newyqlm/utility/qrcode.js

//---------------------------------------------------------------------
//
// QR Code Generator 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
//
//---------------------------------------------------------------------


//---------------------------------------------------------------------
// qrcode
//---------------------------------------------------------------------

/**
 * qrcode
 * @param typeNumber 1 to 40
 * @param errorCorrectionLevel 'L','M','Q','H'
 */
export default function qrcode(typeNumber, errorCorrectionLevel) {

    var PAD0 = 0xEC;
    var PAD1 = 0x11;

    var _typeNumber = typeNumber;
    var _errorCorrectionLevel = QRErrorCorrectionLevel[errorCorrectionLevel];
    var _modules = null;
    var _moduleCount = 0;
    var _dataCache = null;
    var _dataList = [];

    var _this = {};

    var makeImpl = function(test, maskPattern) {

        _moduleCount = _typeNumber * 4 + 17;
        _modules = function(moduleCount) {
            var modules = new Array(moduleCount);
            for (var row = 0; row < moduleCount; row += 1) {
                modules[row] = new Array(moduleCount);
                for (var col = 0; col < moduleCount; col += 1) {
                    modules[row][col] = null;
                }
            }
            return modules;
        }(_moduleCount);

        setupPositionProbePattern(0, 0);
        setupPositionProbePattern(_moduleCount - 7, 0);
        setupPositionProbePattern(0, _moduleCount - 7);
        setupPositionAdjustPattern();
        setupTimingPattern();
        setupTypeInfo(test, maskPattern);

        if (_typeNumber >= 7) {
            setupTypeNumber(test);
        }

        if (_dataCache == null) {
            _dataCache = createData(_typeNumber, _errorCorrectionLevel, _dataList);
        }

        mapData(_dataCache, maskPattern);
    };

    var setupPositionProbePattern = function(row, col) {

        for (var r = -1; r <= 7; r += 1) {

            if (row + r <= -1 || _moduleCount <= row + r) continue;

            for (var c = -1; c <= 7; c += 1) {

                if (col + c <= -1 || _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) ) {
                    _modules[row + r][col + c] = true;
                } else {
                    _modules[row + r][col + c] = false;
                }
            }
        }
    };

    var getBestMaskPattern = function() {

        var minLostPoint = 0;
        var pattern = 0;

        for (var i = 0; i < 8; i += 1) {

            makeImpl(true, i);

            var lostPoint = QRUtil.getLostPoint(_this);

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

        return pattern;
    };

    var setupTimingPattern = function() {

        for (var r = 8; r < _moduleCount - 8; r += 1) {
            if (_modules[r][6] != null) {
                continue;
            }
            _modules[r][6] = (r % 2 == 0);
        }

        for (var c = 8; c < _moduleCount - 8; c += 1) {
            if (_modules[6][c] != null) {
                continue;
            }
            _modules[6][c] = (c % 2 == 0);
        }
    };

    var setupPositionAdjustPattern = function() {

        var pos = QRUtil.getPatternPosition(_typeNumber);

        for (var i = 0; i < pos.length; i += 1) {

            for (var j = 0; j < pos.length; j += 1) {

                var row = pos[i];
                var col = pos[j];

                if (_modules[row][col] != null) {
                    continue;
                }

                for (var r = -2; r <= 2; r += 1) {

                    for (var c = -2; c <= 2; c += 1) {

                        if (r == -2 || r == 2 || c == -2 || c == 2
                            || (r == 0 && c == 0) ) {
                            _modules[row + r][col + c] = true;
                        } else {
                            _modules[row + r][col + c] = false;
                        }
                    }
                }
            }
        }
    };

    var setupTypeNumber = function(test) {

        var bits = QRUtil.getBCHTypeNumber(_typeNumber);

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

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

    var setupTypeInfo = function(test, maskPattern) {

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

        // vertical
        for (var i = 0; i < 15; i += 1) {

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

            if (i < 6) {
                _modules[i][8] = mod;
            } else if (i < 8) {
                _modules[i + 1][8] = mod;
            } else {
                _modules[_moduleCount - 15 + i][8] = mod;
            }
        }

        // horizontal
        for (var i = 0; i < 15; i += 1) {

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

            if (i < 8) {
                _modules[8][_moduleCount - i - 1] = mod;
            } else if (i < 9) {
                _modules[8][15 - i - 1 + 1] = mod;
            } else {
                _modules[8][15 - i - 1] = mod;
            }
        }

        // fixed module
        _modules[_moduleCount - 8][8] = (!test);
    };

    var mapData = function(data, maskPattern) {

        var inc = -1;
        var row = _moduleCount - 1;
        var bitIndex = 7;
        var byteIndex = 0;
        var maskFunc = QRUtil.getMaskFunction(maskPattern);

        for (var col = _moduleCount - 1; col > 0; col -= 2) {

            if (col == 6) col -= 1;

            while (true) {

                for (var c = 0; c < 2; c += 1) {

                    if (_modules[row][col - c] == null) {

                        var dark = false;

