public unsafe static SbitTable Read(DataReader reader, TableRecord[] tables)
{
if (!SfntTables.SeekToTable(reader, tables, FourCC.Eblc))
return null;
// skip version
var baseOffset = reader.Position;
reader.Skip(sizeof(int));
// load each strike table
var count = reader.ReadInt32BE();
if (count > MaxBitmapStrikes)
throw new InvalidFontException("Too many bitmap strikes in font.");
var sizeTableHeaders = stackalloc BitmapSizeTable[count];
for (int i = 0; i < count; i++)
{
sizeTableHeaders[i].SubTableOffset = reader.ReadUInt32BE();
sizeTableHeaders[i].SubTableSize = reader.ReadUInt32BE();
sizeTableHeaders[i].SubTableCount = reader.ReadUInt32BE();
// skip colorRef, metrics entries, start and end glyph indices
reader.Skip(sizeof(uint) + sizeof(ushort) * 2 + 12 * 2);
sizeTableHeaders[i].PpemX = reader.ReadByte();
sizeTableHeaders[i].PpemY = reader.ReadByte();
sizeTableHeaders[i].BitDepth = reader.ReadByte();
sizeTableHeaders[i].Flags = (BitmapSizeFlags)reader.ReadByte();
}
// read index subtables
var indexSubTables = stackalloc IndexSubTable[count];
for (int i = 0; i < count; i++)
{
reader.Seek(baseOffset + sizeTableHeaders[i].SubTableOffset);
indexSubTables[i] = new IndexSubTable
{
FirstGlyph = reader.ReadUInt16BE(),
LastGlyph = reader.ReadUInt16BE(),
Offset = reader.ReadUInt32BE()
};
}
// read the actual data for each strike table
for (int i = 0; i < count; i++)
{
// read the subtable header
reader.Seek(baseOffset + sizeTableHeaders[i].SubTableOffset + indexSubTables[i].Offset);
var indexFormat = reader.ReadUInt16BE();
var imageFormat = reader.ReadUInt16BE();
var imageDataOffset = reader.ReadUInt32BE();
}
return null;
}
static string ExtractString(DataReader reader, uint baseOffset, StringData data)
{
reader.Seek(baseOffset + data.Offset);
var bytes = reader.ReadBytes(data.Length);
return(Encoding.BigEndianUnicode.GetString(bytes));
}
public static byte[] ReadProgram(DataReader reader, TableRecord[] tables, FourCC tag)
{
var index = FindTable(tables, tag);
if (index == -1)
{
return(null);
}
reader.Seek(tables[index].Offset);
return(reader.ReadBytes((int)tables[index].Length));
}
public static bool SeekToTable(DataReader reader, TableRecord[] tables, FourCC tag, bool required = false)
{
// check if we have the desired table and that it's not empty
var index = FindTable(tables, tag);
if (index == -1 || tables[index].Length == 0)
{
if (required)
{
throw new InvalidFontException($"Missing or empty '{tag}' table.");
}
return(false);
}
// seek to the appropriate offset
reader.Seek(tables[index].Offset);
return(true);
}
public static FUnit[] ReadCvt(DataReader reader, TableRecord[] tables)
{
var index = FindTable(tables, FourCC.Cvt);
if (index == -1)
{
return(null);
}
reader.Seek(tables[index].Offset);
var results = new FUnit[tables[index].Length / sizeof(short)];
for (int i = 0; i < results.Length; i++)
{
results[i] = (FUnit)reader.ReadInt16BE();
}
return(results);
}
public static KerningTable ReadKern(DataReader reader, TableRecord[] tables)
{
// kern table is optional
if (!SfntTables.SeekToTable(reader, tables, FourCC.Kern))
return null;
// skip version
reader.Skip(sizeof(short));
// read each subtable and accumulate kerning values
var tableData = new Dictionary<uint, int>();
var subtableCount = reader.ReadUInt16BE();
for (int i = 0; i < subtableCount; i++)
{
// skip version
var currentOffset = reader.Position;
reader.Skip(sizeof(short));
var length = reader.ReadUInt16BE();
var coverage = reader.ReadUInt16BE();
