/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- /
/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
"use strict";
/**
* Maximum file size of the font.
*/
var kMaxFontFileSize = 40000;
/**
* Maximum time to wait for a font to be loaded by @font-face
*/
var kMaxWaitForFontFace = 1000;
/**
* Useful for debugging when you want to certains operations depending on how
* many fonts are loaded.
*/
var fontCount = 0;
var fontName = "";
/**
* If for some reason one want to debug without fonts activated, it just need
* to turn this pref to true/false.
*/
var kDisableFonts = false;
/**
* Hold a map of decoded fonts and of the standard fourteen Type1 fonts and
* their acronyms.
* TODO Add the standard fourteen Type1 fonts list by default
* http://cgit.freedesktop.org/poppler/poppler/tree/poppler/GfxFont.cc#n65
*/
var Fonts = {
_active: null,
get active() {
return this._active;
},
set active(name) {
this._active = this[name];
},
charsToUnicode: function fonts_chars2Unicode(chars) {
var active = this._active;
if (!active)
return chars;
// if we translated this string before, just grab it from the cache
var str = active.cache[chars];
if (str)
return str;
// translate the string using the font's encoding
var encoding = active.properties.encoding;
if (!encoding)
return chars;
str = "";
for (var i = 0; i < chars.length; ++i) {
var charcode = chars.charCodeAt(i);
var unicode = encoding[charcode];
// Check if the glyph has already been converted
if (unicode instanceof Name)
unicode = encoding[unicode] = GlyphsUnicode[unicode.name];
// Handle surrogate pairs
if (unicode > 0xFFFF) {
str += String.fromCharCode(unicode & 0xFFFF);
unicode >>= 16;
}
str += String.fromCharCode(unicode);
}
// Enter the translated string into the cache
return active.cache[chars] = str;
}
};
/**
* 'Font' is the class the outside world should use, it encapsulate all the font
* decoding logics whatever type it is (assuming the font type is supported).
*
* For example to read a Type1 font and to attach it to the document:
* var type1Font = new Font("MyFontName", binaryFile, propertiesObject);
* type1Font.bind();
*/
var Font = (function () {
var constructor = function font_constructor(name, file, properties) {
this.name = name;
this.encoding = properties.encoding;
// If the font has already been decoded simply return it
if (Fonts[name]) {
this.font = Fonts[name].data;
return;
}
fontCount++;
fontName = name;
// If the font is to be ignored, register it like an already loaded font
// to avoid the cost of waiting for it be be loaded by the platform.
if (properties.ignore || properties.type == "TrueType" || kDisableFonts) {
Fonts[name] = {
data: file,
loading: false,
properties: {},
cache: Object.create(null)
}
return;
}
switch (properties.type) {
case "Type1":
var cff = new CFF(name, file, properties);
this.mimetype = "font/opentype";
// Wrap the CFF data inside an OTF font file
this.font = this.convert(name, cff, properties);
break;
case "TrueType":
this.mimetype = "font/opentype";
// Repair the TrueType file if it is can be damaged in the point of
// view of the sanitizer
this.font = this.checkAndRepair(name, file, properties);
break;
default:
warn("Font " + properties.type + " is not supported");
break;
}
Fonts[name] = {
data: this.font,
properties: properties,
loading: true,
cache: Object.create(null)
}
// Attach the font to the document
this.bind();
};
function stringToArray(str) {
var array = [];
for (var i = 0; i < str.length; ++i)
array[i] = str.charCodeAt(i);
return array;
};
function string16(value) {
return String.fromCharCode((value >> 8) & 0xff) +
String.fromCharCode(value & 0xff);
};
function string32(value) {
return String.fromCharCode((value >> 24) & 0xff) +
String.fromCharCode((value >> 16) & 0xff) +
String.fromCharCode((value >> 8) & 0xff) +
String.fromCharCode(value & 0xff);
};
function createOpenTypeHeader(sfnt, file, offsets, numTables) {
// sfnt version (4 bytes)
var header = sfnt;
// numTables (2 bytes)
header += string16(numTables);
// searchRange (2 bytes)
var tablesMaxPower2 = FontsUtils.getMaxPower2(numTables);
var searchRange = tablesMaxPower2 * 16;
header += string16(searchRange);
// entrySelector (2 bytes)
header += string16(Math.log(tablesMaxPower2) / Math.log(2));
// rangeShift (2 bytes)
header += string16(numTables * 16 - searchRange);
file.set(stringToArray(header), offsets.currentOffset);
offsets.currentOffset += header.length;
offsets.virtualOffset += header.length;
};
function createTableEntry(file, offsets, tag, data) {
// offset
var offset = offsets.virtualOffset;
// Per spec tables must be 4-bytes align so add padding as needed
while (data.length & 3)
data.push(0x00);
while (offsets.virtualOffset & 3)
offsets.virtualOffset++;
// length
var length = data.length;
// checksum
var checksum = tag.charCodeAt(0) +
tag.charCodeAt(1) +
tag.charCodeAt(2) +
tag.charCodeAt(3) +
offset +
length;
var tableEntry = tag + string32(checksum) + string32(offset) + string32(length);
tableEntry = stringToArray(tableEntry);
file.set(tableEntry, offsets.currentOffset);
offsets.currentOffset += tableEntry.length;
offsets.virtualOffset += data.length;
};
function getRanges(glyphs) {
// Array.sort() sorts by characters, not numerically, so convert to an
// array of characters.
var codes = [];
var length = glyphs.length;
for (var n = 0; n < length; ++n)
codes.push(String.fromCharCode(glyphs[n].unicode))
codes.sort();
// Split the sorted codes into ranges.