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

                        var mask = maskFunc(row, col - c);

                        if (mask) {
                            dark = !dark;
                        }

                        _modules[row][col - c] = dark;
                        bitIndex -= 1;

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

                row += inc;

                if (row < 0 || _moduleCount <= row) {
                    row -= inc;
                    inc = -inc;
                    break;
                }
            }
        }
    };

    var 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 += 1) {

            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 += 1) {
                dcdata[r][i] = 0xff & buffer.getBuffer()[i + offset];
            }
            offset += dcCount;

            var rsPoly = QRUtil.getErrorCorrectPolynomial(ecCount);
            var rawPoly = 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 += 1) {
                var modIndex = i + modPoly.getLength() - ecdata[r].length;
                ecdata[r][i] = (modIndex >= 0)? modPoly.getAt(modIndex) : 0;
            }
        }

        var totalCodeCount = 0;
        for (var i = 0; i < rsBlocks.length; i += 1) {
            totalCodeCount += rsBlocks[i].totalCount;
        }

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

        for (var i = 0; i < maxDcCount; i += 1) {
            for (var r = 0; r < rsBlocks.length; r += 1) {
                if (i < dcdata[r].length) {
                    data[index] = dcdata[r][i];
                    index += 1;
                }
            }
        }

        for (var i = 0; i < maxEcCount; i += 1) {
            for (var r = 0; r < rsBlocks.length; r += 1) {
                if (i < ecdata[r].length) {
                    data[index] = ecdata[r][i];
                    index += 1;
                }
            }
        }

        return data;
    };

    var createData = function(typeNumber, errorCorrectionLevel, dataList) {

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

        var buffer = qrBitBuffer();

        for (var i = 0; i < dataList.length; i += 1) {
            var data = dataList[i];
            buffer.put(data.getMode(), 4);
            buffer.put(data.getLength(), QRUtil.getLengthInBits(data.getMode(), typeNumber) );
            data.write(buffer);
        }

        // calc num max data.
        var totalDataCount = 0;
        for (var i = 0; i < rsBlocks.length; i += 1) {
            totalDataCount += rsBlocks[i].dataCount;
        }

        if (buffer.getLengthInBits() > totalDataCount * 8) {
            throw '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(PAD0, 8);

            if (buffer.getLengthInBits() >= totalDataCount * 8) {
                break;
            }
            buffer.put(PAD1, 8);
        }

        return createBytes(buffer, rsBlocks);
    };

    _this.addData = function(data, mode) {

        mode = mode || 'Byte';

        var newData = null;

        switch(mode) {
            case 'Numeric' :
                newData = qrNumber(data);
                break;
            case 'Alphanumeric' :
                newData = qrAlphaNum(data);
                break;
            case 'Byte' :
                newData = qr8BitByte(data);
                break;
            case 'Kanji' :
                newData = qrKanji(data);
                break;
            default :
                throw 'mode:' + mode;
        }

        _dataList.push(newData);
        _dataCache = null;
    };

    _this.isDark = function(row, col) {
        if (row < 0 || _moduleCount <= row || col < 0 || _moduleCount <= col) {
            throw row + ',' + col;
        }
        return _modules[row][col];
    };

    _this.getModuleCount = function() {
        return _moduleCount;
    };

    _this.make = function() {
        if (_typeNumber < 1) {
            var typeNumber = 1;

            for (; typeNumber < 40; typeNumber++) {
                var rsBlocks = QRRSBlock.getRSBlocks(typeNumber, _errorCorrectionLevel);
                var buffer = qrBitBuffer();

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

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

                if (buffer.getLengthInBits() <= totalDataCount * 8) {
                    break;
                }
            }

            _typeNumber = typeNumber;
        }

        makeImpl(false, getBestMaskPattern() );
    };

    _this.createTableTag = function(cellSize, margin) {

        cellSize = cellSize || 2;
        margin = (typeof margin == 'undefined')? cellSize * 4 : margin;

        var qrHtml = '';

        qrHtml += '<table style="';
        qrHtml += ' border-width: 0px; border-style: none;';
        qrHtml += ' border-collapse: collapse;';
        qrHtml += ' padding: 0px; margin: ' + margin + 'px;';
        qrHtml += '">';
        qrHtml += '<tbody>';

        for (var r = 0; r < _this.getModuleCount(); r += 1) {

            qrHtml += '<tr>';

            for (var c = 0; c < _this.getModuleCount(); c += 1) {
                qrHtml += '<td style="';
                qrHtml += ' border-width: 0px; border-style: none;';
                qrHtml += ' border-collapse: collapse;';
                qrHtml += ' padding: 0px; margin: 0px;';
                qrHtml += ' width: ' + cellSize + 'px;';
                qrHtml += ' height: ' + cellSize + 'px;';
                qrHtml += ' background-color: ';
                qrHtml += _this.isDark(r, c)? '#000000' : '#ffffff';
                qrHtml += ';';
                qrHtml += '"/>';
            }

            qrHtml += '</tr>';
        }

        qrHtml += '</tbody>';
        qrHtml += '</table>';

        return qrHtml;
    };

