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Add the beginning of a Type1 to Type2 charstring converter

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This commit is contained in:
Vivien Nicolas 2011-06-10 01:20:00 +02:00
parent fcc4ce9bec
commit 74abf984d5
3 changed files with 328 additions and 33 deletions
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358
PDFFont.js
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@ -1,9 +1,15 @@
/*
* This dictionary hold the decoded fonts
/**
* 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) {
@ -16,12 +22,10 @@ var Base64Encoder = {
}
};
var TrueTypeFont = function(aFontName, aFontFile) {
if (Fonts.get(aFontName))
if (_Fonts[aFontName])
return;
_Fonts[aFontName] = true;
//log("Loading a TrueType font: " + aFontName);
var fontData = Base64Encoder.encode(aFontFile);
@ -36,7 +40,16 @@ var TrueTypeFont = function(aFontName, aFontFile) {
var Type1Parser = function(aAsciiStream, aBinaryStream) {
var lexer = new Lexer(aAsciiStream);
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;
@ -46,6 +59,11 @@ var Type1Parser = function(aAsciiStream, aBinaryStream) {
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'
@ -55,6 +73,7 @@ var Type1Parser = function(aAsciiStream, aBinaryStream) {
this.parse = function() {
if (!debug) {
while (!processNextToken()) {};
return fontName;
} else {
// debug mode is used to debug postcript processing
setTimeout(function() {
@ -62,7 +81,7 @@ var Type1Parser = function(aAsciiStream, aBinaryStream) {
self.parse();
}, 0);
}
}
};
/*
* Decrypt a Sequence of Ciphertext Bytes to Produce the Original Sequence
@ -87,7 +106,7 @@ var Type1Parser = function(aAsciiStream, aBinaryStream) {
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
@ -98,7 +117,7 @@ var Type1Parser = function(aAsciiStream, aBinaryStream) {
* 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.
@ -110,7 +129,7 @@ var Type1Parser = function(aAsciiStream, aBinaryStream) {
* 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
@ -157,7 +176,6 @@ var Type1Parser = function(aAsciiStream, aBinaryStream) {
"31": "hcurveto"
};
// XXX Is count++ the right thing to do? Is it not i++?
function decodeCharString(aStream) {
var start = Date.now();
var charString = [];
@ -167,12 +185,10 @@ var Type1Parser = function(aAsciiStream, aBinaryStream) {
for (var i = 0; i < count; i++) {
value = aStream.getByte();
if (value < 0) {
continue;
} else if (value < 32) {
if (value < 32) {
if (value == 12) {
value = charStringDictionary["12"][aStream.getByte()];
count++;
i++;
} else {
value = charStringDictionary[value];
}
@ -180,16 +196,16 @@ var Type1Parser = function(aAsciiStream, aBinaryStream) {
value = parseInt(value) - 139;
} else if (value <= 250) {
value = ((value - 247) * 256) + parseInt(aStream.getByte()) + 108;
count++;
i++;
} else if (value <= 254) {
value = -((value - 251) * 256) - parseInt(aStream.getByte()) - 108;
count++;
i++;
} else {
var byte = aStream.getByte();
var high = (byte >> 1);
value = (byte - high) << 24 | aStream.getByte() << 16 |
aStream.getByte() << 8 | aStream.getByte();
count += 4;
i += 4;
}
charString.push(value);
@ -228,6 +244,10 @@ var Type1Parser = function(aAsciiStream, aBinaryStream) {
return this.__innerStack__[this.__innerStack__.length - 1];
},
get: function(aIndex) {
return this.__innerStack__[aIndex];
},
dump: function() {
log("=== Start Dumping operandStack ===");
var str = [];
@ -345,7 +365,6 @@ var Type1Parser = function(aAsciiStream, aBinaryStream) {
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
@ -531,7 +550,11 @@ var Type1Parser = function(aAsciiStream, aBinaryStream) {
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;
@ -600,6 +623,7 @@ var Type1Parser = function(aAsciiStream, aBinaryStream) {
var decodedCharString = decodeCharString(charStream);
dump("decodedCharString: " + decodedCharString);
operandStack.push(decodedCharString);
// boolean indicating if the operation is a success or not
operandStack.push(true);
break;
@ -630,36 +654,305 @@ var Type1Parser = function(aAsciiStream, aBinaryStream) {
}
break;
}
} else if (obj){
} 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();
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);
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);
this.parser.parse();
this.parser = new Type1Parser(ASCIIStream, binaryStream);
var fontName = this.parser.parse();
this.convertToOTF(fontName);
}
};
var end = Date.now();
//log("Time to parse font is:" + (end - start));
Type1Font.prototype = {
convertToOTF: function(aFontName) {
var font = Fonts.get(aFontName);
this.convert();
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));
}
};
@ -1016,6 +1309,7 @@ var Type2Parser = function(aFilePath) {
// XXX
/*
var xhr = new XMLHttpRequest();
xhr.open("GET", "titi.cff", false);
xhr.mozResponseType = xhr.responseType = "arraybuffer";
@ -1025,4 +1319,4 @@ var cffData = xhr.mozResponseArrayBuffer || xhr.mozResponse ||
xhr.responseArrayBuffer || xhr.response;
var cff = new Type2Parser("titi.cff");
cff.parse(new Stream(cffData));
*/

2
pdf.js
View File

@ -2280,9 +2280,9 @@ var CanvasGraphics = (function() {
var subtype = font.get("Subtype").name;
switch (subtype) {
case "Type1":
break;
var fontDescriptor = font.get("FontDescriptor");
if (fontDescriptor.num) {
// XXX fetchIfRef looks expensive
var fontDescriptor = this.xref.fetchIfRef(fontDescriptor);
var fontFile = this.xref.fetchIfRef(fontDescriptor.get("FontFile"));
font = new Type1Font(fontDescriptor.get("FontName").name, fontFile);

1
test.html
View File

@ -6,6 +6,7 @@
<script type="text/javascript" src="pdf.js"></script>
<script type="text/javascript" src="test.js"></script>
<script type="text/javascript" src="cffStandardStrings.js"></script>
<script type="text/javascript" src="t2data.js"></script>
<script type="text/javascript" src="PDFFont.js"></script>
</head>