var ranges = [];
for (var n = 0; n < length; ) {
var start = codes[n++].charCodeAt(0);
var end = start;
while (n < length && end + 1 == codes[n].charCodeAt(0)) {
++end;
++n;
}
ranges.push([start, end]);
}
return ranges;
};
function createCMAPTable(glyphs) {
var ranges = getRanges(glyphs);
var headerSize = (12 * 2 + (ranges.length * 4 * 2));
var segCount = ranges.length + 1;
var segCount2 = segCount * 2;
var searchRange = FontsUtils.getMaxPower2(segCount) * 2;
var searchEntry = Math.log(segCount) / Math.log(2);
var rangeShift = 2 * segCount - searchRange;
var cmap = "\x00\x00" + // version
"\x00\x01" + // numTables
"\x00\x03" + // platformID
"\x00\x01" + // encodingID
"\x00\x00\x00\x0C" + // start of the table record
"\x00\x04" + // format
string16(headerSize) + // length
"\x00\x00" + // languages
string16(segCount2) +
string16(searchRange) +
string16(searchEntry) +
string16(rangeShift);
// Fill up the 4 parallel arrays describing the segments.
var startCount = "";
var endCount = "";
var idDeltas = "";
var idRangeOffsets = "";
var glyphsIds = "";
var bias = 0;
for (var i = 0; i < segCount - 1; i++) {
var range = ranges[i];
var start = range[0];
var end = range[1];
var delta = (((start - 1) - bias) ^ 0xffff) + 1;
bias += (end - start + 1);
startCount += string16(start);
endCount += string16(end);
idDeltas += string16(delta);
idRangeOffsets += string16(0);
for (var j = start; j <= end; j++)
glyphsIds += String.fromCharCode(j);
}
startCount += "\xFF\xFF";
endCount += "\xFF\xFF";
idDeltas += "\x00\x01";
idRangeOffsets += "\x00\x00";
return stringToArray(cmap + endCount + "\x00\x00" + startCount +
idDeltas + idRangeOffsets + glyphsIds);
};
function createOS2Table() {
var OS2 = stringToArray(
"\x00\x03" + // version
"\x02\x24" + // xAvgCharWidth
"\x01\xF4" + // usWeightClass
"\x00\x05" + // usWidthClass
"\x00\x00" + // fstype
"\x02\x8A" + // ySubscriptXSize
"\x02\xBB" + // ySubscriptYSize
"\x00\x00" + // ySubscriptXOffset
"\x00\x8C" + // ySubscriptYOffset
"\x02\x8A" + // ySuperScriptXSize
"\x02\xBB" + // ySuperScriptYSize
"\x00\x00" + // ySuperScriptXOffset
"\x01\xDF" + // ySuperScriptYOffset
"\x00\x31" + // yStrikeOutSize
"\x01\x02" + // yStrikeOutPosition
"\x00\x00" + // sFamilyClass
"\x02\x00\x06\x03\x00\x00\x00\x00\x00\x00" + // Panose
"\xFF\xFF\xFF\xFF" + // ulUnicodeRange1 (Bits 0-31)
"\xFF\xFF\xFF\xFF" + // ulUnicodeRange1 (Bits 32-63)
"\xFF\xFF\xFF\xFF" + // ulUnicodeRange1 (Bits 64-95)
"\xFF\xFF\xFF\xFF" + // ulUnicodeRange1 (Bits 96-127)
"\x2A\x32\x31\x2A" + // achVendID
"\x00\x20" + // fsSelection
"\x00\x2D" + // usFirstCharIndex
"\x00\x7A" + // usLastCharIndex
"\x00\x03" + // sTypoAscender
"\x00\x20" + // sTypeDescender
"\x00\x38" + // sTypoLineGap
"\x00\x5A" + // usWinAscent
"\x02\xB4" + // usWinDescent
"\x00\xCE\x00\x00" + // ulCodePageRange1 (Bits 0-31)
"\x00\x01\x00\x00" + // ulCodePageRange2 (Bits 32-63)
"\x00\x00" + // sxHeight
"\x00\x00" + // sCapHeight
"\x00\x01" + // usDefaultChar
"\x00\xCD" + // usBreakChar
"\x00\x02" // usMaxContext
);
return OS2;
};
/**
* A bunch of the OpenType code is duplicate between this class and the
* TrueType code, this is intentional and will merge in a future version
* where all the code relative to OpenType will probably have its own
* class and will take decision without the Fonts consent.
* But at the moment it allows to develop around the TrueType rewriting
* on the fly without messing up with the 'regular' Type1 to OTF conversion.
*/
constructor.prototype = {
name: null,
font: null,
mimetype: null,
encoding: null,
checkAndRepair: function font_checkAndRepair(name, font, properties) {
function readTableEntry(file) {
// tag
var tag = file.getBytes(4);
tag = String.fromCharCode(tag[0]) +
String.fromCharCode(tag[1]) +
String.fromCharCode(tag[2]) +
String.fromCharCode(tag[3]);
var checksum = FontsUtils.bytesToInteger(file.getBytes(4));
var offset = FontsUtils.bytesToInteger(file.getBytes(4));
var length = FontsUtils.bytesToInteger(file.getBytes(4));
// Read the table associated data
var currentPosition = file.pos;
file.pos = file.start + offset;
var data = file.getBytes(length);
file.pos = currentPosition;
return {
tag: tag,
checksum: checksum,
length: offset,
offset: length,
data: data
}
};
function readOpenTypeHeader(ttf) {
return {
version: ttf.getBytes(4),
numTables: FontsUtils.bytesToInteger(ttf.getBytes(2)),
searchRange: FontsUtils.bytesToInteger(ttf.getBytes(2)),
entrySelector: FontsUtils.bytesToInteger(ttf.getBytes(2)),
rangeShift: FontsUtils.bytesToInteger(ttf.getBytes(2))
}
};
// Check that required tables are present
var requiredTables = [ "OS/2", "cmap", "head", "hhea",
"hmtx", "maxp", "name", "post" ];
var header = readOpenTypeHeader(font);
var numTables = header.numTables;
// This keep a reference to the CMap and the post tables since they can
// be rewritted
var cmap, post;
var tables = [];
for (var i = 0; i < numTables; i++) {
var table = readTableEntry(font);
var index = requiredTables.indexOf(table.tag);
if (index != -1) {
if (table.tag == "cmap")
cmap = table;
else if (table.tag == "post")
post = table;
requiredTables.splice(index, 1);
}
tables.push(table);
}
// If any tables are still in the array this means some required tables are
// missing, which means that we need to rebuild the font in order to pass
// the sanitizer.