    _this.createSvgTag = function(cellSize, margin) {

        var opts = {};
        if (typeof arguments[0] == 'object') {
            // Called by options.
            opts = arguments[0];
            // overwrite cellSize and margin.
            cellSize = opts.cellSize;
            margin = opts.margin;
        }

        cellSize = cellSize || 2;
        margin = (typeof margin == 'undefined')? cellSize * 4 : margin;
        var size = _this.getModuleCount() * cellSize + margin * 2;
        var c, mc, r, mr, qrSvg='', rect;

        rect = 'l' + cellSize + ',0 0,' + cellSize +
            ' -' + cellSize + ',0 0,-' + cellSize + 'z ';

        qrSvg += '<svg version="1.1" xmlns="http://www.w3.org/2000/svg"';
        qrSvg += !opts.scalable ? ' width="' + size + 'px" height="' + size + 'px"' : '';
        qrSvg += ' viewBox="0 0 ' + size + ' ' + size + '" ';
        qrSvg += ' preserveAspectRatio="xMinYMin meet">';
        qrSvg += '<rect width="100%" height="100%" fill="white" cx="0" cy="0"/>';
        qrSvg += '<path d="';

        for (r = 0; r < _this.getModuleCount(); r += 1) {
            mr = r * cellSize + margin;
            for (c = 0; c < _this.getModuleCount(); c += 1) {
                if (_this.isDark(r, c) ) {
                    mc = c*cellSize+margin;
                    qrSvg += 'M' + mc + ',' + mr + rect;
                }
            }
        }

        qrSvg += '" stroke="transparent" fill="black"/>';
        qrSvg += '</svg>';

        return qrSvg;
    };

    _this.createDataURL = function(cellSize, margin) {

        cellSize = cellSize || 2;
        margin = (typeof margin == 'undefined')? cellSize * 4 : margin;

        var size = _this.getModuleCount() * cellSize + margin * 2;
        var min = margin;
        var max = size - margin;

        return createDataURL(size, size, function(x, y) {
            if (min <= x && x < max && min <= y && y < max) {
                var c = Math.floor( (x - min) / cellSize);
                var r = Math.floor( (y - min) / cellSize);
                return _this.isDark(r, c)? 0 : 1;
            } else {
                return 1;
            }
        } );
    };

    _this.createImgTag = function(cellSize, margin, alt) {

        cellSize = cellSize || 2;
        margin = (typeof margin == 'undefined')? cellSize * 4 : margin;

        var size = _this.getModuleCount() * cellSize + margin * 2;

        var img = '';
        img += '<img';
        img += '\u0020src="';
        img += _this.createDataURL(cellSize, margin);
        img += '"';
        img += '\u0020width="';
        img += size;
        img += '"';
        img += '\u0020height="';
        img += size;
        img += '"';
        if (alt) {
            img += '\u0020alt="';
            img += alt;
            img += '"';
        }
        img += '/>';

        return img;
    };

    var _createHalfASCII = function(margin) {
        var cellSize = 1;
        margin = (typeof margin == 'undefined')? cellSize * 2 : margin;

        var size = _this.getModuleCount() * cellSize + margin * 2;
        var min = margin;
        var max = size - margin;

        var y, x, r1, r2, p;

        var blocks = {
            '██': '█',
            '█ ': '▀',
            ' █': '▄',
            '  ': ' '
        };

        var blocksLastLineNoMargin = {
            '██': '▀',
            '█ ': '▀',
            ' █': ' ',
            '  ': ' '
        };

        var ascii = '';
        for (y = 0; y < size; y += 2) {
            r1 = Math.floor((y - min) / cellSize);
            r2 = Math.floor((y + 1 - min) / cellSize);
            for (x = 0; x < size; x += 1) {
                p = '█';

                if (min <= x && x < max && min <= y && y < max && _this.isDark(r1, Math.floor((x - min) / cellSize))) {
                    p = ' ';
                }

                if (min <= x && x < max && min <= y+1 && y+1 < max && _this.isDark(r2, Math.floor((x - min) / cellSize))) {
                    p += ' ';
                }
                else {
                    p += '█';
                }

                // Output 2 characters per pixel, to create full square. 1 character per pixels gives only half width of square.
                ascii += (margin < 1 && y+1 >= max) ? blocksLastLineNoMargin[p] : blocks[p];
            }

            ascii += '\n';
        }

        if (size % 2 && margin > 0) {
            return ascii.substring(0, ascii.length - size - 1) + Array(size+1).join('▀');
        }

        return ascii.substring(0, ascii.length-1);
    };

