCount : function() {
        return this.moduleCount;
    },

    make : function() {
        // Calculate automatically typeNumber if provided is < 1
        if (this.typeNumber < 1 ){
            var typeNumber = 1;
            for (typeNumber = 1; typeNumber < 40; typeNumber++) {
                var rsBlocks = QRRSBlock.getRSBlocks(typeNumber, this.errorCorrectLevel);

                var buffer = new QRBitBuffer();
                var totalDataCount = 0;
                for (var i = 0; i < rsBlocks.length; i++) {
                    totalDataCount += rsBlocks[i].dataCount;
                }

                for (var i = 0; i < this.dataList.length; i++) {
                    var data = this.dataList[i];
                    buffer.put(data.mode, 4);
                    buffer.put(data.getLength(), QRUtil.getLengthInBits(data.mode, typeNumber) );
                    data.write(buffer);
                }
                if (buffer.getLengthInBits() <= totalDataCount * 8)
                    break;
            }
            this.typeNumber = typeNumber;
        }
        this.makeImpl(false, this.getBestMaskPattern() );
    },

    makeImpl : function(test, maskPattern) {
    
        this.moduleCount = this.typeNumber * 4 + 17;
        this.modules = new Array(this.moduleCount);
    
        for (var row = 0; row < this.moduleCount; row++) {
        
            this.modules[row] = new Array(this.moduleCount);
        
            for (var col = 0; col < this.moduleCount; col++) {
                this.modules[row][col] = null;//(col + row) % 3;
            }
        }

        this.setupPositionProbePattern(0, 0);
        this.setupPositionProbePattern(this.moduleCount - 7, 0);
        this.setupPositionProbePattern(0, this.moduleCount - 7);
        this.setupPositionAdjustPattern();
        this.setupTimingPattern();
        this.setupTypeInfo(test, maskPattern);
    
        if (this.typeNumber >= 7) {
            this.setupTypeNumber(test);
        }

        if (this.dataCache == null) {
            this.dataCache = QRCode.createData(this.typeNumber, this.errorCorrectLevel, this.dataList);
        }

        this.mapData(this.dataCache, maskPattern);
    },

    setupPositionProbePattern : function(row, col)  {
    
        for (var r = -1; r <= 7; r++) {
        
            if (row + r <= -1 || this.moduleCount <= row + r) continue;
        
            for (var c = -1; c <= 7; c++) {
            
                if (col + c <= -1 || this.moduleCount <= col + c) continue;
            
                if ( (0 <= r && r <= 6 && (c == 0 || c == 6) )
                        || (0 <= c && c <= 6 && (r == 0 || r == 6) )
                        || (2 <= r && r <= 4 && 2 <= c && c <= 4) ) {
                    this.modules[row + r][col + c] = true;
                } else {
                    this.modules[row + r][col + c] = false;
                }
            }       
        }       
    },

    getBestMaskPattern : function() {

        var minLostPoint = 0;
        var pattern = 0;

        for (var i = 0; i < 8; i++) {
        
            this.makeImpl(true, i);

            var lostPoint = QRUtil.getLostPoint(this);

            if (i == 0 || minLostPoint >  lostPoint) {
                minLostPoint = lostPoint;
                pattern = i;
            }
        }

        return pattern;
    },

    createMovieClip : function(target_mc, instance_name, depth) {

        var qr_mc = target_mc.createEmptyMovieClip(instance_name, depth);
        var cs = 1;

        this.make();

        for (var row = 0; row < this.modules.length; row++) {
        
            var y = row * cs;
        
            for (var col = 0; col < this.modules[row].length; col++) {

                var x = col * cs;
                var dark = this.modules[row][col];
        
                if (dark) {
                    qr_mc.beginFill(0, 100);
                    qr_mc.moveTo(x, y);
                    qr_mc.lineTo(x + cs, y);
                    qr_mc.lineTo(x + cs, y + cs);
                    qr_mc.lineTo(x, y + cs);
                    qr_mc.endFill();
                }
            }
        }
    
        return qr_mc;
    },

    setupTimingPattern : function() {
    
        for (var r = 8; r < this.moduleCount - 8; r++) {
            if (this.modules[r][6] != null) {
                continue;
            }
            this.modules[r][6] = (r % 2 == 0);
        }

        for (var c = 8; c < this.moduleCount - 8; c++) {
            if (this.modules[6][c] != null) {
                continue;
            }
            this.modules[6][c] = (c % 2 == 0);
        }
    },

