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 (IsEmpty(matrix[i, 6]))
{
matrix[i, 6] = bit;
}
// Vertical line.
if (IsEmpty(matrix[6, i]))
{
matrix[6, i] = bit;
}
}
}
/// <summary>
/// Apply mask penalty rule 3 and return the penalty. Find consecutive cells of 00001011101 or
/// 10111010000, and give penalty to them. If we find patterns like 000010111010000, we give
/// penalties twice (i.e. 40 * 2).
/// </summary>
/// <param name="matrix">The matrix.</param>
/// <returns></returns>
public static int ApplyMaskPenaltyRule3(ByteMatrix matrix)
{
int numPenalties = 0;
byte[][] array = matrix.Array;
int width = matrix.Width;
int height = matrix.Height;
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
byte[] arrayY = array[y]; // We can at least optimize this access
if (x + 6 < width &&
arrayY[x] == 1 &&
arrayY[x + 1] == 0 &&
arrayY[x + 2] == 1 &&
arrayY[x + 3] == 1 &&
arrayY[x + 4] == 1 &&
arrayY[x + 5] == 0 &&
arrayY[x + 6] == 1 &&
(IsWhiteHorizontal(arrayY, x - 4, x) || IsWhiteHorizontal(arrayY, x + 7, x + 11)))
{
numPenalties++;
}
if (y + 6 < height &&
array[y][x] == 1 &&
array[y + 1][x] == 0 &&
array[y + 2][x] == 1 &&
array[y + 3][x] == 1 &&
array[y + 4][x] == 1 &&
array[y + 5][x] == 0 &&
array[y + 6][x] == 1 &&
(IsWhiteVertical(array, x, y - 4, y) || IsWhiteVertical(array, x, y + 7, y + 11)))
{
numPenalties++;
}
}
}
return(numPenalties * N3);
}
/// <summary>
/// Apply mask penalty rule 2 and return the penalty. Find 2x2 blocks with the same color and give
/// penalty to them. This is actually equivalent to the spec's rule, which is to find MxN blocks and give a
/// penalty proportional to (M-1)x(N-1), because this is the number of 2x2 blocks inside such a block.
/// </summary>
/// <param name="matrix">The matrix.</param>
/// <returns></returns>
public static int ApplyMaskPenaltyRule2(ByteMatrix matrix)
{
int penalty = 0;
var array = matrix.Array;
int width = matrix.Width;
int height = matrix.Height;
for (int y = 0; y < height - 1; y++)
{
var arrayY = array[y];
var arrayY1 = array[y + 1];
for (int x = 0; x < width - 1; x++)
{
int value = arrayY[x];
if (value == arrayY[x + 1] && value == arrayY1[x] && value == arrayY1[x + 1])
{
penalty++;
}
}
}
return(N2 * penalty);
}
/// <summary>
/// Apply mask penalty rule 4 and return the penalty. Calculate the ratio of dark cells and give
/// penalty if the ratio is far from 50%. It gives 10 penalty for 5% distance.
/// </summary>
/// <param name="matrix">The matrix.</param>
/// <returns></returns>
public static int ApplyMaskPenaltyRule4(ByteMatrix matrix)
{
int numDarkCells = 0;
var array = matrix.Array;
int width = matrix.Width;
int height = matrix.Height;
for (int y = 0; y < height; y++)
{
var arrayY = array[y];
for (int x = 0; x < width; x++)
{
if (arrayY[x] == 1)
{
numDarkCells++;
}
}
}
var numTotalCells = matrix.Height * matrix.Width;
var darkRatio = (double)numDarkCells / numTotalCells;
var fivePercentVariances = (int)(Math.Abs(darkRatio - 0.5) * 20.0); // * 100.0 / 5.0
return(fivePercentVariances * N4);
}
/// <summary>
/// Apply mask penalty rule 1 and return the penalty. Find repetitive cells with the same color and
/// give penalty to them. Example: 00000 or 11111.
/// </summary>
/// <param name="matrix">The matrix.</param>
/// <returns></returns>
public static int ApplyMaskPenaltyRule1(ByteMatrix matrix)
{
return(ApplyMaskPenaltyRule1Internal(matrix, true) + ApplyMaskPenaltyRule1Internal(matrix, false));
}
/// <summary>
/// Embed type information. On success, modify the matrix.
