zxing/csharp/qrcode/encoder/MatrixUtil.cs

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/*
* 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.
*/
using System;
using WriterException = com.google.zxing.WriterException;
using ByteMatrix = com.google.zxing.common.ByteMatrix;
using ErrorCorrectionLevel = com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
namespace com.google.zxing.qrcode.encoder
{
/// <author> satorux@google.com (Satoru Takabayashi) - creator
/// </author>
/// <author> dswitkin@google.com (Daniel Switkin) - ported from C++
/// </author>
/// <author>www.Redivivus.in (suraj.supekar@redivivus.in) - Ported from ZXING Java Source
/// </author>
public sealed class MatrixUtil
{
private MatrixUtil()
{
// do nothing
}
//UPGRADE_NOTE: Final was removed from the declaration of 'POSITION_DETECTION_PATTERN'. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
private static readonly 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}};
//UPGRADE_NOTE: Final was removed from the declaration of 'HORIZONTAL_SEPARATION_PATTERN'. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
private static readonly int[][] HORIZONTAL_SEPARATION_PATTERN = new int[][]{new int[]{0, 0, 0, 0, 0, 0, 0, 0}};
//UPGRADE_NOTE: Final was removed from the declaration of 'VERTICAL_SEPARATION_PATTERN'. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
private static readonly 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}};
//UPGRADE_NOTE: Final was removed from the declaration of 'POSITION_ADJUSTMENT_PATTERN'. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
private static readonly 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.
//UPGRADE_NOTE: Final was removed from the declaration of 'POSITION_ADJUSTMENT_PATTERN_COORDINATE_TABLE'. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
private static readonly int[][] POSITION_ADJUSTMENT_PATTERN_COORDINATE_TABLE = new int[][]{new int[]{- 1, - 1, - 1, - 1, - 1, - 1, - 1}, new int[]{6, 18, - 1, - 1, - 1, - 1, - 1}, new int[]{6, 22, - 1, - 1, - 1, - 1, - 1}, new int[]{6, 26, - 1, - 1, - 1, - 1, - 1}, new int[]{6, 30, - 1, - 1, - 1, - 1, - 1}, new int[]{6, 34, - 1, - 1, - 1, - 1, - 1}, new int[]{6, 22, 38, - 1, - 1, - 1, - 1}, new int[]{6, 24, 42, - 1, - 1, - 1, - 1}, new int[]{6, 26, 46, - 1, - 1, - 1, - 1}, new int[]{6, 28, 50, - 1, - 1, - 1, - 1}, new int[]{6, 30, 54, - 1, - 1, - 1, - 1}, new int[]{6, 32, 58, - 1, - 1, - 1, - 1}, new int[]{6, 34, 62, - 1, - 1, - 1, - 1}, new int[]{6, 26, 46, 66, - 1, - 1, - 1}, new int[]{6, 26, 48, 70, - 1, - 1, - 1}, new int[]{6, 26, 50, 74, - 1, - 1, - 1}, new int[]{6, 30, 54, 78, - 1, - 1, - 1}, new int[]{6, 30, 56, 82, - 1, - 1, - 1}, new int[]{6, 30, 58, 86, - 1, - 1, - 1}, new int[]{6, 34, 62, 90, - 1, - 1, - 1}, new int[]{6, 28, 50, 72, 94, - 1, - 1}, new int[]{6, 26, 50, 74, 98, - 1, - 1}, new int[]{6, 30, 54, 78, 102, - 1, - 1}, new int[]{6, 28, 54, 80, 106, - 1, - 1}, new int[]{6, 32, 58, 84, 110, - 1, - 1}, new int[]{6, 30, 58, 86, 114, - 1, - 1}, new int[]{6, 34, 62, 90, 118, - 1, - 1}, new int[]{6, 26, 50, 74, 98, 122, - 1}, new int[]{6, 30, 54, 78, 102, 126, - 1}, new int[]{6, 26, 52, 78, 104, 130, - 1}, new int[]{6, 30, 56, 82, 108, 134, - 1}, new int[]{6, 34, 60, 86, 112, 138, - 1}, new int[]{6, 30, 58, 86, 114, 142, - 1}, new int[]{6, 34, 62, 90, 118, 146, - 1}, new int[]{6, 30, 54, 78, 102, 126, 150}, new int[]{6, 24, 50, 76, 102, 128, 154}, new int[]{6, 28, 54, 80, 106, 132, 158}, new int[]{6, 32, 58, 84, 110, 136, 162}, new int[]{6, 26, 54, 82, 110, 138, 166}, new int[]{6, 30, 58, 86, 114, 142, 170}};
// Type info cells at the left top corner.
