public static CharacterMap ReadCmap(DataReader reader, TableRecord[] tables)
{
SfntTables.SeekToTable(reader, tables, FourCC.Cmap, required: true);
// skip version
var cmapOffset = reader.Position;
reader.Skip(sizeof(short));
// read all of the subtable headers
var subtableCount = reader.ReadUInt16BE();
var subtableHeaders = new CmapSubtableHeader[subtableCount];
for (int i = 0; i < subtableHeaders.Length; i++)
{
subtableHeaders[i] = new CmapSubtableHeader
{
PlatformID = reader.ReadUInt16BE(),
EncodingID = reader.ReadUInt16BE(),
Offset = reader.ReadUInt32BE()
};
}
// search for a "full" Unicode table first
var chosenSubtableOffset = 0u;
for (int i = 0; i < subtableHeaders.Length; i++)
{
var platform = subtableHeaders[i].PlatformID;
var encoding = subtableHeaders[i].EncodingID;
if ((platform == PlatformID.Microsoft && encoding == WindowsEncoding.UnicodeFull) ||
(platform == PlatformID.Unicode && encoding == UnicodeEncoding.Unicode32))
{
chosenSubtableOffset = subtableHeaders[i].Offset;
break;
}
}
// if no full unicode table, just grab the first
// one that supports any flavor of Unicode
if (chosenSubtableOffset == 0)
{
for (int i = 0; i < subtableHeaders.Length; i++)
{
var platform = subtableHeaders[i].PlatformID;
var encoding = subtableHeaders[i].EncodingID;
if ((platform == PlatformID.Microsoft && encoding == WindowsEncoding.UnicodeBmp) ||
platform == PlatformID.Unicode)
{
chosenSubtableOffset = subtableHeaders[i].Offset;
break;
}
}
}
// no unicode support at all is an error
if (chosenSubtableOffset == 0)
{
throw new Exception("Font does not support Unicode.");
}
// jump to our chosen table and find out what format it's in
reader.Seek(cmapOffset + chosenSubtableOffset);
var format = reader.ReadUInt16BE();
switch (format)
{
case 4: return(ReadCmapFormat4(reader));
default: throw new Exception("Unsupported cmap format.");
}
}
public static CharacterMap ReadCmap(DataReader reader, TableRecord[] tables)
{
SfntTables.SeekToTable(reader, tables, FourCC.Cmap, required: true);
// skip version
var cmapOffset = reader.Position;
reader.Skip(sizeof(short));
// read all of the subtable headers
var subtableCount = reader.ReadUInt16BE();
var subtableHeaders = new CmapSubtableHeader[subtableCount];
for (int i = 0; i < subtableHeaders.Length; i++)
{
subtableHeaders[i] = new CmapSubtableHeader
{
PlatformID = reader.ReadUInt16BE(),
EncodingID = reader.ReadUInt16BE(),
Offset = reader.ReadUInt32BE()
};
}
// search for a "full" Unicode table first
var chosenSubtableOffset = 0u;
for (int i = 0; i < subtableHeaders.Length; i++)
{
var platform = subtableHeaders[i].PlatformID;
var encoding = subtableHeaders[i].EncodingID;
if ((platform == PlatformID.Microsoft && encoding == WindowsEncoding.UnicodeFull) ||
(platform == PlatformID.Unicode && encoding == UnicodeEncoding.Unicode32))
{
chosenSubtableOffset = subtableHeaders[i].Offset;
break;
}
}
// if no full unicode table, just grab the first
// one that supports any flavor of Unicode
if (chosenSubtableOffset == 0)
{
for (int i = 0; i < subtableHeaders.Length; i++)
{
var platform = subtableHeaders[i].PlatformID;
var encoding = subtableHeaders[i].EncodingID;
if ((platform == PlatformID.Microsoft && encoding == WindowsEncoding.UnicodeBmp) ||
platform == PlatformID.Unicode)
{
chosenSubtableOffset = subtableHeaders[i].Offset;
break;
}
}
}
// no unicode support at all is an error
if (chosenSubtableOffset == 0)
throw new Exception("Font does not support Unicode.");
// jump to our chosen table and find out what format it's in
reader.Seek(cmapOffset + chosenSubtableOffset);
var format = reader.ReadUInt16BE();
switch (format)
{
case 4: return ReadCmapFormat4(reader);
default: throw new Exception("Unsupported cmap format.");
}
}
