private TrueTypeFontTable ReadHorizontalMetrics(uint length, TrueTypeTableEntryList list, BigEndianReader reader)
{
var pos = reader.Position;
//Get the number of entries for the hMetrics list from the horizontal header table.
TrueTypeTableEntry hhead = list["hhea"];
if (hhead == null)
{
throw new ArgumentNullException("No horizontal header (hhea) has been specified in the font file, this is needed to load the hroizontal metrics");
}
if (hhead.Table == null)
{
TrueTypeFontTable tbl = this.ReadTable(hhead, list, reader);
if (tbl == null)
{
throw new ArgumentNullException("No horizontal header (hhea) has been specified in the font file, this is needed to load the hroizontal metrics");
}
hhead.SetTable(tbl);
}
TrueTypeTableEntry os2 = list["OS/2"];
if (os2 == null)
{
throw new ArgumentNullException("No OS2 table has been specified in the font file, this is a required table and needed to load the horizontal metrics");
}
if (os2.Table == null)
{
TrueTypeFontTable tbl = this.ReadTable(os2, list, reader);
if (tbl == null)
{
throw new ArgumentNullException("No OS/2 has been specified in the font file, this is needed to load the hroizontal metrics");
}
os2.SetTable(tbl);
}
if (reader.Position != pos)
{
reader.Position = pos;
}
int firstcharindex = (os2.Table as OS2Table).FirstCharIndex;
HorizontalMetrics hm = new HorizontalMetrics(reader.Position);
ushort count = (hhead.Table as SubTables.HorizontalHeader).NumberOfHMetrics;
List <HMetric> metrics = new List <HMetric>();
for (int i = 0; i < count; i++)
{
SubTables.HMetric metric = new HMetric(reader.ReadUInt16(), reader.ReadInt16(), (char)(i + firstcharindex));
metrics.Add(metric);
}
hm.HMetrics = metrics;
return(hm);
}
public override char RegisterGlyph(char c)
{
WidthMetric metric;
if (!_char2offset.TryGetValue(c, out metric))
{
int offset = this.CharacterMappings.GetCharacterGlyphOffset(c);
int hmindex = offset;
if (hmindex >= this.HMetrics.HMetrics.Count)
{
hmindex = this.HMetrics.HMetrics.Count - 1;
}
HMetric found = this.HMetrics.HMetrics[hmindex];
int width = (found.AdvanceWidth * this.GlyphUnits) / UnitsPerEm;
metric = new WidthMetric()
{
Width = width, Glyph = offset
};
_char2offset.Add(c, metric);
if (!_offset2char.ContainsKey(offset))
{
_offset2char[offset] = c;
}
//else
//{
// System.Diagnostics.Debug.WriteLine("offset '" + offset + "' is already assigned to chararcter '" + _offset2char[offset] + "'");
//}
if (offset < this.MinGlyphIndex)
{
this.MinGlyphIndex = offset;
}
if (offset > this.MaxGlyphIndex)
{
this.MaxGlyphIndex = offset;
}
if (c < this.FirstChar)
{
this.FirstChar = c;
}
if (c > this.LastChar)
{
this.LastChar = c;
}
}
return((char)metric.Glyph);
}
