content: /*
   * Copyright 2008 ZXing authors
   *
   * 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.
   */
  
  package com.ailiwean.core.zxing.core.qrcode.encoder;
  
  import com.ailiwean.core.zxing.core.WriterException;
  import com.ailiwean.core.zxing.core.common.BitArray;
  import com.ailiwean.core.zxing.core.qrcode.decoder.ErrorCorrectionLevel;
  import com.ailiwean.core.zxing.core.qrcode.decoder.Version;
  
  /**
   * @author satorux@google.com (Satoru Takabayashi) - creator
   * @author dswitkin@google.com (Daniel Switkin) - ported from C++
   */
  final class MatrixUtil {
  
    private static final int[][] POSITION_DETECTION_PATTERN = {
        {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},
    };
  
    private static final int[][] POSITION_ADJUSTMENT_PATTERN = {
        {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.
    private static final int[][] POSITION_ADJUSTMENT_PATTERN_COORDINATE_TABLE = {
        {-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.
    private static final int[][] TYPE_INFO_COORDINATES = {
        {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)
    private static final int VERSION_INFO_POLY = 0x1f25;  // 1 1111 0010 0101
  
    // From Appendix C in JISX0510:2004 (p.65).
    private static final int TYPE_INFO_POLY = 0x537;
    private static final int TYPE_INFO_MASK_PATTERN = 0x5412;
  
    private MatrixUtil() {
      // do nothing
    }
  
    // Set all cells to -1.  -1 means that the cell is empty (not set yet).
    //
    // JAVAPORT: We shouldn't need to do this at all. The code should be rewritten to begin encoding
    // with the ByteMatrix initialized all to zero.
    static void clearMatrix(ByteMatrix matrix) {
      matrix.clear((byte) -1);
    }
  
    // Build 2D matrix of QR Code from "dataBits" with "ecLevel", "version" and "getMaskPattern". On
    // success, store the result in "matrix" and return true.
    static void buildMatrix(BitArray dataBits,
                            ErrorCorrectionLevel ecLevel,
                            Version version,
                            int maskPattern,
                            ByteMatrix matrix) throws WriterException {
      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);
    }
  
    // Embed basic patterns. On success, modify the matrix and return true.
    // The basic patterns are:
    // - Position detection patterns
    // - Timing patterns
    // - Dark dot at the left bottom corner
    // - Position adjustment patterns, if need be
    static void embedBasicPatterns(Version version, ByteMatrix matrix) throws WriterException {
      // 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.
    static void embedTypeInfo(ErrorCorrectionLevel ecLevel, int maskPattern, ByteMatrix matrix)
        throws WriterException {
      BitArray typeInfoBits = new BitArray();
      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".
        boolean bit = typeInfoBits.get(typeInfoBits.getSize() - 1 - i);
  
        // Type info bits at the left top corner. See 8.9 of JISX0510:2004 (p.46).
        int[] coordinates = TYPE_INFO_COORDINATES[i];
        int x1 = coordinates[0];
        int y1 = coordinates[1];
        matrix.set(x1, y1, bit);
  
        int x2;
        int y2;
        if (i < 8) {
          // Right top corner.
          x2 = matrix.getWidth() - i - 1;
          y2 = 8;
        } else {
          // Left bottom corner.
          x2 = 8;
          y2 = matrix.getHeight() - 7 + (i - 8);
        }
        matrix.set(x2, y2, bit);
      }
    }
  
    // Embed version information if need be. On success, modify the matrix and return true.
    // See 8.10 of JISX0510:2004 (p.47) for how to embed version information.
    static void maybeEmbedVersionInfo(Version version, ByteMatrix matrix) throws WriterException {
      if (version.getVersionNumber() < 7) {  // Version info is necessary if version >= 7.
        return;  // Don't need version info.
      }
      BitArray versionInfoBits = new BitArray();
      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);
        }
      }
    }
  
    // Embed "dataBits" using "getMaskPattern". On success, modify the matrix and return true.
    // For debugging purposes, it skips masking process if "getMaskPattern" is -1.
    // See 8.7 of JISX0510:2004 (p.38) for how to embed data bits.
    static void embedDataBits(BitArray dataBits, int maskPattern, ByteMatrix matrix)
        throws WriterException {
      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 new WriterException("Not all bits consumed: " + bitIndex + '/' + dataBits.getSize());
      }
    }
  
    // Return the position of the most significant bit set (to one) in the "value". The most
    // significant bit is position 32. If there is no bit set, return 0. Examples:
    // - findMSBSet(0) => 0
    // - findMSBSet(1) => 1
    // - findMSBSet(255) => 8
    static int findMSBSet(int value) {
      return 32 - Integer.numberOfLeadingZeros(value);
    }
  