if (requiredTables.length && requiredTables[0] == "OS/2") {
// Create a new file to hold the new version of our truetype with a new
// header and new offsets
var ttf = Uint8Array(kMaxFontFileSize);
// The offsets object holds at the same time a representation of where
// to write the table entry information about a table and another offset
// representing the offset where to put the actual data of a particular
// table
var numTables = header.numTables + requiredTables.length;
var offsets = {
currentOffset: 0,
virtualOffset: numTables * (4 * 4)
};
// The new numbers of tables will be the last one plus the num of missing
// tables
createOpenTypeHeader("\x00\x01\x00\x00", ttf, offsets, numTables);
// Insert the missing table
var OS2 = createOS2Table();
tables.push({
tag: "OS/2",
data: OS2
});
// If the font is missing a OS/2 table it's could be an old mac font
// without a 3-1-4 Unicode BMP table, so let's rewrite it.
var charset = properties.charset;
var glyphs = [];
for (var i = 0; i < charset.length; i++) {
glyphs.push({
unicode: GlyphsUnicode[charset[i]]
});
}
// Replace the old CMAP table with a shiny new one
cmap.data = createCMAPTable(glyphs);
// Rewrite the 'post' table if needed
if (!post) {
post =
"\x00\x03\x00\x00" + // Version number
"\x00\x00\x01\x00" + // italicAngle
"\x00\x00" + // underlinePosition
"\x00\x00" + // underlineThickness
"\x00\x00\x00\x00" + // isFixedPitch
"\x00\x00\x00\x00" + // minMemType42
"\x00\x00\x00\x00" + // maxMemType42
"\x00\x00\x00\x00" + // minMemType1
"\x00\x00\x00\x00"; // maxMemType1
tables.unshift({
tag: "post",
data: stringToArray(post)
});
}
// Tables needs to be written by ascendant alphabetic order
tables.sort(function tables_sort(a, b) {
return a.tag > b.tag;
});
// rewrite the tables but tweak offsets
for (var i = 0; i < tables.length; i++) {
var table = tables[i];
var data = [];
var tableData = table.data;
for (var j = 0; j < tableData.length; j++)
data.push(tableData[j]);
createTableEntry(ttf, offsets, table.tag, data);
}
// Add the table datas
for (var i = 0; i < tables.length; i++) {
var table = tables[i];
var tableData = table.data;
ttf.set(tableData, offsets.currentOffset);
offsets.currentOffset += tableData.length;
// 4-byte aligned data
while (offsets.currentOffset & 3)
offsets.currentOffset++;
}
var fontData = [];
for (var i = 0; i < offsets.currentOffset; i++)
fontData.push(ttf[i]);
return fontData;
} else if (requiredTables.length) {
error("Table " + requiredTables[0] + " is missing from the TrueType font");
}
return font.getBytes();
},
convert: function font_convert(name, font, properties) {
var otf = Uint8Array(kMaxFontFileSize);
function createNameTable(name) {
var names = [
"See original licence", // Copyright
name, // Font family
"undefined", // Font subfamily (font weight)
"uniqueID", // Unique ID
name, // Full font name
"0.1", // Version
"undefined", // Postscript name
"undefined", // Trademark
"undefined", // Manufacturer
"undefined" // Designer
];
var name =
"\x00\x00" + // format
"\x00\x0A" + // Number of names Record
"\x00\x7E"; // Storage
// Build the name records field
var strOffset = 0;
for (var i = 0; i < names.length; i++) {
var str = names[i];
var nameRecord =
"\x00\x01" + // platform ID
"\x00\x00" + // encoding ID
"\x00\x00" + // language ID
"\x00\x00" + // name ID
string16(str.length) +
string16(strOffset);
name += nameRecord;
strOffset += str.length;
}
name += names.join("");
return name;
}
// Required Tables
var CFF =
font.data, // PostScript Font Program
OS2, // OS/2 and Windows Specific metrics
cmap, // Character to glyphs mapping
head, // Font eader
hhea, // Horizontal header
hmtx, // Horizontal metrics
maxp, // Maximum profile
name, // Naming tables
post; // PostScript informations
var tables = [CFF, OS2, cmap, head, hhea, hmtx, maxp, name, post];
// The offsets object holds at the same time a representation of where
// to write the table entry information about a table and another offset
// representing the offset where to draw the actual data of a particular
// table
var offsets = {
currentOffset: 0,
virtualOffset: tables.length * (4 * 4)
};
// It there is only one font, offset table is the first bytes of the file
createOpenTypeHeader("\x4F\x54\x54\x4F", otf, offsets, tables.length);
/** CFF */
createTableEntry(otf, offsets, "CFF ", CFF);
/** OS/2 */
OS2 = createOS2Table();
createTableEntry(otf, offsets, "OS/2", OS2);
//XXX Getting charstrings here seems wrong since this is another CFF glue
var charstrings = font.getOrderedCharStrings(properties.glyphs);
/** CMAP */
cmap = createCMAPTable(charstrings);
createTableEntry(otf, offsets, "cmap", cmap);
/** HEAD */
head = stringToArray(
"\x00\x01\x00\x00" + // Version number
"\x00\x00\x50\x00" + // fontRevision
"\x00\x00\x00\x00" + // checksumAdjustement
"\x5F\x0F\x3C\xF5" + // magicNumber
"\x00\x00" + // Flags
"\x03\xE8" + // unitsPerEM (defaulting to 1000)
"\x00\x00\x00\x00\x00\x00\x00\x00" + // creation date
"\x00\x00\x00\x00\x00\x00\x00\x00" + // modifification date
"\x00\x00" + // xMin
"\x00\x00" + // yMin
"\x00\x00" + // xMax
"\x00\x00" + // yMax
"\x00\x00" + // macStyle
"\x00\x00" + // lowestRecPPEM
"\x00\x00" + // fontDirectionHint
"\x00\x00" + // indexToLocFormat
