protected override void ReadContentFrom(BinaryReader input)
{
//https://www.microsoft.com/typography/otspec/cmap.htm
long beginAt = input.BaseStream.Position;
//
ushort version = input.ReadUInt16(); // 0
ushort tableCount = input.ReadUInt16();
var entries = new CMapEntry[tableCount];
for (int i = 0; i < tableCount; i++)
{
ushort platformId = input.ReadUInt16();
ushort encodingId = input.ReadUInt16();
uint offset = input.ReadUInt32();
entries[i] = new CMapEntry(platformId, encodingId, offset);
}
charMaps = new CharacterMap[tableCount];
for (int i = 0; i < tableCount; i++)
{
CMapEntry entry = entries[i];
input.BaseStream.Seek(beginAt + entry.Offset, SeekOrigin.Begin);
CharacterMap cmap = charMaps[i] = ReadCharacterMap(entry, input);
cmap.PlatformId = entry.PlatformId;
cmap.EncodingId = entry.EncodingId;
}
}
private static CharacterMap ReadCharacterMap(CMapEntry entry, BinaryReader input)
{
// I want to thank Microsoft for not giving a simple count on the glyphIdArray
long tableStart = input.BaseStream.Position;
var format = input.ReadUInt16();
var length = input.ReadUInt16();
if (format == 4)
{
var version = input.ReadUInt16();
var segCountX2 = input.ReadUInt16();
var searchRange = input.ReadUInt16();
var entrySelector = input.ReadUInt16();
var rangeShift = input.ReadUInt16();
var segCount = segCountX2 / 2;
var endCode = ReadUInt16Array(input, segCount); // last = 0xffff. What does that mean??
input.ReadUInt16(); // Reserved = 0
var startCode = ReadUInt16Array(input, segCount);
var idDelta = ReadUInt16Array(input, segCount);
var idRangeOffset = ReadUInt16Array(input, segCount);
// I want to thank Microsoft for not giving a simple count on the glyphIdArray
var glyphIdArrayLength = (int)((input.BaseStream.Position - tableStart) / sizeof(UInt16));
var glyphIdArray = ReadUInt16Array(input, glyphIdArrayLength);
return new CharacterMap(segCount, startCode, endCode, idDelta, idRangeOffset, glyphIdArray);
}
throw new ApplicationException("Unknown cmap subtable: " + format); // TODO: Replace all applicationexceptions
}
protected override void ReadContentFrom(BinaryReader input)
{
//https://www.microsoft.com/typography/otspec/cmap.htm
long beginAt = input.BaseStream.Position;
//
ushort version = input.ReadUInt16(); // 0
ushort tableCount = input.ReadUInt16();
var entries = new CMapEntry[tableCount];
for (int i = 0; i < tableCount; i++)
{
ushort platformId = input.ReadUInt16();
ushort encodingId = input.ReadUInt16();
uint offset = input.ReadUInt32();
entries[i] = new CMapEntry(platformId, encodingId, offset);
}
charMaps = new CharacterMap[tableCount];
for (int i = 0; i < tableCount; i++)
{
CMapEntry entry = entries[i];
input.BaseStream.Seek(beginAt + entry.Offset, SeekOrigin.Begin);
CharacterMap cmap = charMaps[i] = ReadCharacterMap(entry, input);
cmap.PlatformId = entry.PlatformId;
cmap.EncodingId = entry.EncodingId;
}
}
private static CharacterMap ReadCharacterMap(CMapEntry entry, BinaryReader input)
{
// I want to thank Microsoft for not giving a simple count on the glyphIdArray
long tableStart = input.BaseStream.Position;
var format = input.ReadUInt16();
var length = input.ReadUInt16();
long tableEndAt = tableStart + length;
if (format == 4)
{
var version = input.ReadUInt16();
var segCountX2 = input.ReadUInt16();
var searchRange = input.ReadUInt16();
var entrySelector = input.ReadUInt16();
var rangeShift = input.ReadUInt16();
var segCount = segCountX2 / 2;
var endCode = ReadUInt16Array(input, segCount); // last = 0xffff. What does that mean??
