public void Transform(BigEndianReader reader)
{
//the glyf table is split into several substreams, to group like data together.
//The transformed table consists of a number of fields specifying the size of each of the substreams,
//followed by the substreams in sequence.
//During the decoding process the reverse transformation takes place,
//where data from various separate substreams are recombined to create a complete glyph record
//for each entry of the original glyf table.
//Transformed glyf Table
//Data-Type Semantic Description and value type(if applicable)
//Fixed version = 0x00000000
//UInt16 numGlyphs Number of glyphs
//UInt16 indexFormatOffset format for loca table,
// should be consistent with indexToLocFormat of
// the original head table(see[OFF] specification)
//UInt32 nContourStreamSize Size of nContour stream in bytes
//UInt32 nPointsStreamSize Size of nPoints stream in bytes
//UInt32 flagStreamSize Size of flag stream in bytes
//UInt32 glyphStreamSize Size of glyph stream in bytes(a stream of variable-length encoded values, see description below)
//UInt32 compositeStreamSize Size of composite stream in bytes(a stream of variable-length encoded values, see description below)
//UInt32 bboxStreamSize Size of bbox data in bytes representing combined length of bboxBitmap(a packed bit array) and bboxStream(a stream of Int16 values)
//UInt32 instructionStreamSize Size of instruction stream(a stream of UInt8 values)
//Int16 nContourStream[] Stream of Int16 values representing number of contours for each glyph record
//255UInt16 nPointsStream[] Stream of values representing number of outline points for each contour in glyph records
//UInt8 flagStream[] Stream of UInt8 values representing flag values for each outline point.
//Vary glyphStream[] Stream of bytes representing point coordinate values using variable length encoding format(defined in subclause 5.2)
//Vary compositeStream[] Stream of bytes representing component flag values and associated composite glyph data
//UInt8 bboxBitmap[] Bitmap(a numGlyphs-long bit array) indicating explicit bounding boxes
//Int16 bboxStream[] Stream of Int16 values representing glyph bounding box data
//UInt8 instructionStream[] Stream of UInt8 values representing a set of instructions for each corresponding glyph
uint version = reader.ReadUInt32();
ushort numGlyphs = reader.ReadUInt16();
ushort indexFormatOffset = reader.ReadUInt16();
uint nContourStreamSize = reader.ReadUInt32(); //in bytes
uint nPointsStreamSize = reader.ReadUInt32(); //in bytes
uint flagStreamSize = reader.ReadUInt32(); //in bytes
uint glyphStreamSize = reader.ReadUInt32(); //in bytes
uint compositeStreamSize = reader.ReadUInt32(); //in bytes
uint bboxStreamSize = reader.ReadUInt32(); //in bytes
uint instructionStreamSize = reader.ReadUInt32(); //in bytes
long expected_nCountStartAt = reader.BaseStream.Position;
long expected_nPointStartAt = expected_nCountStartAt + nContourStreamSize;
long expected_FlagStreamStartAt = expected_nPointStartAt + nPointsStreamSize;
long expected_GlyphStreamStartAt = expected_FlagStreamStartAt + flagStreamSize;
long expected_CompositeStreamStartAt = expected_GlyphStreamStartAt + glyphStreamSize;
long expected_BboxStreamStartAt = expected_CompositeStreamStartAt + compositeStreamSize;
long expected_InstructionStreamStartAt = expected_BboxStreamStartAt + bboxStreamSize;
long expected_EndAt = expected_InstructionStreamStartAt + instructionStreamSize;
Glyph[] glyphs = new Glyph[numGlyphs];
TempGlyph[] allGlyphs = new TempGlyph[numGlyphs];
List <ushort> compositeGlyphs = new List <ushort>();
int contourCount = 0;
for (ushort i = 0; i < numGlyphs; ++i)
{
short numContour = reader.ReadInt16();
allGlyphs[i] = new TempGlyph(i, numContour);
if (numContour > 0)
{
contourCount += numContour;
//>0 => simple glyph
//-1 = compound
//0 = empty glyph
}
else if (numContour < 0)
{
//composite glyph, resolve later
compositeGlyphs.Add(i);
}
else
{
}
}
ushort[] pntPerContours = new ushort[contourCount];
for (int i = 0; i < contourCount; ++i)
{
// Each of these is the number of points of that contour.
pntPerContours[i] = reader.Read255UInt16();
}
byte[] flagStream = reader.Read((int)flagStreamSize);
//TODO: Read more from line 296 in OpenFoint.Woff2Reader
using (var composites = new MemoryStream())
{
reader.Position = expected_CompositeStreamStartAt;
var compositeData = reader.Read((int)compositeStreamSize);
composites.Write(compositeData, 0, (int)compositeStreamSize);
int compositeGlyphCount = compositeGlyphs.Count;
using (var compositeReader = new BigEndianReader(composites))
{
for (int i = 0; i < compositeGlyphCount; i++)
{
ushort compositeGlyphIndex = compositeGlyphs[i];
bool hasInstructions = CompositeHasInstructions(compositeReader, compositeGlyphIndex);
if (hasInstructions)
{
break;
}
allGlyphs[compositeGlyphIndex].compositeHasInstructions = hasInstructions;
}
}
}
}