/**
* This dictionary holds decoded fonts data.
*/
var Fonts = new Dict();
/**
* This simple object keep a trace of the fonts that have already been decoded
* by storing a map between the name given by the PDF and the name gather from
* the font (aka the PostScript code of the font itself for Type1 font).
*/
var _Fonts = {};
var Base64Encoder = {
encode: function(aData) {
var str = [];
var count = aData.length;
for (var i = 0; i < count; i++)
str.push(aData.getChar());
return window.btoa(str.join(""));
}
};
var TrueTypeFont = function(aFontName, aFontFile) {
if (_Fonts[aFontName])
return;
_Fonts[aFontName] = true;
//log("Loading a TrueType font: " + aFontName);
var fontData = Base64Encoder.encode(aFontFile);
Fonts.set(aFontName, fontData);
// Add the css rule
var url = "url(data:font/ttf;base64," + fontData + ");";
document.styleSheets[0].insertRule("@font-face { font-family: '" + aFontName + "'; src: " + url + " }", 0);
};
var Type1Parser = function(aAsciiStream, aBinaryStream) {
if (IsStream(aAsciiStream)) {
var lexer = new Lexer(aAsciiStream);
} else {
var lexer = {
__data__: aAsciiStream.slice(),
getObj: function() {
return this.__data__.shift();
}
}
}
// Turn on this flag for additional debugging logs
var debug = false;
var dump = function(aData) {
if (debug)
log(aData);
};
// Hold the fontName as declared inside the /FontName postscript directive
// XXX This is a hack but at the moment I need it to map the name declared
// in the PDF and the name in the PS code.
var fontName = "";
/*
* Parse a whole Type1 font stream (from the first segment to the last)
* assuming the 'eexec' block is binary data and fill up the 'Fonts'
* dictionary with the font informations.
*/
var self = this;
this.parse = function() {
if (!debug) {
while (!processNextToken()) {};
return fontName;
} else {
// debug mode is used to debug postcript processing
setTimeout(function() {
if (!processNextToken())
self.parse();
}, 0);
}
};
/*
* 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 start = Date.now();
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);
}
var end = Date.now();
dump("Time to decrypt string of length " + count + " is " + (end - start));
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.
*/
var charStringDictionary = {
"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"
};
function decodeCharString(aStream) {
var start = Date.now();
var charString = [];
var value = "";
var count = aStream.length;
for (var i = 0; i < count; i++) {
value = aStream.getByte();
if (value < 32) {
if (value == 12) {
value = charStringDictionary["12"][aStream.getByte()];
i++;
} else {
value = charStringDictionary[value];
}
} else if (value <= 246) {
value = parseInt(value) - 139;
} else if (value <= 250) {
value = ((value - 247) * 256) + parseInt(aStream.getByte()) + 108;
i++;
} else if (value <= 254) {
value = -((value - 251) * 256) - parseInt(aStream.getByte()) - 108;
i++;
} else {
var byte = aStream.getByte();
var high = (byte >> 1);
value = (byte - high) << 24 | aStream.getByte() << 16 |
aStream.getByte() << 8 | aStream.getByte();
i += 4;
}
charString.push(value);
}
var end = Date.now();
dump("Time to decode charString of length " + count + " is " + (end - start));
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() {
if (!this.length)
throw new Error("stackunderflow");
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];
},
dump: function() {
log("=== Start Dumping operandStack ===");
var str = [];
for (var i = 0; i < this.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, userDict],
push: function(aDictionary) {
this.__innerStack__.push(aDictionary);
},
pop: function() {
if (this.__innerStack__.length == 3)
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;
},
dump: function() {
log("=== Start Dumping dictionaryStack ===");
var str = [];
for (var i = 0; i < this.length; i++)
log(this.__innerStack__[i]);
log("=== End Dumping dictionaryStack ===");
},
};
/*
* 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;
}
};
/*
* Return the next token in the execution stack
*/
function nextInStack() {
var currentProcedure = executionStack.peek();
if (currentProcedure) {
var command = currentProcedure.shift();
if (!currentProcedure.length)
executionStack.pop();
return command;
}
return lexer.getObj();
};
/*
* Get the next token from the executionStack and process it.
