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 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++)
{
for (int x = 0; x < width - 1; x++)
{
int value = array[y][x];
if (value == array[y][x + 1] && value == array[y + 1][x] && value == array[y + 1][x + 1])
{
penalty++;
}
}
}
return(N2 * penalty);
}
private 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);
}
/// <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>
/// 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,
IDictionary <EncodeHintType, object> hints)
{
// Determine what character encoding has been specified by the caller, if any
#if !SILVERLIGHT || WINDOWS_PHONE
String encoding = hints == null || !hints.ContainsKey(EncodeHintType.CHARACTER_SET) ? null : (String)hints[EncodeHintType.CHARACTER_SET];
if (encoding == null)
{
encoding = DEFAULT_BYTE_MODE_ENCODING;
}
bool generateECI = !DEFAULT_BYTE_MODE_ENCODING.Equals(encoding);
#else
// Silverlight supports only UTF-8 and UTF-16 out-of-the-box
const string encoding = "UTF-8";
// caller of the method can only control if the ECI segment should be written
// character set is fixed to UTF-8; but some scanners doesn't like the ECI segment
bool generateECI = (hints != null && hints.ContainsKey(EncodeHintType.CHARACTER_SET));
#endif
// 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.
Mode mode = chooseMode(content, encoding);
// This will store the header information, like mode and
// length, as well as "header" segments like an ECI segment.
BitArray headerBits = new BitArray();
// Append ECI segment if applicable
if (mode == Mode.BYTE && generateECI)
{
CharacterSetECI eci = CharacterSetECI.getCharacterSetECIByName(encoding);
if (eci != null)
{
var eciIsExplicitDisabled = (hints != null && hints.ContainsKey(EncodeHintType.DISABLE_ECI) ? (bool)hints[EncodeHintType.DISABLE_ECI] : false);
if (!eciIsExplicitDisabled)
{
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.
BitArray dataBits = new BitArray();
appendBytes(content, mode, dataBits, encoding);
// Hard part: need to know version to know how many bits length takes. But need to know how many
// bits it takes to know version. First we take a guess at version by assuming version will be
// the minimum, 1:
int provisionalBitsNeeded = headerBits.Size
+ mode.getCharacterCountBits(Version.getVersionForNumber(1))
+ dataBits.Size;
Version provisionalVersion = chooseVersion(provisionalBitsNeeded, ecLevel);
// Use that guess to calculate the right version. I am still not sure this works in 100% of cases.
int bitsNeeded = headerBits.Size
+ mode.getCharacterCountBits(provisionalVersion)
+ dataBits.Size;
Version version = chooseVersion(bitsNeeded, ecLevel);
BitArray headerAndDataBits = new BitArray();
headerAndDataBits.appendBitArray(headerBits);
// Find "length" of main segment and write it
int numLetters = mode == Mode.BYTE ? dataBits.SizeInBytes : content.Length;
appendLengthInfo(numLetters, version, mode, headerAndDataBits);
// Put data together into the overall payload
headerAndDataBits.appendBitArray(dataBits);
Version.ECBlocks ecBlocks = version.getECBlocksForLevel(ecLevel);
int numDataBytes = version.TotalCodewords - ecBlocks.TotalECCodewords;
// Terminate the bits properly.
terminateBits(numDataBytes, headerAndDataBits);
// Interleave data bits with error correction code.
BitArray finalBits = interleaveWithECBytes(headerAndDataBits,
version.TotalCodewords,
numDataBytes,
ecBlocks.NumBlocks);
QRCode qrCode = new QRCode
{
ECLevel = ecLevel,
Mode = mode,
Version = version
};
// Choose the mask pattern and set to "qrCode".
int dimension = version.DimensionForVersion;
ByteMatrix matrix = new ByteMatrix(dimension, dimension);
int 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);
}
/// <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 x1 = TYPE_INFO_COORDINATES[i][0];
int y1 = TYPE_INFO_COORDINATES[i][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>
/// Build 2D matrix of QR Code from "dataBits" with "ecLevel", "version" and "getMaskPattern". On
/// success, store the result in "matrix" and return true.
/// </summary>
/// <param name="dataBits">The data bits.</param>
/// <param name="ecLevel">The ec level.</param>
/// <param name="version">The version.</param>
/// <param name="maskPattern">The mask pattern.</param>
/// <param name="matrix">The matrix.</param>
public static void buildMatrix(BitArray dataBits, ErrorCorrectionLevel ecLevel, Version 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);
}
/// <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>
/// 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));
}