private bool ReadData(Stream stream)
{
if (stream == null)
{
return(false);
}
int bytesRead = 0;
byte[] header = WoffBuffer.ReadBytes(stream, WoffUtils.Woff1DirSize, out bytesRead);
_tag = WoffBuffer.ReadUInt32BE(header, 0);
_offset = WoffBuffer.ReadUInt32BE(header, 4);
_compLength = WoffBuffer.ReadUInt32BE(header, 8);
_origLength = WoffBuffer.ReadUInt32BE(header, 12);
_origChecksum = WoffBuffer.ReadUInt32BE(header, 16);
if (_origLength > 0)
{
_padding = WoffUtils.CalculatePadding(_origLength);
}
return(true);
}
private bool ReadData(Stream stream, bool isTrueType)
{
if (stream == null)
{
return(false);
}
var tableFlags = WoffTable.TableFlags;
int bytesRead = 0;
// UInt8: flags table type and flags
_flags = (byte)stream.ReadByte();
// The interpretation of the flags field is as follows:
// 1. Bits [0..5] contain an index to the "known tag" table, which represents tags likely to appear in fonts
int tagIndex = _flags & 0x3F;
// If the tag is not present in this table, then the value of this bit field is 63.
if (tagIndex >= 63)
{
// UInt32: tag 4-byte tag (optional)
_tag = WoffBuffer.ReadUInt32BE(WoffBuffer.ReadBytes(stream, 4, out bytesRead), 0);
var name = WoffBuffer.TagString(_tag);
for (int i = 0; i < tableFlags.Count; i++)
{
if (string.Equals(name, tableFlags[i], StringComparison.Ordinal))
{
tagIndex = i;
break;
}
}
}
else
{
_tag = WoffBuffer.TagInt(tableFlags[tagIndex]);
}
// 2. Bits 6 and 7 indicate the preprocessing transformation version number (0-3) that was applied to each table.
int transformVersion = (_flags >> 5) & 0x3;
// UIntBase128: origLength length of original table
if (!WoffBuffer.ReadUIntBase128(stream, out _origLength))
{
return(false);
}
// UIntBase128 transformLength transformed length (if applicable)
// _transformLength = _origLength;
_compLength = _origLength;
_transformLength = 0;
// For all tables in a font, except for 'glyf' and 'loca' tables, transformation version 0
// indicates the null transform where the original table data is passed directly to the
// Brotli compressor for inclusion in the compressed data stream.
if (transformVersion == 0)
{
// "glyf" : 10, "loca" : 11
if (tagIndex == 10 || tagIndex == 11)
{
if (!WoffBuffer.ReadUIntBase128(stream, out _transformLength))
{
return(false);
}
_compLength = _transformLength;
}
}
// The transformation version "1", specified below, is optional and can be applied to
// eliminate certain redundancies in the hmtx table data.
if (transformVersion == 1)
{
// The transformation version 1 described in this subclause is optional and can only
// be used when an input font is TrueType-flavored (i.e. has a glyf table)
// "hmtx" : 3
if (tagIndex == 3 && isTrueType)
{
if (!WoffBuffer.ReadUIntBase128(stream, out _transformLength))
{
return(false);
}
_compLength = _transformLength;
}
}
if (_origLength > 0)
{
_padding = WoffUtils.CalculatePadding(_origLength);
}
return(true);
}
private bool WriteWoff2(Stream stream)
{
if (_woffHeader.IsCollection)
{
return(WriteWoff2Collection(stream));
}
if (stream == null || _woffHeader == null || _woffDirs == null || _woffDirs.Count == 0)
{
return(false);
}
var numTables = _woffHeader.NumTables;
// Re-order tables in output order (by the OpenType Specifications)
var sortedDirs = _woffDirs.ToArray();
Array.Sort(sortedDirs, WoffTableDirectory.GetComparer());
//-------------------------------------------------------------------------------------------------
// 1. Compute the checksums, the paddings of the tables will be recalculated after the transformations.
uint tablesChecksum = 0; // We have only one font here...
for (int i = 0; i < numTables; i++)
{
tablesChecksum += sortedDirs[i].RecalculateChecksum();
}
//-------------------------------------------------------------------------------------------------
// Build the smaller headers + directories data in memory...
var writer = new WoffWriter();
var searchRange = (ushort)(WoffUtils.MaxPower2LE(numTables) * TableSize);
var entrySelector = WoffUtils.Log2(WoffUtils.MaxPower2LE(numTables));
var rangeShift = (ushort)(numTables * TableSize - searchRange);
// Write the font offset table...