input.ReadUInt16(); // Reserved = 0
var startCode = ReadUInt16Array(input, segCount);
var idDelta = ReadUInt16Array(input, segCount);
var idRangeOffset = ReadUInt16Array(input, segCount);
// I want to thank Microsoft for not giving a simple count on the glyphIdArray
//var glyphIdArrayLength = (int)((input.BaseStream.Position - tableStart) / sizeof(UInt16));
//int glyphIdArrayLength = FindGlyphIdArrayLenInBytes(idRangeOffset) / 2;
int glyphIdArrayLength = (int)(tableEndAt - input.BaseStream.Position) / 2;
var glyphIdArray = ReadUInt16Array(input, glyphIdArrayLength);
return(new CharacterMap(segCount, startCode, endCode, idDelta, idRangeOffset, glyphIdArray));
}
else if (format == 0)
{
ushort language = input.ReadUInt16();
byte[] only256Glyphs = input.ReadBytes(256);
ushort[] only256UInt16Glyphs = new ushort[256];
for (int i = 255; i >= 0; --i)
{
//expand
only256UInt16Glyphs[i] = only256Glyphs[i];
}
//convert to format4 cmap table
return(new CharacterMap(1, new ushort[] { 0 }, new ushort[] { 255 }, null, null, only256UInt16Glyphs));
}
throw new NRasterizerException("Unknown cmap subtable: " + format);
}
static CharacterMap ReadCharacterMap(CMapEntry entry, BinaryReader input)
{
ushort format = input.ReadUInt16();
switch (format)
{
default:
throw new Exception("Unknown cmap subtable: " + format); // TODO: Replace all application exceptions
case 0: return(ReadFormat_0(input));
case 2: return(ReadFormat_2(input));
case 4: return(ReadFormat_4(input));
case 6: return(ReadFormat_6(input));
case 12: return(ReadFormat_12(input));
}
}
static CharacterMap ReadCharacterMap(CMapEntry entry, BinaryReader input)
{
ushort format = input.ReadUInt16();
switch (format)
{
default:
Utils.WarnUnimplemented("cmap subtable format {0}", format);
return(new NullCharMap());
case 0: return(ReadFormat_0(input));
case 2: return(ReadFormat_2(input));
case 4: return(ReadFormat_4(input));
case 6: return(ReadFormat_6(input));
case 12: return(ReadFormat_12(input));
}
}
static CharacterMap ReadCharacterMap(CMapEntry entry, BinaryReader input)
{
ushort format = input.ReadUInt16();
ushort length = input.ReadUInt16();
switch (format)
{
default:
{
throw new Exception("Unknown cmap subtable: " + format); // TODO: Replace all application exceptions
}
case 0:
{
//Format 0: Byte encoding table
//This is the Apple standard character to glyph index mapping table.
//Type Name Description
//USHORT format Format number is set to 0.
//USHORT length This is the length in bytes of the subtable.
//USHORT language Please see “Note on the language field in 'cmap' subtables“ in this document.
//BYTE glyphIdArray[256] An array that maps character codes to glyph index values.
//This is a simple 1 to 1 mapping of character codes to glyph indices.
//The glyph set is limited to 256. Note that if this format is used to index into a larger glyph set,
//only the first 256 glyphs will be accessible.
ushort language = input.ReadUInt16();
byte[] only256Glyphs = input.ReadBytes(256);
ushort[] only256UInt16Glyphs = new ushort[256];
for (int i = 255; i >= 0; --i)
{
//expand
only256UInt16Glyphs[i] = only256Glyphs[i];
}
//convert to format4 cmap table
return new CharacterMap(1, new ushort[] { 0 }, new ushort[] { 255 }, null, null, only256UInt16Glyphs);
}
case 4:
{
//This is the Microsoft standard character to glyph index mapping table for fonts that support Unicode ranges other than the range [U+D800 - U+DFFF] (defined as Surrogates Area, in Unicode v 3.0)
//which is used for UCS-4 characters.
//If a font supports this character range (i.e. in turn supports the UCS-4 characters) a subtable in this format with a platform specific encoding ID 1 is yet needed,
//in addition to a subtable in format 12 with a platform specific encoding ID 10. Please see details on format 12 below, for fonts that support UCS-4 characters on Windows.