// we (and Windows) only support Format 0 tables
// only care about tables with horizontal kerning data
var kc = (KernCoverage)coverage;
if ((coverage & FormatMask) == 0 && (kc & KernCoverage.Horizontal) != 0 && (kc & KernCoverage.CrossStream) == 0)
{
// read the number of entries; skip over the rest of the header
var entryCount = reader.ReadUInt16BE();
reader.Skip(sizeof(short) * 3);
var isMin = (kc & KernCoverage.Minimum) != 0;
var isOverride = (kc & KernCoverage.Override) != 0;
// read in each entry and accumulate its kerning data
for (int j = 0; j < entryCount; j++)
{
var left = reader.ReadUInt16BE();
var right = reader.ReadUInt16BE();
var value = reader.ReadInt16BE();
// look up the current value, if we have one; if not, start at zero
int current = 0;
var key = ((uint)left << 16) | right;
tableData.TryGetValue(key, out current);
if (isMin)
{
if (current < value)
tableData[key] = value;
}
else if (isOverride)
tableData[key] = value;
else
tableData[key] = current + value;
}
}
// jump to the next subtable
reader.Seek(currentOffset + length);
}
return new KerningTable(tableData);
}
unsafe static CharacterMap ReadCmapFormat4(DataReader reader)
{
// skip over length and language
reader.Skip(sizeof(short) * 2);
// figure out how many segments we have
var segmentCount = reader.ReadUInt16BE() / 2;
if (segmentCount > MaxSegments)
{
throw new Exception("Too many cmap segments.");
}
// skip over searchRange, entrySelector, and rangeShift
reader.Skip(sizeof(short) * 3);
// read in segment ranges
var endCount = stackalloc int[segmentCount];
for (int i = 0; i < segmentCount; i++)
{
endCount[i] = reader.ReadUInt16BE();
}
reader.Skip(sizeof(short)); // padding
var startCount = stackalloc int[segmentCount];
for (int i = 0; i < segmentCount; i++)
{
startCount[i] = reader.ReadUInt16BE();
}
var idDelta = stackalloc int[segmentCount];
for (int i = 0; i < segmentCount; i++)
{
idDelta[i] = reader.ReadInt16BE();
}
// build table from each segment
var table = new Dictionary <CodePoint, int>();
for (int i = 0; i < segmentCount; i++)
{
// read the "idRangeOffset" for the current segment
// if nonzero, we need to jump into the glyphIdArray to figure out the mapping
// the layout is bizarre; see the OpenType spec for details
var idRangeOffset = reader.ReadUInt16BE();
if (idRangeOffset != 0)
{
var currentOffset = reader.Position;
reader.Seek(currentOffset + idRangeOffset - sizeof(ushort));
var end = endCount[i];
var delta = idDelta[i];
for (var codepoint = startCount[i]; codepoint <= end; codepoint++)
{
var glyphId = reader.ReadUInt16BE();
if (glyphId != 0)
{
var glyphIndex = (glyphId + delta) & 0xFFFF;
if (glyphIndex != 0)
{
table.Add((CodePoint)codepoint, glyphIndex);
}
}
}
reader.Seek(currentOffset);
}
else
{
// otherwise, do a straight iteration through the segment
var end = endCount[i];
var delta = idDelta[i];
for (var codepoint = startCount[i]; codepoint <= end; codepoint++)
{
var glyphIndex = (codepoint + delta) & 0xFFFF;
if (glyphIndex != 0)
{
table.Add((CodePoint)codepoint, glyphIndex);
}
}
}
}
return(new CharacterMap(table));
}
public static CharacterMap ReadCmap(DataReader reader, TableRecord[] tables)
{
SfntTables.SeekToTable(reader, tables, FourCC.Cmap, required: true);
// skip version
var cmapOffset = reader.Position;
reader.Skip(sizeof(short));
// read all of the subtable headers
var subtableCount = reader.ReadUInt16BE();
var subtableHeaders = new CmapSubtableHeader[subtableCount];
for (int i = 0; i < subtableHeaders.Length; i++)
{
