/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- /
/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
/**
* Maximum file size of the font.
*/
var kMaxFontFileSize = 40000;
/**
* Maximum number of glyphs per font.
*/
var kMaxGlyphsCount = 65526;
/**
* 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;
/**
* 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(aFontName) {
this._active = this[aFontName];
},
unicodeFromCode: function fonts_unicodeFromCode(aCode) {
var active = this._active;
if (!active || !active.encoding)
return aCode;
var difference = active.encoding[aCode];
var unicode = GlyphsUnicode[difference];
return unicode ? "0x" + unicode : aCode;
}
};
/**
* '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", binaryData, aFontEncoding, "Type1");
* type1Font.bind();
*
* As an improvment the last parameter can be replaced by an automatic guess
* of the font type based on the first byte of the file.
*
* XXX There is now too many parameters, this should be turned into an
* object containing all the required informations about the font
*/
var Font = function(aName, aFile, aEncoding, aCharset, aBBox, aType) {
this.name = aName;
// If the font has already been decoded simply return
if (Fonts[aName]) {
this.font = Fonts[aName].data;
return;
}
fontCount++;
var start = Date.now();
switch (aType) {
case "Type1":
var cff = new CFF(aName, aBBox, aFile);
this.mimetype = "font/otf";
// Wrap the CFF data inside an OTF font file
this.font = this.cover(cff);
break;
case "TrueType":
this.mimetype = "font/ttf";
var ttf = new TrueType(aFile);
this.font = ttf.data;
break;
default:
warn("Font " + aType + " is not supported");
break;
}
var end = Date.now();
Fonts[aName] = {
data: this.font,
encoding: aEncoding,
charset: aCharset ? aCharset.slice() : null,
loading: true
}
// Attach the font to the document
this.bind();
};
Font.prototype = {
name: null,
font: null,
mimetype: null,
bind: function font_bind() {
var data = this.font;
// Compute the binary data to base 64
var str = [];
var count = data.length;
for (var i = 0; i < count; i++)
str.push(data.getChar ? data.getChar()
: String.fromCharCode(data[i]));
var dataBase64 = window.btoa(str.join(""));
var fontName = this.name;
/** Hack begin */
// Actually there is not event when a font has finished downloading so
// the following tons of code are a dirty hack to 'guess' when a font is
// ready
var debug = false;
var canvas = document.createElement("canvas");
var style = "border: 1px solid black; position:absolute; top: " +
(debug ? (80 * fontCount) : "-200") + "px; left: 100px;";
canvas.setAttribute("style", style);
canvas.setAttribute("width", 100);
canvas.setAttribute("heigth", 70);
document.body.appendChild(canvas);
// Retrieve font charset
var charset = Fonts[fontName].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());
// Get the font size canvas think it will be
var ctx = canvas.getContext("2d");
var testString = "";
for (var i = 0; i < charset.length; i++) {
var unicode = new Number("0x" + GlyphsUnicode[charset[i]]);
if (!unicode)
error("Unicode for " + charset[i] + " is has not been found in the glyphs list");
testString += String.fromCharCode(unicode);
}
ctx.font = "20px " + fontName + ", Symbol";
var textWidth = ctx.mozMeasureText(testString);
if (debug)
ctx.fillText(testString, 20, 20);
var start = Date.now();
var interval = window.setInterval(function(self) {
ctx.font = "20px " + fontName + ", Symbol";
// For some reasons the font has not loaded, so mark it loaded for the
// page to proceed but cry
if ((Date.now() - start) >= kMaxWaitForFontFace) {
window.clearInterval(interval);
Fonts[fontName].loading = false;
warn("Is " + fontName + " for charset: " + charset + " loaded?");
} else if (textWidth != ctx.mozMeasureText(testString)) {
window.clearInterval(interval);
Fonts[fontName].loading = false;
}
if (debug)
ctx.fillText(testString, 20, 50);
}, 20, this);
/** Hack end */
// Add the @font-face rule to the document
var url = "url(data:" + this.mimetype + ";base64," + dataBase64 + ");";
var rule = "@font-face { font-family:'" + fontName + "';src:" + url + "}";
var styleSheet = document.styleSheets[0];