/// </summary>
/// <param name="ecLevel">The ec level.</param>
/// <param name="maskPattern">The mask pattern.</param>
/// <param name="matrix">The matrix.</param>
public static void EmbedTypeInfo(ErrorCorrectionLevel ecLevel, int maskPattern, ByteMatrix matrix)
{
BitArray typeInfoBits = new BitArray();
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[typeInfoBits.Size - 1 - i] ? 1 : 0;
// 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[x1, y1] = bit;
if (i < 8)
{
// Right top corner.
int x2 = matrix.Width - i - 1;
int y2 = 8;
matrix[x2, y2] = bit;
}
else
{
// Left bottom corner.
int x2 = 8;
int y2 = matrix.Height - 7 + (i - 8);
matrix[x2, y2] = bit;
}
}
}
/// <summary>
/// Set all cells to 2. 2 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.
/// </summary>
/// <param name="matrix">The matrix.</param>
public static void ClearMatrix(ByteMatrix matrix)
{
matrix.Clear(2);
}
/// <summary>
/// Encodes the specified content.
/// </summary>
/// <param name="content">The content.</param>
/// <param name="ecLevel">The ec level.</param>
/// <param name="hints">The hints.</param>
/// <returns></returns>
public static QRCode Encode(String content, ErrorCorrectionLevel ecLevel)
{
var encoding = DEFAULT_BYTE_MODE_ENCODING;
var generateECI = !DEFAULT_BYTE_MODE_ENCODING.Equals(encoding);
// Pick an encoding mode appropriate for the content. Note that this will not attempt to use
// multiple modes / segments even if that were more efficient. Twould be nice.
var mode = ChooseMode(content, encoding);
// This will store the header information, like mode and
// length, as well as "header" segments like an ECI segment.
var headerBits = new BitArray();
// Append ECI segment if applicable
if (mode == Mode.BYTE && generateECI)
{
var eci = CharacterSetECI.GetCharacterSetECIByName(encoding);
if (eci != null)
{
AppendECI(eci, headerBits);
}
}
// (With ECI in place,) Write the mode marker
AppendModeInfo(mode, headerBits);
// Collect data within the main segment, separately, to count its size if needed. Don't add it to
// main payload yet.
var dataBits = new BitArray();
AppendBytes(content, mode, dataBits, encoding);
Version version = RecommendVersion(ecLevel, mode, headerBits, dataBits);
var headerAndDataBits = new BitArray();
headerAndDataBits.AppendBitArray(headerBits);
// Find "length" of main segment and write it
var numLetters = mode == Mode.BYTE ? dataBits.SizeInBytes : content.Length;
AppendLengthInfo(numLetters, version, mode, headerAndDataBits);
// Put data together into the overall payload
headerAndDataBits.AppendBitArray(dataBits);
var ecBlocks = version.GetECBlocksForLevel(ecLevel);
var numDataBytes = version.TotalCodewords - ecBlocks.TotalECCodewords;
// Terminate the bits properly.
TerminateBits(numDataBytes, headerAndDataBits);
// Interleave data bits with error correction code.
var finalBits = InterleaveWithECBytes(headerAndDataBits,
version.TotalCodewords,
numDataBytes,
ecBlocks.NumBlocks);
var qrCode = new QRCode
{
ECLevel = ecLevel,
Mode = mode,
Version = version
};
// Choose the mask pattern and set to "qrCode".
var dimension = version.DimensionForVersion;
var matrix = new ByteMatrix(dimension, dimension);
var maskPattern = ChooseMaskPattern(finalBits, ecLevel, version, matrix);
qrCode.MaskPattern = maskPattern;
// Build the matrix and set it to "qrCode".
MatrixUtil.BuildMatrix(finalBits, ecLevel, version, maskPattern, matrix);
qrCode.Matrix = matrix;
return qrCode;
}
static int ChooseMaskPattern(BitArray bits, ErrorCorrectionLevel ecLevel, Version version, ByteMatrix matrix)
{
int minPenalty = Int32.MaxValue; // Lower penalty is better.
int bestMaskPattern = -1;
// We try all mask patterns to choose the best one.
for (int maskPattern = 0; maskPattern < QRCode.NUM_MASK_PATTERNS; maskPattern++)
{
MatrixUtil.BuildMatrix(bits, ecLevel, version, maskPattern, matrix);
int penalty = CalculateMaskPenalty(matrix);
if (penalty < minPenalty)
{
minPenalty = penalty;
bestMaskPattern = maskPattern;
}
}
return bestMaskPattern;
}