qzxing/source/zxing/datamatrix/decoder/BitMatrixParser.cpp

/*
 *  BitMatrixParser.cpp
 *  zxing
 *
 *  Created by Luiz Silva on 09/02/2010.
 *  Copyright 2010 ZXing authors All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <zxing/datamatrix/decoder/BitMatrixParser.h>
#include <zxing/common/IllegalArgumentException.h>

#include <iostream>

namespace zxing {
namespace datamatrix {

int BitMatrixParser::copyBit(size_t x, size_t y, int versionBits) {
  return bitMatrix_->get(x, y) ? (versionBits << 1) | 0x1 : versionBits << 1;
}

BitMatrixParser::BitMatrixParser(Ref<BitMatrix> bitMatrix) : bitMatrix_(NULL),
                                                             parsedVersion_(NULL),
                                                             readBitMatrix_(NULL) {
  size_t dimension = bitMatrix->getDimension();
  if (dimension < 8 || dimension > 144 || (dimension & 0x01) != 0)
    throw ReaderException("Dimension must be even, > 8 < 144");

  parsedVersion_ = readVersion(bitMatrix);
  bitMatrix_ = extractDataRegion(bitMatrix);
  readBitMatrix_ = new BitMatrix(bitMatrix_->getWidth(), bitMatrix_->getHeight());
}

Ref<Version> BitMatrixParser::readVersion(Ref<BitMatrix> bitMatrix) {
  if (parsedVersion_ != 0) {
    return parsedVersion_;
  }

  int numRows = bitMatrix->getHeight();//getDimension();
  int numColumns = bitMatrix->getWidth();//numRows;

  Ref<Version> version = parsedVersion_->getVersionForDimensions(numRows, numColumns);
  if (version != 0) {
    return version;
  }
  throw ReaderException("Couldn't decode version");
}

ArrayRef<unsigned char> BitMatrixParser::readCodewords() {
  	ArrayRef<unsigned char> result(parsedVersion_->getTotalCodewords());
  	int resultOffset = 0;
    int row = 4;
    int column = 0;

    int numRows = bitMatrix_->getHeight();
    int numColumns = bitMatrix_->getWidth();

    bool corner1Read = false;
    bool corner2Read = false;
    bool corner3Read = false;
    bool corner4Read = false;

    // Read all of the codewords
    do {
      // Check the four corner cases
      if ((row == numRows) && (column == 0) && !corner1Read) {
        result[resultOffset++] = (unsigned char) readCorner1(numRows, numColumns);
        row -= 2;
        column +=2;
        corner1Read = true;
      } else if ((row == numRows-2) && (column == 0) && ((numColumns & 0x03) != 0) && !corner2Read) {
        result[resultOffset++] = (unsigned char) readCorner2(numRows, numColumns);
        row -= 2;
        column +=2;
        corner2Read = true;
      } else if ((row == numRows+4) && (column == 2) && ((numColumns & 0x07) == 0) && !corner3Read) {
        result[resultOffset++] = (unsigned char) readCorner3(numRows, numColumns);
        row -= 2;
        column +=2;
        corner3Read = true;
      } else if ((row == numRows-2) && (column == 0) && ((numColumns & 0x07) == 4) && !corner4Read) {
        result[resultOffset++] = (unsigned char) readCorner4(numRows, numColumns);
        row -= 2;
        column +=2;
        corner4Read = true;
      } else {
        // Sweep upward diagonally to the right
        do {
          if ((row < numRows) && (column >= 0) && !readBitMatrix_->get(column, row)) {
            result[resultOffset++] = (unsigned char) readUtah(row, column, numRows, numColumns);
          }
          row -= 2;
          column +=2;
        } while ((row >= 0) && (column < numColumns));
        row += 1;
        column +=3;

        // Sweep downward diagonally to the left
        do {
          if ((row >= 0) && (column < numColumns) && !readBitMatrix_->get(column, row)) {
             result[resultOffset++] = (unsigned char) readUtah(row, column, numRows, numColumns);
          }
          row += 2;
          column -=2;
        } while ((row < numRows) && (column >= 0));
        row += 3;
        column +=1;
      }
    } while ((row < numRows) || (column < numColumns));

    if (resultOffset != parsedVersion_->getTotalCodewords()) {
      throw ReaderException("Did not read all codewords");
    }
    return result;
}

bool BitMatrixParser::readModule(int row, int column, int numRows, int numColumns) {
    // Adjust the row and column indices based on boundary wrapping
    if (row < 0) {
      row += numRows;
      column += 4 - ((numRows + 4) & 0x07);
    }
    if (column < 0) {
      column += numColumns;
      row += 4 - ((numColumns + 4) & 0x07);
    }
    readBitMatrix_->set(column, row);
    return bitMatrix_->get(column, row);
  }

