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 = ""; 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); } /* * CharStrings are encoded following the the CharString Encoding sequence * describe in Chapter 6 of the "Adobe Type1 Font Format" specification. * The value in a byte indicates a command, a number, or subsequent bytes * that are to be interpreted in a special way. * * CharString Number Encoding: * A CharString byte containing the values from 32 through 255 inclusive * indicate an integer. These values are decoded in four ranges. * * 1. A CharString byte containing a value, v, between 32 and 246 inclusive, * indicate the integer v - 139. Thus, the integer values from -107 through * 107 inclusive may be encoded in single byte. * * 2. A CharString byte containing a value, v, between 247 and 250 inclusive, * indicates an integer involving the next byte, w, according to the formula: * [(v - 247) x 256] + w + 108 * * 3. A CharString byte containing a value, v, between 251 and 254 inclusive, * indicates an integer involving the next byte, w, according to the formula: * -[(v - 251) * 256] - w - 108 * * 4. A CharString containing the value 255 indicates that the next 4 bytes * are a two complement signed integer. The first of these bytes contains the * highest order bits, the second byte contains the next higher order bits * and the fourth byte contain the lowest order bits. * * * CharString Command Encoding: * CharStrings commands are encoded in 1 or 2 bytes. * * Single byte commands are encoded in 1 byte that contains a value between * 0 and 31 inclusive. * If a command byte contains the value 12, then the value in the next byte * indicates a command. This "escape" mechanism allows many extra commands * to be encoded and this encoding technique helps to minimize the length of * the charStrings. */ function decodeCharString(aStream) { var charString = []; var cmd = { "1": "hstem", "3": "vstem", "4": "vmoveto", "5": "rlineto", "6": "hlineto", "7": "vlineto", "8": "rrcurveto", "9": "closepath", "10": "callsubr", "11": "return", "12": { "0": "dotsection", "1": "vstem3", "3": "hstem3", "6": "seac", "7": "sbw", "12": "div", "16": "callothersubr", "17": "pop", "33": "setcurrentpoint" }, "13": "hsbw", "14": "endchar", "21": "rmoveto", "22": "hmoveto", "30": "vhcurveto", "31": "hcurveto" } var value = ""; var count = aStream.length; for (var i = 0; i < count; i++) { value = aStream.getByte(); if (value < 0) { continue; } else if (value < 32) { if (value == 12) { value = cmd["12"][aStream.getByte()]; count++; } else { value = cmd[value]; } } else if (value <= 246) { value = parseInt(value) - 139; } else if (value <= 250) { value = ((value - 247) * 256) + parseInt(aStream.getByte()) + 108; count++; } else if (value <= 254) { value = -((value - 251) * 256) - parseInt(aStream.getByte()) - 108; count++; } else { error("Two complement signed integers are ignored for the moment"); } charString.push(value); } return charString; } /* * 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() { if (!this.length) return null; return this.__innerStack__[this.__innerStack__.length - 1]; }, toString: function() { log("=== Start Dumping operandStack ==="); var str = []; for (var i = 0; i < this.__innerStack__.length; i++) log(this.__innerStack__[i]); log("=== End Dumping operandStack ==="); }, get length() { return this.__innerStack__.length; } }; // Flag indicating if the topmost operand of the operandStack is an array var operandIsArray = 0; /* * 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() { if (!this.length) return null; return this.__innerStack__[this.__innerStack__.length - 1]; }, get: function(aIndex) { return this.__innerStack__[aIndex]; }, 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 = { __innerStack__: [], push: function(aProcedure) { this.__innerStack__.push(aProcedure); }, pop: function() { return this.__innerStack__.pop(); }, peek: function() { if (!this.length) return null; return this.__innerStack__[this.__innerStack__.length - 1]; }, get: function(aIndex) { return this.__innerStack__[aIndex]; }, get length() { return this.