"\x00\x00" // glyphDataFormat
);
createTableEntry(otf, offsets, "head", head);
/** HHEA */
hhea = stringToArray(
"\x00\x01\x00\x00" + // Version number
"\x00\x00" + // Typographic Ascent
"\x00\x00" + // Typographic Descent
"\x00\x00" + // Line Gap
"\xFF\xFF" + // advanceWidthMax
"\x00\x00" + // minLeftSidebearing
"\x00\x00" + // minRightSidebearing
"\x00\x00" + // xMaxExtent
"\x00\x00" + // caretSlopeRise
"\x00\x00" + // caretSlopeRun
"\x00\x00" + // caretOffset
"\x00\x00" + // -reserved-
"\x00\x00" + // -reserved-
"\x00\x00" + // -reserved-
"\x00\x00" + // -reserved-
"\x00\x00" + // metricDataFormat
string16(charstrings.length)
);
createTableEntry(otf, offsets, "hhea", hhea);
/** HMTX */
hmtx = "\x01\xF4\x00\x00";
for (var i = 0; i < charstrings.length; i++) {
var charstring = charstrings[i].charstring;
var width = charstring[1];
var lsb = charstring[0];
hmtx += string16(width) + string16(lsb);
}
hmtx = stringToArray(hmtx);
createTableEntry(otf, offsets, "hmtx", hmtx);
/** MAXP */
maxp = "\x00\x00\x50\x00" + // Version number
string16(charstrings.length + 1); // Num of glyphs (+1 to pass the sanitizer...)
maxp = stringToArray(maxp);
createTableEntry(otf, offsets, "maxp", maxp);
/** NAME */
name = stringToArray(createNameTable(name));
createTableEntry(otf, offsets, "name", name);
/** POST */
// TODO: get those informations from the FontInfo structure
post = "\x00\x03\x00\x00" + // Version number
"\x00\x00\x01\x00" + // italicAngle
"\x00\x00" + // underlinePosition
"\x00\x00" + // underlineThickness
"\x00\x00\x00\x00" + // isFixedPitch
"\x00\x00\x00\x00" + // minMemType42
"\x00\x00\x00\x00" + // maxMemType42
"\x00\x00\x00\x00" + // minMemType1
"\x00\x00\x00\x00"; // maxMemType1
post = stringToArray(post);
createTableEntry(otf, offsets, "post", post);
// Once all the table entries header are written, dump the data!
var tables = [CFF, OS2, cmap, head, hhea, hmtx, maxp, name, post];
for (var i = 0; i < tables.length; i++) {
var table = tables[i];
otf.set(table, offsets.currentOffset);
offsets.currentOffset += table.length;
}
var fontData = [];
for (var i = 0; i < offsets.currentOffset; i++)
fontData.push(otf[i]);
return fontData;
},
bind: function font_bind() {
var data = this.font;
var fontName = this.name;
/** Hack begin */
// Actually there is not event when a font has finished downloading so
// the following code are a dirty hack to 'guess' when a font is ready
var canvas = document.createElement("canvas");
var style = "border: 1px solid black; position:absolute; top: " +
(debug ? (100 * fontCount) : "-200") + "px; left: 2px; width: 340px; height: 100px";
canvas.setAttribute("style", style);
canvas.setAttribute("width", 340);
canvas.setAttribute("heigth", 100);
document.body.appendChild(canvas);
// Get the font size canvas think it will be for 'spaces'
var ctx = canvas.getContext("2d");
ctx.font = "bold italic 20px " + fontName + ", Symbol, Arial";
var testString = " ";
// When debugging use the characters provided by the charsets to visually
// see what's happening instead of 'spaces'
var debug = false;
if (debug) {
var name = document.createElement("font");
name.setAttribute("style", "position: absolute; left: 20px; top: " +
(100 * fontCount + 60) + "px");
name.innerHTML = fontName;
document.body.appendChild(name);
// Retrieve font charset
var charset = Fonts[fontName].properties.charset || [];
// if the charset is too small make it repeat a few times
var count = 30;
while (count-- && charset.length <= 30)
charset = charset.concat(charset.slice());
for (var i = 0; i < charset.length; i++) {
var unicode = GlyphsUnicode[charset[i]];
if (!unicode)
continue;
testString += String.fromCharCode(unicode);
}
ctx.fillText(testString, 20, 20);
}
// Periodicaly check for the width of the testString, it will be
// different once the real font has loaded
var textWidth = ctx.measureText(testString).width;
var interval = window.setInterval(function canvasInterval(self) {
this.start = this.start || Date.now();
ctx.font = "bold italic 20px " + fontName + ", Symbol, Arial";
// For some reasons the font has not loaded, so mark it loaded for the
// page to proceed but cry
if ((Date.now() - this.start) >= kMaxWaitForFontFace) {
window.clearInterval(interval);
Fonts[fontName].loading = false;
warn("Is " + fontName + " for charset: " + charset + " loaded?");
this.start = 0;
} else if (textWidth != ctx.measureText(testString).width) {
window.clearInterval(interval);
Fonts[fontName].loading = false;
this.start = 0;
}
if (debug)
ctx.fillText(testString, 20, 50);
}, 30, this);
/** Hack end */
// Get the base64 encoding of the binary font data
var str = "";
var length = data.length;
for (var i = 0; i < length; ++i)
str += String.fromCharCode(data[i]);
var base64 = window.btoa(str);
// Add the @font-face rule to the document
var url = "url(data:" + this.mimetype + ";base64," + base64 + ");";
var rule = "@font-face { font-family:'" + fontName + "';src:" + url + "}";
var styleSheet = document.styleSheets[0];
styleSheet.insertRule(rule, styleSheet.length);
}
};
return constructor;
})();
/**
* FontsUtils is a static class dedicated to hold codes that are not related
* to fonts in particular and needs to be share between them.