    setupPositionAdjustPattern : function() {

        var pos = QRUtil.getPatternPosition(this.typeNumber);
    
        for (var i = 0; i < pos.length; i++) {
    
            for (var j = 0; j < pos.length; j++) {
        
                var row = pos[i];
                var col = pos[j];
            
                if (this.modules[row][col] != null) {
                    continue;
                }
            
                for (var r = -2; r <= 2; r++) {
            
                    for (var c = -2; c <= 2; c++) {
                
                        if (r == -2 || r == 2 || c == -2 || c == 2 
                                || (r == 0 && c == 0) ) {
                            this.modules[row + r][col + c] = true;
                        } else {
                            this.modules[row + r][col + c] = false;
                        }
                    }
                }
            }
        }
    },

    setupTypeNumber : function(test) {

        var bits = QRUtil.getBCHTypeNumber(this.typeNumber);

        for (var i = 0; i < 18; i++) {
            var mod = (!test && ( (bits >> i) & 1) == 1);
            this.modules[Math.floor(i / 3)][i % 3 + this.moduleCount - 8 - 3] = mod;
        }

        for (var i = 0; i < 18; i++) {
            var mod = (!test && ( (bits >> i) & 1) == 1);
            this.modules[i % 3 + this.moduleCount - 8 - 3][Math.floor(i / 3)] = mod;
        }
    },

    setupTypeInfo : function(test, maskPattern) {

        var data = (this.errorCorrectLevel << 3) | maskPattern;
        var bits = QRUtil.getBCHTypeInfo(data);

        // vertical     
        for (var i = 0; i < 15; i++) {

            var mod = (!test && ( (bits >> i) & 1) == 1);

            if (i < 6) {
                this.modules[i][8] = mod;
            } else if (i < 8) {
                this.modules[i + 1][8] = mod;
            } else {
                this.modules[this.moduleCount - 15 + i][8] = mod;
            }
        }

        // horizontal
        for (var i = 0; i < 15; i++) {

            var mod = (!test && ( (bits >> i) & 1) == 1);
        
            if (i < 8) {
                this.modules[8][this.moduleCount - i - 1] = mod;
            } else if (i < 9) {
                this.modules[8][15 - i - 1 + 1] = mod;
            } else {
                this.modules[8][15 - i - 1] = mod;
            }
        }

        // fixed module
        this.modules[this.moduleCount - 8][8] = (!test);

    },

    mapData : function(data, maskPattern) {
    
        var inc = -1;
        var row = this.moduleCount - 1;
        var bitIndex = 7;
        var byteIndex = 0;
    
        for (var col = this.moduleCount - 1; col > 0; col -= 2) {

            if (col == 6) col--;

            while (true) {

                for (var c = 0; c < 2; c++) {
                
                    if (this.modules[row][col - c] == null) {
                    
                        var dark = false;

                        if (byteIndex < data.length) {
                            dark = ( ( (data[byteIndex] >>> bitIndex) & 1) == 1);
                        }

                        var mask = QRUtil.getMask(maskPattern, row, col - c);

                        if (mask) {
                            dark = !dark;
                        }
                    
                        this.modules[row][col - c] = dark;
                        bitIndex--;

                        if (bitIndex == -1) {
                            byteIndex++;
                            bitIndex = 7;
                        }
                    }
                }
                            
                row += inc;

                if (row < 0 || this.moduleCount <= row) {
                    row -= inc;
                    inc = -inc;
                    break;
                }
            }
        }
    
    }

};

QRCode.PAD0 = 0xEC;
QRCode.PAD1 = 0x11;

QRCode.createData = function(typeNumber, errorCorrectLevel, dataList) {

    var rsBlocks = QRRSBlock.getRSBlocks(typeNumber, errorCorrectLevel);

    var buffer = new QRBitBuffer();

    for (var i = 0; i < dataList.length; i++) {
        var data = dataList[i];
        buffer.put(data.mode, 4);
        buffer.put(data.getLength(), QRUtil.getLengthInBits(data.mode, typeNumber) );
        data.write(buffer);
    }

    // calc num max data.
    var totalDataCount = 0;
    for (var i = 0; i < rsBlocks.length; i++) {
        totalDataCount += rsBlocks[i].dataCount;
    }

    if (buffer.getLengthInBits() > totalDataCount * 8) {
        throw new Error("code length overflow. ("
            + buffer.getLengthInBits()
            + ">"
            +  totalDataCount * 8
            + ")");
    }