__innerStack__.length; } } function nextInStack() { var currentProcedure = executionStack.peek(); if (currentProcedure) { var command = currentProcedure.shift(); if (!currentProcedure.length) executionStack.pop(); } return lexer.getObj(); } /* * Parse a font file from the first segment to the last assuming the eexec * block is binary data. * * The method thrown an error if it encounters an unknown token. */ this.getObj = function() { var obj = nextInStack(); if (operandIsArray && !IsCmd(obj, "{") && !IsCmd(obj, "[") && !IsCmd(obj, "}") && !IsCmd(obj, "]")) { dump("Adding: " + obj); operandStack.peek().push(obj); this.getObj(); } else if (IsCmd(obj, "{") || IsCmd(obj, "[")) { dump("Start" + (obj.cmd == "{" ? " Executable " : " ") + "Array"); operandIsArray ? operandStack.peek().push([]) : operandStack.push([]); operandIsArray++; this.getObj(); } else if (IsCmd(obj, "}") || IsCmd(obj, "]")) { dump("End" + (obj.cmd == "}" ? " Executable " : " ") + "Array"); operandIsArray--; this.getObj(); } else if (IsCmd(obj, "if")) { log("if"); var procedure = operandStack.pop(); var bool = operandStack.pop(); if (!IsBool(bool)) { executionStack.push(bool); log("....."); this.getObj(); } log(bool); if (bool) executionStack.push(procedure); this.getObj(); } else if (IsCmd(obj, "ifelse")) { log("ifelse"); var procedure1 = operandStack.pop(); var procedure2 = operandStack.pop(); var bool = !!operandStack.pop(); operandStack.push(bool ? procedure1 : procedure2); 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, "put") || IsCmd(obj, "NP")) { operandStack.toString(); var data = operandStack.pop(); var indexOrKey = operandStack.pop(); var object = operandStack.pop(); log(object); log("put " + data + " in " + obj + "[" + indexOrKey + "]"); if (object.set) object.set(indexOrKey, data); else object[indexOrKey] = data; 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, "noaccess") || 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, "array")) { var size = operandStack.pop(); var array = new Array(size); operandStack.push(array); 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") || IsCmd(obj, "ND")) { var value = operandStack.pop(); var key = operandStack.pop(); log("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(); operandStack.push(!!dict.get(name)); this.getObj(); } else if (IsCmd(obj, "RD")) { dump("RD"); var size = operandStack.pop(); var key = operandStack.pop(); // Add '1' because of the space separator, this is dirty var stream = lexer.stream.makeSubStream(lexer.stream.pos + 1, size); lexer.stream.skip(size + 1); var charString = decrypt(stream, kCharStringsEncryptionKey, 4).join(""); var charStream = new StringStream(charString); // XXX do we want to store that on the top dictionary or somewhere else dictionaryStack.peek().set(key, charStream); var decodedCharString = decodeCharString(charStream); dump(decodedCharString); this.getObj(); } else if (IsCmd(obj, "LenIV")) { error("LenIV: argh! we need to modify the length of discard characters for charStrings"); } else if (IsCmd(obj, "closefile")) { // End of binary data; } else if (IsCmd(obj, "index")) { var operands = []; var size = operandStack.pop(); for (var i = 0; i < size; i++) operands.push(operandStack.pop()); var newOperand = operandStack.peek(); for (var i = 0; i < operands.length; i++) operandStack.push(operands.pop()); operandStack.push(newOperand); this.getObj(); } else if (IsCmd(obj, "StandardEncoding")) { // For some reason the value is considered as a command, maybe it is // because of the uppercae 'S' operandStack.push(obj.cmd); this.getObj(); } else { var command = null; if (IsCmd(obj)) { for (var i = 0; i < dictionaryStack.length; i++) { command = dictionaryStack.get(i).get(obj.cmd); if (command) break; } } if (command) { // XXX add the command to the execution stack this.getObj(); } else { log("operandStack: " + operandStack); log("dictionaryStack: " + dictionaryStack); dump(obj); error("Unknow token while parsing font"); } } return operandStack.peek(); } }; var hack = false; var Type1Font = function(aFontName, aFontFile) { // All Type1 font program should begin with the comment %! if (aFontFile.getByte() != 0x25 || aFontFile.getByte() != 0x21) error("Invalid file header"); if (!hack) { log(aFontName); 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; };