* to fonts in particular and needs to be share between them.
*/
var FontsUtils = {
+ _bytesArray: new Uint8Array(4),
integerToBytes: function fu_integerToBytes(aValue, aBytesCount) {
+ // If we want only one byte, take a fast path
+ if (aBytesCount == 1) {
+ this._bytesArray.set([aValue]);
+ return this._bytesArray[0];
+ }
+
var bytes = [];
for (var i = 0; i < aBytesCount; i++)
bytes[i] = 0x00;
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 = new Stack(40);
-
- // 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 = new Stack();
- dictionaryStack.push(systemDict);
- dictionaryStack.push(globalDict);
- dictionaryStack.push(userDict);
-
- /*
- * 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 = new Stack();
-
- /*
- * Return the next token in the execution stack
- */
- function nextInStack() {
- var currentProcedure = executionStack.peek();
- var command = currentProcedure.shift();
- if (!currentProcedure.length)
- executionStack.pop();
- return command;
- };
-
/**
* Returns an object containing a Subrs array and a CharStrings array
* extracted from and eexec encrypted block of data
subrs: subrs,
charstrings: glyphs
}
- };
-
- /*
- * 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 described in 'Using Subroutines' of 'Adobe Type 1 Font Format',
- * chapter 8.
- */
- this.flattenCharstring = function(aCharstring, aSubrs) {
- operandStack.clear();
- executionStack.clear();
- executionStack.push(aCharstring.slice());
-
- var leftSidebearing = 0;
- var lastPoint = 0;
- while (true) {
- var obj = nextInStack();
- if (IsInt(obj) || IsBool(obj)) {
- operandStack.push(obj);
- } else {
- switch (obj) {
- case "callsubr":
- var index = operandStack.pop();
- executionStack.push(aSubrs[index].slice());
- break;
-
- case "callothersubr":
- var index = operandStack.pop();
- var count = operandStack.pop();
- var data = operandStack.pop();
- // XXX The callothersubr needs to support at least the 3 defaults
- // otherSubrs of the spec
- if (index != 3)
- error("callothersubr for index: " + index);
- operandStack.push(3);
- operandStack.push("callothersubr");
- break;
-
- case "div":
- var num2 = operandStack.pop();
- var num1 = operandStack.pop();
- operandStack.push(num2 / num1);
- break;
-
- case "pop":
- operandStack.pop();
- break;
-
- case "return":
- break;
-
- case "hsbw":
- var charWidthVector = operandStack.pop();
- var leftSidebearing = operandStack.pop();
- operandStack.push(charWidthVector);
-
- if (leftSidebearing) {
- operandStack.push(leftSidebearing);
- operandStack.push("hmoveto");
- }
- break;
-
- case "endchar":
- operandStack.push("endchar");
- return operandStack.clone();
-
- default:
- operandStack.push(obj);
- break;
- }
- }
- }
}
};
return data;
},
- encodeNumber: function(aValue) {
+ encodeNumber: function(aValue, aIsCharstring) {
var x = 0;
- // XXX we don't really care about Type2 optimization here...
- if (aValue >= -32768 && aValue <= 32767) {
+ if (aIsCharstring && aValue >= -107 && aValue <= 107) {
+ return [aValue + 139];
+ } else if (aValue >= -32768 && aValue <= 32767) {
return [
28,
FontsUtils.integerToBytes(aValue >> 8, 1),
return charstrings;
},
+ /*
+ * Flatten the commands by interpreting the postscript code and replacing
+ * every 'callsubr', 'callothersubr' by the real commands.
+ *
+ * TODO This function also do a string to command number transformation
+ * that can probably be avoided if the Type1 decodeCharstring code is smarter
+ */
+ commandsMap: {
+ "hstem": 1,
+ "vstem": 3,
+ "vmoveto": 4,
+ "rlineto": 5,
+ "hlineto": 6,
+ "vlineto": 7,
+ "rrcurveto": 8,
+ "endchar": 14,
+ "rmoveto": 21,
+ "hmoveto": 22,
+ "vhcurveto": 30,
+ "hvcurveto": 31,
+ },
+
+ flattenCharstring: function(aCharstring, aSubrs) {
+ var i = 0;
+ while (true) {
+ var obj = aCharstring[i];
+ if (IsString(obj)) {
+ switch (obj) {
+ case "callsubr":
+ var subr = aSubrs[aCharstring[i- 1]].slice();
+ if (subr.length > 1) {
+ subr = this.flattenCharstring(subr, aSubrs);
+ subr.pop();
+ aCharstring.splice(i - 1, 2, subr);
+ }
+ else
+ aCharstring.splice(i - 1, 2);
+
+ i -= 1;
+ break;
+
+ case "callothersubr":
+ var index = aCharstring[i - 1];
+ var count = aCharstring[i - 2];
+ var data = aCharstring[i - 3];
+
+ // XXX The callothersubr needs to support at least the 3 defaults
+ // otherSubrs of the spec
+ if (index != 3)
+ error("callothersubr for index: " + index + " (" + aCharstring + ")");
+
+ if (!data) {
+ aCharstring.splice(i - 2, 3, "pop", 3);
+ i -= 2;
+ } else {
+ // 5 to remove the arguments, the callothersubr call and the pop command
+ aCharstring.splice(i - 3, 5, 3);
+ i -= 3;
+ }
+ break;
+
+ case "div":
+ var num2 = aCharstring[i - 1];
+ var num1 = aCharstring[i - 2];
+ aCharstring.splice(i - 2, 3, num2 / num1);
+ i -= 2;
+ break;
+
+ case "pop":
+ aCharstring.splice(i - 2, 2);
+ i -= 1;
+ break;
+
+
+ case "hsbw":
+ var charWidthVector = aCharstring[i - 1];
+ var leftSidebearing = aCharstring[i - 2];
+ aCharstring.splice(i - 2, 3, charWidthVector, leftSidebearing, "hmoveto");
+ break;
+
+ case "endchar":
+ case "return":
+ // CharString is ready to be re-encode to commands number at this point
+ for (var j = 0; j < aCharstring.length; j++) {
+ var command = aCharstring[j];
+ if (IsNum(command)) {
+ var number = this.encodeNumber(command, true);
+ aCharstring.splice(j, 1);
+ for (var k = 0; k < number.length; k++)
+ aCharstring.splice(j + k, 0, number[k]);
+ j+= number.length - 1;
+ } else if (IsString(command)) {
+ var command = this.commandsMap[command];
+ if (IsArray(command)) {
+ aCharstring.splice(j - 1, 1, command[0], command[1]);
+ j += 1;
+ } else {
+ aCharstring[j] = command;
+ }
+ } else if (IsArray(command)) {
+ aCharstring.splice(j, 1);
+
+ // command has already been translated, just add them to the
+ // charstring directly
+ for (var k = 0; k < command.length; k++)
+ aCharstring.splice(j + k, 0, command[k]);
+ j+= command.length - 1;
+ } else { // what else?
