} // ReadTableRecord
public UInt64 Validate(long fileLength)
{
// Check that tag is defined and known, and that table
// offset & length are in bounds.
if (!OTFont.IsKnownTableType(_tableTag))
{
_validationStatus |= OTFile.OTFileValidation_UnknownTableTag;
}
if (!OTFont.IsSupportedTableType(_tableTag))
{
_validationStatus |= OTFile.OTFileValidation_UnsupportedTableTag;
}
if (_tableOffset > fileLength)
{
_validationStatus |= OTFile.OTFileValidation_ReferencedStructureOffsetOutOfRange;
}
if (_tableOffset + _tableLength > fileLength)
{
_validationStatus |= OTFile.OTFileValidation_ReferencedStructureLengthOutOfRange;
}
// completed validateions; clear the partial validation flag and check for errors
_validationStatus &= ~OTFile.OTFileValidation_PartialValidation;
if ((_validationStatus & OTFile.OTFileValidation_ValidationIssueMask) == 0)
{
_validationStatus = OTFile.OTFileValidation_Valid;
}
return(_validationStatus);
} // Validate
public OTTable(OTFont parentFont, TableRecord tableRecord)
{
// This is only used temporarily to create a placeholder table if the table type is not supported.
_parentFont = parentFont;
_tableRecord = tableRecord;
CalculateCheckSum();
_validationStatus = OTFile.OTFileValidation_PartialValidation | ValidateTableRecord();
}
public OTTable(OTFont parentFont, TableRecord tableRecord, string expectedTag, bool parseWhenConstructed)
{
// Used for derived classes for specific table types
if (tableRecord.Tag.ToString() != expectedTag)
{
throw new ArgumentException("TableRecord has the wrong tag for the '" + expectedTag + " table");
}
_parentFont = parentFont;
_tableRecord = tableRecord;
CalculateCheckSum();
_validationStatus = OTFile.OTFileValidation_PartialValidation | ValidateTableRecord();
if (parseWhenConstructed)
{
ReadTable_Internal();
}
}
public TableColr(OTFont parentFont, TableRecord tableRecord)
: base(parentFont, tableRecord, _tableTag, /* parseWhenConstructed */ true)
{
// Base class constructor validates table record values, and marks
// validation completion status as partial validation
}
public void ReadOffsetTable(MemoryStream ms, uint fileOffset)
{
// offset was validated as in bounds by upstream caller; set read position
_offsetInFile = fileOffset;
ms.Seek((long)fileOffset, SeekOrigin.Begin);
_validationStatus = OTFile.OTFileValidation_PartialValidation;
// check length to read sfnt version tag and read
if (_offsetInFile + 4 > ms.Length)
{
_validationStatus |= OTFile.OTFileValidation_OffsetTableLengthOutOfRange | OTFile.OTFileValidation_StructureLengthOutOfRange;
}
try
{
_sfntTag = OTTag.ReadTag(ms);
}
catch (OTDataIncompleteReadException e)
{
_validationStatus |= OTFile.OTFileValidation_ReadTrunctated;
throw new OTTableParseException("OT parse error: unable to read Offset Table", e);
}
// check that the sfnt version is supported before continuing
if (!OTFont.IsSupportedSfntVersion(_sfntTag))
{
_validationStatus |= OTFile.OTFileValidation_SfntVersionNotSupported;
throw new OTTableParseException("OT parse error: font resource has an unsupported sfnt version");
}
// check length to read remaining header fields, then read
if (_offsetInFile + 12 > ms.Length)
{
_validationStatus |= OTFile.OTFileValidation_OffsetTableLengthOutOfRange | OTFile.OTFileValidation_StructureLengthOutOfRange;
}
try
{
_numTables = OTFile.ReadUInt16(ms);
_searchRange = OTFile.ReadUInt16(ms);
_entrySelector = OTFile.ReadUInt16(ms);
_rangeShift = OTFile.ReadUInt16(ms);
}
catch (OTDataIncompleteReadException e)
{
_validationStatus |= OTFile.OTFileValidation_ReadTrunctated;
throw new OTTableParseException("OT parse error: unable to read Offset Table", e);
}
// check length to read encoding records array, then read the records
if (_offsetInFile + 12 + _numTables * TableRecord.TableRecordSize > ms.Length)
{
_validationStatus |= OTFile.OTFileValidation_OffsetTableLengthOutOfRange | OTFile.OTFileValidation_StructureLengthOutOfRange;
}
_tableRecords = new TableRecord[_numTables]; // constructs struct records with default values
_tableMap = new Dictionary <string, uint>();
try
{
for (uint i = 0; i < _numTables; i++)
{
_tableRecords[i].ReadTableRecord(ms);
try
{
_tableMap.Add(_tableRecords[i].Tag.ToString(), i);
}
catch (ArgumentException)
{
// duplicate tag; first one wins
_validationStatus |= OTFile.OTFileValidation_StructureHasDuplicateEntries;
}
}
}
catch (OTDataIncompleteReadException e)
{
_validationStatus |= OTFile.OTFileValidation_ReadTrunctated;
throw new OTTableParseException("OT parse error: unable to read Offset Table", e);
}
} // ReadOffsetTable
private void ReadFont_Internal(MemoryStream ms)
{
// results in Offset table for font being read, but no other tables
// assumed: _offsetInFile has already been set and validated as in bounds
try
{
_offsetTable.ReadOffsetTable(ms, _offsetInFile);
}
catch (OTTableParseException e)
{
throw new OTFontParseException("Unable to parse font data", e);
}
// Offset table for font has been read; we know how many and what kind
// of tables.
