/// <summary>
/// Creates a new font image that is a subset of this font image containing only the specified glyphs.
/// </summary>
public OpenTypeFontface CreateFontSubSet(Dictionary <int, object> glyphs, bool cidFont)
{
// Create new font image
OpenTypeFontface fontData = new OpenTypeFontface(this);
// Create new loca and glyf table
IndexToLocationTable locaNew = new IndexToLocationTable();
locaNew.ShortIndex = loca.ShortIndex;
GlyphDataTable glyfNew = new GlyphDataTable();
// Add all required tables
//fontData.AddTable(os2);
if (!cidFont)
{
fontData.AddTable(cmap);
}
if (cvt != null)
{
fontData.AddTable(cvt);
}
if (fpgm != null)
{
fontData.AddTable(fpgm);
}
fontData.AddTable(glyfNew);
fontData.AddTable(head);
fontData.AddTable(hhea);
fontData.AddTable(hmtx);
fontData.AddTable(locaNew);
if (maxp != null)
{
fontData.AddTable(maxp);
}
//fontData.AddTable(name);
if (prep != null)
{
fontData.AddTable(prep);
}
// Get closure of used glyphs.
glyf.CompleteGlyphClosure(glyphs);
// Create a sorted array of all used glyphs.
int glyphCount = glyphs.Count;
int[] glyphArray = new int[glyphCount];
glyphs.Keys.CopyTo(glyphArray, 0);
Array.Sort(glyphArray);
// Calculate new size of glyph table.
int size = 0;
for (int idx = 0; idx < glyphCount; idx++)
{
size += glyf.GetGlyphSize(glyphArray[idx]);
}
glyfNew.DirectoryEntry.Length = size;
// Create new loca table
int numGlyphs = maxp.numGlyphs;
locaNew.LocaTable = new int[numGlyphs + 1];
// Create new glyf table
glyfNew.GlyphTable = new byte[glyfNew.DirectoryEntry.PaddedLength];
// Fill new glyf and loca table
int glyphOffset = 0;
int glyphIndex = 0;
for (int idx = 0; idx < numGlyphs; idx++)
{
locaNew.LocaTable[idx] = glyphOffset;
if (glyphIndex < glyphCount && glyphArray[glyphIndex] == idx)
{
glyphIndex++;
byte[] bytes = glyf.GetGlyphData(idx);
int length = bytes.Length;
if (length > 0)
{
Buffer.BlockCopy(bytes, 0, glyfNew.GlyphTable, glyphOffset, length);
glyphOffset += length;
}
}
}
locaNew.LocaTable[numGlyphs] = glyphOffset;
// Compile font tables into byte array
fontData.Compile();
return(fontData);
}
