zhapp/common/wxqrcode.js

//---------------------------------------------------------------------
// qrcode
//代码第1588行为补充代码
//---------------------------------------------------------------------

/**
 * qrcode
 * @param typeNumber 1 to 40 
 * @param errorCorrectLevel 'L','M','Q','H'
 */
var qrcode = function(typeNumber, errorCorrectLevel) {

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

	var _typeNumber = typeNumber;
	var _errorCorrectLevel = QRErrorCorrectLevel[errorCorrectLevel];
	var _modules = null;
	var _moduleCount = 0;
	var _dataCache = null;
	var _dataList = new Array();

	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, _errorCorrectLevel, _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 = (_errorCorrectLevel << 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, errorCorrectLevel, dataList) {

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

		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 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(PAD0, 8);

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

		return createBytes(buffer, rsBlocks);
	};

	_this.addData = function(data) {
		var newData = qr8BitByte(data);
		_dataList.push(newData);
		_dataCache = null;
	};

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

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

	_this.make = function() {
		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.createImgTag = function(cellSize, margin, size) {

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

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

		return createImgTag(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;
			}
		});
	};

	return _this;
};

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

qrcode.stringToBytes = function(s) {
	var bytes = new Array();
	for (var i = 0; i < s.length; i += 1) {
		var c = s.charCodeAt(i);
		bytes.push(c & 0xff);
	}
	return bytes;
};

//---------------------------------------------------------------------
// qrcode.createStringToBytes
//---------------------------------------------------------------------

/**
 * @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 new Error();
			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 new Error(count + ' != ' + numChars);
		}

		return unicodeMap;
	}();

	var unknownChar = '?'.charCodeAt(0);

	return function(s) {
		var bytes = new Array();
		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
};

//---------------------------------------------------------------------
// 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 = 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 new Error('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 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);
		}
	};

	_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 new Error('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 new Error(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() {