//UPGRADE_NOTE: Final was removed from the declaration of 'TYPE_INFO_COORDINATES'. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
private static readonly 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 const int VERSION_INFO_POLY = 0x1f25; // 1 1111 0010 0101
// From Appendix C in JISX0510:2004 (p.65).
private const int TYPE_INFO_POLY = 0x537;
private const 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)
{
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
public static void embedBasicPatterns(int 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.
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_Renamed(x1, y1, bit);
if (i < 8)
{
// Right top corner.
int x2 = matrix.Width - i - 1;
int y2 = 8;
matrix.set_Renamed(x2, y2, bit);
}
else
{
// Left bottom corner.
int x2 = 8;
int y2 = matrix.Height - 7 + (i - 8);
matrix.set_Renamed(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.
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_Renamed(i, matrix.Height - 11 + j, bit);
// Right bottom corner.
matrix.set_Renamed(matrix.Height - 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.
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_Renamed(xx, y)))
{
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)
{
if (MaskUtil.getDataMaskBit(maskPattern, xx, y))
{
bit ^= 0x1;
}
}
matrix.set_Renamed(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.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_Renamed)
{
int numDigits = 0;
while (value_Renamed != 0)
{
value_Renamed = SupportClass.URShift(value_Renamed, 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_Renamed, 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_Renamed <<= msbSetInPoly - 1;
// Do the division business using exclusive-or operations.
while (findMSBSet(value_Renamed) >= msbSetInPoly)
{
value_Renamed ^= poly << (findMSBSet(value_Renamed) - msbSetInPoly);
}
// Now the "value" is the remainder (i.e. the BCH code)
return value_Renamed;
}
// 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.Bits << 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_Renamed)
{
return value_Renamed == - 1;
}
// Check if "value" is valid.
private static bool isValidValue(int value_Renamed)
{
return (value_Renamed == - 1 || value_Renamed == 0 || value_Renamed == 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_Renamed(i, 6)))
{
throw new WriterException();
}
if (isEmpty(matrix.get_Renamed(i, 6)))
{
matrix.set_Renamed(i, 6, bit);
}
// Vertical line.
if (!isValidValue(matrix.get_Renamed(6, i)))
{
throw new WriterException();
}
if (isEmpty(matrix.get_Renamed(6, i)))
{
matrix.set_Renamed(6, i, bit);
}
}
}
// Embed the lonely dark dot at left bottom corner. JISX0510:2004 (p.46)
private static void embedDarkDotAtLeftBottomCorner(ByteMatrix matrix)
{
if (matrix.get_Renamed(8, matrix.Height - 8) == 0)
{
throw new WriterException();
}
matrix.set_Renamed(8, matrix.Height - 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_Renamed(xStart + x, yStart)))
{
throw new WriterException();
}
matrix.set_Renamed(xStart + x, yStart, 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_Renamed(xStart, yStart + y)))
{
throw new WriterException();
}
matrix.set_Renamed(xStart, yStart + y, 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_Renamed(xStart + x, yStart + y)))
{
throw new WriterException();
}
matrix.set_Renamed(xStart + x, yStart + y, 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_Renamed(xStart + x, yStart + y)))
{
throw new WriterException();
}
matrix.set_Renamed(xStart + x, yStart + y, 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_Renamed(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);
}
}
}
}
}
}