_tables = new OTTable[_offsetTable.NumTables]; // initialized with entries == null
_validationStatusOfTables = new UInt64[_offsetTable.NumTables]; // initialized with entries == NotValidated
// The following is something temporary: populate an array of OTTable objects
// passing each its offset table record. The record is all that's needed to
// parse each table; but once an object is created (OTTable), it can't change
// itself into a different type; it can only be substituted with a different
// type of object, and that substitution would have to be done by something
// else.
for (int i = 0; i < _offsetTable.NumTables; i++)
{
if (OTFont.IsSupportedTableType(_offsetTable.TableRecords[i].Tag))
{
switch (_offsetTable.TableRecords[i].Tag.ToString())
{
case "COLR":
_tables[i] = new TableColr(this, _offsetTable.TableRecords[i]);
break;
case "fmtx":
_tables[i] = new TableFmtx(this, _offsetTable.TableRecords[i]);
break;
case "head":
_tables[i] = new TableHead(this, _offsetTable.TableRecords[i]);
break;
case "hhea":
_tables[i] = new TableHhea(this, _offsetTable.TableRecords[i]);
break;
case "maxp":
_tables[i] = new TableMaxp(this, _offsetTable.TableRecords[i]);
break;
}
}
else
{
_tables[i] = new OTTable(this, _offsetTable.TableRecords[i]);
}
}
} // ReadFont_Internal
public void ReadFromFile(FileInfo fileInfo)
{
// save fileinfo for later reference
_fi = fileInfo;
// Check that file exists. (Handle FileStream exception in advance.)
if (!_fi.Exists)
{
throw new FileNotFoundException("File " + _fi.FullName + " was not found.", _fi.FullName);
}
// read file as a byte array, then construct memory stream from byte array
{
byte[] bytes;
try
{
// File.ReadAllBytes opens a filestream and then ensures it is closed
bytes = File.ReadAllBytes(_fi.FullName);
_ms = new MemoryStream(bytes, 0, bytes.Length, false, true);
}
catch (IOException e)
{
throw e;
}
}
// Read sfntVersion tag
try
{
_sfntVersionTag = OTTag.ReadTag(_ms);
}
catch (OTDataIncompleteReadException e)
{
throw new OTFileParseException("OT parse error: unable to read sfnt tag", e);
}
// supported format?
if (!IsSupportedSfntVersion(_sfntVersionTag))
{
_validationStatus = OTFileValidation_SfntVersionNotSupported;
throw new OTFileParseException("OT parse error: not a known and supported sfnt type (sfnt tag = " + _sfntVersionTag.ToString());
}
_validationStatus = OTFile.OTFileValidation_PartialValidation;
// TTC? get TTC header
if (_sfntVersionTag == (OTTag)"ttcf")
{
try
{
_ttcHeader.ReadTtcHeader(_ms); // will set read position to start of file
}
catch (OTException e)
{
_validationStatus = _ttcHeader.ValidationStatus;
throw new OTFileParseException("OT parse error: unable to read TTC header", e);
}
_numFonts = _ttcHeader.NumFonts;
}
else
{
_numFonts = 1;
}
// initialize new font object(s); this will get the font headers for each font resource
_fonts = new OTFont[_numFonts];
if (_sfntVersionTag == (OTTag)"ttcf")
{
for (uint i = 0; i < _numFonts; i++)
{
_fonts[i] = new OTFont(this, _ttcHeader.OffsetTableOffsets[i], i);
}
}
else // single font
{
_fonts[0] = new OTFont(this);
}
// got TTC header; created font objects and got all the header info for each
// caller can now poke individual fonts to get additional info as needed
// finally, get validation status on ttc header, offset tables
_validationStatusOfFonts = new UInt64[_numFonts];
for (int i = 0; i < _numFonts; i++)
{
// simple validations -- full validation on a table-by-table basis
_fonts[i].Validate(_ms.Length, true);
}
if (_sfntVersionTag == (OTTag)"ttcf")
{
// treat ttc header validation as part of the file validation
_validationStatus |= _ttcHeader.Validate(_ms.Length);
// check for validation issues in any of the font resources
for (int i = 0; i < _numFonts; i++)
{
if ((_fonts[i].ValidationStatus & OTFile.OTFileValidation_ValidationIssueMask) != 0)
{
_validationStatus |= OTFile.OTFileValidation_ValidationIssueInChildStructure;
break;
}
}
}
else
{
// treat font resource validation as part of the file validation
_validationStatus |= (_fonts[0].ValidationStatus & OTFile.OTFileValidation_ValidationIssueMask);
}
} // ReadFromFile
