public OpenTypeFont Deserialize(BinaryReader reader)
{
var font = new OpenTypeFont {
SfntVersion = DataTypeConverter.ReadFixed(reader)
};
if (!_supportedSfntVersions.Contains(font.SfntVersion))
{
throw new NotSupportedException("Bad sfnt version.");
}
// Table directory
var numberOfTables = DataTypeConverter.ReadUShort(reader);
reader.BaseStream.Position += 3 * DataTypeLength.UShort; // searchRange, entrySelector, rangeShift
var entryList = Enumerable.Range(0, numberOfTables).Select(i =>
{
var entry = new TableDirectoryEntry {
Tag = DataTypeConverter.ReadTag(reader)
};
reader.BaseStream.Position += DataTypeLength.ULong; // checksum
entry.Offset = DataTypeConverter.ReadULong(reader);
entry.Length = DataTypeConverter.ReadULong(reader);
return(entry);
}).ToList();
// Tables
font.Tables.AddRange(
entryList.OrderBy(entry => entry.Priority).Select <TableDirectoryEntry, IOpenTypeFontTable>(entry =>
{
switch (entry.Tag)
{
case "cmap":
return(CmapTable.Deserialize(reader, entry.Offset));
case "head":
return(HeadTable.Deserialize(reader, entry.Offset));
case "maxp":
return(MaxpTable.Deserialize(reader, entry.Offset));
case "loca":
return(LocaTable.Deserialize(reader, entry.Offset,
font.Get <MaxpTable>().NumberOfGlyphs,
font.Get <HeadTable>().LocaTableVersion));
case "glyf":
return(GlyfTable.Deserialize(reader, entry.Offset, entry.Length,
font.Get <LocaTable>()));
case "hhea":
return(HheaTable.Deserialize(reader, entry.Offset));
case "hmtx":
return(HmtxTable.Deserialize(reader, entry.Offset, font.Get <HheaTable>().NumberOfHMetrics,
font.Get <MaxpTable>().NumberOfGlyphs));
case "post":
return(PostTable.Deserialize(reader, entry.Offset));
default:
return(BinaryDataTable.Deserialize(reader, entry.Offset, entry.Length, entry.Tag));
}
}));
return(font);
}
public void Serialize(BinaryWriter writer, OpenTypeFont font)
{
DataTypeConverter.WriteFixed(writer, font.SfntVersion);
DataTypeConverter.WriteUShort(writer, (ushort)font.Tables.Count);
var pow = Math.Floor(Math.Log(font.Tables.Count, 2));
var searchRange = Math.Pow(2, pow) * 16;
DataTypeConverter.WriteUShort(writer, (ushort)searchRange);
DataTypeConverter.WriteUShort(writer, (ushort)pow);
DataTypeConverter.WriteUShort(writer, (ushort)(font.Tables.Count * 16 - searchRange));
var tableDirectoryStartOffset = writer.BaseStream.Position;
writer.BaseStream.Position += 4 * DataTypeLength.ULong * font.Tables.Count;
var entryList = new List <TableDirectoryEntry>(font.Tables.Count);
var additionalInfo = new SerializationInfo(); // Shared info among all IOpenTypeFontSerializable class
foreach (
var table in font.Tables.OrderByDescending(table => TableDirectoryEntry.GetPriorityOfTag(table.Tag)))
{
var startOffsetOfThisTable = writer.BaseStream.Position;
table.Serialize(writer, startOffsetOfThisTable, additionalInfo);
entryList.Add(new TableDirectoryEntry
{
Tag = table.Tag,
Offset = (uint)startOffsetOfThisTable,
Length = (uint)(writer.BaseStream.Position - startOffsetOfThisTable)
});
// 4byte padding
if (writer.BaseStream.Position % 4 != 0)
{
var zeroCount = 4 - writer.BaseStream.Position % 4;
for (var i = 0; i < zeroCount; i++)
{
writer.Write((byte)0);
}
}
}
// Write table directory
var reader = new BinaryReader(writer.BaseStream);
writer.BaseStream.Position = tableDirectoryStartOffset;
foreach (var entry in entryList.OrderBy(entry => entry.Tag, StringComparer.Ordinal))
{
DataTypeConverter.WriteTag(writer, entry.Tag);
DataTypeConverter.WriteULong(writer,
EnableChecksum ? CalculateChecksum(reader, entry.Offset, entry.Length) : 0);
DataTypeConverter.WriteULong(writer, entry.Offset);
DataTypeConverter.WriteULong(writer, entry.Length);
}
// Calculate checksum for the entire font
if (EnableChecksum)
{
writer.BaseStream.Position = entryList.Single(entry => entry.Tag == "head").Offset +
2 * DataTypeLength.Fixed;
DataTypeConverter.WriteULong(writer,
0xB1B0AFBA - CalculateChecksum(reader, 0, (uint)reader.BaseStream.Length));
}
}
public void SubsetTo(out OpenTypeFont newFont, HashSet <uint> characters)
{
newFont = DeepCopy();
newFont.Subset(characters);
}
