public static void ReadMaxp(DataReader reader, TableRecord[] tables, ref FaceHeader header)
{
SeekToTable(reader, tables, FourCC.Maxp, required: true);
if (reader.ReadInt32BE() != 0x00010000)
{
throw new InvalidFontException("Font contains an old style maxp table.");
}
header.GlyphCount = reader.ReadUInt16BE();
if (header.GlyphCount > MaxGlyphs)
{
throw new InvalidFontException("Font contains too many glyphs.");
}
// skip maxPoints, maxContours, maxCompositePoints, maxCompositeContours, maxZones
reader.Skip(sizeof(short) * 5);
header.MaxTwilightPoints = reader.ReadUInt16BE();
header.MaxStorageLocations = reader.ReadUInt16BE();
header.MaxFunctionDefs = reader.ReadUInt16BE();
header.MaxInstructionDefs = reader.ReadUInt16BE();
header.MaxStackSize = reader.ReadUInt16BE();
// sanity checking
if (header.MaxTwilightPoints > MaxTwilightPoints || header.MaxStorageLocations > MaxStorageLocations ||
header.MaxFunctionDefs > MaxFunctionDefs || header.MaxInstructionDefs > MaxFunctionDefs ||
header.MaxStackSize > MaxStackSize)
{
throw new InvalidFontException("Font programs have limits that are larger than built-in sanity checks.");
}
}
public static void ReadPost(DataReader reader, TableRecord[] tables, ref FaceHeader header)
{
if (!SeekToTable(reader, tables, FourCC.Post))
{
return;
}
// skip over version and italicAngle
reader.Skip(sizeof(int) * 2);
header.UnderlinePosition = reader.ReadInt16BE();
header.UnderlineThickness = reader.ReadInt16BE();
header.IsFixedPitch = reader.ReadUInt32BE() != 0;
}
public static void ReadHead(DataReader reader, TableRecord[] tables, out FaceHeader header)
{
SeekToTable(reader, tables, FourCC.Head, required: true);
// 'head' table contains global information for the font face
// we only care about a few fields in it
reader.Skip(sizeof(int) * 4); // version, revision, checksum, magic number
header = new FaceHeader
{
Flags = (HeadFlags)reader.ReadUInt16BE(),
UnitsPerEm = reader.ReadUInt16BE()
};
if (header.UnitsPerEm == 0)
{
throw new InvalidFontException("Invalid 'head' table.");
}
// skip over created and modified times, bounding box,
// deprecated style bits, direction hints, and size hints
reader.Skip(sizeof(long) * 2 + sizeof(short) * 7);
header.IndexFormat = (IndexFormat)reader.ReadInt16BE();
}