/* * Copyright 2007 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. */ using System; using System.Text; using com.google.zxing; using com.google.zxing.common; using com.google.zxing.qrcode.decoder; using com.google.zxing.qrcode; namespace com.google.zxing.qrcode.encoder { public sealed class MatrixUtil { private MatrixUtil() { // do nothing } private static int[][] POSITION_DETECTION_PATTERN = new int[][]{ new int[]{1, 1, 1, 1, 1, 1, 1}, new int[]{1, 0, 0, 0, 0, 0, 1}, new int[]{1, 0, 1, 1, 1, 0, 1}, new int[]{1, 0, 1, 1, 1, 0, 1}, new int[]{1, 0, 1, 1, 1, 0, 1}, new int[]{1, 0, 0, 0, 0, 0, 1}, new int[]{1, 1, 1, 1, 1, 1, 1}, }; private static int[][] HORIZONTAL_SEPARATION_PATTERN = new int[][]{ new int[]{0, 0, 0, 0, 0, 0, 0, 0}, }; private static int[][] VERTICAL_SEPARATION_PATTERN = new int[][]{ new int[]{0}, new int[]{0}, new int[]{0}, new int[]{0}, new int[]{0}, new int[]{0}, new int[]{0}, }; private static int[][] POSITION_ADJUSTMENT_PATTERN = new int[][]{ new int[]{1, 1, 1, 1, 1}, new int[]{1, 0, 0, 0, 1}, new int[]{1, 0, 1, 0, 1}, new int[]{1, 0, 0, 0, 1}, new int[]{1, 1, 1, 1, 1}, }; // From Appendix E. Table 1, JIS0510X:2004 (p 71). The table was double-checked by komatsu. private static int[][] POSITION_ADJUSTMENT_PATTERN_COORDINATE_TABLE = new int[][]{ new int[]{-1, -1, -1, -1, -1, -1, -1}, // Version 1 new int[]{ 6, 18, -1, -1, -1, -1, -1}, // Version 2 new int[]{ 6, 22, -1, -1, -1, -1, -1}, // Version 3 new int[]{ 6, 26, -1, -1, -1, -1, -1}, // Version 4 new int[]{ 6, 30, -1, -1, -1, -1, -1}, // Version 5 new int[]{ 6, 34, -1, -1, -1, -1, -1}, // Version 6 new int[]{ 6, 22, 38, -1, -1, -1, -1}, // Version 7 new int[]{ 6, 24, 42, -1, -1, -1, -1}, // Version 8 new int[]{ 6, 26, 46, -1, -1, -1, -1}, // Version 9 new int[]{ 6, 28, 50, -1, -1, -1, -1}, // Version 10 new int[]{ 6, 30, 54, -1, -1, -1, -1}, // Version 11 new int[]{ 6, 32, 58, -1, -1, -1, -1}, // Version 12 new int[]{ 6, 34, 62, -1, -1, -1, -1}, // Version 13 new int[]{ 6, 26, 46, 66, -1, -1, -1}, // Version 14 new int[]{ 6, 26, 48, 70, -1, -1, -1}, // Version 15 new int[]{ 6, 26, 50, 74, -1, -1, -1}, // Version 16 new int[]{ 6, 30, 54, 78, -1, -1, -1}, // Version 17 new int[]{ 6, 30, 56, 82, -1, -1, -1}, // Version 18 new int[]{ 6, 30, 58, 86, -1, -1, -1}, // Version 19 new int[]{ 6, 34, 62, 90, -1, -1, -1}, // Version 20 new int[]{ 6, 28, 50, 72, 94, -1, -1}, // Version 21 new int[]{ 6, 26, 50, 74, 98, -1, -1}, // Version 22 new int[]{ 6, 30, 54, 78, 102, -1, -1}, // Version 23 new int[]{ 6, 28, 54, 80, 106, -1, -1}, // Version 24 new int[]{ 6, 32, 58, 84, 110, -1, -1}, // Version 25 new int[]{ 6, 30, 58, 86, 114, -1, -1}, // Version 26 new int[]{ 6, 34, 62, 90, 118, -1, -1}, // Version 27 new int[]{ 6, 26, 50, 74, 98, 122, -1}, // Version 28 new int[]{ 6, 30, 54, 78, 102, 126, -1}, // Version 29 new int[]{ 6, 26, 52, 78, 104, 130, -1}, // Version 30 new int[]{ 6, 30, 56, 82, 108, 134, -1}, // Version 31 new int[]{ 6, 34, 60, 86, 112, 138, -1}, // Version 32 new int[]{ 6, 30, 58, 86, 114, 142, -1}, // Version 33 new int[]{ 6, 34, 62, 90, 118, 146, -1}, // Version 34 new int[]{ 6, 30, 54, 78, 102, 126, 150}, // Version 35 new int[]{ 6, 24, 50, 76, 102, 128, 154}, // Version 36 new int[]{ 6, 28, 54, 80, 106, 132, 158}, // Version 37 new int[]{ 6, 32, 58, 84, 110, 136, 162}, // Version 38 