public ushort GetUnitWidthOfString(string s)
{
var ids = new ushort[s.Length];
var metrics = new HorizontalMetric[s.Length];
var rsbs = new ushort[s.Length];
for (var i = 0; i < s.Length; i++)
{
ids[i] = cmap.GetGlyphId(s[i]);
metrics[i] = hmtx.Metrics[ids[i]];
var glyphData = glyf.GetGlyphData(ids[i]);
rsbs[i] = (ushort)(metrics[i].AdvanceWidth - (metrics[i].LeftSideBearing + glyphData.XMax - glyphData.XMin));
}
ushort width = 0;
for (var i = 0; i < s.Length; i++)
{
width += metrics[i].AdvanceWidth;
width = width.Sum(metrics[i].LeftSideBearing);
width += rsbs[i];
}
var kerning = GetTotalKernOfString(s);
width = width.Sum(kerning);
return(width);
}
HorizontalMetric[] ParseHmtxTable(Stream stream, BinaryReader reader, TableHeader header, int metricCount, int glyphCount)
{
stream.Position = header.Offset;
var metrics = new HorizontalMetric[glyphCount];
for (int i = 0; i < metricCount; i++)
{
metrics[i] = new HorizontalMetric()
{
AdvanceWidth = reader.ReadUInt16(),
LeftSideBearing = reader.ReadInt16(),
};
}
for (int i = metricCount; i < glyphCount; i++)
{
metrics[i] = new HorizontalMetric()
{
AdvanceWidth = metrics[metricCount - 1].AdvanceWidth,
LeftSideBearing = reader.ReadInt16(),
};
}
return(metrics);
}
public HorizontalMetricsTable Parse(TrueTypeHeaderTable header, TrueTypeDataBytes data, TableRegister.Builder register)
{
var glyphCount = register.MaximumProfileTable.NumberOfGlyphs;
var metricCount = register.HorizontalHeaderTable.NumberOfHeaderMetrics;
data.Seek(header.Offset);
var bytesRead = 0;
var horizontalMetrics = new HorizontalMetric[metricCount];
for (var i = 0; i < metricCount; i++)
{
var width = data.ReadUnsignedShort();
var lsb = data.ReadSignedShort();
horizontalMetrics[i] = new HorizontalMetric(width, lsb);
bytesRead += 4;
}
int numberNonHorizontal = glyphCount - metricCount;
// handle bad fonts with too many hmetrics
if (numberNonHorizontal < 0)
{
numberNonHorizontal = glyphCount;
}
// The number of entries in the left side bearing field per entry is number of glyphs - number of metrics
// For bearings over the metric count, the width is the same as the last width in advanced widths.
var additionalLeftSideBearings = new short[numberNonHorizontal];
for (var i = 0; i < additionalLeftSideBearings.Length; i++)
{
if (bytesRead >= header.Length)
{
break;
}
additionalLeftSideBearings[i] = data.ReadSignedShort();
bytesRead += 2;
}
return(new HorizontalMetricsTable(header, horizontalMetrics, additionalLeftSideBearings));
}
HorizontalMetric[] ParseHmtxTable(Stream stream, BinaryReader reader, TableHeader header, int metricCount, int glyphCount)
{
stream.Position = header.Offset;
var metrics = new HorizontalMetric[glyphCount];
for (int i = 0; i < metricCount; i++)
{
metrics[i] = new HorizontalMetric()
{
AdvanceWidth = reader.ReadUInt16(),
LeftSideBearing = reader.ReadInt16(),
};
}
for (int i = metricCount; i < glyphCount; i++)
{
metrics[i] = new HorizontalMetric()
{
AdvanceWidth = metrics[metricCount - 1].AdvanceWidth,
LeftSideBearing = reader.ReadInt16(),
};
}
return metrics;
}