    _this.createASCII = function(cellSize, margin) {
        cellSize = cellSize || 1;

        if (cellSize < 2) {
            return _createHalfASCII(margin);
        }

        cellSize -= 1;
        margin = (typeof margin == 'undefined')? cellSize * 2 : margin;

        var size = _this.getModuleCount() * cellSize + margin * 2;
        var min = margin;
        var max = size - margin;

        var y, x, r, p;

        var white = Array(cellSize+1).join('██');
        var black = Array(cellSize+1).join('  ');

        var ascii = '';
        var line = '';
        for (y = 0; y < size; y += 1) {
            r = Math.floor( (y - min) / cellSize);
            line = '';
            for (x = 0; x < size; x += 1) {
                p = 1;

                if (min <= x && x < max && min <= y && y < max && _this.isDark(r, Math.floor((x - min) / cellSize))) {
                    p = 0;
                }

                // Output 2 characters per pixel, to create full square. 1 character per pixels gives only half width of square.
                line += p ? white : black;
            }

            for (r = 0; r < cellSize; r += 1) {
                ascii += line + '\n';
            }
        }

        return ascii.substring(0, ascii.length-1);
    };

    _this.renderTo2dContext = function(context, cellSize) {
        cellSize = cellSize || 2;
        var length = _this.getModuleCount();
        for (var row = 0; row < length; row++) {
            for (var col = 0; col < length; col++) {
                context.fillStyle = _this.isDark(row, col) ? 'black' : 'white';
                context.fillRect(row * cellSize, col * cellSize, cellSize, cellSize);
            }
        }
    }

    return _this;
};

//---------------------------------------------------------------------
// qrcode.stringToBytes
//---------------------------------------------------------------------

qrcode.stringToBytesFuncs = {
    'default' : function(s) {
        var bytes = [];
        for (var i = 0; i < s.length; i += 1) {
            var c = s.charCodeAt(i);
            bytes.push(c & 0xff);
        }
        return bytes;
    }
};

qrcode.stringToBytes = qrcode.stringToBytesFuncs['default'];


// /**
//  * @param unicodeData base64 string of byte array.
//  * [16bit Unicode],[16bit Bytes], ...
//  * @param numChars
//  */
// qrcode.createStringToBytes = function(unicodeData, numChars) {
//
//     // create conversion map.
//
//     var unicodeMap = function() {
//
//         var bin = base64DecodeInputStream(unicodeData);
//         var read = function() {
//             var b = bin.read();
//             if (b == -1) throw 'eof';
//             return b;
//         };
//
//         var count = 0;
//         var unicodeMap = {};
//         while (true) {
//             var b0 = bin.read();
//             if (b0 == -1) break;
//             var b1 = read();
//             var b2 = read();
//             var b3 = read();
//             var k = String.fromCharCode( (b0 << 8) | b1);
//             var v = (b2 << 8) | b3;
//             unicodeMap[k] = v;
//             count += 1;
//         }
//         if (count != numChars) {
//             throw count + ' != ' + numChars;
//         }
//
//         return unicodeMap;
//     }();
//
//     var unknownChar = '?'.charCodeAt(0);
//
//     return function(s) {
//         var bytes = [];
//         for (var i = 0; i < s.length; i += 1) {
//             var c = s.charCodeAt(i);
//             if (c < 128) {
//                 bytes.push(c);
//             } else {
//                 var b = unicodeMap[s.charAt(i)];
//                 if (typeof b == 'number') {
//                     if ( (b & 0xff) == b) {
//                         // 1byte
//                         bytes.push(b);
//                     } else {
//                         // 2bytes
//                         bytes.push(b >>> 8);
//                         bytes.push(b & 0xff);
//                     }
//                 } else {
//                     bytes.push(unknownChar);
//                 }
//             }
//         }
//         return bytes;
//     };
// };

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

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

//---------------------------------------------------------------------
// QRErrorCorrectionLevel
//---------------------------------------------------------------------

var QRErrorCorrectionLevel = {
    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 = function() {

    var 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]
    ];
    var G15 = (1 << 10) | (1 << 8) | (1 << 5) | (1 << 4) | (1 << 2) | (1 << 1) | (1 << 0);
    var G18 = (1 << 12) | (1 << 11) | (1 << 10) | (1 << 9) | (1 << 8) | (1 << 5) | (1 << 2) | (1 << 0);
    var G15_MASK = (1 << 14) | (1 << 12) | (1 << 10) | (1 << 4) | (1 << 1);

    var _this = {};

    var getBCHDigit = function(data) {
        var digit = 0;
        while (data != 0) {
            digit += 1;
            data >>>= 1;
        }
        return digit;
    };

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

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

    _this.getPatternPosition = function(typeNumber) {
        return PATTERN_POSITION_TABLE[typeNumber - 1];
    };