* Actually the function does not process the third segment of a Type1 font
* and end on 'closefile'.
*
* The method thrown an error if it encounters an unknown token.
*/
function processNextToken() {
var obj = nextInStack();
if (operandIsArray && !IsCmd(obj, "{") && !IsCmd(obj, "[") &&
!IsCmd(obj, "]") && !IsCmd(obj, "}")) {
dump("Adding an object: " + obj +" to array " + operandIsArray);
var currentArray = operandStack.peek();
for (var i = 1; i < operandIsArray; i++)
currentArray = currentArray[currentArray.length - 1];
currentArray.push(obj);
} else if (IsBool(obj) || IsInt(obj) || IsNum(obj) || IsString(obj)) {
dump("Value: " + obj);
operandStack.push(obj);
} else if (IsName(obj)) {
dump("Name: " + obj.name);
operandStack.push(obj.name);
} else if (IsCmd(obj)) {
var command = obj.cmd;
dump(command);
switch (command) {
case "[":
case "{":
dump("Start" + (command == "{" ? " Executable " : " ") + "Array");
operandIsArray++;
var currentArray = operandStack;
for (var i = 1; i < operandIsArray; i++)
if (currentArray.peek)
currentArray = currentArray.peek();
else
currentArray = currentArray[currentArray.length - 1];
currentArray.push([]);
break;
case "]":
case "}":
var currentArray = operandStack.peek();
for (var i = 1; i < operandIsArray; i++)
currentArray = currentArray[currentArray.length - 1];
dump("End" + (command == "}" ? " Executable " : " ") + "Array: " + currentArray.join(" "));
operandIsArray--;
break;
case "if":
var procedure = operandStack.pop();
var bool = operandStack.pop();
if (!IsBool(bool)) {
dump("if: " + bool);
// we need to execute things, let be dirty
executionStack.push(bool);
} else {
dump("if ( " + bool + " ) { " + procedure + " }");
if (bool)
executionStack.push(procedure);
}
break;
case "ifelse":
var procedure1 = operandStack.pop();
var procedure2 = operandStack.pop();
var bool = !!operandStack.pop();
dump("if ( " + bool + " ) { " + procedure2 + " } else { " + procedure1 + " }");
executionStack.push(bool ? procedure2 : procedure1);
break;
case "for":
var procedure = operandStack.pop();
var limit = operandStack.pop();
var increment = operandStack.pop();
var initial = operandStack.pop();
for (var i = 0; i < limit; i += increment) {
operandStack.push(i);
executionStack.push(procedure.slice());
}
break;
case "dup":
dump("duplicate: " + operandStack.peek());
operandStack.push(operandStack.peek());
break;
case "mark":
operandStack.push("mark");
break;
case "cleartomark":
var command = "";
do {
command = operandStack.pop();
} while (command != "mark");
break;
case "put":
var data = operandStack.pop();
var indexOrKey = operandStack.pop();
var object = operandStack.pop();
dump("put " + data + " in " + object + "[" + indexOrKey + "]");
object.set ? object.set(indexOrKey, data)
: object[indexOrKey] = data;
break;
case "pop":
operandStack.pop();
break;
case "exch":
var operand1 = operandStack.pop();
var operand2 = operandStack.pop();
operandStack.push(operand1);
operandStack.push(operand2);
break;
case "get":
var indexOrKey = operandStack.pop();
var object = operandStack.pop();
var data = object.get ? object.get(indexOrKey) : object[indexOrKey];
dump("get " + object + "[" + indexOrKey + "]: " + data);
operandStack.push(data);
break;
case "currentdict":
var dict = dictionaryStack.peek();
operandStack.push(dict);
break;
case "systemdict":
operandStack.push(systemDict);
break;
case "readonly":
case "executeonly":
case "noaccess":
// Do nothing for the moment
break;
case "currentfile":
operandStack.push("currentfile");
break;
case "array":
var size = operandStack.pop();
var array = new Array(size);
operandStack.push(array);
break;
case "dict":
var size = operandStack.pop();
var dict = new Dict(size);
operandStack.push(dict);
break;
case "begin":
dictionaryStack.push(operandStack.pop());
break;
case "end":
dictionaryStack.pop();
break;
case "def":
var value = operandStack.pop();
var key = operandStack.pop();
// XXX we don't want to do that here but for some reasons the names
// are different between what is declared and the FontName directive
if (key == "FontName" && Fonts.get(value)) {
// The font has already be decoded, stop!