subtableHeaders[i] = new CmapSubtableHeader
{
PlatformID = reader.ReadUInt16BE(),
EncodingID = reader.ReadUInt16BE(),
Offset = reader.ReadUInt32BE()
};
}
// search for a "full" Unicode table first
var chosenSubtableOffset = 0u;
for (int i = 0; i < subtableHeaders.Length; i++)
{
var platform = subtableHeaders[i].PlatformID;
var encoding = subtableHeaders[i].EncodingID;
if ((platform == PlatformID.Microsoft && encoding == WindowsEncoding.UnicodeFull) ||
(platform == PlatformID.Unicode && encoding == UnicodeEncoding.Unicode32))
{
chosenSubtableOffset = subtableHeaders[i].Offset;
break;
}
}
// if no full unicode table, just grab the first
// one that supports any flavor of Unicode
if (chosenSubtableOffset == 0)
{
for (int i = 0; i < subtableHeaders.Length; i++)
{
var platform = subtableHeaders[i].PlatformID;
var encoding = subtableHeaders[i].EncodingID;
if ((platform == PlatformID.Microsoft && encoding == WindowsEncoding.UnicodeBmp) ||
platform == PlatformID.Unicode)
{
chosenSubtableOffset = subtableHeaders[i].Offset;
break;
}
}
}
// no unicode support at all is an error
if (chosenSubtableOffset == 0)
{
throw new Exception("Font does not support Unicode.");
}
// jump to our chosen table and find out what format it's in
reader.Seek(cmapOffset + chosenSubtableOffset);
var format = reader.ReadUInt16BE();
switch (format)
{
case 4: return(ReadCmapFormat4(reader));
default: throw new Exception("Unsupported cmap format.");
}
}
public static byte[] ReadProgram(DataReader reader, TableRecord[] tables, FourCC tag)
{
var index = FindTable(tables, tag);
if (index == -1)
return null;
reader.Seek(tables[index].Offset);
return reader.ReadBytes((int)tables[index].Length);
}
public static CharacterMap ReadCmap(DataReader reader, TableRecord[] tables)
{
SfntTables.SeekToTable(reader, tables, FourCC.Cmap, required: true);
// skip version
var cmapOffset = reader.Position;
reader.Skip(sizeof(short));
// read all of the subtable headers
var subtableCount = reader.ReadUInt16BE();
var subtableHeaders = new CmapSubtableHeader[subtableCount];
for (int i = 0; i < subtableHeaders.Length; i++)
{
subtableHeaders[i] = new CmapSubtableHeader
{
PlatformID = reader.ReadUInt16BE(),
EncodingID = reader.ReadUInt16BE(),
Offset = reader.ReadUInt32BE()
};
}
// search for a "full" Unicode table first
var chosenSubtableOffset = 0u;
for (int i = 0; i < subtableHeaders.Length; i++)
{
var platform = subtableHeaders[i].PlatformID;
var encoding = subtableHeaders[i].EncodingID;
if ((platform == PlatformID.Microsoft && encoding == WindowsEncoding.UnicodeFull) ||
(platform == PlatformID.Unicode && encoding == UnicodeEncoding.Unicode32))
{
chosenSubtableOffset = subtableHeaders[i].Offset;
break;
}
}
// if no full unicode table, just grab the first
// one that supports any flavor of Unicode
if (chosenSubtableOffset == 0)
{
for (int i = 0; i < subtableHeaders.Length; i++)
{
var platform = subtableHeaders[i].PlatformID;
var encoding = subtableHeaders[i].EncodingID;
if ((platform == PlatformID.Microsoft && encoding == WindowsEncoding.UnicodeBmp) ||
platform == PlatformID.Unicode)
{
chosenSubtableOffset = subtableHeaders[i].Offset;
break;
}
}
}
// no unicode support at all is an error
if (chosenSubtableOffset == 0)
throw new Exception("Font does not support Unicode.");
// jump to our chosen table and find out what format it's in
reader.Seek(cmapOffset + chosenSubtableOffset);
var format = reader.ReadUInt16BE();
switch (format)
{
case 4: return ReadCmapFormat4(reader);
default: throw new Exception("Unsupported cmap format.");
