/// <summary>
/// Reads all required table from the font prgram.
/// </summary>
internal void Read()
{
try
{
// Read offset table
this.offsetTable.Version = ReadULong();
this.offsetTable.TableCount = ReadUShort();
this.offsetTable.SearchRange = ReadUShort();
this.offsetTable.EntrySelector = ReadUShort();
this.offsetTable.RangeShift = ReadUShort();
// Move to table dictionary at position 12
Debug.Assert(this.pos == 12);
//this.tableDictionary = (this.offsetTable.TableCount);
for (int idx = 0; idx < this.offsetTable.TableCount; idx++)
{
TableDirectoryEntry entry = TableDirectoryEntry.ReadFrom(this);
this.tableDictionary.Add(entry.Tag, entry);
#if VERBOSE
Debug.WriteLine(String.Format("Font table: {0}", entry.Tag));
#endif
}
// PDFlib checks this, but it is not part of the OpenType spec anymore
if (this.tableDictionary.ContainsKey("bhed"))
throw new NotSupportedException("Bitmap fonts are not supported by PDFsharp.");
// Read required tables
if (Seek(CMapTable.Tag) != -1)
this.cmap = new CMapTable(this);
if (Seek(ControlValueTable.Tag) != -1)
this.cvt = new ControlValueTable(this);
if (Seek(FontProgram.Tag) != -1)
this.fpgm = new FontProgram(this);
if (Seek(MaximumProfileTable.Tag) != -1)
this.maxp = new MaximumProfileTable(this);
if (Seek(NameTable.Tag) != -1)
this.name = new NameTable(this);
if (Seek(FontHeaderTable.Tag) != -1)
this.head = new FontHeaderTable(this);
if (Seek(HorizontalHeaderTable.Tag) != -1)
this.hhea = new HorizontalHeaderTable(this);
if (Seek(HorizontalMetricsTable.Tag) != -1)
this.hmtx = new HorizontalMetricsTable(this);
if (Seek(OS2Table.Tag) != -1)
this.os2 = new OS2Table(this);
if (Seek(PostScriptTable.Tag) != -1)
this.post = new PostScriptTable(this);
if (Seek(GlyphDataTable.Tag) != -1)
this.glyf = new GlyphDataTable(this);
if (Seek(IndexToLocationTable.Tag) != -1)
this.loca = new IndexToLocationTable(this);
if (Seek(GlyphSubstitutionTable.Tag) != -1)
this.gsub = new GlyphSubstitutionTable(this);
if (Seek(ControlValueProgram.Tag) != -1)
this.prep = new ControlValueProgram(this);
}
catch (Exception ex)
{
throw ex;
}
}
/// <summary>
/// Creates a new font image that is a subset of this font image containing only the specified glyphs.
/// </summary>
public FontImage CreateFontSubSet(Dictionary<int, object> glyphs, bool cidFont)
{
// Create new font image
FontImage fontImage = new FontImage(this);
// Create new loca and glyf table
IndexToLocationTable loca = new IndexToLocationTable();
loca.ShortIndex = this.loca.ShortIndex;
GlyphDataTable glyf = new GlyphDataTable();
// Add all required tables
//fontImage.AddTable(this.os2);
if (!cidFont)
fontImage.AddTable(this.cmap);
if (this.cvt != null)
fontImage.AddTable(this.cvt);
if (this.fpgm != null)
fontImage.AddTable(this.fpgm);
fontImage.AddTable(glyf);
fontImage.AddTable(this.head);
fontImage.AddTable(this.hhea);
fontImage.AddTable(this.hmtx);
fontImage.AddTable(loca);
if (this.maxp != null)
fontImage.AddTable(this.maxp);
//fontImage.AddTable(this.name);
if (this.prep != null)
fontImage.AddTable(this.prep);
// Get closure of used glyphs
this.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<int>(glyphArray);
// Calculate new size of glyph table.
int size = 0;
for (int idx = 0; idx < glyphCount; idx++)
size += this.glyf.GetGlyphSize(glyphArray[idx]);
glyf.DirectoryEntry.Length = size;
// Create new loca table
int numGlyphs = this.maxp.numGlyphs;
loca.locaTable = new int[numGlyphs + 1];
// Create new glyf table
glyf.glyphTable = new byte[glyf.DirectoryEntry.PaddedLength];
// Fill new glyf and loca table
int glyphOffset = 0;
int glyphIndex = 0;
for (int idx = 0; idx < numGlyphs; idx++)
{
loca.locaTable[idx] = glyphOffset;
if (glyphIndex < glyphCount && glyphArray[glyphIndex] == idx)
{
glyphIndex++;
byte[] bytes = this.glyf.GetGlyphData(idx);
int length = bytes.Length;
if (length > 0)
{
Buffer.BlockCopy(bytes, 0, glyf.glyphTable, glyphOffset, length);
glyphOffset += length;
}
}
}
loca.locaTable[numGlyphs] = glyphOffset;
// Compile font tables into byte array
fontImage.Compile();
return fontImage;
}
/// <summary>
/// Adds the specified table to this font image.
/// </summary>
public void AddTable(TrueTypeFontTable fontTable)
{
if (!CanWrite)
throw new InvalidOperationException("Font image cannot be modified.");
if (fontTable == null)
throw new ArgumentNullException("fontTable");
if (fontTable.FontImage == null)
{
fontTable.fontImage = this;
}
else
{
Debug.Assert(fontTable.FontImage.CanRead);
// Create a reference to this font table
fontTable = new IRefFontTable(this, fontTable);
}
//Debug.Assert(fontTable.FontImage == null);
//fontTable.fontImage = this;
this.tableDictionary[fontTable.DirectoryEntry.Tag] = fontTable.DirectoryEntry;
switch (fontTable.DirectoryEntry.Tag)
{
case TableTagNames.CMap:
this.cmap = fontTable as CMapTable;
break;
case TableTagNames.Cvt:
this.cvt = fontTable as ControlValueTable;
break;
case TableTagNames.Fpgm:
this.fpgm = fontTable as FontProgram;
break;
case TableTagNames.MaxP:
this.maxp = fontTable as MaximumProfileTable;
break;
case TableTagNames.Name:
this.name = fontTable as NameTable;
break;
case TableTagNames.Head:
this.head = fontTable as FontHeaderTable;
break;
case TableTagNames.HHea:
this.hhea = fontTable as HorizontalHeaderTable;
break;
case TableTagNames.HMtx:
this.hmtx = fontTable as HorizontalMetricsTable;
break;
case TableTagNames.OS2:
this.os2 = fontTable as OS2Table;
break;
case TableTagNames.Post:
this.post = fontTable as PostScriptTable;
break;
case TableTagNames.Glyf:
this.glyf = fontTable as GlyphDataTable;
break;
case TableTagNames.Loca:
this.loca = fontTable as IndexToLocationTable;
break;
case TableTagNames.GSUB:
this.gsub = fontTable as GlyphSubstitutionTable;
break;
case TableTagNames.Prep:
this.prep = fontTable as ControlValueProgram;
break;
}
}