    _this.getMaskFunction = function(maskPattern) {

        switch (maskPattern) {

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

            default :
                throw 'bad maskPattern:' + maskPattern;
        }
    };

    _this.getErrorCorrectPolynomial = function(errorCorrectLength) {
        var a = qrPolynomial([1], 0);
        for (var i = 0; i < errorCorrectLength; i += 1) {
            a = a.multiply(qrPolynomial([1, QRMath.gexp(i)], 0) );
        }
        return a;
    };

    _this.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 '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 '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 'mode:' + mode;
            }

        } else {
            throw 'type:' + type;
        }
    };

    _this.getLostPoint = function(qrcode) {

        var moduleCount = qrcode.getModuleCount();

        var lostPoint = 0;

        // LEVEL1

        for (var row = 0; row < moduleCount; row += 1) {
            for (var col = 0; col < moduleCount; col += 1) {

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

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

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

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

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

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

                        if (dark == qrcode.isDark(row + r, col + c) ) {
                            sameCount += 1;
                        }
                    }
                }

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

        // LEVEL2

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

        // LEVEL3

        for (var row = 0; row < moduleCount; row += 1) {
            for (var col = 0; col < moduleCount - 6; col += 1) {
                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 += 1) {
            for (var row = 0; row < moduleCount - 6; row += 1) {
                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 += 1) {
            for (var row = 0; row < moduleCount; row += 1) {
                if (qrcode.isDark(row, col) ) {
                    darkCount += 1;
                }
            }
        }

        var ratio = Math.abs(100 * darkCount / moduleCount / moduleCount - 50) / 5;
        lostPoint += ratio * 10;

        return lostPoint;
    };

    return _this;
}();

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

var QRMath = function() {

    var EXP_TABLE = new Array(256);
    var LOG_TABLE = new Array(256);

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

    var _this = {};

    _this.glog = function(n) {

        if (n < 1) {
            throw 'glog(' + n + ')';
        }

        return LOG_TABLE[n];
    };

    _this.gexp = function(n) {

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

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

        return EXP_TABLE[n];
    };

    return _this;
}();

//---------------------------------------------------------------------
// qrPolynomial
//---------------------------------------------------------------------

function qrPolynomial(num, shift) {

    if (typeof num.length == 'undefined') {
        throw num.length + '/' + shift;
    }

    var _num = function() {
        var offset = 0;
        while (offset < num.length && num[offset] == 0) {
            offset += 1;
        }
        var _num = new Array(num.length - offset + shift);
        for (var i = 0; i < num.length - offset; i += 1) {
            _num[i] = num[i + offset];
        }
        return _num;
    }();

    var _this = {};

    _this.getAt = function(index) {
        return _num[index];
    };

    _this.getLength = function() {
        return _num.length;
    };

    _this.multiply = function(e) {

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

        for (var i = 0; i < _this.getLength(); i += 1) {
            for (var j = 0; j < e.getLength(); j += 1) {
                num[i + j] ^= QRMath.gexp(QRMath.glog(_this.getAt(i) ) + QRMath.glog(e.getAt(j) ) );
            }
        }

        return qrPolynomial(num, 0);
    };

    _this.mod = function(e) {

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

        var ratio = QRMath.glog(_this.getAt(0) ) - QRMath.glog(e.getAt(0) );

        var num = new Array(_this.getLength() );
        for (var i = 0; i < _this.getLength(); i += 1) {
            num[i] = _this.getAt(i);
        }

        for (var i = 0; i < e.getLength(); i += 1) {
            num[i] ^= QRMath.gexp(QRMath.glog(e.getAt(i) ) + ratio);
        }

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

    return _this;
};

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

var QRRSBlock = function() {

    var 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, 7, 37, 13],

        // 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]
    ];

    var qrRSBlock = function(totalCount, dataCount) {
        var _this = {};
        _this.totalCount = totalCount;
        _this.dataCount = dataCount;
        return _this;
    };

    var _this = {};

    var getRsBlockTable = function(typeNumber, errorCorrectionLevel) {

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

    _this.getRSBlocks = function(typeNumber, errorCorrectionLevel) {

        var rsBlock = getRsBlockTable(typeNumber, errorCorrectionLevel);

        if (typeof rsBlock == 'undefined') {
            throw 'bad rs block @ typeNumber:' + typeNumber +
            '/errorCorrectionLevel:' + errorCorrectionLevel;
        }

        var length = rsBlock.length / 3;

        var list = [];

        for (var i = 0; i < length; i += 1) {

            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 += 1) {
                list.push(qrRSBlock(totalCount, dataCount) );
            }
        }

        return list;
    };

    return _this;
}();

//---------------------------------------------------------------------
// qrBitBuffer
//---------------------------------------------------------------------

var qrBitBuffer = function() {

    var _buffer = [];
    var _length = 0;

    var _this = {};

