private bool ReadData(Stream stream)
{
if (stream == null)
{
return(false);
}
int bytesRead = 0;
byte[] header = WoffBuffer.ReadBytes(stream, WoffUtils.Woff1DirSize, out bytesRead);
_tag = WoffBuffer.ReadUInt32BE(header, 0);
_offset = WoffBuffer.ReadUInt32BE(header, 4);
_compLength = WoffBuffer.ReadUInt32BE(header, 8);
_origLength = WoffBuffer.ReadUInt32BE(header, 12);
_origChecksum = WoffBuffer.ReadUInt32BE(header, 16);
if (_origLength > 0)
{
_padding = WoffUtils.CalculatePadding(_origLength);
}
return(true);
}
private bool ReadData(Stream stream, bool isTrueType)
{
if (stream == null)
{
return(false);
}
var tableFlags = WoffTable.TableFlags;
int bytesRead = 0;
// UInt8: flags table type and flags
_flags = (byte)stream.ReadByte();
// The interpretation of the flags field is as follows:
// 1. Bits [0..5] contain an index to the "known tag" table, which represents tags likely to appear in fonts
int tagIndex = _flags & 0x3F;
// If the tag is not present in this table, then the value of this bit field is 63.
if (tagIndex >= 63)
{
// UInt32: tag 4-byte tag (optional)
_tag = WoffBuffer.ReadUInt32BE(WoffBuffer.ReadBytes(stream, 4, out bytesRead), 0);
var name = WoffBuffer.TagString(_tag);
for (int i = 0; i < tableFlags.Count; i++)
{
if (string.Equals(name, tableFlags[i], StringComparison.Ordinal))
{
tagIndex = i;
break;
}
}
}
else
{
_tag = WoffBuffer.TagInt(tableFlags[tagIndex]);
}
// 2. Bits 6 and 7 indicate the preprocessing transformation version number (0-3) that was applied to each table.
int transformVersion = (_flags >> 5) & 0x3;
// UIntBase128: origLength length of original table
if (!WoffBuffer.ReadUIntBase128(stream, out _origLength))
{
return(false);
}
// UIntBase128 transformLength transformed length (if applicable)
// _transformLength = _origLength;
_compLength = _origLength;
_transformLength = 0;
// For all tables in a font, except for 'glyf' and 'loca' tables, transformation version 0
// indicates the null transform where the original table data is passed directly to the
// Brotli compressor for inclusion in the compressed data stream.
if (transformVersion == 0)
{
// "glyf" : 10, "loca" : 11
if (tagIndex == 10 || tagIndex == 11)
{
if (!WoffBuffer.ReadUIntBase128(stream, out _transformLength))
{
return(false);
}
_compLength = _transformLength;
}
}
// The transformation version "1", specified below, is optional and can be applied to
// eliminate certain redundancies in the hmtx table data.
if (transformVersion == 1)
{
// The transformation version 1 described in this subclause is optional and can only
// be used when an input font is TrueType-flavored (i.e. has a glyf table)
// "hmtx" : 3
if (tagIndex == 3 && isTrueType)
{
if (!WoffBuffer.ReadUIntBase128(stream, out _transformLength))
{
return(false);
}
_compLength = _transformLength;
}
}
if (_origLength > 0)
{
_padding = WoffUtils.CalculatePadding(_origLength);
}
return(true);
}
