npm
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a package manager for JavaScript
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JavaScript
var QRMode = require('./QRMode');
var QRPolynomial = require('./QRPolynomial');
var QRMath = require('./QRMath');
var QRMaskPattern = require('./QRMaskPattern');
var QRUtil = {
PATTERN_POSITION_TABLE : [
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],
G15 : (1 << 10) | (1 << 8) | (1 << 5) | (1 << 4) | (1 << 2) | (1 << 1) | (1 << 0),
G18 : (1 << 12) | (1 << 11) | (1 << 10) | (1 << 9) | (1 << 8) | (1 << 5) | (1 << 2) | (1 << 0),
G15_MASK : (1 << 14) | (1 << 12) | (1 << 10) | (1 << 4) | (1 << 1),
getBCHTypeInfo : function(data) {
var d = data << 10;
while (QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G15) >= 0) {
d ^= (QRUtil.G15 << (QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G15) ) );
}
return ( (data << 10) | d) ^ QRUtil.G15_MASK;
},
getBCHTypeNumber : function(data) {
var d = data << 12;
while (QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G18) >= 0) {
d ^= (QRUtil.G18 << (QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G18) ) );
}
return (data << 12) | d;
},
getBCHDigit : function(data) {
var digit = 0;
while (data !== 0) {
digit++;
data >>>= 1;
}
return digit;
},
getPatternPosition : function(typeNumber) {
return QRUtil.PATTERN_POSITION_TABLE[typeNumber - 1];
},
getMask : function(maskPattern, i, j) {
switch (maskPattern) {
case QRMaskPattern.PATTERN000 : return (i + j) % 2 === 0;
case QRMaskPattern.PATTERN001 : return i % 2 === 0;
case QRMaskPattern.PATTERN010 : return j % 3 === 0;
case QRMaskPattern.PATTERN011 : return (i + j) % 3 === 0;
case QRMaskPattern.PATTERN100 : return (Math.floor(i / 2) + Math.floor(j / 3) ) % 2 === 0;
case QRMaskPattern.PATTERN101 : return (i * j) % 2 + (i * j) % 3 === 0;
case QRMaskPattern.PATTERN110 : return ( (i * j) % 2 + (i * j) % 3) % 2 === 0;
case QRMaskPattern.PATTERN111 : return ( (i * j) % 3 + (i + j) % 2) % 2 === 0;
default :
throw new Error("bad maskPattern:" + maskPattern);
}
},
getErrorCorrectPolynomial : function(errorCorrectLength) {
var a = new QRPolynomial([1], 0);
for (var i = 0; i < errorCorrectLength; i++) {
a = a.multiply(new QRPolynomial([1, QRMath.gexp(i)], 0) );
}
return a;
},
getLengthInBits : function(mode, type) {
if (1 <= type && type < 10) {
// 1 - 9
switch(mode) {
case QRMode.MODE_NUMBER : return 10;
case QRMode.MODE_ALPHA_NUM : return 9;
case QRMode.MODE_8BIT_BYTE : return 8;
case QRMode.MODE_KANJI : return 8;
default :
throw new Error("mode:" + mode);
}
} else if (type < 27) {
// 10 - 26
switch(mode) {
case QRMode.MODE_NUMBER : return 12;
case QRMode.MODE_ALPHA_NUM : return 11;
case QRMode.MODE_8BIT_BYTE : return 16;
case QRMode.MODE_KANJI : return 10;
default :
throw new Error("mode:" + mode);
}
} else if (type < 41) {
// 27 - 40
switch(mode) {
case QRMode.MODE_NUMBER : return 14;
case QRMode.MODE_ALPHA_NUM : return 13;
case QRMode.MODE_8BIT_BYTE : return 16;
case QRMode.MODE_KANJI : return 12;
default :
throw new Error("mode:" + mode);
}
} else {
throw new Error("type:" + type);
}
},
getLostPoint : function(qrCode) {
var moduleCount = qrCode.getModuleCount();
var lostPoint = 0;
var row = 0;
var col = 0;
// LEVEL1
for (row = 0; row < moduleCount; row++) {
for (col = 0; col < moduleCount; col++) {
var sameCount = 0;
var dark = qrCode.isDark(row, col);
for (var r = -1; r <= 1; r++) {
if (row + r < 0 || moduleCount <= row + r) {
continue;
}
for (var c = -1; c <= 1; c++) {
if (col + c < 0 || moduleCount <= col + c) {
continue;
}
if (r === 0 && c === 0) {
continue;
}
if (dark === qrCode.isDark(row + r, col + c) ) {
sameCount++;
}
}
}
if (sameCount > 5) {
lostPoint += (3 + sameCount - 5);
}
}
}
// LEVEL2
for (row = 0; row < moduleCount - 1; row++) {
for (col = 0; col < moduleCount - 1; col++) {
var count = 0;
if (qrCode.isDark(row, col ) ) count++;
if (qrCode.isDark(row + 1, col ) ) count++;
if (qrCode.isDark(row, col + 1) ) count++;
if (qrCode.isDark(row + 1, col + 1) ) count++;
if (count === 0 || count === 4) {
lostPoint += 3;
}
}
}
// LEVEL3
for (row = 0; row < moduleCount; row++) {
for (col = 0; col < moduleCount - 6; col++) {
if (qrCode.isDark(row, col) &&
!qrCode.isDark(row, col + 1) &&
qrCode.isDark(row, col + 2) &&
qrCode.isDark(row, col + 3) &&
qrCode.isDark(row, col + 4) &&
!qrCode.isDark(row, col + 5) &&
qrCode.isDark(row, col + 6) ) {
lostPoint += 40;
}
}
}
for (col = 0; col < moduleCount; col++) {
for (row = 0; row < moduleCount - 6; row++) {
if (qrCode.isDark(row, col) &&
!qrCode.isDark(row + 1, col) &&
qrCode.isDark(row + 2, col) &&
qrCode.isDark(row + 3, col) &&
qrCode.isDark(row + 4, col) &&
!qrCode.isDark(row + 5, col) &&
qrCode.isDark(row + 6, col) ) {
lostPoint += 40;
}
}
}
// LEVEL4
var darkCount = 0;
for (col = 0; col < moduleCount; col++) {
for (row = 0; row < moduleCount; row++) {
if (qrCode.isDark(row, col) ) {
darkCount++;
}
}
}
var ratio = Math.abs(100 * darkCount / moduleCount / moduleCount - 50) / 5;
lostPoint += ratio * 10;
return lostPoint;
}
};
module.exports = QRUtil;