Add a the beggining of a Type1 font reader
This commit is contained in:
Vivien Nicolas
parent
c76e2c5114
commit
fe11af4b57
226
PDFFont.js
Normal file
226
PDFFont.js
Normal file
@ -0,0 +1,226 @@
|
||||
|
||||
|
||||
var Type1Parser = function(aLexer) {
|
||||
var lexer = aLexer;
|
||||
|
||||
|
||||
/*
|
||||
* 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 = [];
|
||||
|
||||
|
||||
/*
|
||||
* 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];
|
||||
}
|
||||
}
|
||||
var currentDict = dictionaryStack.peek();
|
||||
|
||||
|
||||
/*
|
||||
* 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 isExecutionStack = false;
|
||||
var executionStack = [];
|
||||
|
||||
/* Stub to inhibit the logs */
|
||||
|
||||
this.getObj = function() {
|
||||
var obj = lexer.getObj();
|
||||
if (isExecutionStack && !IsCmd(obj, "}") && !IsCmd(obj, "]")) {
|
||||
executionStack.push(obj);
|
||||
this.getObj();
|
||||
} else if (IsBool(obj) || IsInt(obj) || IsNum(obj) || IsString(obj)) {
|
||||
log("Value: " + obj);
|
||||
operandStack.push(obj);
|
||||
this.getObj();
|
||||
} else if (IsCmd(obj, "dup") || IsCmd(obj, "readonly") ||
|
||||
IsCmd(obj, "currentdict") || IsCmd(obj, "currentfile")) {
|
||||
// Do nothing for the moment
|
||||
this.getObj();
|
||||
} else if (IsName(obj)) {
|
||||
log("Name: " + obj.name);
|
||||
operandStack.push(obj.name);
|
||||
this.getObj();
|
||||
} else if (IsCmd(obj, "dict")) {
|
||||
log("Dict: " + obj);
|
||||
|
||||
// XXX handling of dictionary is wrong here
|
||||
var size = operandStack.pop();
|
||||
var name = operandStack.pop();
|
||||
if (!name) {
|
||||
log ("Creating the global dict");
|
||||
currentDict = dictionaryStack.peek();
|
||||
} else {
|
||||
var dict = new Dict();
|
||||
log("Assign name: " + name + " for the dictionary");
|
||||
currentDict.set(name, dict);
|
||||
dictionaryStack.push(dict);
|
||||
}
|
||||
|
||||
this.getObj();
|
||||
} else if (IsCmd(obj, "begin")) {
|
||||
log("begin a dictionary");
|
||||
currentDict = dictionaryStack.peek();
|
||||
this.getObj();
|
||||
} else if (IsCmd(obj, "end")) {
|
||||
log("Ending a dictionary");
|
||||
dictionaryStack.pop();
|
||||
currentDict = dictionaryStack.peek();
|
||||
this.getObj();
|
||||
} else if (IsCmd(obj, "def")) {
|
||||
if (executionStack.length) {
|
||||
var value = [];
|
||||
while (executionStack.length)
|
||||
value.push(executionStack.shift());
|
||||
} else {
|
||||
var value = operandStack.pop();
|
||||
}
|
||||
|
||||
var key = operandStack.pop();
|
||||
// XXX this happen because of a bad way to handle dictionary
|
||||
if (key) {
|
||||
log("def: " + key + " = " + value);
|
||||
currentDict.set(key, value);
|
||||
}
|
||||
this.getObj();
|
||||
} else if (IsCmd(obj, "{")) {
|
||||
log("Start Proc: " + obj);
|
||||
executionStack = [];
|
||||
isExecutionStack = true;
|
||||
this.getObj();
|
||||
} else if (IsCmd(obj, "}")) {
|
||||
log("End Proc: " + obj);
|
||||
isExecutionStack = false;
|
||||
this.getObj();
|
||||
} else if (IsCmd(obj, "[")) {
|
||||
isExecutionStack = true;
|
||||
executionStack = [];
|
||||
this.getObj();
|
||||
log("Start array: " + obj);
|
||||
} else if (IsCmd(obj, "]")) {
|
||||
log("End array: " + obj);
|
||||
isExecutionStack = false;
|
||||
this.getObj();
|
||||
} else if (IsCmd(obj, "eexec")) {
|
||||
return; // end of the ASCII header
|
||||
} else {
|