    _this.getBuffer = function() {
        return _buffer;
    };

    _this.getAt = function(index) {
        var bufIndex = Math.floor(index / 8);
        return ( (_buffer[bufIndex] >>> (7 - index % 8) ) & 1) == 1;
    };

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

    _this.getLengthInBits = function() {
        return _length;
    };

    _this.putBit = function(bit) {

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

        if (bit) {
            _buffer[bufIndex] |= (0x80 >>> (_length % 8) );
        }

        _length += 1;
    };

    return _this;
};

//---------------------------------------------------------------------
// qrNumber
//---------------------------------------------------------------------

var qrNumber = function(data) {

    var _mode = QRMode.MODE_NUMBER;
    var _data = data;

    var _this = {};

    _this.getMode = function() {
        return _mode;
    };

    _this.getLength = function(buffer) {
        return _data.length;
    };

    _this.write = function(buffer) {

        var data = _data;

        var i = 0;

        while (i + 2 < data.length) {
            buffer.put(strToNum(data.substring(i, i + 3) ), 10);
            i += 3;
        }

        if (i < data.length) {
            if (data.length - i == 1) {
                buffer.put(strToNum(data.substring(i, i + 1) ), 4);
            } else if (data.length - i == 2) {
                buffer.put(strToNum(data.substring(i, i + 2) ), 7);
            }
        }
    };

    var strToNum = function(s) {
        var num = 0;
        for (var i = 0; i < s.length; i += 1) {
            num = num * 10 + chatToNum(s.charAt(i) );
        }
        return num;
    };

    var chatToNum = function(c) {
        if ('0' <= c && c <= '9') {
            return c.charCodeAt(0) - '0'.charCodeAt(0);
        }
        throw 'illegal char :' + c;
    };

    return _this;
};

//---------------------------------------------------------------------
// qrAlphaNum
//---------------------------------------------------------------------

var qrAlphaNum = function(data) {

    var _mode = QRMode.MODE_ALPHA_NUM;
    var _data = data;

    var _this = {};

    _this.getMode = function() {
        return _mode;
    };

    _this.getLength = function(buffer) {
        return _data.length;
    };

    _this.write = function(buffer) {

        var s = _data;

        var i = 0;

        while (i + 1 < s.length) {
            buffer.put(
                getCode(s.charAt(i) ) * 45 +
                getCode(s.charAt(i + 1) ), 11);
            i += 2;
        }

        if (i < s.length) {
            buffer.put(getCode(s.charAt(i) ), 6);
        }
    };

    var getCode = function(c) {

        if ('0' <= c && c <= '9') {
            return c.charCodeAt(0) - '0'.charCodeAt(0);
        } else if ('A' <= c && c <= 'Z') {
            return c.charCodeAt(0) - 'A'.charCodeAt(0) + 10;
        } else {
            switch (c) {
                case ' ' : return 36;
                case '$' : return 37;
                case '%' : return 38;
                case '*' : return 39;
                case '+' : return 40;
                case '-' : return 41;
                case '.' : return 42;
                case '/' : return 43;
                case ':' : return 44;
                default :
                    throw 'illegal char :' + c;
            }
        }
    };

    return _this;
};

//---------------------------------------------------------------------
// qr8BitByte
//---------------------------------------------------------------------

var qr8BitByte = function(data) {

    var _mode = QRMode.MODE_8BIT_BYTE;
    var _data = data;
    var _bytes = qrcode.stringToBytes(data);

    var _this = {};

    _this.getMode = function() {
        return _mode;
    };

    _this.getLength = function(buffer) {
        return _bytes.length;
    };

    _this.write = function(buffer) {
        for (var i = 0; i < _bytes.length; i += 1) {
            buffer.put(_bytes[i], 8);
        }
    };

    return _this;
};

//---------------------------------------------------------------------
// qrKanji
//---------------------------------------------------------------------

var qrKanji = function(data) {

    var _mode = QRMode.MODE_KANJI;
    var _data = data;

    var stringToBytes = qrcode.stringToBytesFuncs['SJIS'];
    if (!stringToBytes) {
        throw 'sjis not supported.';
    }
    !function(c, code) {
        // self test for sjis support.
        var test = stringToBytes(c);
        if (test.length != 2 || ( (test[0] << 8) | test[1]) != code) {
            throw 'sjis not supported.';
        }
    }('\u53cb', 0x9746);

    var _bytes = stringToBytes(data);

    var _this = {};

    _this.getMode = function() {
        return _mode;
    };

    _this.getLength = function(buffer) {
        return ~~(_bytes.length / 2);
    };

