/// <summary>
/// Creates a segment representing the specified binary data
/// encoded in byte mode. All input byte arrays are acceptable.
/// <para>
/// Any text string can be converted to UTF-8 bytes (using <c>Encoding.UTF8.GetBytes(str)</c>)
/// and encoded as a byte mode segment.
/// </para>
/// </summary>
/// <param name="data">The binary data to encode.</param>
/// <returns>The created segment containing the specified data.</returns>
/// <exception cref="ArgumentNullException"><c>data</c> is <c>null</c>.</exception>
public static QrSegment MakeBytes(byte[] data)
{
Objects.RequireNonNull(data);
BitArray ba = new BitArray(0);
foreach (byte b in data)
{
ba.AppendBits(b, 8);
}
return(new QrSegment(Mode.Byte, data.Length, ba));
}
/// <summary>
/// Initializes a QR code segment with the specified attributes and data.
/// <para>
/// The character count <paramref name="numChars"/> must agree with the mode and the bit array length,
/// but the constraint isn't checked. The specified bit array is cloned.
/// </para>
/// </summary>
/// <param name="mode">The segment mode used to encode this segment.</param>
/// <param name="numChars">The data length in characters or bytes (depending on the segment mode).</param>
/// <param name="data">The data bits.</param>
/// <exception cref="ArgumentNullException"><paramref name="mode"/> or <paramref name="data"/> is <c>null</c>.</exception>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="numChars"/> is negative.</exception>
public QrSegment(Mode mode, int numChars, BitArray data)
{
EncodingMode = Objects.RequireNonNull(mode);
Objects.RequireNonNull(data);
if (numChars < 0)
{
throw new ArgumentOutOfRangeException(nameof(numChars), "Invalid value");
}
NumChars = numChars;
_data = (BitArray)data.Clone(); // Make defensive copy
}
/// <summary>
/// Tests whether the specified string can be encoded as a segment in Kanji mode.
/// <para>
/// Broadly speaking, the set of encodable characters are Kanji used in Japan,
/// Hiragana, Katakana, East Asian punctuation, full-width ASCII, Greek, and Cyrillic.
/// Examples of non-encodable characters include ordinary ASCII, half-width Katakana,
/// more extensive Chinese Hanzi.
/// </para>
/// </summary>
/// <param name="text">The text to test for encodability.</param>
/// <returns><c>true</c> iff each character is in the Kanji mode character set.</returns>
/// <exception cref="ArgumentNullException"><paramref name="text"/> is <c>null</c>.</exception>
public static bool IsEncodableAsKanji(string text)
{
Objects.RequireNonNull(text);
foreach (char t in text)
{
if (!IsKanji(t))
{
return(false);
}
}
return(true);
}
/// <summary>
/// Appends the content of the specified bit array to the end of this array.
/// </summary>
/// <param name="bitArray">The BitArray instance that this method extends.</param>
/// <param name="otherArray">The bit array to append</param>
/// <exception cref="ArgumentNullException">If <c>bitArray</c> is <c>null</c>.</exception>
public static void AppendData(this BitArray bitArray, BitArray otherArray)
{
Objects.RequireNonNull(otherArray);
int bitLength = bitArray.Length;
bitArray.Length = bitLength + otherArray.Length;
for (int i = 0; i < otherArray.Length; i++, bitLength++) // Append bit by bit
{
if (otherArray[i])
{
bitArray.Set(bitLength, true);
}
}
}
/// <summary>
/// Creates a list of zero or more segments to represent the specified text string.
/// The resulting list optimally minimizes the total encoded bit length, subjected to the constraints
/// of the specified error correction level, minimum and maximum version number.
/// <para>
/// This function potentially uses all four text encoding modes: numeric, alphanumeric, byte (UTF-8),
/// and Kanji. It is a more sophisticated but slower replacement for <see cref="MakeSegments"/>.
/// </para>
/// <para>
/// The text to be encoded can contain the full set of Unicode characters (code points).