    // end code
    if (buffer.getLengthInBits() + 4 <= totalDataCount * 8) {
        buffer.put(0, 4);
    }

    // padding
    while (buffer.getLengthInBits() % 8 != 0) {
        buffer.putBit(false);
    }

    // padding
    while (true) {
    
        if (buffer.getLengthInBits() >= totalDataCount * 8) {
            break;
        }
        buffer.put(QRCode.PAD0, 8);
    
        if (buffer.getLengthInBits() >= totalDataCount * 8) {
            break;
        }
        buffer.put(QRCode.PAD1, 8);
    }

    return QRCode.createBytes(buffer, rsBlocks);
}

QRCode.createBytes = function(buffer, rsBlocks) {

    var offset = 0;

    var maxDcCount = 0;
    var maxEcCount = 0;

    var dcdata = new Array(rsBlocks.length);
    var ecdata = new Array(rsBlocks.length);

    for (var r = 0; r < rsBlocks.length; r++) {

        var dcCount = rsBlocks[r].dataCount;
        var ecCount = rsBlocks[r].totalCount - dcCount;

        maxDcCount = Math.max(maxDcCount, dcCount);
        maxEcCount = Math.max(maxEcCount, ecCount);
    
        dcdata[r] = new Array(dcCount);
    
        for (var i = 0; i < dcdata[r].length; i++) {
            dcdata[r][i] = 0xff & buffer.buffer[i + offset];
        }
        offset += dcCount;
    
        var rsPoly = QRUtil.getErrorCorrectPolynomial(ecCount);
        var rawPoly = new QRPolynomial(dcdata[r], rsPoly.getLength() - 1);

        var modPoly = rawPoly.mod(rsPoly);
        ecdata[r] = new Array(rsPoly.getLength() - 1);
        for (var i = 0; i < ecdata[r].length; i++) {
            var modIndex = i + modPoly.getLength() - ecdata[r].length;
            ecdata[r][i] = (modIndex >= 0)? modPoly.get(modIndex) : 0;
        }

    }

    var totalCodeCount = 0;
    for (var i = 0; i < rsBlocks.length; i++) {
        totalCodeCount += rsBlocks[i].totalCount;
    }

    var data = new Array(totalCodeCount);
    var index = 0;

    for (var i = 0; i < maxDcCount; i++) {
        for (var r = 0; r < rsBlocks.length; r++) {
            if (i < dcdata[r].length) {
                data[index++] = dcdata[r][i];
            }
        }
    }

    for (var i = 0; i < maxEcCount; i++) {
        for (var r = 0; r < rsBlocks.length; r++) {
            if (i < ecdata[r].length) {
                data[index++] = ecdata[r][i];
            }
        }
    }

    return data;

}

//---------------------------------------------------------------------
// QRMode
//---------------------------------------------------------------------

var QRMode = {
    MODE_NUMBER :       1 << 0,
    MODE_ALPHA_NUM :    1 << 1,
    MODE_8BIT_BYTE :    1 << 2,
    MODE_KANJI :        1 << 3
};

//---------------------------------------------------------------------
// QRErrorCorrectLevel
//---------------------------------------------------------------------

var QRErrorCorrectLevel = {
    L : 1,
    M : 0,
    Q : 3,
    H : 2
};

//---------------------------------------------------------------------
// QRMaskPattern
//---------------------------------------------------------------------

var QRMaskPattern = {
    PATTERN000 : 0,
    PATTERN001 : 1,
    PATTERN010 : 2,
    PATTERN011 : 3,
    PATTERN100 : 4,
    PATTERN101 : 5,
    PATTERN110 : 6,
    PATTERN111 : 7
};

//---------------------------------------------------------------------
// QRUtil
//---------------------------------------------------------------------