    _this.write = function(buffer) {

        var data = _bytes;

        var i = 0;

        while (i + 1 < data.length) {

            var c = ( (0xff & data[i]) << 8) | (0xff & data[i + 1]);

            if (0x8140 <= c && c <= 0x9FFC) {
                c -= 0x8140;
            } else if (0xE040 <= c && c <= 0xEBBF) {
                c -= 0xC140;
            } else {
                throw 'illegal char at ' + (i + 1) + '/' + c;
            }

            c = ( (c >>> 8) & 0xff) * 0xC0 + (c & 0xff);

            buffer.put(c, 13);

            i += 2;
        }

        if (i < data.length) {
            throw 'illegal char at ' + (i + 1);
        }
    };

    return _this;
};

//=====================================================================
// GIF Support etc.
//

//---------------------------------------------------------------------
// byteArrayOutputStream
//---------------------------------------------------------------------

var byteArrayOutputStream = function() {

    var _bytes = [];

    var _this = {};

    _this.writeByte = function(b) {
        _bytes.push(b & 0xff);
    };

    _this.writeShort = function(i) {
        _this.writeByte(i);
        _this.writeByte(i >>> 8);
    };

    _this.writeBytes = function(b, off, len) {
        off = off || 0;
        len = len || b.length;
        for (var i = 0; i < len; i += 1) {
            _this.writeByte(b[i + off]);
        }
    };

    _this.writeString = function(s) {
        for (var i = 0; i < s.length; i += 1) {
            _this.writeByte(s.charCodeAt(i) );
        }
    };

    _this.toByteArray = function() {
        return _bytes;
    };

    _this.toString = function() {
        var s = '';
        s += '[';
        for (var i = 0; i < _bytes.length; i += 1) {
            if (i > 0) {
                s += ',';
            }
            s += _bytes[i];
        }
        s += ']';
        return s;
    };

    return _this;
};

//---------------------------------------------------------------------
// base64EncodeOutputStream
//---------------------------------------------------------------------

var base64EncodeOutputStream = function() {

    var _buffer = 0;
    var _buflen = 0;
    var _length = 0;
    var _base64 = '';

    var _this = {};

    var writeEncoded = function(b) {
        _base64 += String.fromCharCode(encode(b & 0x3f) );
    };

    var encode = function(n) {
        if (n < 0) {
            // error.
        } else if (n < 26) {
            return 0x41 + n;
        } else if (n < 52) {
            return 0x61 + (n - 26);
        } else if (n < 62) {
            return 0x30 + (n - 52);
        } else if (n == 62) {
            return 0x2b;
        } else if (n == 63) {
            return 0x2f;
        }
        throw 'n:' + n;
    };

    _this.writeByte = function(n) {

        _buffer = (_buffer << 8) | (n & 0xff);
        _buflen += 8;
        _length += 1;

        while (_buflen >= 6) {
            writeEncoded(_buffer >>> (_buflen - 6) );
            _buflen -= 6;
        }
    };

    _this.flush = function() {

        if (_buflen > 0) {
            writeEncoded(_buffer << (6 - _buflen) );
            _buffer = 0;
            _buflen = 0;
        }

        if (_length % 3 != 0) {
            // padding
            var padlen = 3 - _length % 3;
            for (var i = 0; i < padlen; i += 1) {
                _base64 += '=';
            }
        }
    };

    _this.toString = function() {
        return _base64;
    };

    return _this;
};


//---------------------------------------------------------------------
// gifImage (B/W)
//---------------------------------------------------------------------

var gifImage = function(width, height) {

    var _width = width;
    var _height = height;
    var _data = new Array(width * height);

    var _this = {};

    _this.setPixel = function(x, y, pixel) {
        _data[y * _width + x] = pixel;
    };

    _this.write = function(out) {

        //---------------------------------
        // GIF Signature

        out.writeString('GIF87a');

        //---------------------------------
        // Screen Descriptor

        out.writeShort(_width);
        out.writeShort(_height);

        out.writeByte(0x80); // 2bit
        out.writeByte(0);
        out.writeByte(0);

        //---------------------------------
        // Global Color Map

        // black
        out.writeByte(0x00);
        out.writeByte(0x00);
        out.writeByte(0x00);

        // white
        out.writeByte(0xff);
        out.writeByte(0xff);
        out.writeByte(0xff);

        //---------------------------------
        // Image Descriptor

        out.writeString(',');
        out.writeShort(0);
        out.writeShort(0);
        out.writeShort(_width);
        out.writeShort(_height);
        out.writeByte(0);

        //---------------------------------
        // Local Color Map

        //---------------------------------
        // Raster Data

        var lzwMinCodeSize = 2;
        var raster = getLZWRaster(lzwMinCodeSize);

        out.writeByte(lzwMinCodeSize);

        var offset = 0;

        while (raster.length - offset > 255) {
            out.writeByte(255);
            out.writeBytes(raster, offset, 255);
            offset += 255;
        }

        out.writeByte(raster.length - offset);
        out.writeBytes(raster, offset, raster.length - offset);
        out.writeByte(0x00);