return true;
}
dump("def: " + key + " = " + value);
dictionaryStack.peek().set(key, value);
break;
case "definefont":
var font = operandStack.pop();
var key = operandStack.pop();
dump("definefont " + font + " with key: " + key);
// The key will be the identifier to recognize this font
fontName = key;
Fonts.set(key, font);
operandStack.push(font);
break;
case "known":
var name = operandStack.pop();
var dict = operandStack.pop();
var data = !!dict.get(name);
dump("known: " + data + " :: " + name + " in dict: " + dict);
operandStack.push(data);
break;
case "exec":
executionStack.push(operandStack.pop());
break;
case "eexec":
// All the first segment data has been read, decrypt the second segment
// and start interpreting it in order to decode it
var file = operandStack.pop();
var eexecString = decrypt(aBinaryStream, kEexecEncryptionKey, 4).join("");
dump(eexecString);
lexer = new Lexer(new StringStream(eexecString));
break;
case "LenIV":
error("LenIV: argh! we need to modify the length of discard characters for charStrings");
break;
case "closefile":
var file = operandStack.pop();
return true;
break;
case "index":
var operands = [];
var size = operandStack.pop();
for (var i = 0; i < size; i++)
operands.push(operandStack.pop());
var newOperand = operandStack.peek();
while (operands.length)
operandStack.push(operands.pop());
operandStack.push(newOperand);
break;
case "string":
var size = operandStack.pop();
var str = (new Array(size + 1)).join(" ");
operandStack.push(str);
break;
case "readstring":
var str = operandStack.pop();
var size = str.length;
var file = 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);
var decodedCharString = decodeCharString(charStream);
dump("decodedCharString: " + decodedCharString);
operandStack.push(decodedCharString);
// boolean indicating if the operation is a success or not
operandStack.push(true);
break;
case "StandardEncoding":
// For some reason the value is considered as a command, maybe it is
// because of the uppercase 'S'
operandStack.push(obj.cmd);
break;
default:
var command = null;
if (IsCmd(obj)) {
for (var i = 0; i < dictionaryStack.length; i++) {
if (command = dictionaryStack.get(i).get(obj.cmd)) {
dump("found in dictionnary for " + obj.cmd + " command: " + command);
executionStack.push(command.slice());
break;
}
}
}
if (!command) {
log("operandStack: " + operandStack);
log("dictionaryStack: " + dictionaryStack);
log(obj);
error("Unknow command while parsing font");
}
break;
}
} else if (obj) {
dump("unknow: " + obj);
operandStack.push(obj);
} else { // The End!