var QRUtil = {

    PATTERN_POSITION_TABLE : [
        [],
        [6, 18],
        [6, 22],
        [6, 26],
        [6, 30],
        [6, 34],
        [6, 22, 38],
        [6, 24, 42],
        [6, 26, 46],
        [6, 28, 50],
        [6, 30, 54],        
        [6, 32, 58],
        [6, 34, 62],
        [6, 26, 46, 66],
        [6, 26, 48, 70],
        [6, 26, 50, 74],
        [6, 30, 54, 78],
        [6, 30, 56, 82],
        [6, 30, 58, 86],
        [6, 34, 62, 90],
        [6, 28, 50, 72, 94],
        [6, 26, 50, 74, 98],
        [6, 30, 54, 78, 102],
        [6, 28, 54, 80, 106],
        [6, 32, 58, 84, 110],
        [6, 30, 58, 86, 114],
        [6, 34, 62, 90, 118],
        [6, 26, 50, 74, 98, 122],
        [6, 30, 54, 78, 102, 126],
        [6, 26, 52, 78, 104, 130],
        [6, 30, 56, 82, 108, 134],
        [6, 34, 60, 86, 112, 138],
        [6, 30, 58, 86, 114, 142],
        [6, 34, 62, 90, 118, 146],
        [6, 30, 54, 78, 102, 126, 150],
        [6, 24, 50, 76, 102, 128, 154],
        [6, 28, 54, 80, 106, 132, 158],
        [6, 32, 58, 84, 110, 136, 162],
        [6, 26, 54, 82, 110, 138, 166],
        [6, 30, 58, 86, 114, 142, 170]
    ],

    G15 : (1 << 10) | (1 << 8) | (1 << 5) | (1 << 4) | (1 << 2) | (1 << 1) | (1 << 0),
    G18 : (1 << 12) | (1 << 11) | (1 << 10) | (1 << 9) | (1 << 8) | (1 << 5) | (1 << 2) | (1 << 0),
    G15_MASK : (1 << 14) | (1 << 12) | (1 << 10)    | (1 << 4) | (1 << 1),

    getBCHTypeInfo : function(data) {
        var d = data << 10;
        while (QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G15) >= 0) {
            d ^= (QRUtil.G15 << (QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G15) ) );    
        }
        return ( (data << 10) | d) ^ QRUtil.G15_MASK;
    },

    getBCHTypeNumber : function(data) {
        var d = data << 12;
        while (QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G18) >= 0) {
            d ^= (QRUtil.G18 << (QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G18) ) );    
        }
        return (data << 12) | d;
    },

    getBCHDigit : function(data) {

        var digit = 0;

        while (data != 0) {
            digit++;
            data >>>= 1;
        }

        return digit;
    },

    getPatternPosition : function(typeNumber) {
        return QRUtil.PATTERN_POSITION_TABLE[typeNumber - 1];
    },

    getMask : function(maskPattern, i, j) {
    
        switch (maskPattern) {
        
        case QRMaskPattern.PATTERN000 : return (i + j) % 2 == 0;
        case QRMaskPattern.PATTERN001 : return i % 2 == 0;
        case QRMaskPattern.PATTERN010 : return j % 3 == 0;
        case QRMaskPattern.PATTERN011 : return (i + j) % 3 == 0;
        case QRMaskPattern.PATTERN100 : return (Math.floor(i / 2) + Math.floor(j / 3) ) % 2 == 0;
        case QRMaskPattern.PATTERN101 : return (i * j) % 2 + (i * j) % 3 == 0;
        case QRMaskPattern.PATTERN110 : return ( (i * j) % 2 + (i * j) % 3) % 2 == 0;
        case QRMaskPattern.PATTERN111 : return ( (i * j) % 3 + (i + j) % 2) % 2 == 0;

        default :
            throw new Error("bad maskPattern:" + maskPattern);
        }
    },

    getErrorCorrectPolynomial : function(errorCorrectLength) {

        var a = new QRPolynomial([1], 0);

        for (var i = 0; i < errorCorrectLength; i++) {
            a = a.multiply(new QRPolynomial([1, QRMath.gexp(i)], 0) );
        }

        return a;
    },

    getLengthInBits : function(mode, type) {

        if (1 <= type && type < 10) {

            // 1 - 9

            switch(mode) {
            case QRMode.MODE_NUMBER     : return 10;
            case QRMode.MODE_ALPHA_NUM  : return 9;
            case QRMode.MODE_8BIT_BYTE  : return 8;
            case QRMode.MODE_KANJI      : return 8;
            default :
                throw new Error("mode:" + mode);
            }

        } else if (type < 27) {

            // 10 - 26

            switch(mode) {
            case QRMode.MODE_NUMBER     : return 12;
            case QRMode.MODE_ALPHA_NUM  : return 11;
            case QRMode.MODE_8BIT_BYTE  : return 16;
            case QRMode.MODE_KANJI      : return 10;
            default :
                throw new Error("mode:" + mode);
            }

