/// <summary>
/// Create a new <see cref="Type1Font"/>.
/// </summary>
internal Type1Font(string name, IReadOnlyDictionary <int, string> encoding, ArrayToken fontMatrix, PdfRectangle boundingBox,
Type1PrivateDictionary privateDictionary,
Type1CharStrings charStrings)
{
Name = name;
Encoding = encoding;
FontMatrix = GetFontTransformationMatrix(fontMatrix);
BoundingBox = boundingBox;
PrivateDictionary = privateDictionary ?? throw new ArgumentNullException(nameof(privateDictionary));
CharStrings = charStrings ?? throw new ArgumentNullException(nameof(charStrings));
}
/// <summary>
/// Create a new <see cref="Type1FontProgram"/> from the information retrieved from the PDF document.
/// </summary>
/// <param name="name">The name of the font.</param>
/// <param name="encoding"></param>
/// <param name="fontMatrix"></param>
/// <param name="boundingBox"></param>
/// <param name="privateDictionary"></param>
/// <param name="charStrings"></param>
public Type1FontProgram(string name, IReadOnlyDictionary <int, string> encoding, ArrayToken fontMatrix, PdfRectangle boundingBox,
Type1PrivateDictionary privateDictionary,
Type1CharStrings charStrings)
{
Name = name;
Encoding = encoding;
FontMatrix = fontMatrix;
BoundingBox = boundingBox;
PrivateDictionary = privateDictionary ?? throw new ArgumentNullException(nameof(privateDictionary));
CharStrings = charStrings ?? throw new ArgumentNullException(nameof(charStrings));
}
public (Type1PrivateDictionary, Type1CharStrings) Parse(IReadOnlyList <byte> bytes, bool isLenientParsing)
{
if (!IsBinary(bytes))
{
bytes = ConvertHexToBinary(bytes);
}
var decrypted = Decrypt(bytes, EexecEncryptionKey, EexecRandomBytes);
if (decrypted.Count == 0)
{
var defaultPrivateDictionary = new Type1PrivateDictionary(new Type1PrivateDictionary.Builder());
var defaultCharstrings = new Type1CharStrings(new Dictionary <string, Type1CharStrings.CommandSequence>(),
new Dictionary <int, string>(),
new Dictionary <int, Type1CharStrings.CommandSequence>());
return(defaultPrivateDictionary, defaultCharstrings);
}
var tokenizer = new Type1Tokenizer(new ByteArrayInputBytes(decrypted));
/*
* After 4 random characters follows the /Private dictionary and the /CharString dictionary.
* The first defines a number of technical terms involving character construction, and contains also an array of subroutines used in character paths.
* The second contains the character descriptions themselves.
* Both the subroutines and the character descriptions are yet again encrypted in a fashion similar to the entire binary segment, but now with an initial value of R = 4330 instead of 55665.
*/
while (!tokenizer.CurrentToken.IsPrivateDictionary)
{
tokenizer.GetNext();
if (tokenizer.CurrentToken == null)
{
throw new InvalidOperationException("Did not find the private dictionary start token.");
}
}
var next = tokenizer.GetNext();
if (next?.Type != Type1Token.TokenType.Integer)
{
throw new InvalidOperationException($"No length token was present in the stream following the private dictionary start, instead got {next}.");
}
var length = next.AsInt();
ReadExpected(tokenizer, Type1Token.TokenType.Name, "dict");
// Could also be "/Private 10 dict def Private begin" instead of the "dup"
ReadExpectedAfterOptional(tokenizer, Type1Token.TokenType.Name, "def", Type1Token.TokenType.Name, "dup");
ReadExpected(tokenizer, Type1Token.TokenType.Name, "begin");
/*
* The lenIV entry is an integer specifying the number of random bytes at the beginning of charstrings for charstring encryption.
* The default value of lenIV is 4.
