FontCollectionHeader ReadTTCHeader(ByteOrderSwappingBinaryReader input)
{
//https://docs.microsoft.com/en-us/typography/opentype/spec/otff#ttc-header
//TTC Header Version 1.0:
//Type Name Description
//TAG ttcTag Font Collection ID string: 'ttcf' (used for fonts with CFF or CFF2 outlines as well as TrueType outlines)
//uint16 majorVersion Major version of the TTC Header, = 1.
//uint16 minorVersion Minor version of the TTC Header, = 0.
//uint32 numFonts Number of fonts in TTC
//Offset32 offsetTable[numFonts] Array of offsets to the OffsetTable for each font from the beginning of the file
//TTC Header Version 2.0:
//Type Name Description
//TAG ttcTag Font Collection ID string: 'ttcf'
//uint16 majorVersion Major version of the TTC Header, = 2.
//uint16 minorVersion Minor version of the TTC Header, = 0.
//uint32 numFonts Number of fonts in TTC
//Offset32 offsetTable[numFonts] Array of offsets to the OffsetTable for each font from the beginning of the file
//uint32 dsigTag Tag indicating that a DSIG table exists, 0x44534947 ('DSIG') (null if no signature)
//uint32 dsigLength The length (in bytes) of the DSIG table (null if no signature)
//uint32 dsigOffset The offset (in bytes) of the DSIG table from the beginning of the TTC file (null if no signature)
var ttcHeader = new FontCollectionHeader();
ttcHeader.majorVersion = input.ReadUInt16();
ttcHeader.minorVersion = input.ReadUInt16();
uint numFonts = input.ReadUInt32();
int[] offsetTables = new int[numFonts];
for (uint i = 0; i < numFonts; ++i)
{
offsetTables[i] = input.ReadInt32();
}
ttcHeader.numFonts = numFonts;
ttcHeader.offsetTables = offsetTables;
//
if (ttcHeader.majorVersion == 2)
{
ttcHeader.dsigTag = input.ReadUInt32();
ttcHeader.dsigLength = input.ReadUInt32();
ttcHeader.dsigOffset = input.ReadUInt32();
if (ttcHeader.dsigTag == 0x44534947)
{
//Tag indicating that a DSIG table exists
//TODO: goto DSIG add read signature
}
}
return(ttcHeader);
}
public Typeface Read(Stream stream)
{
var little = BitConverter.IsLittleEndian;
using (BinaryReader input = new ByteOrderSwappingBinaryReader(stream))
{
UInt32 version = input.ReadUInt32();
UInt16 tableCount = input.ReadUInt16();
UInt16 searchRange = input.ReadUInt16();
UInt16 entrySelector = input.ReadUInt16();
UInt16 rangeShift = input.ReadUInt16();
var tables = new List <TableEntry>(tableCount);
for (int i = 0; i < tableCount; i++)
{
tables.Add(TableEntry.ReadFrom(input));
}
var header = Head.From(FindTable(tables, "head"));
var maximumProfile = MaxProfile.From(FindTable(tables, "maxp"));
var glyphLocations = new GlyphLocations(FindTable(tables, "loca"), maximumProfile.GlyphCount, header.WideGlyphLocations);
var glyphs = Glyf.From(FindTable(tables, "glyf"), glyphLocations);
var cmaps = CmapReader.From(FindTable(tables, "cmap"));
var horizontalHeader = HorizontalHeader.From(FindTable(tables, "hhea"));
var horizontalMetrics = HorizontalMetrics.From(FindTable(tables, "hmtx"),
horizontalHeader.HorizontalMetricsCount, maximumProfile.GlyphCount);
return(new Typeface(header.Bounds, header.UnitsPerEm, glyphs, cmaps, horizontalMetrics));
}
}