        } else if (type < 41) {

            // 27 - 40

            switch(mode) {
            case QRMode.MODE_NUMBER     : return 14;
            case QRMode.MODE_ALPHA_NUM  : return 13;
            case QRMode.MODE_8BIT_BYTE  : return 16;
            case QRMode.MODE_KANJI      : return 12;
            default :
                throw new Error("mode:" + mode);
            }

        } else {
            throw new Error("type:" + type);
        }
    },

    getLostPoint : function(qrCode) {
    
        var moduleCount = qrCode.getModuleCount();
    
        var lostPoint = 0;
    
        // LEVEL1
    
        for (var row = 0; row < moduleCount; row++) {

            for (var col = 0; col < moduleCount; col++) {

                var sameCount = 0;
                var dark = qrCode.isDark(row, col);

                for (var r = -1; r <= 1; r++) {

                    if (row + r < 0 || moduleCount <= row + r) {
                        continue;
                    }

                    for (var c = -1; c <= 1; c++) {

                        if (col + c < 0 || moduleCount <= col + c) {
                            continue;
                        }

                        if (r == 0 && c == 0) {
                            continue;
                        }

                        if (dark == qrCode.isDark(row + r, col + c) ) {
                            sameCount++;
                        }
                    }
                }

                if (sameCount > 5) {
                    lostPoint += (3 + sameCount - 5);
                }
            }
        }

        // LEVEL2

        for (var row = 0; row < moduleCount - 1; row++) {
            for (var col = 0; col < moduleCount - 1; col++) {
                var count = 0;
                if (qrCode.isDark(row,     col    ) ) count++;
                if (qrCode.isDark(row + 1, col    ) ) count++;
                if (qrCode.isDark(row,     col + 1) ) count++;
                if (qrCode.isDark(row + 1, col + 1) ) count++;
                if (count == 0 || count == 4) {
                    lostPoint += 3;
                }
            }
        }

        // LEVEL3

        for (var row = 0; row < moduleCount; row++) {
            for (var col = 0; col < moduleCount - 6; col++) {
                if (qrCode.isDark(row, col)
                        && !qrCode.isDark(row, col + 1)
                        &&  qrCode.isDark(row, col + 2)
                        &&  qrCode.isDark(row, col + 3)
                        &&  qrCode.isDark(row, col + 4)
                        && !qrCode.isDark(row, col + 5)
                        &&  qrCode.isDark(row, col + 6) ) {
                    lostPoint += 40;
                }
            }
        }

        for (var col = 0; col < moduleCount; col++) {
            for (var row = 0; row < moduleCount - 6; row++) {
                if (qrCode.isDark(row, col)
                        && !qrCode.isDark(row + 1, col)
                        &&  qrCode.isDark(row + 2, col)
                        &&  qrCode.isDark(row + 3, col)
                        &&  qrCode.isDark(row + 4, col)
                        && !qrCode.isDark(row + 5, col)
                        &&  qrCode.isDark(row + 6, col) ) {
                    lostPoint += 40;
                }
            }
        }

        // LEVEL4
    
        var darkCount = 0;

        for (var col = 0; col < moduleCount; col++) {
            for (var row = 0; row < moduleCount; row++) {
                if (qrCode.isDark(row, col) ) {
                    darkCount++;
                }
            }
        }
    
        var ratio = Math.abs(100 * darkCount / moduleCount / moduleCount - 50) / 5;
        lostPoint += ratio * 10;

        return lostPoint;       
    }

};


//---------------------------------------------------------------------
// QRMath
//---------------------------------------------------------------------

var QRMath = {

    glog : function(n) {

        if (n < 1) {
            throw new Error("glog(" + n + ")");
        }
    
        return QRMath.LOG_TABLE[n];
    },

    gexp : function(n) {

        while (n < 0) {
            n += 255;
        }

        while (n >= 256) {
            n -= 255;
        }

        return QRMath.EXP_TABLE[n];
    },

    EXP_TABLE : new Array(256),

    LOG_TABLE : new Array(256)

};

for (var i = 0; i < 8; i++) {
    QRMath.EXP_TABLE[i] = 1 << i;
}
for (var i = 8; i < 256; i++) {
    QRMath.EXP_TABLE[i] = QRMath.EXP_TABLE[i - 4]
        ^ QRMath.EXP_TABLE[i - 5]
        ^ QRMath.EXP_TABLE[i - 6]
        ^ QRMath.EXP_TABLE[i - 8];
}
for (var i = 0; i < 255; i++) {
    QRMath.LOG_TABLE[QRMath.EXP_TABLE[i] ] = i;
}

