private static ICompactFontFormatCharset ReadCharset(CompactFontFormatData data, CompactFontFormatTopLevelDictionary topDictionary,
CompactFontFormatIndex charStringIndex, IReadOnlyList <string> stringIndex)
{
data.Seek(topDictionary.CharSetOffset);
var format = data.ReadCard8();
switch (format)
{
case 0:
{
var glyphToNamesAndStringId = new List <(int glyphId, int stringId, string name)>();
for (var glyphId = 1; glyphId < charStringIndex.Count; glyphId++)
{
var stringId = data.ReadSid();
glyphToNamesAndStringId.Add((glyphId, stringId, ReadString(stringId, stringIndex)));
}
return(new CompactFontFormatFormat0Charset(glyphToNamesAndStringId));
}
case 1:
case 2:
{
var glyphToNamesAndStringId = new List <(int glyphId, int stringId, string name)>();
for (var glyphId = 1; glyphId < charStringIndex.Count; glyphId++)
{
var firstSid = data.ReadSid();
var numberInRange = format == 1 ? data.ReadCard8() : data.ReadCard16();
glyphToNamesAndStringId.Add((glyphId, firstSid, ReadString(firstSid, stringIndex)));
for (var i = 0; i < numberInRange; i++)
{
glyphId++;
var sid = firstSid + i + 1;
glyphToNamesAndStringId.Add((glyphId, sid, ReadString(sid, stringIndex)));
}
}
if (format == 1)
{
return(new CompactFontFormatFormat1Charset(glyphToNamesAndStringId));
}
return(new CompactFontFormatFormat2Charset(glyphToNamesAndStringId));
}
default:
throw new InvalidOperationException($"Unrecognized format for the Charset table in a CFF font. Got: {format}.");
}
}
private static IReadOnlyList <CompactFontFormatBuiltInEncoding.Supplement> ReadSupplement(CompactFontFormatData dataInput,
IReadOnlyList <string> stringIndex)
{
var numberOfSupplements = dataInput.ReadCard8();
var supplements = new CompactFontFormatBuiltInEncoding.Supplement[numberOfSupplements];
for (var i = 0; i < supplements.Length; i++)
{
var code = dataInput.ReadCard8();
var sid = dataInput.ReadSid();
var name = ReadString(sid, stringIndex);
supplements[i] = new CompactFontFormatBuiltInEncoding.Supplement(code, sid, name);
}
return(supplements);
}
public CompactFontFormatFont Parse(CompactFontFormatData data, string name, IReadOnlyList <byte> topDictionaryIndex, IReadOnlyList <string> stringIndex,
CompactFontFormatIndex globalSubroutineIndex)
{
var individualData = new CompactFontFormatData(topDictionaryIndex.ToArray());
var topDictionary = topLevelDictionaryReader.Read(individualData, stringIndex);
var privateDictionary = CompactFontFormatPrivateDictionary.GetDefault();
if (topDictionary.PrivateDictionaryLocation.HasValue)
{
var privateDictionaryBytes = data.SnapshotPortion(topDictionary.PrivateDictionaryLocation.Value.Offset,
topDictionary.PrivateDictionaryLocation.Value.Size);
privateDictionary = privateDictionaryReader.Read(privateDictionaryBytes, stringIndex);
}
if (topDictionary.CharStringsOffset < 0)
{
throw new InvalidOperationException("Expected CFF to contain a CharString offset.");
}
var localSubroutines = CompactFontFormatIndex.None;
if (privateDictionary.LocalSubroutineOffset.HasValue && topDictionary.PrivateDictionaryLocation.HasValue)
{
data.Seek(privateDictionary.LocalSubroutineOffset.Value + topDictionary.PrivateDictionaryLocation.Value.Offset);
localSubroutines = indexReader.ReadDictionaryData(data);
}
data.Seek(topDictionary.CharStringsOffset);
var charStringIndex = indexReader.ReadDictionaryData(data);
ICompactFontFormatCharset charset = null;
if (topDictionary.IsCidFont && topDictionary.CharSetOffset >= 0 && topDictionary.CharSetOffset <= 2)
{
switch (topDictionary.CharSetOffset)
{
case 0:
charset = CompactFontFormatIsoAdobeCharset.Value;
break;
case 1:
charset = CompactFontFormatExpertCharset.Value;
break;
case 2:
charset = CompactFontFormatExpertSubsetCharset.Value;
break;
}
}
else
{
data.Seek(topDictionary.CharSetOffset);
var format = data.ReadCard8();
switch (format)
{
case 0:
{
var glyphToNamesAndStringId = new List <(int glyphId, int stringId, string name)>();
for (var glyphId = 1; glyphId < charStringIndex.Count; glyphId++)
{
var stringId = data.ReadSid();
glyphToNamesAndStringId.Add((glyphId, stringId, ReadString(stringId, stringIndex)));
}
charset = new CompactFontFormatFormat0Charset(glyphToNamesAndStringId);
break;
}
case 1:
case 2:
{
var glyphToNamesAndStringId = new List <(int glyphId, int stringId, string name)>();
for (var glyphId = 1; glyphId < charStringIndex.Count; glyphId++)
{
var firstSid = data.ReadSid();
var numberInRange = format == 1 ? data.ReadCard8() : data.ReadCard16();
glyphToNamesAndStringId.Add((glyphId, firstSid, ReadString(firstSid, stringIndex)));
for (var i = 0; i < numberInRange; i++)
{
glyphId++;
var sid = firstSid + i + 1;
glyphToNamesAndStringId.Add((glyphId, sid, ReadString(sid, stringIndex)));
}
}
if (format == 1)
{
charset = new CompactFontFormatFormat1Charset(glyphToNamesAndStringId);
}
else
{
charset = new CompactFontFormatFormat2Charset(glyphToNamesAndStringId);
}
break;
}
default:
throw new InvalidOperationException($"Unrecognized format for the Charset table in a CFF font. Got: {format}.");
}
}
data.Seek(topDictionary.CharStringsOffset);
Type2CharStrings charStrings;
switch (topDictionary.CharStringType)
{
case CompactFontFormatCharStringType.Type1:
throw new NotImplementedException();
case CompactFontFormatCharStringType.Type2:
charStrings = Type2CharStringParser.Parse(charStringIndex, localSubroutines, globalSubroutineIndex, charset);
break;
default:
throw new ArgumentOutOfRangeException($"Unexpected CharString type in CFF font: {topDictionary.CharStringType}.");
}
return(new CompactFontFormatFont(topDictionary, privateDictionary, charset, Union <Type1CharStrings, Type2CharStrings> .Two(charStrings)));
}