private static async Task <IList <string> > GetTableNameAsync(FontReader reader, uint offset)
{
await reader.SeekAsync(offset);
await reader.SkipAsync(2); //version
var nameRecordCount = await reader.ReadUInt16BEAsync();
ushort storageOffset = await reader.ReadUInt16BEAsync();
var items = new List <string>();
for (int i = 0; i < nameRecordCount; i++)
{
var platformID = await reader.ReadUInt16BEAsync();
var encodingID = await reader.ReadUInt16BEAsync();
var languageID = await reader.ReadUInt16BEAsync();
var nameID = await reader.ReadUInt16BEAsync();
var length = await reader.ReadUInt16BEAsync();
var stringOffset = (ushort)(await reader.ReadUInt16BEAsync() + storageOffset);
var actualPosition = reader.BaseStream.Position;
if (nameID != NameID.Family)
{
continue;
}
var data = await ExtractStringFromNameRecordAsync(reader,
offset,
stringOffset,
length,
platformID,
encodingID);
reader.BaseStream.Seek(actualPosition, SeekOrigin.Begin);
items.Add(data);
}
return(items);
}
private static async Task <string> ExtractStringFromNameRecordAsync(FontReader reader,
uint offset, ushort stringOffset, ushort length, ushort platformID,
ushort encodingID)
{
await reader.SeekAsync(offset + stringOffset);
var data = await reader.ReadBytesAsync(length);
if (platformID == PlatformID.Windows)
{
return(Encoding.BigEndianUnicode.GetString(data));
}
if (platformID == PlatformID.Unicode)
{
return(Encoding.BigEndianUnicode.GetString(data));
}
if (platformID == PlatformID.Macintosh)
{
return(Encoding.ASCII.GetString(data));
}
return(Encoding.UTF8.GetString(data));
}
public static async Task <List <string> > GetFontFamilyAsync(FontReader reader)
{
var sfntVersion = await reader.ReadUInt32BEAsync();
FontCheck.ValidateSfntVersion(sfntVersion);
var tableCount = await reader.ReadUInt16BEAsync();
await reader.SkipAsync(6);
var offsetItems = new List <uint>();
for (var i = 0; i < tableCount; i++)
{
var tagByte = await reader.ReadBytesAsync(4);
var checksum = await reader.ReadUInt32BEAsync();
var offset = await reader.ReadUInt32BEAsync();
var length = await reader.ReadUInt32BEAsync();
var tag = FontCheck.ConvertToTagName(tagByte);
if (tag != Tables.NAME)
{
continue;
}
offsetItems.Add(offset);
}
var items = new List <string>();
foreach (var item in offsetItems)
{
items.AddRange(await GetTableNameAsync(reader, item));
}
return(items);
}
public static async Task <List <string> > GetFontFamilyAsync(Stream fs)
{
using var reader = new FontReader(fs);
return(await GetFontFamilyAsync(reader));
}