int BitMatrixParser::readUtah(int row, int column, int numRows, int numColumns) {
    int currentByte = 0;
    if (readModule(row - 2, column - 2, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(row - 2, column - 1, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(row - 1, column - 2, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(row - 1, column - 1, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(row - 1, column, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(row, column - 2, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(row, column - 1, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(row, column, numRows, numColumns)) {
      currentByte |= 1;
    }
    return currentByte;
  }

int BitMatrixParser::readCorner1(int numRows, int numColumns) {
    int currentByte = 0;
    if (readModule(numRows - 1, 0, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(numRows - 1, 1, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(numRows - 1, 2, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(0, numColumns - 2, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(0, numColumns - 1, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(1, numColumns - 1, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(2, numColumns - 1, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(3, numColumns - 1, numRows, numColumns)) {
      currentByte |= 1;
    }
    return currentByte;
  }

int BitMatrixParser::readCorner2(int numRows, int numColumns) {
    int currentByte = 0;
    if (readModule(numRows - 3, 0, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(numRows - 2, 0, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(numRows - 1, 0, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(0, numColumns - 4, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(0, numColumns - 3, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(0, numColumns - 2, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(0, numColumns - 1, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(1, numColumns - 1, numRows, numColumns)) {
      currentByte |= 1;
    }
    return currentByte;
  }

int BitMatrixParser::readCorner3(int numRows, int numColumns) {
    int currentByte = 0;
    if (readModule(numRows - 1, 0, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(numRows - 1, numColumns - 1, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(0, numColumns - 3, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(0, numColumns - 2, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(0, numColumns - 1, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(1, numColumns - 3, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(1, numColumns - 2, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(1, numColumns - 1, numRows, numColumns)) {
      currentByte |= 1;
    }
    return currentByte;
  }

int BitMatrixParser::readCorner4(int numRows, int numColumns) {
    int currentByte = 0;
    if (readModule(numRows - 3, 0, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(numRows - 2, 0, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(numRows - 1, 0, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(0, numColumns - 2, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(0, numColumns - 1, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(1, numColumns - 1, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(2, numColumns - 1, numRows, numColumns)) {
      currentByte |= 1;
    }
    currentByte <<= 1;
    if (readModule(3, numColumns - 1, numRows, numColumns)) {
      currentByte |= 1;
    }
    return currentByte;
  }

Ref<BitMatrix> BitMatrixParser::extractDataRegion(Ref<BitMatrix> bitMatrix) {
    int symbolSizeRows = parsedVersion_->getSymbolSizeRows();
    int symbolSizeColumns = parsedVersion_->getSymbolSizeColumns();

    if ((int)bitMatrix->getHeight() != symbolSizeRows) {
      throw IllegalArgumentException("Dimension of bitMatrix must match the version size");
    }

    int dataRegionSizeRows = parsedVersion_->getDataRegionSizeRows();
    int dataRegionSizeColumns = parsedVersion_->getDataRegionSizeColumns();

    int numDataRegionsRow = symbolSizeRows / dataRegionSizeRows;
    int numDataRegionsColumn = symbolSizeColumns / dataRegionSizeColumns;

    int sizeDataRegionRow = numDataRegionsRow * dataRegionSizeRows;
    int sizeDataRegionColumn = numDataRegionsColumn * dataRegionSizeColumns;

    Ref<BitMatrix> bitMatrixWithoutAlignment(new BitMatrix(sizeDataRegionColumn, sizeDataRegionRow));
    for (int dataRegionRow = 0; dataRegionRow < numDataRegionsRow; ++dataRegionRow) {
      int dataRegionRowOffset = dataRegionRow * dataRegionSizeRows;
      for (int dataRegionColumn = 0; dataRegionColumn < numDataRegionsColumn; ++dataRegionColumn) {
        int dataRegionColumnOffset = dataRegionColumn * dataRegionSizeColumns;
        for (int i = 0; i < dataRegionSizeRows; ++i) {
          int readRowOffset = dataRegionRow * (dataRegionSizeRows + 2) + 1 + i;
          int writeRowOffset = dataRegionRowOffset + i;
          for (int j = 0; j < dataRegionSizeColumns; ++j) {
            int readColumnOffset = dataRegionColumn * (dataRegionSizeColumns + 2) + 1 + j;
            if (bitMatrix->get(readColumnOffset, readRowOffset)) {
              int writeColumnOffset = dataRegionColumnOffset + j;
              bitMatrixWithoutAlignment->set(writeColumnOffset, writeRowOffset);
            }
          }
        }
      }
    }
    return bitMatrixWithoutAlignment;
}

}
}