//---------------------------------------------------------------------
// QRPolynomial
//---------------------------------------------------------------------

function QRPolynomial(num, shift) {

    if (num.length == undefined) {
        throw new Error(num.length + "/" + shift);
    }

    var offset = 0;

    while (offset < num.length && num[offset] == 0) {
        offset++;
    }

    this.num = new Array(num.length - offset + shift);
    for (var i = 0; i < num.length - offset; i++) {
        this.num[i] = num[i + offset];
    }
}

QRPolynomial.prototype = {

    get : function(index) {
        return this.num[index];
    },

    getLength : function() {
        return this.num.length;
    },

    multiply : function(e) {

        var num = new Array(this.getLength() + e.getLength() - 1);

        for (var i = 0; i < this.getLength(); i++) {
            for (var j = 0; j < e.getLength(); j++) {
                num[i + j] ^= QRMath.gexp(QRMath.glog(this.get(i) ) + QRMath.glog(e.get(j) ) );
            }
        }

        return new QRPolynomial(num, 0);
    },

    mod : function(e) {

        if (this.getLength() - e.getLength() < 0) {
            return this;
        }

        var ratio = QRMath.glog(this.get(0) ) - QRMath.glog(e.get(0) );

        var num = new Array(this.getLength() );
    
        for (var i = 0; i < this.getLength(); i++) {
            num[i] = this.get(i);
        }
    
        for (var i = 0; i < e.getLength(); i++) {
            num[i] ^= QRMath.gexp(QRMath.glog(e.get(i) ) + ratio);
        }

        // recursive call
        return new QRPolynomial(num, 0).mod(e);
    }
};

//---------------------------------------------------------------------
// QRRSBlock
//---------------------------------------------------------------------

function QRRSBlock(totalCount, dataCount) {
    this.totalCount = totalCount;
    this.dataCount  = dataCount;
}

QRRSBlock.RS_BLOCK_TABLE = [

    // L
    // M
    // Q
    // H

    // 1
    [1, 26, 19],
    [1, 26, 16],
    [1, 26, 13],
    [1, 26, 9],

    // 2
    [1, 44, 34],
    [1, 44, 28],
    [1, 44, 22],
    [1, 44, 16],

    // 3
    [1, 70, 55],
    [1, 70, 44],
    [2, 35, 17],
    [2, 35, 13],

    // 4        
    [1, 100, 80],
    [2, 50, 32],
    [2, 50, 24],
    [4, 25, 9],

    // 5
    [1, 134, 108],
    [2, 67, 43],
    [2, 33, 15, 2, 34, 16],
    [2, 33, 11, 2, 34, 12],

    // 6
    [2, 86, 68],
    [4, 43, 27],
    [4, 43, 19],
    [4, 43, 15],

    // 7        
    [2, 98, 78],
    [4, 49, 31],
    [2, 32, 14, 4, 33, 15],
    [4, 39, 13, 1, 40, 14],

    // 8
    [2, 121, 97],
    [2, 60, 38, 2, 61, 39],
    [4, 40, 18, 2, 41, 19],
    [4, 40, 14, 2, 41, 15],

    // 9
    [2, 146, 116],
    [3, 58, 36, 2, 59, 37],
    [4, 36, 16, 4, 37, 17],
    [4, 36, 12, 4, 37, 13],

    // 10       
    [2, 86, 68, 2, 87, 69],
    [4, 69, 43, 1, 70, 44],
    [6, 43, 19, 2, 44, 20],
    [6, 43, 15, 2, 44, 16],

    // 11
    [4, 101, 81],
    [1, 80, 50, 4, 81, 51],
    [4, 50, 22, 4, 51, 23],
    [3, 36, 12, 8, 37, 13],

    // 12
    [2, 116, 92, 2, 117, 93],
    [6, 58, 36, 2, 59, 37],
    [4, 46, 20, 6, 47, 21],
    [7, 42, 14, 4, 43, 15],

    // 13
    [4, 133, 107],
    [8, 59, 37, 1, 60, 38],
    [8, 44, 20, 4, 45, 21],
    [12, 33, 11, 4, 34, 12],

    // 14
    [3, 145, 115, 1, 146, 116],
    [4, 64, 40, 5, 65, 41],
    [11, 36, 16, 5, 37, 17],
    [11, 36, 12, 5, 37, 13],

    // 15
    [5, 109, 87, 1, 110, 88],
    [5, 65, 41, 5, 66, 42],
    [5, 54, 24, 7, 55, 25],
    [11, 36, 12],