styleSheet.insertRule(rule, styleSheet.length);
},
_createOpenTypeHeader: function font_createOpenTypeHeader(aFile, aOffsets, aNumTables) {
// sfnt version (4 bytes)
var version = [0x4F, 0x54, 0x54, 0X4F];
// numTables (2 bytes)
var numTables = aNumTables;
// searchRange (2 bytes)
var tablesMaxPower2 = FontsUtils.getMaxPower2(numTables);
var searchRange = tablesMaxPower2 * 16;
// entrySelector (2 bytes)
var entrySelector = Math.log(tablesMaxPower2) / Math.log(2);
// rangeShift (2 bytes)
var rangeShift = numTables * 16 - searchRange;
var header = [].concat(version,
FontsUtils.integerToBytes(numTables, 2),
FontsUtils.integerToBytes(searchRange, 2),
FontsUtils.integerToBytes(entrySelector, 2),
FontsUtils.integerToBytes(rangeShift, 2));
aFile.set(header, aOffsets.currentOffset);
aOffsets.currentOffset += header.length;
aOffsets.virtualOffset += header.length;
},
_createTableEntry: function font_createTableEntry(aFile, aOffsets, aTag, aData) {
// tag
var tag = [
aTag.charCodeAt(0),
aTag.charCodeAt(1),
aTag.charCodeAt(2),
aTag.charCodeAt(3)
];
// offset
var offset = aOffsets.virtualOffset;
// Per spec tables must be 4-bytes align so add some 0x00 if needed
while (aData.length & 3)
aData.push(0x00);
// length
var length = aData.length;
// checksum
var checksum = FontsUtils.bytesToInteger(tag) + offset + length;
var tableEntry = [].concat(tag,
FontsUtils.integerToBytes(checksum, 4),
FontsUtils.integerToBytes(offset, 4),
FontsUtils.integerToBytes(length, 4));
aFile.set(tableEntry, aOffsets.currentOffset);
aOffsets.currentOffset += tableEntry.length;
aOffsets.virtualOffset += aData.length;
},
_createCMAPTable: function font_createCMAPTable(aGlyphs) {
var characters = new Array(kMaxGlyphsCount);
for (var i = 0; i < aGlyphs.length; i++) {
characters[aGlyphs[i].unicode] = i + 1;
}
// Separate the glyphs into continuous range of codes, aka segment.
var ranges = [];
var range = [];
for (var i = 0; i < characters.length; i++) {
if (characters[i]) {
range.push(i);
} else if (range.length) {
ranges.push(range.slice());
range = [];
}
}
// The size in bytes of the header is equal to the size of the
// different fields * length of a short + (size of the 4 parallels arrays
// describing segments * length of a short).
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 = [].concat(
[
0x00, 0x00, // version
0x00, 0x01, // numTables
0x00, 0x03, // platformID
0x00, 0x01, // encodingID
0x00, 0x00, 0x00, 0x0C, // start of the table record
0x00, 0x04 // format
],
FontsUtils.integerToBytes(headerSize, 2), // length
[0x00, 0x00], // language
FontsUtils.integerToBytes(segCount2, 2),
FontsUtils.integerToBytes(searchRange, 2),
FontsUtils.integerToBytes(searchEntry, 2),
FontsUtils.integerToBytes(rangeShift, 2)
);
// Fill up the 4 parallel arrays describing the segments.
var startCount = [];
var endCount = [];
var idDeltas = [];
var idRangeOffsets = [];
var glyphsIdsArray = [];
var bias = 0;
for (var i = 0; i < segCount - 1; i++) {
var range = ranges[i];
var start = FontsUtils.integerToBytes(range[0], 2);
var end = FontsUtils.integerToBytes(range[range.length - 1], 2);
var delta = FontsUtils.integerToBytes(((range[0] - 1) - bias) % 65536, 2);
bias += range.length;
// deltas are signed shorts
delta[0] ^= 0xFF;
delta[1] ^= 0xFF;
delta[1] += 1;
startCount.push(start[0], start[1]);
endCount.push(end[0], end[1]);
idDeltas.push(delta[0], delta[1]);
idRangeOffsets.push(0x00, 0x00);
for (var j = 0; j < range.length; j++)
glyphsIdsArray.push(range[j]);
}
startCount.push(0xFF, 0xFF);
endCount.push(0xFF, 0xFF);
idDeltas.push(0x00, 0x01);
idRangeOffsets.push(0x00, 0x00);
return cmap.concat(endCount, [0x00, 0x00], startCount,
idDeltas, idRangeOffsets, glyphsIdsArray);
},
cover: function font_cover(aFont) {
var otf = new Uint8Array(kMaxFontFileSize);
// Required Tables
var CFF = aFont.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)
};
// For files with only one font the offset table is the first thing of the
// file
this._createOpenTypeHeader(otf, offsets, tables.length);
// XXX It is probable that in a future we want to get rid of this glue
// between the CFF and the OTF format in order to be able to embed TrueType
// data.
