function decrypt(aStream, aKey, aDiscardNumber) {
var r = aKey, c1 = 52845, c2 = 22719;
-
var decryptedString = [];
- var value = null;
+ var value = "";
var count = aStream.length;
for (var i = 0; i < count; i++) {
value = aStream.getByte();
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
};
// Flag indicating if the topmost operand of the operandStack is an array
- var operandIsArray = false;
+ var operandIsArray = 0;
/*
* The dictionary stack holds only dictionary objects. The current set of
*/
var executionStack = [];
+
+ /*
+ * 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 = lexer.getObj();
- if (operandIsArray && !IsCmd(obj, "}") && !IsCmd(obj, "]")) {
+ if (operandIsArray && !IsCmd(obj, "{") && !IsCmd(obj, "[") &&
+ !IsCmd(obj, "}") && !IsCmd(obj, "]")) {
operandStack.peek().push(obj);
this.getObj();
} else if (IsCmd(obj, "{") || IsCmd(obj, "[")) {
dump("Start Array: " + obj);
operandStack.push([]);
- operandIsArray = true;
+ operandIsArray++;
this.getObj();
} else if (IsCmd(obj, "}") || IsCmd(obj, "]")) {
dump("End Array: " + obj);
- operandIsArray = false;
+ operandIsArray--;
this.getObj();
} else if (IsBool(obj) || IsInt(obj) || IsNum(obj) || IsString(obj)) {
- dump("Value: " + obj);
+ //dump("Value: " + obj);
operandStack.push(obj);
this.getObj();
} else if (IsCmd(obj, "dup")) {
operandStack.push(systemDict);
this.getObj();
} else if (IsCmd(obj, "readonly") || IsCmd(obj, "executeonly") ||
- IsCmd(obj, "currentfile")) {
+ IsCmd(obj, "currentfile") || IsCmd(obj, "NP")) {
// Do nothing for the moment
this.getObj();
} else if (IsName(obj)) {
- dump("Name: " + obj.name);
+ //dump("Name: " + obj.name);
operandStack.push(obj.name);
this.getObj();
} else if (IsCmd(obj, "dict")) {
var size = operandStack.pop();
var key = operandStack.pop();
- var stream = lexer.stream.makeSubStream(lexer.stream.pos, size);
+ // 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, new StringStream(charString));
- log (new StringStream(charString));
+ dictionaryStack.peek().set(key, charStream);
+
+ var decodedCharString = decodeCharString(charStream);
+ log(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, "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 {
- dump("Getting an unknow token, adding it to the stack just in case");
dump(obj);
- operandStack.push(obj);
- this.getObj();
+ error("Unknow token while parsing font");
}
return operandStack.peek();
var Type1Font = function(aFontName, aFontFile) {
// All Type1 font program should begin with the comment %!
- var validHeader = aFontFile.getByte() == 0x25 && aFontFile.getByte() == 0x21;
- if (!validHeader)
+ if (aFontFile.getByte() != 0x25 || aFontFile.getByte() != 0x21)
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);
var binaryStream = aFontFile.makeSubStream(aFontFile.dict.get("Length1"), aFontFile.dict.get("Length2"), aFontFile.dict);
projects / pdf.js.git / commitdiff