MatrixUtil.cpp Example File

 #include "MatrixUtil.h"
 #include "MaskUtil.h"
 #include <zxing/WriterException.h>
 #include "QRCode.h"

 namespace zxing {
 namespace qrcode {

 const int MatrixUtil::POSITION_DETECTION_PATTERN[7][7] =  {
     {1, 1, 1, 1, 1, 1, 1},
     {1, 0, 0, 0, 0, 0, 1},
     {1, 0, 1, 1, 1, 0, 1},
     {1, 0, 1, 1, 1, 0, 1},
     {1, 0, 1, 1, 1, 0, 1},
     {1, 0, 0, 0, 0, 0, 1},
     {1, 1, 1, 1, 1, 1, 1},
 };

 const int MatrixUtil::POSITION_ADJUSTMENT_PATTERN[5][5] = {
     {1, 1, 1, 1, 1},
     {1, 0, 0, 0, 1},
     {1, 0, 1, 0, 1},
     {1, 0, 0, 0, 1},
     {1, 1, 1, 1, 1},
 };

 // From Appendix E. Table 1, JIS0510X:2004 (p 71). The table was double-checked by komatsu.
 const int MatrixUtil::POSITION_ADJUSTMENT_PATTERN_COORDINATE_TABLE[40][7] = {
     {-1, -1, -1, -1,  -1,  -1,  -1},  // Version 1
     { 6, 18, -1, -1,  -1,  -1,  -1},  // Version 2
     { 6, 22, -1, -1,  -1,  -1,  -1},  // Version 3
     { 6, 26, -1, -1,  -1,  -1,  -1},  // Version 4
     { 6, 30, -1, -1,  -1,  -1,  -1},  // Version 5
     { 6, 34, -1, -1,  -1,  -1,  -1},  // Version 6
     { 6, 22, 38, -1,  -1,  -1,  -1},  // Version 7
     { 6, 24, 42, -1,  -1,  -1,  -1},  // Version 8
     { 6, 26, 46, -1,  -1,  -1,  -1},  // Version 9
     { 6, 28, 50, -1,  -1,  -1,  -1},  // Version 10
     { 6, 30, 54, -1,  -1,  -1,  -1},  // Version 11
     { 6, 32, 58, -1,  -1,  -1,  -1},  // Version 12
     { 6, 34, 62, -1,  -1,  -1,  -1},  // Version 13
     { 6, 26, 46, 66,  -1,  -1,  -1},  // Version 14
     { 6, 26, 48, 70,  -1,  -1,  -1},  // Version 15
     { 6, 26, 50, 74,  -1,  -1,  -1},  // Version 16
     { 6, 30, 54, 78,  -1,  -1,  -1},  // Version 17
     { 6, 30, 56, 82,  -1,  -1,  -1},  // Version 18
     { 6, 30, 58, 86,  -1,  -1,  -1},  // Version 19
     { 6, 34, 62, 90,  -1,  -1,  -1},  // Version 20
     { 6, 28, 50, 72,  94,  -1,  -1},  // Version 21
     { 6, 26, 50, 74,  98,  -1,  -1},  // Version 22
     { 6, 30, 54, 78, 102,  -1,  -1},  // Version 23
     { 6, 28, 54, 80, 106,  -1,  -1},  // Version 24
     { 6, 32, 58, 84, 110,  -1,  -1},  // Version 25
     { 6, 30, 58, 86, 114,  -1,  -1},  // Version 26
     { 6, 34, 62, 90, 118,  -1,  -1},  // Version 27
     { 6, 26, 50, 74,  98, 122,  -1},  // Version 28
     { 6, 30, 54, 78, 102, 126,  -1},  // Version 29
     { 6, 26, 52, 78, 104, 130,  -1},  // Version 30
     { 6, 30, 56, 82, 108, 134,  -1},  // Version 31
     { 6, 34, 60, 86, 112, 138,  -1},  // Version 32
     { 6, 30, 58, 86, 114, 142,  -1},  // Version 33
     { 6, 34, 62, 90, 118, 146,  -1},  // Version 34
     { 6, 30, 54, 78, 102, 126, 150},  // Version 35
     { 6, 24, 50, 76, 102, 128, 154},  // Version 36
     { 6, 28, 54, 80, 106, 132, 158},  // Version 37
     { 6, 32, 58, 84, 110, 136, 162},  // Version 38
     { 6, 26, 54, 82, 110, 138, 166},  // Version 39
     { 6, 30, 58, 86, 114, 142, 170},  // Version 40
 };