operandStack.dump();
return true;
}
return false;
}
function aggregateCommand(aCommand) {
var command = aCommand;
switch (command) {
case "hstem":
case "vstem":
break;
case "rrcurveto":
var stack = [operandStack.pop(), operandStack.pop(),
operandStack.pop(), operandStack.pop(),
operandStack.pop(), operandStack.pop()];
var next = true;
while (next) {
var op = operandStack.peek();
if (op == "rrcurveto") {
operandStack.pop();
stack.push(operandStack.pop());
stack.push(operandStack.pop());
stack.push(operandStack.pop());
stack.push(operandStack.pop());
stack.push(operandStack.pop());
stack.push(operandStack.pop());
} else {
next = false;
}
}
break;
case "hlineto":
case "vlineto":
var last = command;
var stack = [operandStack.pop()];
var next = true;
while (next) {
var op = operandStack.peek();
if (op == "vlineto" && last == "hlineto") {
operandStack.pop();
stack.push(operandStack.pop());
} else if (op == "hlineto" && last == "vlineto") {
operandStack.pop();
stack.push(operandStack.pop());
} else if (op == "rlineto" && command == "hlineto") {
operandStack.pop();
var x = stack.pop();
operandStack.push(0);
operandStack.push(x);
command = "rlineto";
} else if (op == "rlineto" && command == "vlineto") {
operandStack.pop();
operandStack.push(0);
command = "rlineto";
} else {
next = false;
}
last = op;
}
break;
case "rlineto":
var stack = [operandStack.pop(), operandStack.pop()];
var next = true;
while (next) {
var op = operandStack.peek();
if (op == "rlineto") {
operandStack.pop();
stack.push(operandStack.pop());
stack.push(operandStack.pop());
} else if (op == "hlineto") {
operandStack.pop();
stack.push(0);
stack.push(operandStack.pop());
} else if (op == "vlineto") {
operandStack.pop();
stack.push(operandStack.pop());
stack.push(0);
} else {
next= false;
}
}
break;
}
while (stack.length)
operandStack.push(stack.pop());
operandStack.push(command);
};
/*
* Flatten the commands by interpreting the postscript code and replacing
* every 'callsubr', 'callothersubr' by the real commands.
* At the moment OtherSubrs are not fully supported and only otherSubrs 0-4
* as descrived in 'Using Subroutines' of 'Adobe Type 1 Font Format',
* chapter 8.
*/
this.flattenCharstring = function(aCharString, aDefaultWidth, aNominalWidth, aSubrs) {
var leftSidebearing = 0;
var lastPoint = 0;
while (true) {
var obj = nextInStack();
if (IsBool(obj) || IsInt(obj) || IsNum(obj)) {
dump("Value: " + obj);
operandStack.push(obj);
} else if (IsString(obj)) {
dump("String: " + obj);
switch (obj) {
case "hsbw":
var charWidthVector = operandStack.pop();
leftSidebearing = operandStack.pop();
if (charWidthVector != aDefaultWidth)
operandStack.push(charWidthVector - aNominalWidth);
break;
case "setcurrentpoint":
case "dotsection":
case "seac":
case "sbw":
error(obj + " parsing is not implemented (yet)");
break;
case "vstem3":
operandStack.push("vstem");
break;
case "vstem":
log(obj + " is not converted (yet?)");
operandStack.push("vstem");
break;
case "closepath":
case "return":
break;
case "hlineto":
case "vlineto":
case "rlineto":
case "rrcurveto":
aggregateCommand(obj);
break;
case "rmoveto":
var dy = operandStack.pop();
var dx = operandStack.pop();
if (leftSidebearing) {
dx += leftSidebearing;
leftSidebearing = 0;
}
operandStack.push(dx);
operandStack.push(dy);
operandStack.push("rmoveto");
break;
case "hstem":
case "hstem3":
var dy = operandStack.pop();
var y = operandStack.pop();
if (operandStack.peek() == "hstem" ||
operandStack.peek() == "hstem3")
operandStack.pop();
operandStack.push(y - lastPoint);
lastPoint = y + dy;
operandStack.push(dy);
operandStack.push("hstem");
break;
case "callsubr":
var index = operandStack.pop();
executionStack.push(aSubrs[index].slice());
break;
case "callothersubr":
log("callothersubr");
// XXX need to be improved
var index = operandStack.pop();
var count = operandStack.pop();
var data = operandStack.pop();
operandStack.push(3);
operandStack.push("callothersubr");
break;
case "endchar":
operandStack.push("endchar");
return operandStack.__innerStack__.slice();
case "pop":
operandStack.pop();
break;
default:
operandStack.push(obj);
break;
}
}
}
}
};
var type1hack = false;
var Type1Font = function(aFontName, aFontFile) {
if (_Fonts[aFontName])
return;
_Fonts[aFontName] = true;
// All Type1 font program should begin with the comment %!
