internal static bool TryReadHeaderAfterVersion(BigEndianReader reader, TrueTypeVersionReader version, bool validate, out TrueTypeHeader header)
{
header = null;
ushort numtables = reader.ReadUInt16();
ushort search = reader.ReadUInt16();
ushort entry = reader.ReadUInt16();
ushort range = reader.ReadUInt16();
//Validate values returned.
if (validate)
{
//searchRange is the (Maximum power of 2 <= numTables) * 16
ushort max2 = 2;
while (max2 * 2 <= numtables)
{
max2 *= 2;
}
if (search != max2 * 16)
{
return(false);
}
//entrySelector is Log2(max2)
if (Math.Log(max2, 2) != entry)
{
return(false);
}
//rangeShift = numTables * 16-searchRange
if (range != ((numtables * 16) - search))
{
return(false);
}
}
header = new TrueTypeHeader(version, numtables);
header.SearchRange = search;
header.EntrySelector = entry;
header.RangeShift = range;
return(true);
}
internal static bool TryReadHeader(BigEndianReader reader, out TrueTypeHeader header)
{
header = null;
TypefaceVersionReader vers;
if (TypefaceVersionReader.TryGetVersion(reader, out vers) == false)
{
return(false);
}
else if (vers is TrueTypeVersionReader ttv)
{
return(TryReadHeaderAfterVersion(reader, ttv, false, out header));
}
else
{
return(false);
}
}
/// <summary>
/// Performs the actual reading and loading of the file with the BigEndian reader
/// </summary>
/// <param name="reader"></param>
/// <param name="fullpath"></param>
/// <returns></returns>
private static TTFRef DoLoadRef(BigEndianReader reader, string fullpath)
{
TrueTypeHeader head;
if (TrueTypeHeader.TryReadHeader(reader, out head) == false)
{
return(null);
}
TrueTypeTableEntryList list = new TrueTypeTableEntryList();
bool hasOs2 = false;
bool hasFHead = false;
bool hasName = false;
for (int i = 0; i < head.NumberOfTables; i++)
{
TrueTypeTableEntry dir = new TrueTypeTableEntry();
dir.Read(reader);
list.Add(dir);
if (dir.Tag == TrueTypeTableNames.WindowsMetrics)
{
hasOs2 = true;
}
else if (dir.Tag == TrueTypeTableNames.FontHeader)
{
hasFHead = true;
}
else if (dir.Tag == TrueTypeTableNames.NamingTable)
{
hasName = true;
}
}
TrueTypeTableFactory fact = (head.Version as TrueTypeVersionReader).GetTableFactory();
SubTables.NamingTable ntable = null;
if (hasName)
{
ntable = fact.ReadTable(TrueTypeTableNames.NamingTable, list, reader) as SubTables.NamingTable;
}
else
{
throw new ArgumentNullException("The required '" + TrueTypeTableNames.NamingTable + "' is not present in this font file. The OpenType file is corrupt");
}
//if (fhead == null)
// throw new ArgumentNullException("The required '" + FontHeaderTable + "' is not present in this font file. The OpenType file is corrupt");
TTFRef ttfref = new TTFRef(fullpath);
NameEntry entry;
int FamilyNameID = 1;
if (ntable.Names.TryGetEntry(FamilyNameID, out entry))
{
ttfref.FamilyName = entry.ToString();
}
if (hasOs2)
{
SubTables.OS2Table os2table = fact.ReadTable(TrueTypeTableNames.WindowsMetrics, list, reader) as SubTables.OS2Table;
ttfref.FontRestrictions = os2table.FSType;
ttfref.FontWidth = os2table.WidthClass;
ttfref.FontWeight = os2table.WeightClass;
ttfref.FontSelection = os2table.Selection;
}
else if (hasFHead)
{
SubTables.FontHeader fhead = fact.ReadTable(TrueTypeTableNames.FontHeader, list, reader) as SubTables.FontHeader;
var mac = fhead.MacStyle;
ttfref.FontRestrictions = FontRestrictions.InstallableEmbedding;
ttfref.FontWeight = WeightClass.Normal;
if ((mac & FontStyleFlags.Condensed) > 0)
{
ttfref.FontWidth = WidthClass.Condensed;
}
else if ((mac & FontStyleFlags.Extended) > 0)
{
ttfref.FontWidth = WidthClass.Expanded;
}
ttfref.FontSelection = 0;
if ((mac & FontStyleFlags.Italic) > 0)
{
ttfref.FontSelection |= FontSelection.Italic;
}
if ((mac & FontStyleFlags.Bold) > 0)
{
ttfref.FontSelection |= FontSelection.Bold;
ttfref.FontWeight = WeightClass.Bold;
}
if ((mac & FontStyleFlags.Outline) > 0)
{
ttfref.FontSelection |= FontSelection.Outlined;
}
if ((mac & FontStyleFlags.Underline) > 0)
{
ttfref.FontSelection |= FontSelection.Underscore;
}
}
else
{
throw new ArgumentNullException("The required '" + TrueTypeTableNames.WindowsMetrics + "' or '" + TrueTypeTableNames.FontHeader + " are not present in this font file. The OpenType file is corrupt");
}
return(ttfref);
}