new int[]{ 6, 26, 54, 82, 110, 138, 166}, // Version 39 new int[]{ 6, 30, 58, 86, 114, 142, 170}, // Version 40 }; // Type info cells at the left top corner. private static int[][] TYPE_INFO_COORDINATES = new int[][]{ new int[]{8, 0}, new int[]{8, 1}, new int[]{8, 2}, new int[]{8, 3}, new int[]{8, 4}, new int[]{8, 5}, new int[]{8, 7}, new int[]{8, 8}, new int[]{7, 8}, new int[]{5, 8}, new int[]{4, 8}, new int[]{3, 8}, new int[]{2, 8}, new int[]{1, 8}, new int[]{0, 8}, }; // From Appendix D in JISX0510:2004 (p. 67) private static int VERSION_INFO_POLY = 0x1f25; // 1 1111 0010 0101 // From Appendix C in JISX0510:2004 (p.65). private static int TYPE_INFO_POLY = 0x537; private static int TYPE_INFO_MASK_PATTERN = 0x5412; // 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. public static void clearMatrix(ByteMatrix matrix) { matrix.clear((sbyte)(-1)); } // Build 2D matrix of QR Code from "dataBits" with "ecLevel", "version" and "getMaskPattern". On // success, store the result in "matrix" and return true. public static void buildMatrix(BitVector dataBits, ErrorCorrectionLevel ecLevel, int version,int maskPattern, ByteMatrix matrix) { try{ 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); }catch(Exception e){ throw new WriterException(e.Message); } } // 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 public static void embedBasicPatterns(int version, ByteMatrix matrix){ try { // 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); }catch(Exception e){ throw new WriterException (e.Message); } } // Embed type information. On success, modify the matrix. public static void embedTypeInfo(ErrorCorrectionLevel ecLevel, int maskPattern, ByteMatrix matrix) { BitVector typeInfoBits = new BitVector(); makeTypeInfoBits(ecLevel, maskPattern, typeInfoBits); for (int i = 0; i < typeInfoBits.size(); ++i) { // Place bits in LSB to MSB order. LSB (least significant bit) is the last value in // "typeInfoBits". int bit = typeInfoBits.at(typeInfoBits.size() - 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(y1, x1, bit); if (i < 8) { // Right top corner. int x2 = matrix.width() - i - 1; int y2 = 8; matrix.set(y2, x2, bit); } else { // Left bottom corner. int x2 = 8; int y2 = matrix.height() - 7 + (i - 8); matrix.set(y2, x2, 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. public static void maybeEmbedVersionInfo(int version, ByteMatrix matrix){ if (version < 7) { // Version info is necessary if version >= 7. return; // Don't need version info. } BitVector versionInfoBits = new BitVector(); 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. int bit = versionInfoBits.at(bitIndex); bitIndex--; // Left bottom corner. matrix.set(matrix.height() - 11 + j, i, bit); // Right bottom corner. matrix.set(i, matrix.height() - 11 + j, 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. public static void embedDataBits(BitVector dataBits, int maskPattern, ByteMatrix matrix) { int bitIndex = 0; int direction = -1; // Start from the right bottom cell. int x = matrix.width() - 1; int y = matrix.height() - 1; while (x > 0) { // Skip the vertical timing pattern. if (x == 6) { x -= 1; } while (y >= 0 && y < matrix.height()) { for (int i = 0; i < 2; ++i) { int xx = x - i; // Skip the cell if it's not empty. if (!isEmpty(matrix.get(y, xx))) { continue; } int bit; if (bitIndex < dataBits.size()) { bit = dataBits.at(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 = 0; } // Skip masking if mask_pattern is -1. if (maskPattern != -1) { int mask = MaskUtil.getDataMaskBit(maskPattern, xx, y); bit ^= mask; } matrix.set(y, xx, bit); } y += direction; } direction = -direction; // Reverse the direction. y += direction; x -= 2; // Move to the left. } // All bits should be consumed. if (bitIndex != dataBits.size()) { throw new WriterException("Not all bits consumed: " + bitIndex + '/' + dataBits.size()); } } // 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 public static int findMSBSet(int value) { int numDigits = 0; while (value != 0) { value >>= 1; ++numDigits; } return numDigits; } // 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^2 + x^1 // 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 cofficients are positive or negative. public static int 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. public static void makeTypeInfoBits(ErrorCorrectionLevel ecLevel, int maskPattern, BitVector bits) { 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); BitVector maskBits = new BitVector(); maskBits.appendBits(TYPE_INFO_MASK_PATTERN, 15); bits.xor(maskBits); if (bits.size() != 15) { // Just in case. throw new WriterException("should not happen but we got: " + bits.size()); } } // 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. public static void makeVersionInfoBits(int version, BitVector bits){ bits.appendBits(version, 6); int bchCode = calculateBCHCode(version, VERSION_INFO_POLY); bits.appendBits(bchCode, 12); if (bits.size() != 18) { // Just in case. throw new WriterException("should not happen but we got: " + bits.size()); } } // Check if "value" is empty. private static bool isEmpty(int value) { return value == -1; } // Check if "value" is valid. private static bool isValidValue(int value) { return (value == -1 || // Empty. value == 0 || // Light (white). value == 1); // Dark (black). } 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.width() - 8; ++i) { int bit = (i + 1) % 2; // Horizontal line. if (!isValidValue(matrix.get(6, i))) { throw new WriterException(); } if (isEmpty(matrix.get(6, i))) { matrix.set(6, i, bit); } // Vertical line. if (!isValidValue(matrix.get(i, 6))) { throw new WriterException(); } if (isEmpty(matrix.get(i, 6))) { matrix.set(i, 6, bit); } } } // Embed the lonely dark dot at left bottom corner. JISX0510:2004 (p.46) private static void embedDarkDotAtLeftBottomCorner(ByteMatrix matrix){ if (matrix.get(matrix.height() - 8, 8) == 0) { throw new WriterException(); } matrix.set(matrix.height() - 8, 8, 1); } private static void embedHorizontalSeparationPattern(int xStart, int yStart,ByteMatrix matrix) { // We know the width and height. if (HORIZONTAL_SEPARATION_PATTERN[0].Length != 8 || HORIZONTAL_SEPARATION_PATTERN.Length != 1) { throw new WriterException("Bad horizontal separation pattern"); } for (int x = 0; x < 8; ++x) { if (!isEmpty(matrix.get(yStart, xStart + x))) { throw new WriterException(); } matrix.set(yStart, xStart + x, HORIZONTAL_SEPARATION_PATTERN[0][x]); } } private static void embedVerticalSeparationPattern(int xStart, int yStart,ByteMatrix matrix){ // We know the width and height. if (VERTICAL_SEPARATION_PATTERN[0].Length != 1 || VERTICAL_SEPARATION_PATTERN.Length != 7) { throw