 // Type info cells at the left top corner.
 const int MatrixUtil::TYPE_INFO_COORDINATES[16][2] = {
     {8, 0},
     {8, 1},
     {8, 2},
     {8, 3},
     {8, 4},
     {8, 5},
     {8, 7},
     {8, 8},
     {7, 8},
     {5, 8},
     {4, 8},
     {3, 8},
     {2, 8},
     {1, 8},
     {0, 8},
 };

 // From Appendix D in JISX0510:2004 (p. 67)
 const int MatrixUtil::VERSION_INFO_POLY = 0x1f25;  // 1 1111 0010 0101

 // From Appendix C in JISX0510:2004 (p.65).
 const int MatrixUtil::TYPE_INFO_POLY = 0x537;
 const int MatrixUtil::TYPE_INFO_MASK_PATTERN = 0x5412;

 void MatrixUtil::buildMatrix(const BitArray& dataBits,
                              const ErrorCorrectionLevel& ecLevel,
                              Version& version,
                              int maskPattern,
                              ByteMatrix& matrix)
 {
     clearMatrix(matrix);
     embedBasicPatterns(version, matrix);
     // Type information appear with any version.
     embedTypeInfo(ecLevel, maskPattern, matrix);
     // Version info appear if version >= 7.
     maybeEmbedVersionInfo(version, matrix);
     // Data should be embedded at end.
     embedDataBits(dataBits, maskPattern, matrix);
 }

 void MatrixUtil::embedBasicPatterns(const Version& version, ByteMatrix& matrix)
 {
     // Let's get started with embedding big squares at corners.
     embedPositionDetectionPatternsAndSeparators(matrix);
     // Then, embed the dark dot at the left bottom corner.
     embedDarkDotAtLeftBottomCorner(matrix);

     // Position adjustment patterns appear if version >= 2.
     maybeEmbedPositionAdjustmentPatterns(version, matrix);
     // Timing patterns should be embedded after position adj. patterns.
     embedTimingPatterns(matrix);
 }

 // Embed type information. On success, modify the matrix.
 void MatrixUtil::embedTypeInfo(const ErrorCorrectionLevel& ecLevel, int maskPattern, ByteMatrix& matrix)
 {
     BitArray typeInfoBits;
     makeTypeInfoBits(ecLevel, maskPattern, typeInfoBits);

     for (int i = 0; i < typeInfoBits.getSize(); ++i) {
         // Place bits in LSB to MSB order.  LSB (least significant bit) is the last value in
         // "typeInfoBits".
         bool bit = typeInfoBits.get(typeInfoBits.getSize() - 1 - i);

         // Type info bits at the left top corner. See 8.9 of JISX0510:2004 (p.46).
         int x1 = TYPE_INFO_COORDINATES[i][0];
         int y1 = TYPE_INFO_COORDINATES[i][1];
         matrix.set(x1, y1, bit);

         if (i < 8) {
             // Right top corner.
             int x2 = matrix.getWidth() - i - 1;
             int y2 = 8;
             matrix.set(x2, y2, bit);
         } else {
             // Left bottom corner.
             int x2 = 8;
             int y2 = matrix.getHeight() - 7 + (i - 8);
             matrix.set(x2, y2, bit);
         }
     }
 }

 void MatrixUtil::maybeEmbedVersionInfo(const Version& version, ByteMatrix& matrix)
 {
     if (version.getVersionNumber() < 7) {  // Version info is necessary if version >= 7.
         return;  // Don't need version info.
     }
     BitArray versionInfoBits;
     makeVersionInfoBits(version, versionInfoBits);

     int bitIndex = 6 * 3 - 1;  // It will decrease from 17 to 0.
     for (int i = 0; i < 6; ++i) {
         for (int j = 0; j < 3; ++j) {
             // Place bits in LSB (least significant bit) to MSB order.
             boolean bit = versionInfoBits.get(bitIndex);
             bitIndex--;
             // Left bottom corner.
             matrix.set(i, matrix.getHeight() - 11 + j, bit);
             // Right bottom corner.
             matrix.set(matrix.getHeight() - 11 + j, i, bit);
         }
     }
 }