+ error("Error while flattening the Type1 charstring: " + aCharstring);
+ }
+ }
+ return aCharstring;
+
+ default:
+ break;
+ }
+ }
+ i++;
+ }
+ error("failing with i = " + i + " in charstring:" + aCharstring + "(" + aCharstring.length + ")");
+ },
+
convertToCFF: function(aFontInfo) {
var debug = false;
function dump(aMsg) {
var charstrings = this.getOrderedCharStrings(aFontInfo.charstrings);
+ // Starts the conversion of the Type1 charstrings to Type2
+ var start = Date.now();
var charstringsCount = 0;
var charstringsDataLength = 0;
var glyphs = [];
- var glyphsChecker = {};
- var subrs = aFontInfo.subrs;
-
- // FIXME This code is actually the only reason the dummy PS Interpreter
- // called Type1Parser continue to lives, basically the goal here is
- // to embed the OtherSubrs/Subrs into the charstring directly.
- // But since Type2 charstrings use a bias to index Subrs and can
- // theorically store twice the number of Type1 we could directly
- // save the OtherSubrs and Subrs in the Type2 table for Subrs
- // and avoid this 'flattening' slow method.
- //
- // The other thinds done by this method is splitting the initial
- // 'width lsb hswb' command of Type1 to something similar in Type2
- // that is: 'width dx moveto' but this can be done in the
- // decodeCharstring method directly (maybe one day it will be called
- // translateCharstring?)
- var parser = new Type1Parser();
for (var i = 0; i < charstrings.length; i++) {
var charstring = charstrings[i].charstring.slice();
var glyph = charstrings[i].glyph;
- if (glyphsChecker[glyph])
- error("glyphs already exists!");
- glyphsChecker[glyph] = true;
- var flattened = parser.flattenCharstring(charstring, subrs);
+ var flattened = this.flattenCharstring(charstring, aFontInfo.subrs);
glyphs.push(flattened);
charstringsCount++;
charstringsDataLength += flattened.length;
}
+
+ var end = Date.now();
dump("There is " + charstringsCount + " glyphs (size: " + charstringsDataLength + ")");
+ dump("Time to flatten the strings is : " + (end -start));
// Create a CFF font data
var cff = new Uint8Array(kMaxFontFileSize);
charset.push(bytes[1]);
}
- // Convert charstrings
- var getNumFor = {
- "hstem": 1,
- "vstem": 3,
- "vmoveto": 4,
- "rlineto": 5,
- "hlineto": 6,
- "vlineto": 7,
- "rrcurveto": 8,
- "endchar": 14,
- "rmoveto": 21,
- "hmoveto": 22,
- "vhcurveto": 30,
- "hvcurveto": 31,
- };
-
- // FIXME Concatenating array with this algorithm (O²) is expensive and
- // can be avoided if the voodoo's dance of charstrings decoding
- // encoding is left for dead. Actually charstrings command number
- // are converted to a string and then back to a number with the
- // next few lines of code...
- var r = [[0x40, 0x0E]];
- for (var i = 0; i < glyphs.length; i++) {
- var data = glyphs[i].slice();
- var charstring = [];
- for (var j = 0; j < data.length; j++) {
- var c = data[j];
- if (!IsNum(c)) {
- var token = getNumFor[c];
- if (!token)
- error("Token " + c + " is not recognized in charstring " + data);
- charstring.push(token);
- } else {
- try {
- var bytes = this.encodeNumber(c);
- } catch(e) {
- log("Glyph " + i + " has a wrong value: " + c + " in charstring: " + data);
- log("the default value is glyph " + charstrings[i].glyph + " and is supposed to be: " + charstrings[i].charstring);
- }
- charstring = charstring.concat(bytes);
- }
- }
- r.push(charstring);
- }
-
- var charstringsIndex = this.createCFFIndexHeader(r, true);
+ var charstringsIndex = this.createCFFIndexHeader([[0x40, 0x0E]].concat(glyphs), true);
charstringsIndex = charstringsIndex.join(" ").split(" "); // XXX why?
//Top Dict Index
projects / pdf.js.git / commitdiff