new WriterException("Bad vertical separation pattern"); } for (int y = 0; y < 7; ++y) { if (!isEmpty(matrix.get(yStart + y, xStart))) { throw new WriterException(); } matrix.set(yStart + y, xStart, VERTICAL_SEPARATION_PATTERN[y][0]); } } // Note that we cannot unify the function with embedPositionDetectionPattern() despite they are // almost identical, since we cannot write a function that takes 2D arrays in different sizes in // C/C++. We should live with the fact. private static void embedPositionAdjustmentPattern(int xStart, int yStart,ByteMatrix matrix){ // We know the width and height. if (POSITION_ADJUSTMENT_PATTERN[0].Length != 5 || POSITION_ADJUSTMENT_PATTERN.Length != 5) { throw new WriterException("Bad position adjustment"); } for (int y = 0; y < 5; ++y) { for (int x = 0; x < 5; ++x) { if (!isEmpty(matrix.get(yStart + y, xStart + x))) { throw new WriterException(); } matrix.set(yStart + y, xStart + x, POSITION_ADJUSTMENT_PATTERN[y][x]); } } } private static void embedPositionDetectionPattern(int xStart, int yStart,ByteMatrix matrix){ // We know the width and height. if (POSITION_DETECTION_PATTERN[0].Length != 7 || POSITION_DETECTION_PATTERN.Length != 7) { throw new WriterException("Bad position detection pattern"); } for (int y = 0; y < 7; ++y) { for (int x = 0; x < 7; ++x) { if (!isEmpty(matrix.get(yStart + y, xStart + x))) { throw new WriterException(); } matrix.set(yStart + y, xStart + x, POSITION_DETECTION_PATTERN[y][x]); } } } // Embed position detection patterns and surrounding vertical/horizontal separators. private static void embedPositionDetectionPatternsAndSeparators(ByteMatrix matrix) { // 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.width() - pdpWidth, 0, matrix); // Left bottom corner. embedPositionDetectionPattern(0, matrix.width() - pdpWidth, matrix); // Embed horizontal separation patterns around the squares. int hspWidth = HORIZONTAL_SEPARATION_PATTERN[0].Length; // Left top corner. embedHorizontalSeparationPattern(0, hspWidth - 1, matrix); // Right top corner. embedHorizontalSeparationPattern(matrix.width() - hspWidth, hspWidth - 1, matrix); // Left bottom corner. embedHorizontalSeparationPattern(0, matrix.width() - hspWidth, matrix); // Embed vertical separation patterns around the squares. int vspSize = VERTICAL_SEPARATION_PATTERN.Length; // Left top corner. embedVerticalSeparationPattern(vspSize, 0, matrix); // Right top corner. embedVerticalSeparationPattern(matrix.height() - vspSize - 1, 0, matrix); // Left bottom corner. embedVerticalSeparationPattern(vspSize, matrix.height() - vspSize, matrix); } // Embed position adjustment patterns if need be. private static void maybeEmbedPositionAdjustmentPatterns(int version, ByteMatrix matrix) { if (version < 2) { // The patterns appear if version >= 2 return; } int index = version - 1; int[] coordinates = POSITION_ADJUSTMENT_PATTERN_COORDINATE_TABLE[index]; int numCoordinates = POSITION_ADJUSTMENT_PATTERN_COORDINATE_TABLE[index].Length; for (int i = 0; i < numCoordinates; ++i) { for (int j = 0; j < numCoordinates; ++j) { int y = coordinates[i]; int x = coordinates[j]; if (x == -1 || y == -1) { continue; } // If the cell is unset, we embed the position adjustment pattern here. if (isEmpty(matrix.get(y, x))) { // -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); } } } } } }