    // 16
    [5, 122, 98, 1, 123, 99],
    [7, 73, 45, 3, 74, 46],
    [15, 43, 19, 2, 44, 20],
    [3, 45, 15, 13, 46, 16],

    // 17
    [1, 135, 107, 5, 136, 108],
    [10, 74, 46, 1, 75, 47],
    [1, 50, 22, 15, 51, 23],
    [2, 42, 14, 17, 43, 15],

    // 18
    [5, 150, 120, 1, 151, 121],
    [9, 69, 43, 4, 70, 44],
    [17, 50, 22, 1, 51, 23],
    [2, 42, 14, 19, 43, 15],

    // 19
    [3, 141, 113, 4, 142, 114],
    [3, 70, 44, 11, 71, 45],
    [17, 47, 21, 4, 48, 22],
    [9, 39, 13, 16, 40, 14],

    // 20
    [3, 135, 107, 5, 136, 108],
    [3, 67, 41, 13, 68, 42],
    [15, 54, 24, 5, 55, 25],
    [15, 43, 15, 10, 44, 16],

    // 21
    [4, 144, 116, 4, 145, 117],
    [17, 68, 42],
    [17, 50, 22, 6, 51, 23],
    [19, 46, 16, 6, 47, 17],

    // 22
    [2, 139, 111, 7, 140, 112],
    [17, 74, 46],
    [7, 54, 24, 16, 55, 25],
    [34, 37, 13],

    // 23
    [4, 151, 121, 5, 152, 122],
    [4, 75, 47, 14, 76, 48],
    [11, 54, 24, 14, 55, 25],
    [16, 45, 15, 14, 46, 16],

    // 24
    [6, 147, 117, 4, 148, 118],
    [6, 73, 45, 14, 74, 46],
    [11, 54, 24, 16, 55, 25],
    [30, 46, 16, 2, 47, 17],

    // 25
    [8, 132, 106, 4, 133, 107],
    [8, 75, 47, 13, 76, 48],
    [7, 54, 24, 22, 55, 25],
    [22, 45, 15, 13, 46, 16],

    // 26
    [10, 142, 114, 2, 143, 115],
    [19, 74, 46, 4, 75, 47],
    [28, 50, 22, 6, 51, 23],
    [33, 46, 16, 4, 47, 17],

    // 27
    [8, 152, 122, 4, 153, 123],
    [22, 73, 45, 3, 74, 46],
    [8, 53, 23, 26, 54, 24],
    [12, 45, 15, 28, 46, 16],

    // 28
    [3, 147, 117, 10, 148, 118],
    [3, 73, 45, 23, 74, 46],
    [4, 54, 24, 31, 55, 25],
    [11, 45, 15, 31, 46, 16],

    // 29
    [7, 146, 116, 7, 147, 117],
    [21, 73, 45, 7, 74, 46],
    [1, 53, 23, 37, 54, 24],
    [19, 45, 15, 26, 46, 16],

    // 30
    [5, 145, 115, 10, 146, 116],
    [19, 75, 47, 10, 76, 48],
    [15, 54, 24, 25, 55, 25],
    [23, 45, 15, 25, 46, 16],

    // 31
    [13, 145, 115, 3, 146, 116],
    [2, 74, 46, 29, 75, 47],
    [42, 54, 24, 1, 55, 25],
    [23, 45, 15, 28, 46, 16],

    // 32
    [17, 145, 115],
    [10, 74, 46, 23, 75, 47],
    [10, 54, 24, 35, 55, 25],
    [19, 45, 15, 35, 46, 16],

    // 33
    [17, 145, 115, 1, 146, 116],
    [14, 74, 46, 21, 75, 47],
    [29, 54, 24, 19, 55, 25],
    [11, 45, 15, 46, 46, 16],

    // 34
    [13, 145, 115, 6, 146, 116],
    [14, 74, 46, 23, 75, 47],
    [44, 54, 24, 7, 55, 25],
    [59, 46, 16, 1, 47, 17],

    // 35
    [12, 151, 121, 7, 152, 122],
    [12, 75, 47, 26, 76, 48],
    [39, 54, 24, 14, 55, 25],
    [22, 45, 15, 41, 46, 16],

    // 36
    [6, 151, 121, 14, 152, 122],
    [6, 75, 47, 34, 76, 48],
    [46, 54, 24, 10, 55, 25],
    [2, 45, 15, 64, 46, 16],