//
//This format is used when the character codes for the characters represented by a font fall into several contiguous ranges,
//possibly with holes in some or all of the ranges (that is, some of the codes in a range may not have a representation in the font).
//The format-dependent data is divided into three parts, which must occur in the following order:
// A four-word header gives parameters for an optimized search of the segment list;
// Four parallel arrays describe the segments (one segment for each contiguous range of codes);
// A variable-length array of glyph IDs (unsigned words).
long tableStartEndAt = input.BaseStream.Position + length;
ushort language = input.ReadUInt16();
//Note on the language field in 'cmap' subtables:
//Note on the language field in 'cmap' subtables:
//The language field must be set to zero for all cmap subtables whose platform IDs are other than Macintosh (platform ID 1).
//For cmap subtables whose platform IDs are Macintosh, set this field to the Macintosh language ID of the cmap subtable plus one,
//or to zero if the cmap subtable is not language-specific.
//For example, a Mac OS Turkish cmap subtable must set this field to 18, since the Macintosh language ID for Turkish is 17.
//A Mac OS Roman cmap subtable must set this field to 0, since Mac OS Roman is not a language-specific encoding.
ushort segCountX2 = input.ReadUInt16(); //2 * segCount
ushort searchRange = input.ReadUInt16(); //2 * (2**FLOOR(log2(segCount)))
ushort entrySelector = input.ReadUInt16();//2 * (2**FLOOR(log2(segCount)))
ushort rangeShift = input.ReadUInt16(); //2 * (2**FLOOR(log2(segCount)))
int segCount = segCountX2 / 2;
ushort[] endCode = Utils.ReadUInt16Array(input, segCount);//Ending character code for each segment, last = 0xFFFF.
//>To ensure that the search will terminate, the final endCode value must be 0xFFFF.
//>This segment need not contain any valid mappings. It can simply map the single character code 0xFFFF to the missing character glyph, glyph 0.
input.ReadUInt16(); // Reserved = 0
ushort[] startCode = Utils.ReadUInt16Array(input, segCount); //Starting character code for each segment
ushort[] idDelta = Utils.ReadUInt16Array(input, segCount); //Delta for all character codes in segment
ushort[] idRangeOffset = Utils.ReadUInt16Array(input, segCount); //Offset in bytes to glyph indexArray, or 0
//------------------------------------------------------------------------------------
long remainingLen = tableStartEndAt - input.BaseStream.Position;
int recordNum2 = (int)(remainingLen / 2);
ushort[] glyphIdArray = Utils.ReadUInt16Array(input, recordNum2);//Glyph index array
return new CharacterMap(segCount, startCode, endCode, idDelta, idRangeOffset, glyphIdArray);
}
}
}
static CharacterMap ReadCharacterMap(CMapEntry entry, BinaryReader input)
{
ushort format = input.ReadUInt16();
ushort length = input.ReadUInt16();
switch (format)
{
default:
{
throw new Exception("Unknown cmap subtable: " + format); // TODO: Replace all application exceptions
}
case 0:
{
//Format 0: Byte encoding table
//This is the Apple standard character to glyph index mapping table.
//Type Name Description
//USHORT format Format number is set to 0.
//USHORT length This is the length in bytes of the subtable.
//USHORT language Please see “Note on the language field in 'cmap' subtables“ in this document.
//BYTE glyphIdArray[256] An array that maps character codes to glyph index values.
//This is a simple 1 to 1 mapping of character codes to glyph indices.
//The glyph set is limited to 256. Note that if this format is used to index into a larger glyph set,
//only the first 256 glyphs will be accessible.
ushort language = input.ReadUInt16();
byte[] only256Glyphs = input.ReadBytes(256);
ushort[] only256UInt16Glyphs = new ushort[256];
for (int i = 255; i >= 0; --i)
{
//expand
only256UInt16Glyphs[i] = only256Glyphs[i];
}
//convert to format4 cmap table
return(CharacterMap.BuildFromFormat4(1, new ushort[] { 0 }, new ushort[] { 255 }, null, null, only256UInt16Glyphs));
}
case 4:
{
//This is the Microsoft standard character to glyph index mapping table for fonts that support Unicode ranges other than the range [U+D800 - U+DFFF] (defined as Surrogates Area, in Unicode v 3.0)
//which is used for UCS-4 characters.