if (aFontFile.getByte() != 0x25 || aFontFile.getByte() != 0x21)
error("Invalid file header");
if (!type1hack) {
type1hack = true;
var start = Date.now();
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 fontName = this.parser.parse();
this.convertToOTF(fontName);
}
};
Type1Font.prototype = {
convertToOTF: function(aFontName) {
var font = Fonts.get(aFontName);
var private = font.get("Private");
var subrs = private.get("Subrs");
var otherSubrs = private.get("OtherSubrs");
var charstrings = font.get("CharStrings")
// Try to get the most used glyph width
var widths = {};
for (var glyph in charstrings.map) {
var glyphData = charstrings.get(glyph);
var glyphWidth = glyphData[1];
if (widths[glyphWidth])
widths[glyphWidth]++;
else
widths[glyphWidth] = 1;
}
var defaultWidth = 0;
var used = 0;
for (var width in widths) {
if (widths[width] > used) {
defaultWidth = width;
used = widths[width];
}
}
log("defaultWidth to used: " + defaultWidth);
var maxNegDistance = 0;
var maxPosDistance = 0;
for (var width in widths) {
var diff = width - defaultWidth;
if (diff < 0 && diff < maxNegDistance) {
maxNegDistance = diff;
} else if (diff > 0 && diff > maxPosDistance) {
maxPosDistance = diff;
}
}
var nominalWidth = parseInt(defaultWidth) + (parseInt(maxPosDistance) + parseInt(maxNegDistance)) / 2;
log("nominalWidth to used: " + nominalWidth);
log("Hack nonimal:" + (nominalWidth = 615));
for (var glyph in charstrings.map) {
if (glyph == ".notdef")
continue;
var glyphData = charstrings.get(glyph);
var parser = new Type1Parser(glyphData);
log("=================================== " + glyph + " ==============================");
log(charstrings.get(glyph));
log(parser.flattenCharstring("A", defaultWidth, nominalWidth, subrs));
log(validationData[glyph]);
}
/*
log(charStrings.get("A"));
log(newCharStrings.get("A"));
log(validationData["A"]);
*/
var end = Date.now();
//log("Time to parse font is:" + (end - start));
}
};
/**
* The Type2 reader code below is only used for debugging purpose since Type2
* is only a CharString format and is never used directly as a Font file.
*
* So the code here is useful for dumping the data content of a .cff file in
* order to investigate the similarity between a Type1 CharString and a Type2
* CharString.
*/
/**
* Build a charset by assigning the glyph name and the human readable form
* of the glyph data.
*/
function readCharset(aStream, aCharstrings) {
var charset = {};
var format = aStream.getByte();
if (format == 0) {
charset[".notdef"] = readCharstringEncoding(aCharstrings[0]);
var count = aCharstrings.length - 1;
for (var i = 1; i < count + 1; i++) {
var sid = aStream.getByte() << 8 | aStream.getByte();
charset[CFFStrings[sid]] = readCharstringEncoding(aCharstrings[i]);
log(CFFStrings[sid] + "::" + charset[CFFStrings[sid]]);
}
} else if (format == 1) {
error("Charset Range are not supported");
} else {
error("Invalid charset format");
}
return charset;
};
/**
* Take a Type2 binary charstring as input and transform it to a human
* readable representation as specified by the 'The Type 2 Charstring Format',
* chapter 3.1.