*/
var FontsUtils = {
_bytesArray: new Uint8Array(4),
integerToBytes: function fu_integerToBytes(value, bytesCount) {
var bytes = this._bytesArray;
if (bytesCount == 1) {
bytes.set([value]);
return bytes[0];
} else if (bytesCount == 2) {
bytes.set([value >> 8, value]);
return [bytes[0], bytes[1]];
} else if (bytesCount == 4) {
bytes.set([value >> 24, value >> 16, value >> 8, value]);
return [bytes[0], bytes[1], bytes[2], bytes[3]];
}
},
bytesToInteger: function fu_bytesToInteger(bytesArray) {
var value = 0;
for (var i = 0; i < bytesArray.length; i++)
value = (value << 8) + bytesArray[i];
return value;
},
getMaxPower2: function fu_getMaxPower2(number) {
var maxPower = 0;
var value = number;
while (value >= 2) {
value /= 2;
maxPower++;
}
value = 2;
for (var i = 1; i < maxPower; i++)
value *= 2;
return value;
}
};
/**
* Type1Parser encapsulate the needed code for parsing a Type1 font
* program.
* Some of its logic depends on the Type2 charstrings structure.
*/
var Type1Parser = function() {
/*
* 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(stream, key, discardNumber) {
var r = key, c1 = 52845, c2 = 22719;
var decryptedString = [];
var value = "";
var count = stream.length;
for (var i = 0; i < count; i++) {
value = stream[i];
decryptedString[i] = value ^ (r >> 8);
r = ((value + r) * c1 + c2) & ((1 << 16) - 1);
}
return decryptedString.slice(discardNumber);
};
/*
* 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",
// closepath is a Type1 command that do not take argument and is useless
// in Type2 and it can simply be ignored.
"9": null, // closepath
"10": "callsubr",
// return is normally used inside sub-routines to tells to the execution
// flow that it can be back to normal.
// During the translation process Type1 charstrings will be flattened and
// sub-routines will be embedded directly into the charstring directly, so
// this can be ignored safely.
"11": "return",
"12": {
// dotsection is a Type1 command to specify some hinting feature for dots
// that do not take a parameter and it can safely be ignored for Type2.
"0": null, // dotsection
// [vh]stem3 are Type1 only and Type2 supports [vh]stem with multiple
// parameters, so instead of returning [vh]stem3 take a shortcut and
// return [vhstem] instead.
"1": "vstem",
"2": "hstem",
// Type1 only command with command not (yet) built-in ,throw an error
"6": -1, // seac
"7": -1, //sbw
"12": "div",
// callothersubr is a mechanism to make calls on the postscript
// interpreter.
// TODO When decodeCharstring encounter such a command it should
// directly do:
// - pop the previous charstring[] command into 'index'
// - pop the previous charstring[] command and ignore it, it is
// normally the number of element to push on the stack before
// the command but since everything will be pushed on the stack
// by the PS interpreter when it will read them that is safe to
// ignore this command
// - push the content of the OtherSubrs[index] inside charstring[]
"16": "callothersubr",
"17": "pop",
// setcurrentpoint sets the current point to x, y without performing a
// moveto (this is a one shot positionning command). This is used only
// with the return of an OtherSubrs call.
// TODO Implement the OtherSubrs charstring embedding and replace this
// call by a no-op, like 2 'pop' commands for example.