    // Calculate BCH (Bose-Chaudhuri-Hocquenghem) code for "value" using polynomial "poly". The BCH
    // code is used for encoding type information and version information.
    // Example: Calculation of version information of 7.
    // f(x) is created from 7.
    //   - 7 = 000111 in 6 bits
    //   - f(x) = x^2 + x^1 + x^0
    // g(x) is given by the standard (p. 67)
    //   - g(x) = x^12 + x^11 + x^10 + x^9 + x^8 + x^5 + x^2 + 1
    // Multiply f(x) by x^(18 - 6)
    //   - f'(x) = f(x) * x^(18 - 6)
    //   - f'(x) = x^14 + x^13 + x^12
    // Calculate the remainder of f'(x) / g(x)
    //         x^2
    //         __________________________________________________
    //   g(x) )x^14 + x^13 + x^12
    //         x^14 + x^13 + x^12 + x^11 + x^10 + x^7 + x^4 + x^2
    //         --------------------------------------------------
    //                              x^11 + x^10 + x^7 + x^4 + x^2
    //
    // The remainder is x^11 + x^10 + x^7 + x^4 + x^2
    // Encode it in binary: 110010010100
    // The return value is 0xc94 (1100 1001 0100)
    //
    // Since all coefficients in the polynomials are 1 or 0, we can do the calculation by bit
    // operations. We don't care if coefficients are positive or negative.
    static int calculateBCHCode(int value, int poly) {
      if (poly == 0) {
        throw new IllegalArgumentException("0 polynomial");
      }
      // 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.
    static void makeTypeInfoBits(ErrorCorrectionLevel ecLevel, int maskPattern, BitArray bits)
        throws WriterException {
      if (!QRCode.isValidMaskPattern(maskPattern)) {
        throw new WriterException("Invalid mask pattern");
      }
      int typeInfo = (ecLevel.getBits() << 3) | maskPattern;
      bits.appendBits(typeInfo, 5);
  
      int bchCode = calculateBCHCode(typeInfo, TYPE_INFO_POLY);
      bits.appendBits(bchCode, 10);
  
      BitArray maskBits = new BitArray();
      maskBits.appendBits(TYPE_INFO_MASK_PATTERN, 15);
      bits.xor(maskBits);
  
      if (bits.getSize() != 15) {  // Just in case.
        throw new 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.
    static void makeVersionInfoBits(Version version, BitArray bits) throws WriterException {
      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 new WriterException("should not happen but we got: " + bits.getSize());
      }
    }
  
    // Check if "value" is empty.
    private static boolean isEmpty(int value) {
      return value == -1;
    }
  
    private static void 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 (int i = 8; i < matrix.getWidth() - 8; ++i) {
        int bit = (i + 1) % 2;
        // Horizontal line.
        if (isEmpty(matrix.get(i, 6))) {
          matrix.set(i, 6, bit);
        }
        // Vertical line.
        if (isEmpty(matrix.get(6, i))) {
          matrix.set(6, i, bit);
        }
      }
    }
  
    // Embed the lonely dark dot at left bottom corner. JISX0510:2004 (p.46)
    private static void embedDarkDotAtLeftBottomCorner(ByteMatrix matrix) throws WriterException {
      if (matrix.get(8, matrix.getHeight() - 8) == 0) {
        throw new WriterException();
      }
      matrix.set(8, matrix.getHeight() - 8, 1);
    }
  
    private static void embedHorizontalSeparationPattern(int xStart,
                                                         int yStart,
                                                         ByteMatrix matrix) throws WriterException {
      for (int x = 0; x < 8; ++x) {
        if (!isEmpty(matrix.get(xStart + x, yStart))) {
          throw new WriterException();
        }
        matrix.set(xStart + x, yStart, 0);
      }
    }
  
    private static void embedVerticalSeparationPattern(int xStart,
                                                       int yStart,
                                                       ByteMatrix matrix) throws WriterException {
      for (int y = 0; y < 7; ++y) {
        if (!isEmpty(matrix.get(xStart, yStart + y))) {
          throw new WriterException();
        }
        matrix.set(xStart, yStart + y, 0);
      }
    }
  
    private static void embedPositionAdjustmentPattern(int xStart, int yStart, ByteMatrix matrix) {
      for (int y = 0; y < 5; ++y) {
        int[] patternY = POSITION_ADJUSTMENT_PATTERN[y];
        for (int x = 0; x < 5; ++x) {
          matrix.set(xStart + x, yStart + y, patternY[x]);
        }
      }
    }
  
    private static void embedPositionDetectionPattern(int xStart, int yStart, ByteMatrix matrix) {
      for (int y = 0; y < 7; ++y) {
        int[] patternY = POSITION_DETECTION_PATTERN[y];
        for (int x = 0; x < 7; ++x) {
          matrix.set(xStart + x, yStart + y, patternY[x]);
        }
      }
    }
  
    // Embed position detection patterns and surrounding vertical/horizontal separators.
    private static void embedPositionDetectionPatternsAndSeparators(ByteMatrix matrix) throws WriterException {
      // Embed three big squares at corners.
      int pdpWidth = 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);
    }
  
    // Embed position adjustment patterns if need be.
    private static void maybeEmbedPositionAdjustmentPatterns(Version version, ByteMatrix matrix) {
      if (version.getVersionNumber() < 2) {  // The patterns appear if version >= 2
        return;
      }
      int index = version.getVersionNumber() - 1;
      int[] coordinates = POSITION_ADJUSTMENT_PATTERN_COORDINATE_TABLE[index];
      for (int y : coordinates) {
        if (y >= 0) {
          for (int x : coordinates) {
            if (x >= 0 && isEmpty(matrix.get(x, y))) {
              // If the cell is unset, we embed the position adjustment pattern here.
              // -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);
            }
          }
        }
      }
    }
  
  }
  