||||
log("Getting an unknow token, adding it to the stack just in case");
|
||||
log(obj);
|
||||
operandStack.push(obj);
|
||||
this.getObj();
|
||||
}
|
||||
return currentDict;
|
||||
}
|
||||
};
|
||||
|
||||
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);
|
||||
this.parser = new Type1Parser(new Lexer(ASCIIStream));
|
||||
|
||||
var fontDictionary = this.parser.getObj();
|
||||
log(fontDictionary + "\t" +
|
||||
"fontInfo: " + fontDictionary.get("FontInfo") + "\t" +
|
||||
"charStrings: " + fontDictionary.get("charStrings"));
|
||||
|
||||
var binaryStream = aFontFile.makeSubStream(aFontFile.dict.get("Length1"), aFontFile.dict.get("Length2"), aFontFile.dict);
|
||||
function decrypt(aBinaryStream, aKey) {
|
||||
var c1 = 52845, c2 = 22719;
|
||||
var R = aKey;
|
||||
|
||||
var streamSize = aBinaryStream.length;
|
||||
var decryptedString = [];
|
||||
|
||||
var value = null;
|
||||
for (var i = 0; i < streamSize; i++) {
|
||||
value = aBinaryStream.getByte();
|
||||
decryptedString[i] = String.fromCharCode(value ^ (R >> 8));
|
||||
R = ((value + R) * c1 + c2) & ((1 << 16) - 1);
|
||||
}
|
||||
return decryptedString.slice(4);
|
||||
}
|
||||
|
||||
var eexecString = decrypt(binaryStream, 55665).join("");
|
||||
log(eexecString);
|
||||
|
||||
TODO("decrypt charStrings data with the key 4330");
|
||||
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;
|
||||
};
|
||||
|
||||
36
pdf.js
36
pdf.js
@ -1032,6 +1032,12 @@ var Dict = (function() {
|
||||
},
|
||||
set: function(key, value) {
|
||||
this.map[key] = value;
|
||||
},
|
||||
toString: function() {
|
||||
var keys = [];
|
||||
for (var key in this.map)
|
||||
keys.push(key);
|
||||
return "Dict with " + keys.length + " keys: " + keys;
|
||||
}
|
||||
};
|
||||
|
||||
@ -1360,10 +1366,11 @@ var Lexer = (function() {
|
||||
stream.skip();
|
||||
return new Cmd(">>");
|
||||
}
|
||||
case "{":
|
||||
case "}":
|
||||
return new Cmd(ch);
|
||||
// fall through
|
||||
case ')':
|
||||
case '{':
|
||||
case '}':
|
||||
error("Illegal character");
|
||||
return Error;
|
||||
}
|
||||
@ -2258,11 +2265,34 @@ var CanvasGraphics = (function() {
|
||||
},
|
||||
setFont: function(fontRef, size) {
|
||||
var font = this.res.get("Font").get(fontRef.name);
|
||||
font = this.xref.fetchIfRef(font);
|
||||
if (!font)
|
||||
return;
|
||||
|
||||
var fontName = "Nimbus Roman No9 L";
|
||||
var subtype = font.get("Subtype").name;
|
||||
switch (subtype) {
|
||||
case "Type1":
|
||||
var fontDescriptor = font.get("FontDescriptor");
|
||||
if (fontDescriptor.num) {
|
||||
var fontDescriptor = this.xref.fetchIfRef(fontDescriptor);
|
||||
var fontFile = this.xref.fetchIfRef(fontDescriptor.get("FontFile"));
|
||||
font = new Type1Font(fontDescriptor.get("FontName").name, fontFile);
|
||||
}
|
||||
break;
|
||||
|
||||
case "Type3":
|
||||
TODO("support Type3 font");
|
||||
break;
|
||||
|
||||
default:
|
||||
error("Unsupported font type: " + subtype);
|
||||
break;
|
||||
}
|
||||
|
||||
this.current.fontSize = size;
|
||||
TODO("using hard-coded font for testing");
|
||||
this.ctx.font = this.current.fontSize +'px "Nimbus Roman No9 L"';
|
||||
this.ctx.font = this.current.fontSize +'px "' + fontName + '"';
|
||||
},
|
||||
moveText: function (x, y) {
|
||||
this.current.x = this.current.lineX += x;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user