private static ICmapSubtable ReadSubtable(FontReader reader, out CMapSubtableFormat format)
{
var start = reader.Position;
format = (CMapSubtableFormat)reader.ReadUInt16BigEndian();
reader.Seek(start);
switch (format)
{
// Ordered from most to least used, on the Windows platform
case CMapSubtableFormat.SegmentMappingToDeltaValues: // Format 4
return(SegmentMappingToDeltaValuesTable.FromReader(reader));
case CMapSubtableFormat.TrimmedTableMapping: // Format 6
return(TrimmedTableMappingTable.FromReader(reader));
case CMapSubtableFormat.SegmentedCoverage: // Format 12
return(SegmentedCoverageTable.FromReader(reader));
case CMapSubtableFormat.ByteEncodingTable: // Format 0
return(ByteEncodingTable.FromReader(reader));
// Used for specifying variations of the same glyph in a single font
case CMapSubtableFormat.UnicodeVariationSequences: // Format 14
return(null);
// The following formats are not used by any of the default fonts in Windows 10
case CMapSubtableFormat.HighByteMappingThroughTable:
return(null);
case CMapSubtableFormat.MixedCoverage:
return(null);
case CMapSubtableFormat.TrimmedArray:
return(null);
case CMapSubtableFormat.ManyToOneRangeMappings:
return(null);
default:
return(null);
}
}
private EncodingRecord(Platform platformId, WindowsEncoding encodingId, uint offset, ICmapSubtable subtable, CMapSubtableFormat format)
{
this.PlatformId = platformId;
this.WindowsEncodingId = encodingId;
this.Offset = offset;
this.Subtable = subtable;
this.Format = format;
}