//If a font supports this character range (i.e. in turn supports the UCS-4 characters) a subtable in this format with a platform specific encoding ID 1 is yet needed,
//in addition to a subtable in format 12 with a platform specific encoding ID 10. Please see details on format 12 below, for fonts that support UCS-4 characters on Windows.
//
//This format is used when the character codes for the characters represented by a font fall into several contiguous ranges,
//possibly with holes in some or all of the ranges (that is, some of the codes in a range may not have a representation in the font).
//The format-dependent data is divided into three parts, which must occur in the following order:
// A four-word header gives parameters for an optimized search of the segment list;
// Four parallel arrays describe the segments (one segment for each contiguous range of codes);
// A variable-length array of glyph IDs (unsigned words).
long tableStartEndAt = input.BaseStream.Position + length;
ushort language = input.ReadUInt16();
//Note on the language field in 'cmap' subtables:
//Note on the language field in 'cmap' subtables:
//The language field must be set to zero for all cmap subtables whose platform IDs are other than Macintosh (platform ID 1).
//For cmap subtables whose platform IDs are Macintosh, set this field to the Macintosh language ID of the cmap subtable plus one,
//or to zero if the cmap subtable is not language-specific.
//For example, a Mac OS Turkish cmap subtable must set this field to 18, since the Macintosh language ID for Turkish is 17.
//A Mac OS Roman cmap subtable must set this field to 0, since Mac OS Roman is not a language-specific encoding.
ushort segCountX2 = input.ReadUInt16(); //2 * segCount
ushort searchRange = input.ReadUInt16(); //2 * (2**FLOOR(log2(segCount)))
ushort entrySelector = input.ReadUInt16(); //2 * (2**FLOOR(log2(segCount)))
ushort rangeShift = input.ReadUInt16(); //2 * (2**FLOOR(log2(segCount)))
int segCount = segCountX2 / 2;
ushort[] endCode = Utils.ReadUInt16Array(input, segCount); //Ending character code for each segment, last = 0xFFFF.
//>To ensure that the search will terminate, the final endCode value must be 0xFFFF.
//>This segment need not contain any valid mappings. It can simply map the single character code 0xFFFF to the missing character glyph, glyph 0.
input.ReadUInt16(); // Reserved = 0
ushort[] startCode = Utils.ReadUInt16Array(input, segCount); //Starting character code for each segment
ushort[] idDelta = Utils.ReadUInt16Array(input, segCount); //Delta for all character codes in segment
ushort[] idRangeOffset = Utils.ReadUInt16Array(input, segCount); //Offset in bytes to glyph indexArray, or 0
//------------------------------------------------------------------------------------
long remainingLen = tableStartEndAt - input.BaseStream.Position;
int recordNum2 = (int)(remainingLen / 2);
ushort[] glyphIdArray = Utils.ReadUInt16Array(input, recordNum2); //Glyph index array
return(CharacterMap.BuildFromFormat4(segCount, startCode, endCode, idDelta, idRangeOffset, glyphIdArray));
}
case 6:
{
//Format 6: Trimmed table mapping
//Type Name Description
//USHORT format Format number is set to 6.
//USHORT length This is the length in bytes of the subtable.
//USHORT language Please see “Note on the language field in 'cmap' subtables“ in this document.
//USHORT firstCode First character code of subrange.
//USHORT entryCount Number of character codes in subrange.
//USHORT glyphIdArray[entryCount] Array of glyph index values for character codes in the range.
//The firstCode and entryCount values specify a subrange(beginning at firstCode, length = entryCount) within the range of possible character codes.
//Codes outside of this subrange are mapped to glyph index 0.
//The offset of the code(from the first code) within this subrange is used as index to the glyphIdArray,
//which provides the glyph index value.
long tableStartEndAt = input.BaseStream.Position + length;
ushort language = input.ReadUInt16();
ushort firstCode = input.ReadUInt16();
ushort entryCount = input.ReadUInt16();
ushort[] glyphIdArray = Utils.ReadUInt16Array(input, entryCount);
return(CharacterMap.BuildFromFormat6(firstCode, glyphIdArray));
}
}
}