*/
var lenIv = Len4Bytes;
var builder = new Type1PrivateDictionary.Builder();
for (var i = 0; i < length; i++)
{
var token = tokenizer.GetNext();
// premature end
if (token == null || token.Type != Type1Token.TokenType.Literal)
{
break;
}
var key = token.Text;
switch (key)
{
case Type1Symbols.RdProcedure:
case Type1Symbols.RdProcedureAlt:
{
var procedureTokens = ReadProcedure(tokenizer);
builder.Rd = procedureTokens;
ReadTillDef(tokenizer);
break;
}
case Type1Symbols.NoAccessDef:
case Type1Symbols.NoAccessDefAlt:
{
var procedureTokens = ReadProcedure(tokenizer);
builder.NoAccessDef = procedureTokens;
ReadTillDef(tokenizer);
break;
}
case Type1Symbols.NoAccessPut:
case Type1Symbols.NoAccessPutAlt:
{
var procedureTokens = ReadProcedure(tokenizer);
builder.NoAccessPut = procedureTokens;
ReadTillDef(tokenizer);
break;
}
case Type1Symbols.BlueValues:
{
var blueValues = ReadArrayValues(tokenizer, x => x.AsInt());
builder.BlueValues = blueValues;
break;
}
case Type1Symbols.OtherBlues:
{
var otherBlues = ReadArrayValues(tokenizer, x => x.AsInt());
builder.OtherBlues = otherBlues;
break;
}
case Type1Symbols.StdHorizontalStemWidth:
{
var widths = ReadArrayValues(tokenizer, x => x.AsDecimal());
var width = widths[0];
builder.StandardHorizontalWidth = width;
break;
}
case Type1Symbols.StdVerticalStemWidth:
{
var widths = ReadArrayValues(tokenizer, x => x.AsDecimal());
var width = widths[0];
builder.StandardVerticalWidth = width;
break;
}
case Type1Symbols.StemSnapHorizontalWidths:
{
var widths = ReadArrayValues(tokenizer, x => x.AsDecimal());
builder.StemSnapHorizontalWidths = widths;
break;
}
case Type1Symbols.StemSnapVerticalWidths:
{
var widths = ReadArrayValues(tokenizer, x => x.AsDecimal());
builder.StemSnapVerticalWidths = widths;
break;
}
case Type1Symbols.BlueScale:
{
builder.BlueScale = ReadNumeric(tokenizer);
ReadTillDef(tokenizer);
break;
}
case Type1Symbols.ForceBold:
{
builder.ForceBold = ReadBoolean(tokenizer);
ReadTillDef(tokenizer);
break;
}
case Type1Symbols.MinFeature:
{
var procedureTokens = ReadProcedure(tokenizer);
builder.MinFeature = new MinFeature(procedureTokens[0].AsInt(), procedureTokens[1].AsInt());
ReadTillDef(tokenizer);
break;
}
case Type1Symbols.Password:
{
var password = (int)ReadNumeric(tokenizer);
if (password != Password && !isLenientParsing)
{
throw new InvalidOperationException($"Type 1 font had the wrong password: {password}");
}
builder.Password = password;
ReadTillDef(tokenizer);
break;
}
case Type1Symbols.UniqueId:
{
var id = (int)ReadNumeric(tokenizer);
builder.UniqueId = id;
ReadTillDef(tokenizer);
break;
}
case Type1Symbols.Len4:
{
lenIv = (int)ReadNumeric(tokenizer);
ReadTillDef(tokenizer);
break;
}
case Type1Symbols.BlueShift:
{
builder.BlueShift = (int)ReadNumeric(tokenizer);
ReadTillDef(tokenizer);
break;
}
case Type1Symbols.BlueFuzz:
{
builder.BlueFuzz = (int)ReadNumeric(tokenizer);
ReadTillDef(tokenizer);
break;
}
case Type1Symbols.FamilyBlues:
{
builder.FamilyBlues = ReadArrayValues(tokenizer, x => x.AsInt());
break;
}
case Type1Symbols.FamilyOtherBlues:
{
builder.FamilyOtherBlues = ReadArrayValues(tokenizer, x => x.AsInt());
break;
}
case Type1Symbols.LanguageGroup:
{
builder.LanguageGroup = (int)ReadNumeric(tokenizer);
ReadTillDef(tokenizer);
break;
}
case Type1Symbols.RndStemUp:
{
builder.RoundStemUp = ReadBoolean(tokenizer);
ReadTillDef(tokenizer);
break;
}
case Type1Symbols.Subroutines:
{
builder.Subroutines = ReadSubroutines(tokenizer, lenIv, isLenientParsing);
break;
}
case Type1Symbols.OtherSubroutines:
{
ReadOtherSubroutines(tokenizer, isLenientParsing);
ReadTillDef(tokenizer);
break;
}
case Type1Symbols.ExpansionFactor:
{
builder.ExpansionFactor = ReadNumeric(tokenizer);
ReadTillDef(tokenizer);
break;
}
case Type1Symbols.Erode:
{
ReadTillDef(tokenizer, true);
break;
}
default:
{
ReadTillDef(tokenizer, true);
break;
}
}
}
var currentToken = tokenizer.CurrentToken;
IReadOnlyList <Type1CharstringDecryptedBytes> charStrings;
if (currentToken != null)
{
while (currentToken != null && currentToken.Type != Type1Token.TokenType.Literal &&
!string.Equals(currentToken.Text, "CharStrings", StringComparison.OrdinalIgnoreCase))
{
currentToken = tokenizer.GetNext();
}
if (currentToken != null)
{
charStrings = ReadCharStrings(tokenizer, lenIv, isLenientParsing);
}
else
{
charStrings = new Type1CharstringDecryptedBytes[0];
}
}
else
{
charStrings = new Type1CharstringDecryptedBytes[0];
}
var privateDictionary = builder.Build();
var instructions = Type1CharStringParser.Parse(charStrings, builder.Subroutines ?? new Type1CharstringDecryptedBytes[0]);
return(privateDictionary, instructions);
}