"33": null, //setcurrentpoint
},
"13": "hsbw",
"14": "endchar",
"21": "rmoveto",
"22": "hmoveto",
"30": "vhcurveto",
"31": "hvcurveto"
};
function decodeCharString(array) {
var charString = [];
var value = "";
var count = array.length;
for (var i = 0; i < count; i++) {
value = parseInt(array[i]);
if (value < 32) {
var command = null;
if (value == 12) {
var escape = array[++i];
command = charStringDictionary["12"][escape];
} else {
command = charStringDictionary[value];
}
// Some charstring commands are meaningless in Type2 and will return
// a null, let's just ignored them
if (!command && i < count) {
continue;
} else if (!command) {
break;
} else if (command == -1) {
error("Support for Type1 command " + value + " (" + escape + ") is not implemented in charstring: " + charString);
}
value = command;
} else if (value <= 246) {
value = parseInt(value) - 139;
} else if (value <= 250) {
value = ((value - 247) * 256) + parseInt(array[++i]) + 108;
} else if (value <= 254) {
value = -((value - 251) * 256) - parseInt(array[++i]) - 108;
} else {
var byte = array[++i];
var high = (byte >> 1);
value = (byte - high) << 24 | array[++i] << 16 |
array[++i] << 8 | array[++i];
}
charString.push(value);
}
return charString;
};
/**
* Returns an object containing a Subrs array and a CharStrings array
* extracted from and eexec encrypted block of data
*/
this.extractFontProgram = function t1_extractFontProgram(stream) {
var eexecString = decrypt(stream, kEexecEncryptionKey, 4);
var subrs = [], glyphs = [];
var inGlyphs = false;
var inSubrs = false;
var glyph = "";
var token = "";
var index = 0;
var length = 0;
var c = "";
var count = eexecString.length;
for (var i = 0; i < count; i++) {
var c = eexecString[i];
if (inSubrs && c == 0x52) {
length = parseInt(length);
var data = eexecString.slice(i + 3, i + 3 + length);
var encodedSubr = decrypt(data, kCharStringsEncryptionKey, 4);
var subr = decodeCharString(encodedSubr);
subrs.push(subr);
i += 3 + length;
} else if (inGlyphs && c == 0x52) {
length = parseInt(length);
var data = eexecString.slice(i + 3, i + 3 + length);
var encodedCharstring = decrypt(data, kCharStringsEncryptionKey, 4);
var subr = decodeCharString(encodedCharstring);
glyphs.push({
glyph: glyph,
data: subr
});
i += 3 + length;
} else if (inGlyphs && c == 0x2F) {
token = "";
glyph = "";
while ((c = eexecString[++i]) != 0x20)
glyph += String.fromCharCode(c);
} else if (!inSubrs && !inGlyphs && c == 0x2F && eexecString[i+1] == 0x53) {
while ((c = eexecString[++i]) != 0x20) {};
inSubrs = true;
} else if (c == 0x20) {
index = length;
length = token;
token = "";
} else if (c == 0x2F && eexecString[i+1] == 0x43 && eexecString[i+2] == 0x68) {
while ((c = eexecString[++i]) != 0x20) {};
inSubrs = false;
inGlyphs = true;
} else {
token += String.fromCharCode(c);
}
}
return {
subrs: subrs,
charstrings: glyphs
}
}
};
/**
* The CFF class takes a Type1 file and wrap it into a 'Compact Font Format',
* which itself embed Type2 charstrings.
*/
const CFFStrings = [
".notdef","space","exclam","quotedbl","numbersign","dollar","percent","ampersand",
"quoteright","parenleft","parenright","asterisk","plus","comma","hyphen","period",
"slash","zero","one","two","three","four","five","six","seven","eight","nine",
"colon","semicolon","less","equal","greater","question","at","A","B","C","D","E",
"F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y",
"Z","bracketleft","backslash","bracketright","asciicircum","underscore",
"quoteleft","a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q",
"r","s","t","u","v","w","x","y","z","braceleft","bar","braceright","asciitilde",
"exclamdown","cent","sterling","fraction","yen","florin","section","currency",
"quotesingle","quotedblleft","guillemotleft","guilsinglleft","guilsinglright",
"fi","fl","endash","dagger","daggerdbl","periodcentered","paragraph","bullet",
"quotesinglbase","quotedblbase","quotedblright","guillemotright","ellipsis",
"perthousand","questiondown","grave","acute","circumflex","tilde","macron",
"breve","dotaccent","dieresis","ring","cedilla","hungarumlaut","ogonek","caron",
"emdash","AE","ordfeminine","Lslash","Oslash","OE","ordmasculine","ae","dotlessi",
"lslash","oslash","oe","germandbls","onesuperior","logicalnot","mu","trademark",
"Eth","onehalf","plusminus","Thorn","onequarter","divide","brokenbar","degree",
"thorn","threequarters","twosuperior","registered","minus","eth","multiply",
"threesuperior","copyright","Aacute","Acircumflex","Adieresis","Agrave","Aring",
"Atilde","Ccedilla","Eacute","Ecircumflex","Edieresis","Egrave","Iacute",
"Icircumflex","Idieresis","Igrave","Ntilde","Oacute","Ocircumflex","Odieresis",
"Ograve","Otilde","Scaron","Uacute","Ucircumflex","Udieresis","Ugrave","Yacute",
"Ydieresis","Zcaron","aacute","acircumflex","adieresis","agrave","aring","atilde",
"ccedilla","eacute","ecircumflex","edieresis","egrave","iacute","icircumflex",
"idieresis","igrave","ntilde","oacute","ocircumflex","odieresis","ograve",
"otilde","scaron","uacute","ucircumflex","udieresis","ugrave","yacute",
"ydieresis","zcaron","exclamsmall","Hungarumlautsmall","dollaroldstyle",
"dollarsuperior","ampersandsmall","Acutesmall","parenleftsuperior",
"parenrightsuperior","266 ff","onedotenleader","zerooldstyle","oneoldstyle",
"twooldstyle","threeoldstyle","fouroldstyle","fiveoldstyle","sixoldstyle",