    // 37
    [17, 152, 122, 4, 153, 123],
    [29, 74, 46, 14, 75, 47],
    [49, 54, 24, 10, 55, 25],
    [24, 45, 15, 46, 46, 16],

    // 38
    [4, 152, 122, 18, 153, 123],
    [13, 74, 46, 32, 75, 47],
    [48, 54, 24, 14, 55, 25],
    [42, 45, 15, 32, 46, 16],

    // 39
    [20, 147, 117, 4, 148, 118],
    [40, 75, 47, 7, 76, 48],
    [43, 54, 24, 22, 55, 25],
    [10, 45, 15, 67, 46, 16],

    // 40
    [19, 148, 118, 6, 149, 119],
    [18, 75, 47, 31, 76, 48],
    [34, 54, 24, 34, 55, 25],
    [20, 45, 15, 61, 46, 16]
];

QRRSBlock.getRSBlocks = function(typeNumber, errorCorrectLevel) {

    var rsBlock = QRRSBlock.getRsBlockTable(typeNumber, errorCorrectLevel);

    if (rsBlock == undefined) {
        throw new Error("bad rs block @ typeNumber:" + typeNumber + "/errorCorrectLevel:" + errorCorrectLevel);
    }

    var length = rsBlock.length / 3;

    var list = new Array();

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

        var count = rsBlock[i * 3 + 0];
        var totalCount = rsBlock[i * 3 + 1];
        var dataCount  = rsBlock[i * 3 + 2];

        for (var j = 0; j < count; j++) {
            list.push(new QRRSBlock(totalCount, dataCount) );   
        }
    }

    return list;
}

QRRSBlock.getRsBlockTable = function(typeNumber, errorCorrectLevel) {

    switch(errorCorrectLevel) {
    case QRErrorCorrectLevel.L :
        return QRRSBlock.RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 0];
    case QRErrorCorrectLevel.M :
        return QRRSBlock.RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 1];
    case QRErrorCorrectLevel.Q :
        return QRRSBlock.RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 2];
    case QRErrorCorrectLevel.H :
        return QRRSBlock.RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 3];
    default :
        return undefined;
    }
}

//---------------------------------------------------------------------
// QRBitBuffer
//---------------------------------------------------------------------

function QRBitBuffer() {
    this.buffer = new Array();
    this.length = 0;
}

QRBitBuffer.prototype = {

    get : function(index) {
        var bufIndex = Math.floor(index / 8);
        return ( (this.buffer[bufIndex] >>> (7 - index % 8) ) & 1) == 1;
    },

    put : function(num, length) {
        for (var i = 0; i < length; i++) {
            this.putBit( ( (num >>> (length - i - 1) ) & 1) == 1);
        }
    },

    getLengthInBits : function() {
        return this.length;
    },

    putBit : function(bit) {

        var bufIndex = Math.floor(this.length / 8);
        if (this.buffer.length <= bufIndex) {
            this.buffer.push(0);
        }

        if (bit) {
            this.buffer[bufIndex] |= (0x80 >>> (this.length % 8) );
        }

        this.length++;
    }
};

module.exports = {
    toDataURL: function(text, opts) {
        var options = Object.assign({
            render : "canvas",
            width : 256,
            height : 256,
            typeNumber : -1,
            correctLevel : QRErrorCorrectLevel.H,
            background : "#ffffff",
            foreground : "#000000"
        }, opts);

        var qrcode = new QRCode(options.typeNumber, options.correctLevel);
        qrcode.addData(text);
        qrcode.make();

        // create canvas element
        var canvas = options.canvas || document.createElement('canvas');
        canvas.width = options.width;
        canvas.height = options.height;
        var ctx = canvas.getContext('2d');

        // compute tileW/tileH based on options.width/options.height
        var tileW = options.width / qrcode.getModuleCount();
        var tileH = options.height / qrcode.getModuleCount();

        // draw in the canvas
        for( var row = 0; row < qrcode.getModuleCount(); row++ ){
            for( var col = 0; col < qrcode.getModuleCount(); col++ ){
                ctx.fillStyle = qrcode.isDark(row, col) ? options.foreground : options.background;
                var w = (Math.ceil((col+1)*tileW) - Math.floor(col*tileW));
                var h = (Math.ceil((row+1)*tileW) - Math.floor(row*tileW));
                ctx.fillRect(Math.round(col*tileW),Math.round(row*tileH), w, h);  
            }   
        }
        var dataURL = canvas.toDataURL();
        return dataURL;
    }
}