public TtfTableOS2(BinaryReader file, OffsetEntry table)
{
if (file == null)
{
throw new ArgumentNullException(nameof(file));
}
file.Seek(table.Offset);
// See https://docs.microsoft.com/en-gb/typography/opentype/spec/os2
// See https://github.com/fontforge/fontforge/blob/master/fontforge/ttf.h#L467
Version = file.GetUint16();
switch (Version)
{
case 5:
ReadVersion5(file);
break;
case 2:
case 3:
case 4:
ReadVersion4(file);
break;
default: throw new Exception("OS/2 version not supported: " + Version);
}
}
public TtfTableName(BinaryReader file, OffsetEntry table)
{
file.Seek(table.Offset);
TableBase = table.Offset;
// See https://docs.microsoft.com/en-gb/typography/opentype/spec/name
Format = file.GetUint16();
switch (Format)
{
case 0:
case 1: // format 1 has extra info, but starts the same as zero
ReadFormatZero(file);
break;
default:
break;
}
}
private Dictionary <string, OffsetEntry> ReadOffsetTables()
{
var tables = new Dictionary <string, OffsetEntry>();
// DO NOT REARRANGE CALLS!
_scalarType = _file.GetUint32();
var numTables = _file.GetUint16();
_searchRange = _file.GetUint16();
_entrySelector = _file.GetUint16();
_rangeShift = _file.GetUint16();
for (int i = 0; i < numTables; i++)
{
var tag = _file.GetString(4);
if (string.IsNullOrEmpty(tag))
{
break; // malformatted? End of file?
}
var entry = new OffsetEntry {
Checksum = _file.GetUint32(),
Offset = _file.GetUint32(),
Length = _file.GetUint32()
};
if (tables.ContainsKey(tag))
{
Console.WriteLine($"duplicate tag: {tag}");
}
else
{
tables.Add(tag, entry);
}
/* if (tag != "head") {
* if (CalculateTableChecksum(file, tables[tag].Offset, tables[tag].Length) != tables[tag].Checksum)
* throw new Exception("Bad file format: checksum fail in offset tables");
* }*/
}
return(tables);
}
public Ttf_HorizontalMetricsTable(BinaryReader file, OffsetEntry table, Ttf_HorizontalHeaderTable header, Ttf_MaximumProfileTable profile)
{
file.Seek(table.Offset);
TableBase = table.Offset;
int numMetrics = header.NumberOfHMetrics;
int extraLeftSideBearings = profile.NumGlyphs - numMetrics;
_advanceWidths = new List <ushort>(numMetrics);
_leftSideBearings = new List <short>(numMetrics + extraLeftSideBearings);
for (int idx = 0; idx < numMetrics; idx++)
{
_advanceWidths.Add(file.GetUint16());
_leftSideBearings.Add(file.GetInt16());
}
for (int idx = 0; idx < extraLeftSideBearings; idx++)
{
_leftSideBearings.Add(file.GetInt16());
}
}