 void MatrixUtil::embedDataBits(const BitArray& dataBits, int maskPattern, ByteMatrix& matrix)
 {
     int bitIndex = 0;
     int direction = -1;
     // Start from the right bottom cell.
     int x = matrix.getWidth() - 1;
     int y = matrix.getHeight() - 1;
     while (x > 0) {
         // Skip the vertical timing pattern.
         if (x == 6) {
             x -= 1;
         }
         while (y >= 0 && y < matrix.getHeight()) {
             for (int i = 0; i < 2; ++i) {
                 int xx = x - i;
                 // Skip the cell if it's not empty.
                 if (!isEmpty(matrix.get(xx, y))) {
                     continue;
                 }
                 boolean bit;
                 if (bitIndex < dataBits.getSize()) {
                     bit = dataBits.get(bitIndex);
                     ++bitIndex;
                 } else {
                     // Padding bit. If there is no bit left, we'll fill the left cells with 0, as described
                     // in 8.4.9 of JISX0510:2004 (p. 24).
                     bit = false;
                 }

                 // Skip masking if mask_pattern is -1.
                 if (maskPattern != -1 && MaskUtil::getDataMaskBit(maskPattern, xx, y)) {
                     bit = !bit;
                 }
                 matrix.set(xx, y, bit);
             }
             y += direction;
         }
         direction = -direction;  // Reverse the direction.
         y += direction;
         x -= 2;  // Move to the left.
     }
     // All bits should be consumed.
     if (bitIndex != dataBits.getSize()) {
         throw zxing::WriterException("Not all bits consumed: " + bitIndex + '/' + dataBits.getSize());
     }
 }

 int MatrixUtil::findMSBSet(int value)
 {
     int sizeOfTypeBits = (sizeof(int)*8);
     int sample = ( value < 0 ) ? 0 : value;
     int leadingZeros = ( value < 0 ) ? 0 : sizeOfTypeBits;

     while(sample) {
         sample >>= 1;
         --leadingZeros;
     }

     return sizeOfTypeBits - leadingZeros;
 }

 int MatrixUtil::calculateBCHCode(int value, int poly)
 {
     // If poly is "1 1111 0010 0101" (version info poly), msbSetInPoly is 13. We'll subtract 1
     // from 13 to make it 12.
     int msbSetInPoly = findMSBSet(poly);
     value <<= msbSetInPoly - 1;
     // Do the division business using exclusive-or operations.
     while (findMSBSet(value) >= msbSetInPoly) {
         value ^= poly << (findMSBSet(value) - msbSetInPoly);
     }
     // Now the "value" is the remainder (i.e. the BCH code)
     return value;
 }

 // Make bit vector of type information. On success, store the result in "bits" and return true.
 // Encode error correction level and mask pattern. See 8.9 of
 // JISX0510:2004 (p.45) for details.
 void MatrixUtil::makeTypeInfoBits(const ErrorCorrectionLevel& ecLevel, int maskPattern, BitArray& bits)
 {
     if (!QRCode::isValidMaskPattern(maskPattern)) {
         throw WriterException("Invalid mask pattern");
     }
     int typeInfo = (ecLevel.bits() << 3) | maskPattern;
     bits.appendBits(typeInfo, 5);

     int bchCode = calculateBCHCode(typeInfo, TYPE_INFO_POLY);
     bits.appendBits(bchCode, 10);

     BitArray maskBits;
     maskBits.appendBits(TYPE_INFO_MASK_PATTERN, 15);
     bits.xor_(maskBits);

     if (bits.getSize() != 15) {  // Just in case.
         throw WriterException("should not happen but we got: " + bits.getSize());
     }
 }

 // Make bit vector of version information. On success, store the result in "bits" and return true.
 // See 8.10 of JISX0510:2004 (p.45) for details.
 void MatrixUtil::makeVersionInfoBits(const Version& version, BitArray& bits)
 {
     bits.appendBits(version.getVersionNumber(), 6);
     int bchCode = calculateBCHCode(version.getVersionNumber(), VERSION_INFO_POLY);
     bits.appendBits(bchCode, 12);

     if (bits.getSize() != 18) {  // Just in case.
         throw WriterException("should not happen but we got: " + bits.getSize());
     }
 }

 void MatrixUtil::embedTimingPatterns(ByteMatrix& matrix)
 {
     // -8 is for skipping position detection patterns (size 7), and two horizontal/vertical
     // separation patterns (size 1). Thus, 8 = 7 + 1.
     for (size_t i = 8; i < matrix.getWidth() - 8; ++i) {
         int bit = (i + 1) % 2;
         // Horizontal line.
         if (isEmpty(matrix.get(i, 6))) {
             matrix.set(i, 6, (byte)bit);
         }
         // Vertical line.
         if (isEmpty(matrix.get(6, i))) {
             matrix.set(6, i, (byte)bit);
         }
     }
 }