/// </para>
/// </summary>
/// <param name="text">The text to be encoded.</param>
/// <param name="ecl">The error correction level to use.</param>
/// <param name="minVersion">The minimum version (size) of the QR code (between 1 and 40).</param>
/// <param name="maxVersion">The maximum version (size) of the QR code (between 1 and 40).</param>
/// <returns>The created mutable list of segments encoding the specified text with a minimal bit length.</returns>
/// <exception cref="ArgumentNullException"><paramref name="text"/> or <paramref name="ecl"/> is <c>null</c>.</exception>
/// <exception cref="ArgumentOutOfRangeException">1 ≤ minVersion ≤ maxVersion ≤ 40 is violated.</exception>
/// <exception cref="DataTooLongException">The text is too long to fit into the QR code with the given encoding parameters.</exception>
public static List <QrSegment> MakeSegmentsOptimally(string text, QrCode.Ecc ecl, int minVersion = QrCode.MinVersion, int maxVersion = QrCode.MaxVersion)
{
// Check arguments
Objects.RequireNonNull(text);
Objects.RequireNonNull(ecl);
if (minVersion < QrCode.MinVersion || minVersion > maxVersion)
{
throw new ArgumentOutOfRangeException(nameof(minVersion), "Invalid value");
}
if (maxVersion > QrCode.MaxVersion)
{
throw new ArgumentOutOfRangeException(nameof(maxVersion), "Invalid value");
}
// Iterate through version numbers, and make tentative segments
List <QrSegment> segs = null;
var codePoints = ToCodePoints(text);
for (int version = minVersion;; version++)
{
if (version == minVersion || version == 10 || version == 27)
{
segs = MakeSegmentsOptimally(codePoints, version);
}
Debug.Assert(segs != null);
// Check if the segments fit
int dataCapacityBits = QrCode.GetNumDataCodewords(version, ecl) * 8;
int dataUsedBits = GetTotalBits(segs, version);
if (dataUsedBits != -1 && dataUsedBits <= dataCapacityBits)
{
return(segs); // This version number is found to be suitable
}
if (version < maxVersion)
{
continue;
}
// All versions in the range could not fit the given text
var msg = "Segment too long";
if (dataUsedBits != -1)
{
msg = $"Data length = {dataUsedBits} bits, Max capacity = {dataCapacityBits} bits";
}
throw new DataTooLongException(msg);
}
}
// Returns a new byte string representing the given data with the appropriate error correction
// codewords appended to it, based on this object's version and error correction level.
private byte[] AddEccAndInterleave(byte[] data)
{
Objects.RequireNonNull(data);
if (data.Length != GetNumDataCodewords(Version, ErrorCorrectionLevel))
{
throw new ArgumentOutOfRangeException();
}
// Calculate parameter numbers
int numBlocks = NumErrorCorrectionBlocks[ErrorCorrectionLevel.Ordinal, Version];
int blockEccLen = EccCodewordsPerBlock[ErrorCorrectionLevel.Ordinal, Version];
int rawCodewords = GetNumRawDataModules(Version) / 8;
int numShortBlocks = numBlocks - rawCodewords % numBlocks;
int shortBlockLen = rawCodewords / numBlocks;
// Split data into blocks and append ECC to each block
byte[][] blocks = new byte[numBlocks][];
ReedSolomonGenerator rs = new ReedSolomonGenerator(blockEccLen);
for (int i = 0, k = 0; i < numBlocks; i++)
{
byte[] dat = CopyOfRange(data, k, k + shortBlockLen - blockEccLen + (i < numShortBlocks ? 0 : 1));
k += dat.Length;
byte[] block = CopyOf(dat, shortBlockLen + 1);
byte[] ecc = rs.GetRemainder(dat);
Array.Copy(ecc, 0, block, block.Length - blockEccLen, ecc.Length);
blocks[i] = block;
}
// Interleave (not concatenate) the bytes from every block into a single sequence
byte[] result = new byte[rawCodewords];
for (int i = 0, k = 0; i < blocks[0].Length; i++)
{
for (int j = 0; j < blocks.Length; j++)
{
// Skip the padding byte in short blocks
if (i != shortBlockLen - blockEccLen || j >= numShortBlocks)
{
result[k] = blocks[j][i];
k++;
}
}
}
return(result);
}
/// <summary>
/// Computes the Reed-Solomon error correction codewords for the specified
/// sequence of data codewords.
/// <para>
/// This method does not alter this object's state (as it is immutable).
/// </para>
/// </summary>
/// <param name="data">The sequence of data codewords.</param>
/// <returns>The Reed-Solomon error correction codewords, as a byte array.</returns>
/// <exception cref="ArgumentNullException">If <c>data</c> is <c>null</c>.</exception>
internal byte[] GetRemainder(byte[] data)
{
Objects.RequireNonNull(data);
// Compute the remainder by performing polynomial division
byte[] result = new byte[_coefficients.Length];
foreach (byte b in data)
{
uint factor = (uint)(b ^ result[0]);
Array.Copy(result, 1, result, 0, result.Length - 1);
result[result.Length - 1] = 0;
for (int i = 0; i < result.Length; i++)
{
result[i] ^= Multiply(_coefficients[i], factor);
}
}
return(result);
}
/// <summary>
/// Creates a segment encoding the specified text in Kanji mode.
/// <para>
/// Broadly speaking, the set of encodable characters are Kanji used in Japan,
/// Hiragana, Katakana, East Asian punctuation, full-width ASCII, Greek, and Cyrillic.