*/
function readCharstringEncoding(aString) {
var charstringTokens = [];
var count = aString.length;
for (var i = 0; i < count; ) {
var value = aString[i++];
var token = null;
if (value < 0) {
continue;
} else if (value <= 11) {
token = CFFEncodingMap[value];
} else if (value == 12) {
token = CFFEncodingMap[value][aString[i++]];
} else if (value <= 18) {
token = CFFEncodingMap[value];
} else if (value <= 20) {
var mask = aString[i++];
token = CFFEncodingMap[value];
} else if (value <= 27) {
token = CFFEncodingMap[value];
} else if (value == 28) {
token = aString[i++] << 8 | aString[i++];
} else if (value <= 31) {
token = CFFEncodingMap[value];
} else if (value < 247) {
token = parseInt(value) - 139;
} else if (value < 251) {
token = ((value - 247) * 256) + aString[i++] + 108;
} else if (value < 255) {
token = -((value - 251) * 256) - aString[i++] - 108;
} else {// value == 255
token = aString[i++] << 24 | aString[i++] << 16 |
aString[i++] << 8 | aString[i];
}
charstringTokens.push(token);
}
return charstringTokens;
};
/**
* Take a binary DICT Data as input and transform it into a human readable
* form as specified by 'The Compact Font Format Specification', chapter 5.
*/
function readFontDictData(aString, aMap) {
var fontDictDataTokens = [];
var count = aString.length;
for (var i = 0; i < count; i) {
var value = aString[i++];
var token = null;
if (value == 12) {
token = aMap[value][aString[i++]];
} else if (value == 28) {
token = aString[i++] << 8 | aString[i++];
} else if (value == 29) {
token = aString[i++] << 24 |
aString[i++] << 16 |
aString[i++] << 8 |
aString[i++];
} else if (value == 30) {
token = "";
var parsed = false;
while (!parsed) {
var byte = aString[i++];
var nibbles = [parseInt(byte / 16), parseInt(byte % 16)];
for (var j = 0; j < nibbles.length; j++) {
var nibble = nibbles[j];
switch (nibble) {
case 0xA:
token += ".";
break;
case 0xB:
token += "E";
break;
case 0xC:
token += "E-";
break;
case 0xD:
break;
case 0xE:
token += "-";
break;
case 0xF:
parsed = true;
break;
default:
token += nibble;
break;
}
}
};
token = parseFloat(token);
} else if (value <= 31) {
token = aMap[value];
} else if (value <= 246) {
token = parseInt(value) - 139;
} else if (value <= 250) {
token = ((value - 247) * 256) + aString[i++] + 108;
} else if (value <= 254) {
token = -((value - 251) * 256) - aString[i++] - 108;
} else if (value == 255) {
error("255 is not a valid DICT command");
}
fontDictDataTokens.push(token);
}
return fontDictDataTokens;
};
/**
* Take a stream as input and return an array of objects.
* In CFF an INDEX is a structure with the following format:
* {
* count: 2 bytes (Number of objects stored in INDEX),
* offsize: 1 byte (Offset array element size),
* offset: [count + 1] bytes (Offsets array),
* data: - (Objects data)
* }
*
* More explanation are given in the 'CFF Font Format Specification',
* chapter 5.