 void MatrixUtil::embedDarkDotAtLeftBottomCorner(ByteMatrix& matrix)
 {
     if (matrix.get(8, matrix.getHeight() - 8) == 0) {
         throw WriterException();
     }
     matrix.set(8, matrix.getHeight() - 8, (byte)1);
 }

 void MatrixUtil::embedHorizontalSeparationPattern(int xStart,
                                                   int yStart,
                                                   ByteMatrix& matrix)
 {
     for (int x = 0; x < 8; ++x) {
         if (!isEmpty(matrix.get(xStart + x, yStart))) {
             throw WriterException();
         }
         matrix.set(xStart + x, yStart, (byte)0);
     }
 }

 void MatrixUtil::embedVerticalSeparationPattern(int xStart,
                                                 int yStart,
                                                 ByteMatrix& matrix)
 {
     for (int y = 0; y < 7; ++y) {
         if (!isEmpty(matrix.get(xStart, yStart + y))) {
             throw WriterException();
         }
         matrix.set(xStart, yStart + y, (byte)0);
     }
 }

 void MatrixUtil::embedPositionAdjustmentPattern(int xStart, int yStart, ByteMatrix& matrix)
 {
     for (int y = 0; y < 5; ++y) {
         for (int x = 0; x < 5; ++x) {
             matrix.set(xStart + x, yStart + y, (byte)POSITION_ADJUSTMENT_PATTERN[y][x]);
         }
     }
 }

 void MatrixUtil::embedPositionDetectionPattern(int xStart, int yStart, ByteMatrix& matrix)
 {
     for (int y = 0; y < 7; ++y) {
         for (int x = 0; x < 7; ++x) {
             matrix.set(xStart + x, yStart + y, (byte)POSITION_DETECTION_PATTERN[y][x]);
         }
     }
 }

 void MatrixUtil::embedPositionDetectionPatternsAndSeparators(ByteMatrix& matrix)
 {
     // Embed three big squares at corners.
     int pdpWidth = 7;//need to change this, old version: POSITION_DETECTION_PATTERN[0].length;
     // Left top corner.
     embedPositionDetectionPattern(0, 0, matrix);
     // Right top corner.
     embedPositionDetectionPattern(matrix.getWidth() - pdpWidth, 0, matrix);
     // Left bottom corner.
     embedPositionDetectionPattern(0, matrix.getWidth() - pdpWidth, matrix);

     // Embed horizontal separation patterns around the squares.
     int hspWidth = 8;
     // Left top corner.
     embedHorizontalSeparationPattern(0, hspWidth - 1, matrix);
     // Right top corner.
     embedHorizontalSeparationPattern(matrix.getWidth() - hspWidth,
                                      hspWidth - 1, matrix);
     // Left bottom corner.
     embedHorizontalSeparationPattern(0, matrix.getWidth() - hspWidth, matrix);

     // Embed vertical separation patterns around the squares.
     int vspSize = 7;
     // Left top corner.
     embedVerticalSeparationPattern(vspSize, 0, matrix);
     // Right top corner.
     embedVerticalSeparationPattern(matrix.getHeight() - vspSize - 1, 0, matrix);
     // Left bottom corner.
     embedVerticalSeparationPattern(vspSize, matrix.getHeight() - vspSize,
                                    matrix);
 }

 void MatrixUtil::maybeEmbedPositionAdjustmentPatterns(const Version& version, ByteMatrix& matrix)
 {
     if (version.getVersionNumber() < 2) {  // The patterns appear if version >= 2
         return;
     }
     int index = version.getVersionNumber() - 1;
     const int *coordinates = POSITION_ADJUSTMENT_PATTERN_COORDINATE_TABLE[index];
     int numCoordinates = 7; //POSITION_ADJUSTMENT_PATTERN_COORDINATE_TABLE[index].length; //need to change the constant 7

     for (int i = 0; i < numCoordinates; i++) {
         int y = coordinates[i];
         if(y < 0)
             continue;

         for (int j = 0; j < numCoordinates; j++) {
             int x = coordinates[j];
             if (x < 0)
                 continue;

             // If the cell is unset, we embed the position adjustment pattern here.
             if (isEmpty(matrix.get(x, y))) {
                 // -2 is necessary since the x/y coordinates point to the center of the pattern, not the
                 // left top corner.
                 embedPositionAdjustmentPattern(x - 2, y - 2, matrix);
             }
         }
     }
 }

 }
 }