}
}
static unsafe CharacterMap ReadCmapFormat4(DataReader reader)
{
// skip over length and language
reader.Skip(sizeof(short) * 2);
// figure out how many segments we have
var segmentCount = reader.ReadUInt16BE() / 2;
if (segmentCount > MaxSegments)
throw new Exception("Too many cmap segments.");
// skip over searchRange, entrySelector, and rangeShift
reader.Skip(sizeof(short) * 3);
// read in segment ranges
var endCount = stackalloc int[segmentCount];
for (int i = 0; i < segmentCount; i++)
endCount[i] = reader.ReadUInt16BE();
reader.Skip(sizeof(short)); // padding
var startCount = stackalloc int[segmentCount];
for (int i = 0; i < segmentCount; i++)
startCount[i] = reader.ReadUInt16BE();
var idDelta = stackalloc int[segmentCount];
for (int i = 0; i < segmentCount; i++)
idDelta[i] = reader.ReadInt16BE();
// build table from each segment
var table = new Dictionary<CodePoint, int>();
for (int i = 0; i < segmentCount; i++)
{
// read the "idRangeOffset" for the current segment
// if nonzero, we need to jump into the glyphIdArray to figure out the mapping
// the layout is bizarre; see the OpenType spec for details
var idRangeOffset = reader.ReadUInt16BE();
if (idRangeOffset != 0)
{
var currentOffset = reader.Position;
reader.Seek(currentOffset + idRangeOffset - sizeof(ushort));
var end = endCount[i];
var delta = idDelta[i];
for (var codepoint = startCount[i]; codepoint <= end; codepoint++)
{
var glyphId = reader.ReadUInt16BE();
if (glyphId != 0)
{
var glyphIndex = (glyphId + delta) & 0xFFFF;
if (glyphIndex != 0)
table.Add((CodePoint)codepoint, glyphIndex);
}
}
reader.Seek(currentOffset);
}
else
{
// otherwise, do a straight iteration through the segment
var end = endCount[i];
var delta = idDelta[i];
for (var codepoint = startCount[i]; codepoint <= end; codepoint++)
{
var glyphIndex = (codepoint + delta) & 0xFFFF;
if (glyphIndex != 0)
table.Add((CodePoint)codepoint, glyphIndex);
}
}
}
return new CharacterMap(table);
}
public static KerningTable ReadKern(DataReader reader, TableRecord[] tables)
{
// kern table is optional
if (!SfntTables.SeekToTable(reader, tables, FourCC.Kern))
{
return(null);
}
// skip version
reader.Skip(sizeof(short));
// read each subtable and accumulate kerning values
var tableData = new Dictionary <uint, int>();
var subtableCount = reader.ReadUInt16BE();
for (int i = 0; i < subtableCount; i++)
{
// skip version
var currentOffset = reader.Position;
reader.Skip(sizeof(short));
var length = reader.ReadUInt16BE();
var coverage = reader.ReadUInt16BE();
// we (and Windows) only support Format 0 tables
// only care about tables with horizontal kerning data
var kc = (KernCoverage)coverage;
if ((coverage & FormatMask) == 0 && (kc & KernCoverage.Horizontal) != 0 && (kc & KernCoverage.CrossStream) == 0)
{
// read the number of entries; skip over the rest of the header
var entryCount = reader.ReadUInt16BE();
reader.Skip(sizeof(short) * 3);
var isMin = (kc & KernCoverage.Minimum) != 0;
var isOverride = (kc & KernCoverage.Override) != 0;
// read in each entry and accumulate its kerning data
for (int j = 0; j < entryCount; j++)
{
var left = reader.ReadUInt16BE();
var right = reader.ReadUInt16BE();
var value = reader.ReadInt16BE();
// look up the current value, if we have one; if not, start at zero
int current = 0;
var key = ((uint)left << 16) | right;
tableData.TryGetValue(key, out current);
if (isMin)
{
if (current < value)
{
tableData[key] = value;
}
}
else if (isOverride)
{
tableData[key] = value;