*/
function readFontIndexData(aStream, aIsByte) {
var count = aStream.getByte() << 8 | aStream.getByte();
var offsize = aStream.getByte();
function getNextOffset() {
switch (offsize) {
case 0:
return 0;
case 1:
return aStream.getByte();
case 2:
return aStream.getByte() << 8 | aStream.getByte();
case 3:
return aStream.getByte() << 16 | aStream.getByte() << 8 |
aStream.getByte();
case 4:
return aStream.getByte() << 24 | aStream.getByte() << 16 |
aStream.getByte() << 8 | aStream.getByte();
}
};
var offsets = [];
for (var i = 0; i < count + 1; i++)
offsets.push(getNextOffset());
log("Found " + count + " objects at offsets :" + offsets + " (offsize: " + offsize + ")");
// Now extract the objects
var relativeOffset = aStream.pos;
var objects = [];
for (var i = 0; i < count; i++) {
var offset = offsets[i];
aStream.pos = relativeOffset + offset - 1;
var data = [];
var length = offsets[i + 1] - 1;
for (var j = offset - 1; j < length; j++)
data.push(aIsByte ? aStream.getByte() : aStream.getChar());
objects.push(data);
}
return objects;
};
var Type2Parser = function(aFilePath) {
var font = new Dict();
// Turn on this flag for additional debugging logs
var debug = true;
function dump(aStr) {
if (debug)
log(aStr);
};
function parseAsToken(aString, aMap) {
var decoded = readFontDictData(aString, aMap);
log(decoded);
var stack = [];
var count = decoded.length;
for (var i = 0; i < count; i++) {
var token = decoded[i];
if (IsNum(token)) {
stack.push(token);
} else {
switch (token.operand) {
case "SID":
font.set(token.name, CFFStrings[stack.pop()]);
break;
case "number number":
font.set(token.name, {
offset: stack.pop(),
size: stack.pop()
});
break;
case "boolean":
font.set(token.name, stack.pop());
break;
case "delta":
font.set(token.name, stack.pop());
break;
default:
if (token.operand && token.operand.length) {
var array = [];
for (var j = 0; j < token.operand.length; j++)
array.push(stack.pop());
font.set(token.name, array);
} else {
font.set(token.name, stack.pop());
}
break;
}
}
}
};
this.parse = function(aStream) {
font.set("major", aStream.getByte());
font.set("minor", aStream.getByte());
font.set("hdrSize", aStream.getByte());
font.set("offsize", aStream.getByte());
// Move the cursor after the header
aStream.skip(font.get("hdrSize") - aStream.pos);
// Read the NAME Index
dump("Reading Index: Names");
font.set("Names", readFontIndexData(aStream));
// Read the Top Dict Index
dump("Reading Index: TopDict");
var topDict = readFontIndexData(aStream, true);
// Read the String Index
dump("Reading Index: Strings");
var strings = readFontIndexData(aStream);
// Fill up the Strings dictionary with the new unique strings
for (var i = 0; i < strings.length; i++)
CFFStrings.push(strings[i].join(""));
// Parse the TopDict operator
var objects = [];
var count = topDict.length;
for (var i = 0; i < count; i++)
parseAsToken(topDict[i], CFFDictDataMap);
// Read the Global Subr Index that comes just after the Strings Index
// (cf. "The Compact Font Format Specification" Chapter 16)
dump("Reading Global Subr Index");
var subrs = readFontIndexData(aStream);
// Reading Private Dict
var private = font.get("Private");
log("Reading Private Dict (offset: " + private.offset + " size: " + private.size + ")");
aStream.pos = private.offset;
var privateDict = [];
for (var i = 0; i < private.size; i++)
privateDict.push(aStream.getByte());
parseAsToken(privateDict, CFFDictPrivateDataMap);
for (var p in font.map)
dump(p + "::" + font.get(p));
// Read CharStrings Index
var charStringsOffset = font.get("CharStrings");
dump("Read CharStrings Index (offset: " + charStringsOffset + ")");
aStream.pos = charStringsOffset;
var charStrings = readFontIndexData(aStream, true);
var charsetEntry = font.get("charset");
if (charsetEntry == 0) {
throw new Error("Need to support CFFISOAdobeCharset");
} else if (charsetEntry == 1) {
throw new Error("Need to support CFFExpert");
} else if (charsetEntry == 2) {
throw new Error("Need to support CFFExpertSubsetCharset");
} else {
aStream.pos = charsetEntry;
var charset = readCharset(aStream, charStrings);
}
}
};
// XXX
/*
var xhr = new XMLHttpRequest();
xhr.open("GET", "titi.cff", false);
xhr.mozResponseType = xhr.responseType = "arraybuffer";
xhr.expected = (document.URL.indexOf("file:") == 0) ? 0 : 200;
xhr.send(null);
var cffData = xhr.mozResponseArrayBuffer || xhr.mozResponse ||
xhr.responseArrayBuffer || xhr.response;
var cff = new Type2Parser("titi.cff");
cff.parse(new Stream(cffData));
*/