// uint32: sfntVersion 0x00010000 or 0x4F54544F ('OTTO')
writer.WriteUInt32(_woffHeader.Flavor);
// uint16: numTables Number of tables.
writer.WriteUInt16(_woffHeader.NumTables);
// uint16 searchRange (Maximum power of 2 <= numTables) x 16.
writer.WriteUInt16(searchRange);
// uint16: entrySelector Log2(maximum power of 2 <= numTables).
writer.WriteUInt16(entrySelector);
// uint16: rangeShift NumTables x 16-searchRange.
writer.WriteUInt16(rangeShift);
uint tablesOffset = HeaderSize + numTables * TableSize;
for (int i = 0; i < numTables; i++)
{
var woffDir = sortedDirs[i];
// Tag: tableTag Table identifier.
writer.WriteUInt32(woffDir.Tag);
// uint32: checkSum CheckSum for this table.
writer.WriteUInt32(woffDir.OrigChecksum);
// Offset32 offset Offset from beginning of TrueType font file.
writer.WriteUInt32(tablesOffset);
// uint32 length Length of this table.
writer.WriteUInt32(woffDir.OrigLength);
tablesOffset += woffDir.OrigLength;
if (tablesOffset % 4 != 0)
{
tablesOffset += 4 - (tablesOffset % 4);
}
}
// Get the buffer of the collection header and font headers...
var fontBuffer = writer.GetBuffer();
// For the font headers, calculate the checksum to create the font checksum
_woffFonts[0].ChecksumAdjustment(fontBuffer, 0, (uint)fontBuffer.Length, tablesChecksum);
//-------------------------------------------------------------------------------------------------
// Write the actual tables data to the stream, with the required offsets...
stream.Write(fontBuffer, 0, fontBuffer.Length);
var paddingBuffer = new byte[4];
for (int i = 0; i < numTables; i++)
{
var woffDir = sortedDirs[i];
stream.Write(woffDir.OrigTable, 0, (int)woffDir.OrigLength);
stream.Write(paddingBuffer, 0, (int)woffDir.Padding);
}
return(true);
}
/// <summary>
/// This writes the transformed WOFF2 font collection data to the TTC OpenType.
/// </summary>
/// <param name="stream"></param>
/// <returns></returns>
/// <remarks>
/// The strategy is to produce a layout similar to the simple layout used in the WOFF2 data structure and
/// still confirm to the OpenType format.
/// <code>
/// <![CDATA[
/// +---------------------+
/// | TTC Header |
/// +---------------------+
/// | All TTC Directories |
/// +---------------------+
/// | All the Table Data |
/// +---------------------+
/// ]]>
/// </code>
/// </remarks>
private bool WriteWoff2Collection(Stream stream)
{
if (stream == null || _woffHeader == null || _woffDirs == null || _woffDirs.Count == 0)
{
return(false);
}
var numFonts = _collectionHeader.NumFonts;
//-------------------------------------------------------------------------------------------------
// 1. Compute the checksums, the paddings of the tables will be recalculated after the transformations.
for (int i = 0; i < _woffDirs.Count; i++)
{
_woffDirs[i].RecalculateChecksum();
}
// Compute the sizes of the data structures to determine the offsets...