}
else
{
tableData[key] = current + value;
}
}
}
// jump to the next subtable
reader.Seek(currentOffset + length);
}
return(new KerningTable(tableData));
}
static string ExtractString(DataReader reader, uint baseOffset, StringData data)
{
reader.Seek(baseOffset + data.Offset);
var bytes = reader.ReadBytes(data.Length);
return Encoding.BigEndianUnicode.GetString(bytes);
}
public static void ReadGlyph(
DataReader reader, int glyphIndex, int recursionDepth,
BaseGlyph[] glyphTable, uint glyfOffset, uint glyfLength, uint* loca
)
{
// check if this glyph has already been loaded; this can happen
// if we're recursively loading subglyphs as part of a composite
if (glyphTable[glyphIndex] != null)
return;
// prevent bad font data from causing infinite recursion
if (recursionDepth > MaxRecursion)
throw new InvalidFontException("Bad font data; infinite composite recursion.");
// check if this glyph doesn't have any actual data
GlyphHeader header;
var offset = loca[glyphIndex];
if ((glyphIndex < glyphTable.Length - 1 && offset == loca[glyphIndex + 1]) || offset >= glyfLength)
{
// this is an empty glyph, so synthesize a header
header = default(GlyphHeader);
}
else
{
// seek to the right spot and load the header
reader.Seek(glyfOffset + loca[glyphIndex]);
header = new GlyphHeader
{
ContourCount = reader.ReadInt16BE(),
MinX = reader.ReadInt16BE(),
MinY = reader.ReadInt16BE(),
MaxX = reader.ReadInt16BE(),
MaxY = reader.ReadInt16BE()
};
if (header.ContourCount < -1 || header.ContourCount > MaxContours)
throw new InvalidFontException("Invalid number of contours for glyph.");
}
if (header.ContourCount > 0)
{
// positive contours means a simple glyph
glyphTable[glyphIndex] = ReadSimpleGlyph(reader, header.ContourCount);
}
else if (header.ContourCount == -1)
{
// -1 means composite glyph
var composite = ReadCompositeGlyph(reader);
var subglyphs = composite.Subglyphs;
// read each subglyph recrusively
for (int i = 0; i < subglyphs.Length; i++)
ReadGlyph(reader, subglyphs[i].Index, recursionDepth + 1, glyphTable, glyfOffset, glyfLength, loca);
glyphTable[glyphIndex] = composite;
}
else
{
// no data, so synthesize an empty glyph
glyphTable[glyphIndex] = new SimpleGlyph
{
Points = new Point[0],
ContourEndpoints = new int[0]
};
}
// save bounding box
var glyph = glyphTable[glyphIndex];
glyph.MinX = header.MinX;
glyph.MinY = header.MinY;
glyph.MaxX = header.MaxX;
glyph.MaxY = header.MaxY;
}
public static bool SeekToTable(DataReader reader, TableRecord[] tables, FourCC tag, bool required = false)
{
// check if we have the desired table and that it's not empty
var index = FindTable(tables, tag);
if (index == -1 || tables[index].Length == 0)
{
if (required)
//throw new InvalidFontException($"Missing or empty '{tag}' table.");
throw new InvalidFontException(string.Format(
"Missing or empty '{0}' table.", tag));
return false;
}
// seek to the appropriate offset
reader.Seek(tables[index].Offset);
return true;
}
public static void ReadGlyph(
DataReader reader, int glyphIndex, int recursionDepth,
BaseGlyph[] glyphTable, uint glyfOffset, uint glyfLength, uint *loca
)
{
// check if this glyph has already been loaded; this can happen
// if we're recursively loading subglyphs as part of a composite
if (glyphTable[glyphIndex] != null)
{
return;
}
// prevent bad font data from causing infinite recursion
if (recursionDepth > MaxRecursion)
{
throw new InvalidFontException("Bad font data; infinite composite recursion.");
}
// check if this glyph doesn't have any actual data
