// Reads through the header information of the cmap format 6 table
private CmapFormat6Header ParseCmapFormat6Header(byte[] source, ref uint offset)
{
CmapFormat6Header header = new CmapFormat6Header();
header.format = ReadDataAndIncreaseIndex <ushort>(source, ref offset, sizeof(ushort));
Debug.Assert(header.format == 6);
header.length = ReadDataAndIncreaseIndex <ushort>(source, ref offset, sizeof(ushort));
header.language = ReadDataAndIncreaseIndex <ushort>(source, ref offset, sizeof(ushort));
header.firstCode = ReadDataAndIncreaseIndex <ushort>(source, ref offset, sizeof(ushort));
header.entryCount = ReadDataAndIncreaseIndex <ushort>(source, ref offset, sizeof(ushort));
return(header);
}
// Parses the format 6 cmap table
// Refer to https://www.microsoft.com/typography/otspec/cmap.htm to learn about how this format is organized
private void ParseFormat6(byte[] source, ref uint offset, List <GlyphModel> allChars)
{
CmapFormat6Header header = ParseCmapFormat6Header(source, ref offset);
for (uint i = 0; i < header.entryCount; i++)
{
ushort gID = ReadDataAndIncreaseIndex <ushort>(source, ref offset, sizeof(ushort));
if (gID != 0)
{
GlyphModel newChar = new GlyphModel();
newChar.CodePoint = i;
newChar.GlyphID = gID;
byte[] byteI = BitConverter.GetBytes(i);
newChar.Definition = Encoding.UTF32.GetString(byteI);
if (!allChars.Contains(newChar))
{
allChars.Add(newChar);
}
}
}
}