/// Examples of non-encodable characters include ordinary ASCII, half-width Katakana,
/// more extensive Chinese Hanzi.
/// </para>
/// </summary>
/// <param name="text">The text to encoding, containing only characters allowed by the Kanji encoding.</param>
/// <returns>The created segment respresenting the specified text.</returns>
/// <exception cref="ArgumentNullException"><paramref name="text"/> is <c>null</c>.</exception>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="text"/> contains non-encodable characters.</exception>
/// <seealso cref="IsEncodableAsKanji"/>
public static QrSegment MakeKanji(string text)
{
Objects.RequireNonNull(text);
var ba = new BitArray(0);
foreach (char t in text)
{
ushort val = UnicodeToQrKanji[t];
if (val == 0xffff)
{
throw new ArgumentOutOfRangeException(nameof(text), "String contains non-kanji-mode characters");
}
ba.AppendBits(val, 13);
}
return(new QrSegment(Mode.Kanji, text.Length, ba));
}
/// <summary>
/// Creates a segment representing the specified string of decimal digits.
/// The segment is encoded in numeric mode.
/// </summary>
/// <param name="digits">The text to encode, consisting of digits from 0 to 9 only.</param>
/// <returns>The created segment containing the text.</returns>
/// <exception cref="ArgumentNullException"><c>digits</c> is <c>null</c>.</exception>
/// <exception cref="ArgumentOutOfRangeException"><c>digits</c> contains non-digit characters</exception>
public static QrSegment MakeNumeric(string digits)
{
Objects.RequireNonNull(digits);
if (!NumericRegex.IsMatch(digits))
{
throw new ArgumentOutOfRangeException(nameof(digits), "String contains non-numeric characters");
}
BitArray ba = new BitArray(0);
for (int i = 0; i < digits.Length;)
{
// Consume up to 3 digits per iteration
int n = Math.Min(digits.Length - i, 3);
ba.AppendBits(uint.Parse(digits.Substring(i, n)), n * 3 + 1);
i += n;
}
return(new QrSegment(Mode.Numeric, digits.Length, ba));
}
// Draws the given sequence of 8-bit codewords (data and error correction) onto the entire
// data area of this QR code. Function modules need to be marked off before this is called.
private void DrawCodewords(byte[] data)
{
Objects.RequireNonNull(data);
if (data.Length != GetNumRawDataModules(Version) / 8)
{
throw new ArgumentOutOfRangeException();
}
int i = 0; // Bit index into the data
// Do the funny zigzag scan
for (int right = Size - 1; right >= 1; right -= 2)
{
// Index of right column in each column pair
if (right == 6)
{
right = 5;
}
for (int vert = 0; vert < Size; vert++)
{
// Vertical counter
for (int j = 0; j < 2; j++)
{
int x = right - j; // Actual x coordinate
bool upward = ((right + 1) & 2) == 0;
int y = upward ? Size - 1 - vert : vert; // Actual y coordinate
if (_isFunction[y * Size + x] || i >= data.Length * 8)
{
continue;
}
_modules[y * Size + x] = GetBit(data[(uint)i >> 3], 7 - (i & 7));
i++;
// If this QR code has any remainder bits (0 to 7), they were assigned as
// 0/false/white by the constructor and are left unchanged by this method
}
}
}
Debug.Assert(i == data.Length * 8);
}
// Calculates the number of bits needed to encode the given segments at the given version.
// Returns a non-negative number if successful. Otherwise returns -1 if a segment has too
// many characters to fit its length field, or the total bits exceeds int.MaxValue.
internal static int GetTotalBits(List <QrSegment> segs, int version)
{
Objects.RequireNonNull(segs);
long result = 0;
foreach (QrSegment seg in segs)
{
Objects.RequireNonNull(seg);
int ccbits = seg.EncodingMode.NumCharCountBits(version);
if (seg.NumChars >= 1 << ccbits)
{
return(-1); // The segment's length doesn't fit the field's bit width
}
result += 4L + ccbits + seg._data.Length;
if (result > int.MaxValue)
{
return(-1); // The sum will overflow an int type
}
}
return((int)result);
}
/// <summary>
/// Creates a QR code representing the specified segments with the specified encoding parameters.
/// <para>
/// The smallest possible QR code version (size) is used. The range of versions can be
/// restricted by the <paramref name="minVersion"/> and <paramref name="maxVersion"/> parameters.
/// </para>
/// <para>
/// If <paramref name="boostEcl"/> is <c>true</c>, the resulting ECC level will be higher than the
/// one specified if it can be achieved without increasing the size (version).
/// </para>
/// <para>
/// The QR code mask is usually automatically chosen. It can be explicitly set with the <paramref name="mask"/>
/// parameter by using a value between 0 to 7 (inclusive). -1 is for automatic mode (which may be slow).
