var Type1Parser = function(aAsciiStream, aBinaryStream) { var lexer = new Lexer(aAsciiStream); // Turn on this flag for additional debugging logs var debug = false; var dump = function(aData) { if (debug) log(aData); }; /* * Decrypt a Sequence of Ciphertext Bytes to Produce the Original Sequence * of Plaintext Bytes. The function took a key as a parameter which can be * for decrypting the eexec block of for decoding charStrings. */ var kEexecEncryptionKey = 55665; var kCharStringsEncryptionKey = 4330; function decrypt(aStream, aKey, aDiscardNumber) { var r = aKey, c1 = 52845, c2 = 22719; var decryptedString = []; var value = null; var count = aStream.length; for (var i = 0; i < count; i++) { value = aStream.getByte(); decryptedString[i] = String.fromCharCode(value ^ (r >> 8)); r = ((value + r) * c1 + c2) & ((1 << 16) - 1); } return decryptedString.slice(aDiscardNumber); } /* * The operand stack holds arbitrary PostScript objects that are the operands * and results of PostScript operators being executed. The interpreter pushes * objects on the operand stack when it encounters them as literal data in a * program being executed. When an operator requires one or more operands, it * obtains them by popping them off the top of the operand stack. When an * operator returns one or more results, it does so by pushing them on the * operand stack. */ var operandStack = { __innerStack__: [], push: function(aOperand) { this.__innerStack__.push(aOperand); }, pop: function() { return this.__innerStack__.pop(); }, peek: function() { return this.__innerStack__[this.__innerStack__.length - 1]; }, get length() { return this.__innerStack__.length; } }; // Flag indicating if the topmost operand of the operandStack is an array var operandIsArray = false; /* * The dictionary stack holds only dictionary objects. The current set of * dictionaries on the dictionary stack defines the environment for all * implicit name searches, such as those that occur when the interpreter * encounters an executable name. The role of the dictionary stack is * introduced in Section 3.3, “Data Types and Objects,” and is further * explained in Section 3.5, “Execution.” of the PostScript Language * Reference. */ var systemDict = new Dict(), globalDict = new Dict(), userDict = new Dict(); var dictionaryStack = { __innerStack__: [systemDict, globalDict], push: function(aDictionary) { this.__innerStack__.push(aDictionary); }, pop: function() { if (this.__innerStack__.length == 2) return null; return this.__innerStack__.pop(); }, peek: function() { return this.__innerStack__[this.__innerStack__.length - 1]; }, get length() { return this.__innerStack__.length; } } /* * The execution stack holds executable objects (mainly procedures and files) * that are in intermediate stages of execution. At any point in the * execution of a PostScript program, this stack represents the program’s * call stack. Whenever the interpreter suspends execution of an object to * execute some other object, it pushes the new object on the execution * stack. When the interpreter finishes executing an object, it pops that * object off the execution stack and resumes executing the suspended object * beneath it. */ var executionStack = []; this.getObj = function() { var obj = lexer.getObj(); if (operandIsArray && !IsCmd(obj, "}") && !IsCmd(obj, "]")) { operandStack.peek().push(obj); this.getObj(); } else if (IsCmd(obj, "{") || IsCmd(obj, "[")) { dump("Start Array: " + obj); operandStack.push([]); operandIsArray = true; this.getObj(); } else if (IsCmd(obj, "}") || IsCmd(obj, "]")) { dump("End Array: " + obj); operandIsArray = false; this.getObj(); } else if (IsBool(obj) || IsInt(obj) || IsNum(obj) || IsString(obj)) { dump("Value: " + obj); operandStack.push(obj); this.getObj(); } else if (IsCmd(obj, "dup")) { dump("Duplicate"); operandStack.push(operandStack.peek()); this.getObj(); } else if (IsCmd(obj, "currentdict")) { dump("currentdict"); operandStack.push(dictionaryStack.peek()); this.getObj(); } else if (IsCmd(obj, "systemdict")) { dump("systemdict"); operandStack.push(systemDict); this.getObj(); } else if (IsCmd(obj, "readonly") || IsCmd(obj, "executeonly") || IsCmd(obj, "currentfile")) { // Do nothing for the moment this.getObj(); } else if (IsName(obj)) { dump("Name: " + obj.name); operandStack.push(obj.name); this.getObj(); } else if (IsCmd(obj, "dict")) { dump("Dict: " + obj); var size = operandStack.pop(); var dict = new Dict(size); operandStack.push(dict); this.getObj(); } else if (IsCmd(obj, "begin")) { dump("begin a dictionary"); dictionaryStack.push(operandStack.pop()); this.getObj(); } else if (IsCmd(obj, "end")) { dump("Ending a dictionary"); dictionaryStack.pop(); this.getObj(); } else if (IsCmd(obj, "def")) { var value = operandStack.pop(); var key = operandStack.pop(); dump("def: " + key + " = " + value); dictionaryStack.peek().set(key, value); this.getObj(); } else if (IsCmd(obj, "eexec")) { // All the first segment data has been read, decrypt the second segment // and start interpreting it in order to decode it var eexecString = decrypt(aBinaryStream, kEexecEncryptionKey, 4).join(""); lexer = new Lexer(new StringStream(eexecString)); this.getObj(); } else if (IsCmd(obj, "known")) { dump("known"); var name = operandStack.pop(); var dict = operandStack.pop(); // returns dict.hasKey(name); this.getObj(); } else if (IsCmd(obj, "RD")) { dump("RD"); var size = operandStack.pop(); var key = operandStack.pop(); var stream = lexer.stream.makeSubStream(lexer.stream.pos, size); var charString = decrypt(stream, kCharStringsEncryptionKey, 4).join(""); // XXX do we want to store that on the top dictionary or somewhere else dictionaryStack.peek().set(key, new StringStream(charString)); log (new StringStream(charString)); this.getObj(); } else if (IsCmd(obj, "LenIV")) { error("LenIV: argh! we need to modify the length of discard characters for charStrings"); } else { dump("Getting an unknow token, adding it to the stack just in case"); dump(obj); operandStack.push(obj); this.getObj(); } return operandStack.peek(); } }; var hack = false; var Type1Font = function(aFontName, aFontFile) { // All Type1 font program should begin with the comment %! var validHeader = aFontFile.getByte() == 0x25 && aFontFile.getByte() == 0x21; if (!validHeader) error("Invalid file header"); var programType = "PS-AdobeFont"; for (var i = 0; i < programType.length; i++) aFontFile.getChar(); // Ignore the '-' separator aFontFile.getChar(); var version = parseFloat(aFontFile.getChar() + aFontFile.getChar() + aFontFile.getChar()); if (!hack) { log(aFontName); log("Version is: " + version); var ASCIIStream = aFontFile.makeSubStream(0, aFontFile.dict.get("Length1"), aFontFile.dict); var binaryStream = aFontFile.makeSubStream(aFontFile.dict.get("Length1"), aFontFile.dict.get("Length2"), aFontFile.dict); this.parser = new Type1Parser(ASCIIStream, binaryStream); var fontDictionary = this.parser.getObj(); log(fontDictionary + "\t" + "fontInfo: " + fontDictionary.get("FontInfo")); hack = true; } this.info = {}; this.name = aFontName; this.encoding = []; this.paintType = 0; this.fontType = 0; this.fontMatrix = []; this.fontBBox = []; this.uniqueID = 0; this.metrics = {}; this.strokeWidth = 0.0; this.private = {}; this.charStrings = {} this.FID = 0; };