GlyphHeader header;
var offset = loca[glyphIndex];
if ((glyphIndex < glyphTable.Length - 1 && offset == loca[glyphIndex + 1]) || offset >= glyfLength)
{
// this is an empty glyph, so synthesize a header
header = default(GlyphHeader);
}
else
{
// seek to the right spot and load the header
reader.Seek(glyfOffset + loca[glyphIndex]);
header = new GlyphHeader {
ContourCount = reader.ReadInt16BE(),
MinX = reader.ReadInt16BE(),
MinY = reader.ReadInt16BE(),
MaxX = reader.ReadInt16BE(),
MaxY = reader.ReadInt16BE()
};
if (header.ContourCount < -1 || header.ContourCount > MaxContours)
{
throw new InvalidFontException("Invalid number of contours for glyph.");
}
}
if (header.ContourCount > 0)
{
// positive contours means a simple glyph
glyphTable[glyphIndex] = ReadSimpleGlyph(reader, header.ContourCount);
}
else if (header.ContourCount == -1)
{
// -1 means composite glyph
var composite = ReadCompositeGlyph(reader);
var subglyphs = composite.Subglyphs;
// read each subglyph recrusively
for (int i = 0; i < subglyphs.Length; i++)
{
ReadGlyph(reader, subglyphs[i].Index, recursionDepth + 1, glyphTable, glyfOffset, glyfLength, loca);
}
glyphTable[glyphIndex] = composite;
}
else
{
// no data, so synthesize an empty glyph
glyphTable[glyphIndex] = new SimpleGlyph {
Points = new Point[0],
ContourEndpoints = new int[0]
};
}
// save bounding box
var glyph = glyphTable[glyphIndex];
glyph.MinX = header.MinX;
glyph.MinY = header.MinY;
glyph.MaxX = header.MaxX;
glyph.MaxY = header.MaxY;
}
public unsafe static SbitTable Read(DataReader reader, TableRecord[] tables)
{
if (!SfntTables.SeekToTable(reader, tables, FourCC.Eblc))
{
return(null);
}
// skip version
var baseOffset = reader.Position;
reader.Skip(sizeof(int));
// load each strike table
var count = reader.ReadInt32BE();
if (count > MaxBitmapStrikes)
{
throw new Exception("Too many bitmap strikes in font.");
}
var sizeTableHeaders = stackalloc BitmapSizeTable[count];
for (int i = 0; i < count; i++)
{
sizeTableHeaders[i].SubTableOffset = reader.ReadUInt32BE();
sizeTableHeaders[i].SubTableSize = reader.ReadUInt32BE();
sizeTableHeaders[i].SubTableCount = reader.ReadUInt32BE();
// skip colorRef, metrics entries, start and end glyph indices
reader.Skip(sizeof(uint) + sizeof(ushort) * 2 + 12 * 2);
sizeTableHeaders[i].PpemX = reader.ReadByte();
sizeTableHeaders[i].PpemY = reader.ReadByte();
sizeTableHeaders[i].BitDepth = reader.ReadByte();
sizeTableHeaders[i].Flags = (BitmapSizeFlags)reader.ReadByte();
}
// read index subtables
var indexSubTables = stackalloc IndexSubTable[count];
for (int i = 0; i < count; i++)
{
reader.Seek(baseOffset + sizeTableHeaders[i].SubTableOffset);
indexSubTables[i] = new IndexSubTable
{
FirstGlyph = reader.ReadUInt16BE(),
LastGlyph = reader.ReadUInt16BE(),
Offset = reader.ReadUInt32BE()
};
}
// read the actual data for each strike table
for (int i = 0; i < count; i++)
{
// read the subtable header
reader.Seek(baseOffset + sizeTableHeaders[i].SubTableOffset + indexSubTables[i].Offset);
var indexFormat = reader.ReadUInt16BE();
var imageFormat = reader.ReadUInt16BE();
var imageDataOffset = reader.ReadUInt32BE();
}
return(null);
}
public static FUnit[] ReadCvt(DataReader reader, TableRecord[] tables)
{
var index = FindTable(tables, FourCC.Cvt);
if (index == -1)
return null;
reader.Seek(tables[index].Offset);
var results = new FUnit[tables[index].Length / sizeof(short)];
for (int i = 0; i < results.Length; i++)
results[i] = (FUnit)reader.ReadInt16BE();
return results;
}