/// </para>
/// <para>
/// This function allows the user to create a custom sequence of segments that switches
/// between modes (such as alphanumeric and byte) to encode text in less space and gives full control over all
/// encoding paramters.
/// </para>
/// </summary>
/// <remarks>
/// This is a mid-level API; the high-level APIs are <see cref="EncodeText(string, Ecc)"/>
/// and <see cref="EncodeBinary(byte[], Ecc)"/>.
/// </remarks>
/// <param name="segments">The segments to encode.</param>
/// <param name="ecl">The minimal or fixed error correction level to use .</param>
/// <param name="minVersion">The minimum version (size) of the QR code (between 1 and 40).</param>
/// <param name="maxVersion">The maximum version (size) of the QR code (between 1 and 40).</param>
/// <param name="mask">The mask number to use (between 0 and 7), or -1 for automatic mask selection.</param>
/// <param name="boostEcl">If <c>true</c> the ECC level wil be increased if it can be achieved without increasing the size (version).</param>
/// <returns>The created QR code representing the segments.</returns>
/// <exception cref="ArgumentNullException"><paramref name="segments"/>, any list element, or <paramref name="ecl"/> is <c>null</c>.</exception>
/// <exception cref="ArgumentOutOfRangeException">1 ≤ minVersion ≤ maxVersion ≤ 40
/// or -1 ≤ mask ≤ 7 is violated.</exception>
/// <exception cref="DataTooLongException">The segments are too long to fit in the largest QR code size (version)
/// at the specified error correction level.</exception>
public static QrCode EncodeSegments(List <QrSegment> segments, Ecc ecl, int minVersion = MinVersion, int maxVersion = MaxVersion, int mask = -1, bool boostEcl = true)
{
Objects.RequireNonNull(segments);
Objects.RequireNonNull(ecl);
if (minVersion < MinVersion || minVersion > maxVersion)
{
throw new ArgumentOutOfRangeException(nameof(minVersion), "Invalid value");
}
if (maxVersion > MaxVersion)
{
throw new ArgumentOutOfRangeException(nameof(maxVersion), "Invalid value");
}
if (mask < -1 || mask > 7)
{
throw new ArgumentOutOfRangeException(nameof(mask), "Invalid value");
}
// Find the minimal version number to use
int version, dataUsedBits;
for (version = minVersion; ; version++)
{
int numDataBits = GetNumDataCodewords(version, ecl) * 8; // Number of data bits available
dataUsedBits = QrSegment.GetTotalBits(segments, version);
if (dataUsedBits != -1 && dataUsedBits <= numDataBits)
{
break; // This version number is found to be suitable
}
if (version >= maxVersion)
{ // All versions in the range could not fit the given data
string msg = "Segment too long";
if (dataUsedBits != -1)
{
msg = $"Data length = {dataUsedBits} bits, Max capacity = {numDataBits} bits";
}
throw new DataTooLongException(msg);
}
}
Debug.Assert(dataUsedBits != -1);
// Increase the error correction level while the data still fits in the current version number
foreach (Ecc newEcl in Ecc.AllValues)
{ // From low to high
if (boostEcl && dataUsedBits <= GetNumDataCodewords(version, newEcl) * 8)
{
ecl = newEcl;
}
}
// Concatenate all segments to create the data bit string
BitArray ba = new BitArray(0);
foreach (QrSegment seg in segments)
{
ba.AppendBits(seg.EncodingMode.ModeBits, 4);
ba.AppendBits((uint)seg.NumChars, seg.EncodingMode.NumCharCountBits(version));
ba.AppendData(seg.GetData());
}
Debug.Assert(ba.Length == dataUsedBits);
// Add terminator and pad up to a byte if applicable
int dataCapacityBits = GetNumDataCodewords(version, ecl) * 8;
Debug.Assert(ba.Length <= dataCapacityBits);
ba.AppendBits(0, Math.Min(4, dataCapacityBits - ba.Length));
ba.AppendBits(0, (8 - ba.Length % 8) % 8);
Debug.Assert(ba.Length % 8 == 0);
// Pad with alternating bytes until data capacity is reached
for (uint padByte = 0xEC; ba.Length < dataCapacityBits; padByte ^= 0xEC ^ 0x11)
{
ba.AppendBits(padByte, 8);
}
// Pack bits into bytes in big endian
byte[] dataCodewords = new byte[ba.Length / 8];
for (int i = 0; i < ba.Length; i++)
{
if (ba.Get(i))
{
dataCodewords[i >> 3] |= (byte)(1 << (7 - (i & 7)));
}
}
// Create the QR code object
return(new QrCode(version, ecl, dataCodewords, mask));
}