"sevenoldstyle","eightoldstyle","nineoldstyle","commasuperior",
"threequartersemdash","periodsuperior","questionsmall","asuperior","bsuperior",
"centsuperior","dsuperior","esuperior","isuperior","lsuperior","msuperior",
"nsuperior","osuperior","rsuperior","ssuperior","tsuperior","ff","ffi","ffl",
"parenleftinferior","parenrightinferior","Circumflexsmall","hyphensuperior",
"Gravesmall","Asmall","Bsmall","Csmall","Dsmall","Esmall","Fsmall","Gsmall",
"Hsmall","Ismall","Jsmall","Ksmall","Lsmall","Msmall","Nsmall","Osmall","Psmall",
"Qsmall","Rsmall","Ssmall","Tsmall","Usmall","Vsmall","Wsmall","Xsmall","Ysmall",
"Zsmall","colonmonetary","onefitted","rupiah","Tildesmall","exclamdownsmall",
"centoldstyle","Lslashsmall","Scaronsmall","Zcaronsmall","Dieresissmall",
"Brevesmall","Caronsmall","Dotaccentsmall","Macronsmall","figuredash",
"hypheninferior","Ogoneksmall","Ringsmall","Cedillasmall","questiondownsmall",
"oneeighth","threeeighths","fiveeighths","seveneighths","onethird","twothirds",
"zerosuperior","foursuperior","fivesuperior","sixsuperior","sevensuperior",
"eightsuperior","ninesuperior","zeroinferior","oneinferior","twoinferior",
"threeinferior","fourinferior","fiveinferior","sixinferior","seveninferior",
"eightinferior","nineinferior","centinferior","dollarinferior","periodinferior",
"commainferior","Agravesmall","Aacutesmall","Acircumflexsmall","Atildesmall",
"Adieresissmall","Aringsmall","AEsmall","Ccedillasmall","Egravesmall",
"Eacutesmall","Ecircumflexsmall","Edieresissmall","Igravesmall","Iacutesmall",
"Icircumflexsmall","Idieresissmall","Ethsmall","Ntildesmall","Ogravesmall",
"Oacutesmall","Ocircumflexsmall","Otildesmall","Odieresissmall","OEsmall",
"Oslashsmall","Ugravesmall","Uacutesmall","Ucircumflexsmall","Udieresissmall",
"Yacutesmall","Thornsmall","Ydieresissmall","001.000","001.001","001.002",
"001.003","Black","Bold","Book","Light","Medium","Regular","Roman","Semibold"
];
var CFF = function(name, file, properties) {
// Get the data block containing glyphs and subrs informations
var length1 = file.dict.get("Length1");
var length2 = file.dict.get("Length2");
file.skip(length1);
var eexecBlock = file.getBytes(length2);
// Decrypt the data blocks and retrieve the informations from it
var parser = new Type1Parser();
var fontInfo = parser.extractFontProgram(eexecBlock);
properties.subrs = fontInfo.subrs;
properties.glyphs = fontInfo.charstrings;
this.data = this.wrap(name, properties);
};
CFF.prototype = {
createCFFIndexHeader: function(objects, isByte) {
// First 2 bytes contains the number of objects contained into this index
var count = objects.length;
// If there is no object, just create an array saying that with another
// offset byte.
if (count == 0)
return [0x00, 0x00, 0x00];
var data = [];
var bytes = FontsUtils.integerToBytes(count, 2);
for (var i = 0; i < bytes.length; i++)
data.push(bytes[i]);
// Next byte contains the offset size use to reference object in the file
// Actually we're using 0x04 to be sure to be able to store everything
// without thinking of it while coding.
data.push(0x04);
// Add another offset after this one because we need a new offset
var relativeOffset = 1;
for (var i = 0; i < count + 1; i++) {
var bytes = FontsUtils.integerToBytes(relativeOffset, 4);
for (var j = 0; j < bytes.length; j++)
data.push(bytes[j]);
if (objects[i])
relativeOffset += objects[i].length;
}
for (var i =0; i < count; i++) {
for (var j = 0; j < objects[i].length; j++)
data.push(isByte ? objects[i][j] : objects[i].charCodeAt(j));
}
return data;
},
encodeNumber: function(value) {
var x = 0;
if (value >= -32768 && value <= 32767) {
return [ 28, value >> 8, value & 0xFF ];
} else if (value >= (-2147483647-1) && value <= 2147483647) {
return [ 0xFF, value >> 24, Value >> 16, value >> 8, value & 0xFF ];
} else {
error("Value: " + value + " is not allowed");
}
},
getOrderedCharStrings: function(glyphs) {
var charstrings = [];
for (var i = 0; i < glyphs.length; i++) {
var glyph = glyphs[i].glyph;
var unicode = GlyphsUnicode[glyph];
if (!unicode) {
if (glyph != ".notdef")
warn(glyph + " does not have an entry in the glyphs unicode dictionary");
} else {
charstrings.push({
glyph: glyph,
unicode: unicode,
charstring: glyphs[i].data.slice()
});
}
};
charstrings.sort(function charstrings_sort(a, b) {
return a.unicode > b.unicode;
});
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 flattenCharstring(glyph, charstring, subrs) {
var i = 0;
while (true) {
var obj = charstring[i];
if (obj == null)
return [];
if (obj.charAt) {
switch (obj) {
case "callsubr":
var subr = subrs[charstring[i - 1]].slice();
if (subr.length > 1) {
subr = this.flattenCharstring(glyph, subr, subrs);
subr.pop();
charstring.splice(i - 1, 2, subr);
} else {
charstring.splice(i - 1, 2);
}
i -= 1;
break;
case "callothersubr":
var index = charstring[i - 1];
var count = charstring[i - 2];
var data = charstring[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 + " (" + charstring + ")");
if (!data) {
charstring.splice(i - 2, 4, "pop", 3);
i -= 3;
} else {
// 5 to remove the arguments, the callothersubr call and the pop command
charstring.splice(i - 3, 5, 3);
i -= 3;
}
break;
case "div":
var num2 = charstring[i - 1];
var num1 = charstring[i - 2];
charstring.splice(i - 2, 3, num1 / num2);