	// [1: [L, M, Q, H], ..]
	var RS_BLOCK_TABLE = [
		[1, 26, 19],
		[1, 26, 16],
		[1, 26, 13],
		[1, 26, 9],
		[1, 44, 34],
		[1, 44, 28],
		[1, 44, 22],
		[1, 44, 16],
		[1, 70, 55],
		[1, 70, 44],
		[2, 35, 17],
		[2, 35, 13],
		[1, 100, 80],
		[2, 50, 32],
		[2, 50, 24],
		[4, 25, 9],
		[1, 134, 108],
		[2, 67, 43],
		[2, 33, 15, 2, 34, 16],
		[2, 33, 11, 2, 34, 12],
		[2, 86, 68],
		[4, 43, 27],
		[4, 43, 19],
		[4, 43, 15],
		[2, 98, 78],
		[4, 49, 31],
		[2, 32, 14, 4, 33, 15],
		[4, 39, 13, 1, 40, 14],
		[2, 121, 97],
		[2, 60, 38, 2, 61, 39],
		[4, 40, 18, 2, 41, 19],
		[4, 40, 14, 2, 41, 15],
		[2, 146, 116],
		[3, 58, 36, 2, 59, 37],
		[4, 36, 16, 4, 37, 17],
		[4, 36, 12, 4, 37, 13],
		[2, 86, 68, 2, 87, 69],
		[4, 69, 43, 1, 70, 44],
		[6, 43, 19, 2, 44, 20],
		[6, 43, 15, 2, 44, 16],
		[4, 101, 81],
		[1, 80, 50, 4, 81, 51],
		[4, 50, 22, 4, 51, 23],
		[3, 36, 12, 8, 37, 13],
		[2, 116, 92, 2, 117, 93],
		[6, 58, 36, 2, 59, 37],
		[4, 46, 20, 6, 47, 21],
		[7, 42, 14, 4, 43, 15],
		[4, 133, 107],
		[8, 59, 37, 1, 60, 38],
		[8, 44, 20, 4, 45, 21],
		[12, 33, 11, 4, 34, 12],
		[3, 145, 115, 1, 146, 116],
		[4, 64, 40, 5, 65, 41],
		[11, 36, 16, 5, 37, 17],
		[11, 36, 12, 5, 37, 13],
		[5, 109, 87, 1, 110, 88],
		[5, 65, 41, 5, 66, 42],
		[5, 54, 24, 7, 55, 25],
		[11, 36, 12],
		[5, 122, 98, 1, 123, 99],
		[7, 73, 45, 3, 74, 46],
		[15, 43, 19, 2, 44, 20],
		[3, 45, 15, 13, 46, 16],
		[1, 135, 107, 5, 136, 108],
		[10, 74, 46, 1, 75, 47],
		[1, 50, 22, 15, 51, 23],
		[2, 42, 14, 17, 43, 15],
		[5, 150, 120, 1, 151, 121],
		[9, 69, 43, 4, 70, 44],
		[17, 50, 22, 1, 51, 23],
		[2, 42, 14, 19, 43, 15],
		[3, 141, 113, 4, 142, 114],
		[3, 70, 44, 11, 71, 45],
		[17, 47, 21, 4, 48, 22],
		[9, 39, 13, 16, 40, 14],
		[3, 135, 107, 5, 136, 108],
		[3, 67, 41, 13, 68, 42],
		[15, 54, 24, 5, 55, 25],
		[15, 43, 15, 10, 44, 16],
		[4, 144, 116, 4, 145, 117],
		[17, 68, 42],
		[17, 50, 22, 6, 51, 23],
		[19, 46, 16, 6, 47, 17],
		[2, 139, 111, 7, 140, 112],
		[17, 74, 46],
		[7, 54, 24, 16, 55, 25],
		[34, 37, 13],
		[4, 151, 121, 5, 152, 122],
		[4, 75, 47, 14, 76, 48],
		[11, 54, 24, 14, 55, 25],
		[16, 45, 15, 14, 46, 16],
		[6, 147, 117, 4, 148, 118],
		[6, 73, 45, 14, 74, 46],
		[11, 54, 24, 16, 55, 25],
		[30, 46, 16, 2, 47, 17],
		[8, 132, 106, 4, 133, 107],
		[8, 75, 47, 13, 76, 48],
		[7, 54, 24, 22, 55, 25],
		[22, 45, 15, 13, 46, 16],
		[10, 142, 114, 2, 143, 115],
		[19, 74, 46, 4, 75, 47],
		[28, 50, 22, 6, 51, 23],
		[33, 46, 16, 4, 47, 17],
		[8, 152, 122, 4, 153, 123],
		[22, 73, 45, 3, 74, 46],
		[8, 53, 23, 26, 54, 24],
		[12, 45, 15, 28, 46, 16],
		[3, 147, 117, 10, 148, 118],
		[3, 73, 45, 23, 74, 46],
		[4, 54, 24, 31, 55, 25],
		[11, 45, 15, 31, 46, 16],
		[7, 146, 116, 7, 147, 117],
		[21, 73, 45, 7, 74, 46],
		[1, 53, 23, 37, 54, 24],
		[19, 45, 15, 26, 46, 16],
		[5, 145, 115, 10, 146, 116],
		[19, 75, 47, 10, 76, 48],
		[15, 54, 24, 25, 55, 25],
		[23, 45, 15, 25, 46, 16],
		[13, 145, 115, 3, 146, 116],
		[2, 74, 46, 29, 75, 47],
		[42, 54, 24, 1, 55, 25],
		[23, 45, 15, 28, 46, 16],
		[17, 145, 115],
		[10, 74, 46, 23, 75, 47],
		[10, 54, 24, 35, 55, 25],
		[19, 45, 15, 35, 46, 16],
		[17, 145, 115, 1, 146, 116],
		[14, 74, 46, 21, 75, 47],
		[29, 54, 24, 19, 55, 25],
		[11, 45, 15, 46, 46, 16],
		[13, 145, 115, 6, 146, 116],
		[14, 74, 46, 23, 75, 47],
		[44, 54, 24, 7, 55, 25],
		[59, 46, 16, 1, 47, 17],
		[12, 151, 121, 7, 152, 122],
		[12, 75, 47, 26, 76, 48],
		[39, 54, 24, 14, 55, 25],
		[22, 45, 15, 41, 46, 16],
		[6, 151, 121, 14, 152, 122],
		[6, 75, 47, 34, 76, 48],
		[46, 54, 24, 10, 55, 25],
		[2, 45, 15, 64, 46, 16],
		[17, 152, 122, 4, 153, 123],
		[29, 74, 46, 14, 75, 47],
		[49, 54, 24, 10, 55, 25],
		[24, 45, 15, 46, 46, 16],
		[4, 152, 122, 18, 153, 123],
		[13, 74, 46, 32, 75, 47],
		[48, 54, 24, 14, 55, 25],
		[42, 45, 15, 32, 46, 16],
		[20, 147, 117, 4, 148, 118],
		[40, 75, 47, 7, 76, 48],
		[43, 54, 24, 22, 55, 25],
		[10, 45, 15, 67, 46, 16],
		[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, errorCorrectLevel) {