        //---------------------------------
        // GIF Terminator
        out.writeString(';');
    };

    var bitOutputStream = function(out) {

        var _out = out;
        var _bitLength = 0;
        var _bitBuffer = 0;

        var _this = {};

        _this.write = function(data, length) {

            if ( (data >>> length) != 0) {
                throw 'length over';
            }

            while (_bitLength + length >= 8) {
                _out.writeByte(0xff & ( (data << _bitLength) | _bitBuffer) );
                length -= (8 - _bitLength);
                data >>>= (8 - _bitLength);
                _bitBuffer = 0;
                _bitLength = 0;
            }

            _bitBuffer = (data << _bitLength) | _bitBuffer;
            _bitLength = _bitLength + length;
        };

        _this.flush = function() {
            if (_bitLength > 0) {
                _out.writeByte(_bitBuffer);
            }
        };

        return _this;
    };

    var getLZWRaster = function(lzwMinCodeSize) {

        var clearCode = 1 << lzwMinCodeSize;
        var endCode = (1 << lzwMinCodeSize) + 1;
        var bitLength = lzwMinCodeSize + 1;

        // Setup LZWTable
        var table = lzwTable();

        for (var i = 0; i < clearCode; i += 1) {
            table.add(String.fromCharCode(i) );
        }
        table.add(String.fromCharCode(clearCode) );
        table.add(String.fromCharCode(endCode) );

        var byteOut = byteArrayOutputStream();
        var bitOut = bitOutputStream(byteOut);

        // clear code
        bitOut.write(clearCode, bitLength);

        var dataIndex = 0;

        var s = String.fromCharCode(_data[dataIndex]);
        dataIndex += 1;

        while (dataIndex < _data.length) {

            var c = String.fromCharCode(_data[dataIndex]);
            dataIndex += 1;

            if (table.contains(s + c) ) {

                s = s + c;

            } else {

                bitOut.write(table.indexOf(s), bitLength);

                if (table.size() < 0xfff) {

                    if (table.size() == (1 << bitLength) ) {
                        bitLength += 1;
                    }

                    table.add(s + c);
                }

                s = c;
            }
        }

        bitOut.write(table.indexOf(s), bitLength);

        // end code
        bitOut.write(endCode, bitLength);

        bitOut.flush();

        return byteOut.toByteArray();
    };

    var lzwTable = function() {

        var _map = {};
        var _size = 0;

        var _this = {};

        _this.add = function(key) {
            if (_this.contains(key) ) {
                throw 'dup key:' + key;
            }
            _map[key] = _size;
            _size += 1;
        };

        _this.size = function() {
            return _size;
        };

        _this.indexOf = function(key) {
            return _map[key];
        };

        _this.contains = function(key) {
            return typeof _map[key] != 'undefined';
        };

        return _this;
    };

    return _this;
};

var createDataURL = function(width, height, getPixel) {
    var gif = gifImage(width, height);
    for (var y = 0; y < height; y += 1) {
        for (var x = 0; x < width; x += 1) {
            gif.setPixel(x, y, getPixel(x, y) );
        }
    }

    var b = byteArrayOutputStream();
    gif.write(b);

    var base64 = base64EncodeOutputStream();
    var bytes = b.toByteArray();
    for (var i = 0; i < bytes.length; i += 1) {
        base64.writeByte(bytes[i]);
    }
    base64.flush();

    return 'data:image/gif;base64,' + base64;
};



qrcode.stringToBytesFuncs['UTF-8'] = function(s) {
    // http://stackoverflow.com/questions/18729405/how-to-convert-utf8-string-to-byte-array
    function toUTF8Array(str) {
        var utf8 = [];
        for (var i=0; i < str.length; i++) {
            var charcode = str.charCodeAt(i);
            if (charcode < 0x80) utf8.push(charcode);
            else if (charcode < 0x800) {
                utf8.push(0xc0 | (charcode >> 6),
                    0x80 | (charcode & 0x3f));
            }
            else if (charcode < 0xd800 || charcode >= 0xe000) {
                utf8.push(0xe0 | (charcode >> 12),
                    0x80 | ((charcode>>6) & 0x3f),
                    0x80 | (charcode & 0x3f));
            }
            // surrogate pair
            else {
                i++;
                // UTF-16 encodes 0x10000-0x10FFFF by
                // subtracting 0x10000 and splitting the
                // 20 bits of 0x0-0xFFFFF into two halves
                charcode = 0x10000 + (((charcode & 0x3ff)<<10)
                    | (str.charCodeAt(i) & 0x3ff));
                utf8.push(0xf0 | (charcode >>18),
                    0x80 | ((charcode>>12) & 0x3f),
                    0x80 | ((charcode>>6) & 0x3f),
                    0x80 | (charcode & 0x3f));
            }
        }
        return utf8;
    }
    return toUTF8Array(s);
};