// 2. Compute the font collection header size
int collectionOffset = 0;
collectionOffset += WoffBuffer.SizeOfUInt; // TAG ttcTag
collectionOffset += WoffBuffer.SizeOfUShort; // uint16 majorVersion
collectionOffset += WoffBuffer.SizeOfUShort; // uint16 minorVersion
collectionOffset += WoffBuffer.SizeOfUInt; // uint32 numFonts
collectionOffset += WoffBuffer.SizeOfUInt * numFonts; // Offset32 tableDirectoryOffsets[numFonts]
if (_collectionHeader.IsVersion(2))
{
collectionOffset += WoffBuffer.SizeOfUInt; // uint32 dsigTag
collectionOffset += WoffBuffer.SizeOfUInt; // uint32 dsigLength
collectionOffset += WoffBuffer.SizeOfUInt; // uint32 dsigOffset
}
var headerOffset = (uint)collectionOffset;
// 3. Compute for each for in the collection the (Header + Directories) size
// and sum all to get the size/offset of the fonts
var directoryOffsets = new uint[numFonts];
uint directoryOffset = headerOffset;
for (ushort i = 0; i < numFonts; i++)
{
directoryOffsets[i] = directoryOffset;
// TableDirectory = HeaderSize + Total Table Records
var HeaderDirSize = HeaderSize + _collectionEntries[i].NumTables * TableSize;
directoryOffset += HeaderDirSize;
}
// 4. Compute for each directory in the collection the offsets
uint[] tablesOffsets = new uint[_woffDirs.Count];
uint tablesOffset = directoryOffset;
for (ushort i = 0; i < _woffDirs.Count; i++)
{
var woffDir = _woffDirs[i];
tablesOffsets[i] = tablesOffset;
tablesOffset += woffDir.OrigLength;
if (tablesOffset % 4 != 0)
{
tablesOffset += 4 - (tablesOffset % 4);
}
}
//-------------------------------------------------------------------------------------------------
// Build the smaller headers + directories data in memory...
var writer = new WoffWriter();
// 1. The Font Collection File Structure
// A font collection file consists of a single TTC Header table, one or more Table Directories
// (each corresponding to a different font resource), and a number of OpenType tables.
// The TTC Header must be located at the beginning of the TTC file.
// TAG ttcTag - Font Collection ID string: 'ttcf'
writer.WriteUInt32(_collectionHeader.TtcTag);
// uint16 majorVersion - Major version of the TTC Header.
writer.WriteUInt16(_collectionHeader.MajorVersion);
// uint16 minorVersion - Minor version of the TTC Header.
writer.WriteUInt16(_collectionHeader.MinorVersion);
// uint32 numFonts - Number of fonts in TTC
writer.WriteUInt32(_collectionHeader.NumFonts);
// Offset32 tableDirectoryOffsets[numFonts] Array of offsets to the TableDirectory for each font from the beginning of the file
for (ushort i = 0; i < numFonts; i++)
{
writer.WriteUInt32(directoryOffsets[i]);
}
// For the version 2.0 only add the empty DSIG information.
if (_collectionHeader.IsVersion(2))
{
// uint32 dsigTag - Tag indicating that a DSIG table exists, 0x44534947 ('DSIG') (null if no signature)
writer.WriteUInt32(_collectionHeader.DsigTag);
// uint32 dsigLength - The length (in bytes) of the DSIG table (null if no signature)
writer.WriteUInt32(_collectionHeader.DsigLength);
// uint32 dsigOffset - The offset (in bytes) of the DSIG table from the beginning of the TTC file (null if no signature)
writer.WriteUInt32(_collectionHeader.DsigOffset);
}
// Write out the header for each font
uint fontHeaderOffset = writer.Offset;
var fontHeaderOffsets = new List <uint>(numFonts + 1);
for (ushort j = 0; j < numFonts; j++)
{
fontHeaderOffsets.Add(fontHeaderOffset);
var collectionEntry = _collectionEntries[j];
var numTables = collectionEntry.NumTables;
var searchRange = (ushort)(WoffUtils.MaxPower2LE(numTables) * TableSize);
var entrySelector = WoffUtils.Log2(WoffUtils.MaxPower2LE(numTables));
var rangeShift = (ushort)(numTables * TableSize - searchRange);
// Write the font offset table...
// uint32: sfntVersion 0x00010000 or 0x4F54544F ('OTTO')
writer.WriteUInt32(collectionEntry.Flavor);
// uint16: numTables Number of tables.
writer.WriteUInt16(numTables);
// uint16 searchRange (Maximum power of 2 <= numTables) x 16.
writer.WriteUInt16(searchRange);
// uint16: entrySelector Log2(maximum power of 2 <= numTables).
writer.WriteUInt16(entrySelector);
// uint16: rangeShift NumTables x 16-searchRange.
writer.WriteUInt16(rangeShift);
var sortedIndices = collectionEntry.SortedIndices;
for (ushort i = 0; i < numTables; i++)
{
var dirIndex = sortedIndices[i];
var woffDir = _woffDirs[dirIndex];
// Tag: tableTag Table identifier.