i -= 2;
break;
case "pop":
if (i)
charstring.splice(i - 2, 2);
else
charstring.splice(i - 1, 1);
i -= 1;
break;
case "hsbw":
var charWidthVector = charstring[i - 1];
var leftSidebearing = charstring[i - 2];
if (leftSidebearing)
charstring.splice(i - 2, 3, charWidthVector, leftSidebearing, "hmoveto");
else
charstring.splice(i - 2, 3, charWidthVector);
break;
case "endchar":
case "return":
// CharString is ready to be re-encode to commands number at this point
for (var j = 0; j < charstring.length; j++) {
var command = charstring[j];
if (parseFloat(command) == command) {
charstring.splice(j, 1, 28, command >> 8, command);
j+= 2;
} else if (command.charAt) {
var command = this.commandsMap[command];
if (IsArray(command)) {
charstring.splice(j - 1, 1, command[0], command[1]);
j += 1;
} else {
charstring[j] = command;
}
} else {
charstring.splice(j, 1);
// command has already been translated, just add them to the
// charstring directly
for (var k = 0; k < command.length; k++)
charstring.splice(j + k, 0, command[k]);
j+= command.length - 1;
}
}
return charstring;
default:
break;
}
}
i++;
}
error("failing with i = " + i + " in charstring:" + charstring + "(" + charstring.length + ")");
},
wrap: function wrap(name, properties) {
var charstrings = this.getOrderedCharStrings(properties.glyphs);
// Starts the conversion of the Type1 charstrings to Type2
var charstringsCount = 0;
var charstringsDataLength = 0;
var glyphs = [];
for (var i = 0; i < charstrings.length; i++) {
var charstring = charstrings[i].charstring.slice();
var glyph = charstrings[i].glyph;
var flattened = this.flattenCharstring(glyph, charstring, properties.subrs);
glyphs.push(flattened);
charstringsCount++;
charstringsDataLength += flattened.length;
}
// Create a CFF font data
var cff = new Uint8Array(kMaxFontFileSize);
var currentOffset = 0;
// Font header (major version, minor version, header size, offset size)
var header = [0x01, 0x00, 0x04, 0x04];
currentOffset += header.length;
cff.set(header);
// Names Index
var nameIndex = this.createCFFIndexHeader([name]);
cff.set(nameIndex, currentOffset);
currentOffset += nameIndex.length;
// Calculate strings before writing the TopDICT index in order
// to calculate correct relative offsets for storing 'charset'
// and 'charstrings' data
var version = "";
var notice = "";
var fullName = "";
var familyName = "";
var weight = "";
var strings = [version, notice, fullName,
familyName, weight];
var stringsIndex = this.createCFFIndexHeader(strings);
var stringsDataLength = stringsIndex.length;
// Create the global subroutines index
var globalSubrsIndex = this.createCFFIndexHeader([]);
// Fill the charset header (first byte is the encoding)
var charset = [0x00];
for (var i = 0; i < glyphs.length; i++) {
var index = CFFStrings.indexOf(charstrings[i].glyph);
if (index == -1)
index = CFFStrings.length + strings.indexOf(glyph);
var bytes = FontsUtils.integerToBytes(index, 2);
charset.push(bytes[0]);
charset.push(bytes[1]);
}
var charstringsIndex = this.createCFFIndexHeader([[0x40, 0x0E]].concat(glyphs), true);
charstringsIndex = charstringsIndex.join(" ").split(" "); // XXX why?
//Top Dict Index
var topDictIndex = [
0x00, 0x01, 0x01, 0x01, 0x30,
248, 27, 0, // version
248, 28, 1, // Notice
248, 29, 2, // FullName
248, 30, 3, // FamilyName
248, 31, 4 // Weight
];
var fontBBox = properties.bbox;
for (var i = 0; i < fontBBox.length; i++)
topDictIndex = topDictIndex.concat(this.encodeNumber(fontBBox[i]));
topDictIndex.push(5) // FontBBox;
var charsetOffset = currentOffset +
(topDictIndex.length + (4 + 4 + 4 + 7)) +
stringsIndex.length +
globalSubrsIndex.length;
topDictIndex = topDictIndex.concat(this.encodeNumber(charsetOffset));
topDictIndex.push(15); // charset
topDictIndex = topDictIndex.concat([28, 0, 0, 16]) // Encoding
var charstringsOffset = charsetOffset + (charstringsCount * 2) + 1;
topDictIndex = topDictIndex.concat(this.encodeNumber(charstringsOffset));
topDictIndex.push(17); // charstrings
topDictIndex = topDictIndex.concat([28, 0, 55])
var privateOffset = charstringsOffset + charstringsIndex.length;
topDictIndex = topDictIndex.concat(this.encodeNumber(privateOffset));
topDictIndex.push(18); // Private
topDictIndex = topDictIndex.join(" ").split(" ");
var indexes = [
topDictIndex, stringsIndex,
globalSubrsIndex, charset,
charstringsIndex
];
for (var i = 0; i < indexes.length; i++) {
var index = indexes[i];
cff.set(index, currentOffset);
currentOffset += index.length;
}
// Private Data
var defaultWidth = this.encodeNumber(0);
var privateData = [].concat(
defaultWidth, [20],
[139, 21], // nominalWidth
[
119, 159, 248, 97, 159, 247, 87, 159, 6,
30, 10, 3, 150, 37, 255, 12, 9,
139, 12,
10, 172, 10,
172, 150, 143, 146, 150, 146, 12, 12,
247, 32, 11,
247, 10, 161, 147, 154, 150, 143, 12, 13,
139, 12, 14,
28, 0, 55, 19
]);
privateData = privateData.join(" ").split(" ");
cff.set(privateData, currentOffset);
currentOffset += privateData.length;
// Dump shit at the end of the file
var shit = [
0x00, 0x01, 0x01, 0x01,
0x13, 0x5D, 0x65, 0x64,
0x5E, 0x5B, 0xAF, 0x66,
0xBA, 0xBB, 0xB1, 0xB0,
0xB9, 0xBA, 0x65, 0xB2,
0x5C, 0x1F, 0x0B
];
cff.set(shit, currentOffset);
currentOffset += shit.length;
var fontData = [];
for (var i = 0; i < currentOffset; i++)
fontData.push(cff[i]);
return fontData;
}
};