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

	_this.getRSBlocks = function(typeNumber, errorCorrectLevel) {

		var rsBlock = getRsBlockTable(typeNumber, errorCorrectLevel);

		if (typeof rsBlock == 'undefined') {
			throw new Error('bad rs block [url=home.php?mod=space&uid=5302]@[/url] typeNumber:' + typeNumber +
				'/errorCorrectLevel:' + errorCorrectLevel);
		}

		var length = rsBlock.length / 3;

		var list = new Array();

		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 = new Array();
	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;
};

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

var qr8BitByte = function(data) {

	var _mode = QRMode.MODE_8BIT_BYTE;
	var _data = data;
	var _parsedData = [];

	var _this = {};


	// Added to support UTF-8 Characters
	for (var i = 0, l = _data.length; i < l; i++) {
		var byteArray = [];
		var code = _data.charCodeAt(i);

		if (code > 0x10000) {
			byteArray[0] = 0xF0 | ((code & 0x1C0000) >>> 18);
			byteArray[1] = 0x80 | ((code & 0x3F000) >>> 12);
			byteArray[2] = 0x80 | ((code & 0xFC0) >>> 6);
			byteArray[3] = 0x80 | (code & 0x3F);
		} else if (code > 0x800) {
			byteArray[0] = 0xE0 | ((code & 0xF000) >>> 12);
			byteArray[1] = 0x80 | ((code & 0xFC0) >>> 6);
			byteArray[2] = 0x80 | (code & 0x3F);
		} else if (code > 0x80) {
			byteArray[0] = 0xC0 | ((code & 0x7C0) >>> 6);
			byteArray[1] = 0x80 | (code & 0x3F);
		} else {
			byteArray[0] = code;
		}

		// Fix Unicode corruption bug
		_parsedData.push(byteArray);
	}

	_parsedData = Array.prototype.concat.apply([], _parsedData);

	if (_parsedData.length != _data.length) {
		_parsedData.unshift(191);
		_parsedData.unshift(187);
		_parsedData.unshift(239);
	}

	var _bytes = _parsedData;

	_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;
};

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

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

var byteArrayOutputStream = function() {

	var _bytes = new Array();

	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 new Error('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;
};

//---------------------------------------------------------------------
// base64DecodeInputStream
//---------------------------------------------------------------------

var base64DecodeInputStream = function(str) {

	var _str = str;
	var _pos = 0;
	var _buffer = 0;
	var _buflen = 0;

	var _this = {};

	_this.read = function() {

		while (_buflen < 8) {

			if (_pos >= _str.length) {
				if (_buflen == 0) {
					return -1;
				}
				throw new Error('unexpected end of file./' + _buflen);
			}

			var c = _str.charAt(_pos);
			_pos += 1;

			if (c == '=') {
				_buflen = 0;
				return -1;
			} else if (c.match(/^\s$/)) {
				// ignore if whitespace.
				continue;
			}

			_buffer = (_buffer << 6) | decode(c.charCodeAt(0));
			_buflen += 6;
		}

		var n = (_buffer >>> (_buflen - 8)) & 0xff;
		_buflen -= 8;
		return n;
	};

	var decode = function(c) {
		if (0x41 <= c && c <= 0x5a) {
			return c - 0x41;
		} else if (0x61 <= c && c <= 0x7a) {
			return c - 0x61 + 26;
		} else if (0x30 <= c && c <= 0x39) {
			return c - 0x30 + 52;
		} else if (c == 0x2b) {
			return 62;
		} else if (c == 0x2f) {
			return 63;
		} else {
			throw new Error('c:' + c);
		}
	};

	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 new Error('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 new Error('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 createImgTag = function(width, height, getPixel, alt) {

	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();

	var img = '';
	img += 'data:image/gif;base64,';
	img += base64;

	return img;
};

//---------------------------------------------------------------------
// returns qrcode function.

var createQrCodeImg = function(text, options) {
	options = options || {};
	var typeNumber = options.typeNumber || 4;
	var errorCorrectLevel = options.errorCorrectLevel || 'M';
	var size = options.size || 500;

	var qr;

	try {
		qr = qrcode(typeNumber, errorCorrectLevel || 'M');
		qr.addData(text);
		qr.make();
	} catch (e) {
		if (typeNumber >= 40) {
			throw new Error('Text too long to encode');
		} else {
			return createQrCodeImg(text, {
				size: size,
				errorCorrectLevel: errorCorrectLevel,
				typeNumber: typeNumber + 1
			});
		}
	}

	// calc cellsize and margin
	var cellsize = parseInt(size / qr.getModuleCount());
	var margin = parseInt((size - qr.getModuleCount() * cellsize) / 2);

	return qr.createImgTag(cellsize, margin, size);
};
// var module = {}; 需要注释这一行，否则微信小程序无法使用
module.exports = {
	createQrCodeImg: createQrCodeImg
};