writer.WriteUInt32(woffDir.Tag);
// uint32: checkSum CheckSum for this table.
writer.WriteUInt32(woffDir.OrigChecksum);
// Offset32 offset Offset from beginning of TrueType font file.
writer.WriteUInt32(tablesOffsets[dirIndex]);
// uint32 length Length of this table.
writer.WriteUInt32(woffDir.OrigLength);
}
fontHeaderOffset += writer.Offset;
}
fontHeaderOffsets.Add(fontHeaderOffset);
// Get the buffer of the collection header and font headers...
var fontBuffer = writer.GetBuffer();
// For the font headers, calculate the checksum to create the font checksum
for (ushort i = 0; i < numFonts; i += 2)
{
uint fontOffset = fontHeaderOffsets[i];
uint fontLength = fontHeaderOffsets[i + 1] - fontOffset;
_woffFonts[i].ChecksumAdjustment(fontBuffer, fontOffset, fontLength);
}
//-------------------------------------------------------------------------------------------------
// Write the actual tables data to the stream, with the required offsets...
stream.Write(fontBuffer, 0, fontBuffer.Length);
var paddingBuffer = new byte[4];
for (int i = 0; i < _woffDirs.Count; i++)
{
var woffDir = _woffDirs[i];
stream.Write(woffDir.OrigTable, 0, (int)woffDir.OrigLength);
stream.Write(paddingBuffer, 0, (int)woffDir.Padding);
}
return(true);
}
private bool WriteWoff1(Stream stream)
{
if (stream == null || _woffHeader == null || _woffDirs == null || _woffDirs.Count == 0)
{
return(false);
}
var numTables = _woffHeader.NumTables;
var searchRange = (ushort)(WoffUtils.MaxPower2LE(numTables) * TableSize);
var entrySelector = WoffUtils.Log2(WoffUtils.MaxPower2LE(numTables));
var rangeShift = (ushort)(numTables * TableSize - searchRange);
int offset = 0;
// Write the font offset table...
var headerBuffer = new byte[HeaderSize];
// uint32: sfntVersion 0x00010000 or 0x4F54544F ('OTTO')
offset += WoffBuffer.WriteUInt32BE(headerBuffer, offset, _woffHeader.Flavor);
// uint16: numTables Number of tables.
offset += WoffBuffer.WriteUInt16BE(headerBuffer, offset, _woffHeader.NumTables);
// uint16 searchRange (Maximum power of 2 <= numTables) x 16.
offset += WoffBuffer.WriteUInt16BE(headerBuffer, offset, searchRange);
// uint16: entrySelector Log2(maximum power of 2 <= numTables).
offset += WoffBuffer.WriteUInt16BE(headerBuffer, offset, entrySelector);
// uint16: rangeShift NumTables x 16-searchRange.
offset += WoffBuffer.WriteUInt16BE(headerBuffer, offset, rangeShift);
stream.Write(headerBuffer, 0, (int)HeaderSize);
uint tablesOffset = HeaderSize + numTables * TableSize;
var tableBuffer = new byte[TableSize];
for (int i = 0; i < numTables; i++)
{
offset = 0;
var woffDir = _woffDirs[i];
// Tag: tableTag Table identifier.
offset += WoffBuffer.WriteUInt32BE(tableBuffer, offset, woffDir.Tag);
// uint32: checkSum CheckSum for this table.
offset += WoffBuffer.WriteUInt32BE(tableBuffer, offset, woffDir.OrigChecksum);
// Offset32 offset Offset from beginning of TrueType font file.
offset += WoffBuffer.WriteUInt32BE(tableBuffer, offset, tablesOffset);
// uint32 length Length of this table.
offset += WoffBuffer.WriteUInt32BE(tableBuffer, offset, woffDir.OrigLength);
stream.Write(tableBuffer, 0, (int)TableSize);
tablesOffset += woffDir.OrigLength;
if (tablesOffset % 4 != 0)
{
tablesOffset += 4 - (tablesOffset % 4);
}
}
var paddingBuffer = new byte[4];
for (int i = 0; i < numTables; i++)
{
var woffDir = _woffDirs[i];
stream.Write(woffDir.OrigTable, 0, (int)woffDir.OrigLength);
stream.Write(paddingBuffer, 0, (int)woffDir.Padding);
}
return(true);
}