this._createTableEntry(otf, offsets, "CFF ", CFF);
/** OS/2 */
OS2 = [
0x00, 0x03, // version
0x02, 0x24, // xAvgCharWidth
0x01, 0xF4, // usWeightClass
0x00, 0x05, // usWidthClass
0x00, 0x00, // fstype
0x02, 0x8A, // ySubscriptXSize
0x02, 0xBB, // ySubscriptYSize
0x00, 0x00, // ySubscriptXOffset
0x00, 0x8C, // ySubscriptYOffset
0x02, 0x8A, // ySuperScriptXSize
0x02, 0xBB, // ySuperScriptYSize
0x00, 0x00, // ySuperScriptXOffset
0x01, 0xDF, // ySuperScriptYOffset
0x00, 0x31, // yStrikeOutSize
0x01, 0x02, // yStrikeOutPosition
0x00, 0x00, // sFamilyClass
0x02, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Panose
0xFF, 0xFF, 0xFF, 0xFF, // ulUnicodeRange1 (Bits 0-31)
0xFF, 0xFF, 0xFF, 0xFF, // ulUnicodeRange1 (Bits 32-63)
0xFF, 0xFF, 0xFF, 0xFF, // ulUnicodeRange1 (Bits 64-95)
0xFF, 0xFF, 0xFF, 0xFF, // ulUnicodeRange1 (Bits 96-127)
0x2A, 0x32, 0x31, 0x2A, // achVendID
0x00, 0x20, // fsSelection
0x00, 0x2D, // usFirstCharIndex
0x00, 0x7A, // usLastCharIndex
0x00, 0x03, // sTypoAscender
0x00, 0x20, // sTypeDescender
0x00, 0x38, // sTypoLineGap
0x00, 0x5A, // usWinAscent
0x02, 0xB4, // usWinDescent
0x00, 0xCE, 0x00, 0x00, // ulCodePageRange1 (Bits 0-31)
0x00, 0x01, 0x00, 0x00, // ulCodePageRange2 (Bits 32-63)
0x00, 0x00, // sxHeight
0x00, 0x00, // sCapHeight
0x00, 0x01, // usDefaultChar
0x00, 0xCD, // usBreakChar
0x00, 0x02 // usMaxContext
];
this._createTableEntry(otf, offsets, "OS/2", OS2);
//XXX Getting charstrings here seems wrong since this is another CFF glue
var charstrings = aFont.getOrderedCharStrings(aFont.glyphs);
/** CMAP */
cmap = this._createCMAPTable(charstrings);
this._createTableEntry(otf, offsets, "cmap", cmap);
/** HEAD */
head = [
0x00, 0x01, 0x00, 0x00, // Version number
0x00, 0x00, 0x50, 0x00, // fontRevision
0x00, 0x00, 0x00, 0x00, // checksumAdjustement
0x5F, 0x0F, 0x3C, 0xF5, // magicNumber
0x00, 0x00, // Flags
0x03, 0xE8, // unitsPerEM (defaulting to 1000)
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // creation date
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // modifification date
0x00, 0x00, // xMin
0x00, 0x00, // yMin
0x00, 0x00, // xMax
0x00, 0x00, // yMax
0x00, 0x00, // macStyle
0x00, 0x00, // lowestRecPPEM
0x00, 0x00, // fontDirectionHint
0x00, 0x00, // indexToLocFormat
0x00, 0x00 // glyphDataFormat
];
this._createTableEntry(otf, offsets, "head", head);
/** HHEA */
hhea = [].concat(
[
0x00, 0x01, 0x00, 0x00, // Version number
0x00, 0x00, // Typographic Ascent
0x00, 0x00, // Typographic Descent
0x00, 0x00, // Line Gap
0xFF, 0xFF, // advanceWidthMax
0x00, 0x00, // minLeftSidebearing
0x00, 0x00, // minRightSidebearing
0x00, 0x00, // xMaxExtent
0x00, 0x00, // caretSlopeRise
0x00, 0x00, // caretSlopeRun
0x00, 0x00, // caretOffset
0x00, 0x00, // -reserved-
0x00, 0x00, // -reserved-
0x00, 0x00, // -reserved-
0x00, 0x00, // -reserved-
0x00, 0x00 // metricDataFormat
],
FontsUtils.integerToBytes(charstrings.length, 2) // numberOfHMetrics
);
this._createTableEntry(otf, offsets, "hhea", hhea);
/** HMTX */
hmtx = [0x01, 0xF4, 0x00, 0x00];
for (var i = 0; i < charstrings.length; i++) {
// XXX this can easily broke
var charstring = charstrings[i].charstring;
var width = FontsUtils.integerToBytes(charstring[1], 2);
var lsb = FontsUtils.integerToBytes(charstring[0], 2);
hmtx = hmtx.concat(width, lsb);
}
this._createTableEntry(otf, offsets, "hmtx", hmtx);
/** MAXP */
maxp = [].concat(
[
0x00, 0x00, 0x50, 0x00, // Version number
],
FontsUtils.integerToBytes(charstrings.length + 1, 2) // Num of glyphs (+1 to pass the sanitizer...)
);
this._createTableEntry(otf, offsets, "maxp", maxp);
/** NAME */
name = [
0x00, 0x00, // format
0x00, 0x00, // Number of names Record
0x00, 0x00 // Storage
];
this._createTableEntry(otf, offsets, "name", name);
/** POST */
// XXX get those info from the Font dict!
post = [
0x00, 0x03, 0x00, 0x00, // Version number
0x00, 0x00, 0x01, 0x00, // italicAngle
0x00, 0x00, // underlinePosition
0x00, 0x00, // underlineThickness
0x00, 0x00, 0x00, 0x00, // isFixedPitch
0x00, 0x00, 0x00, 0x00, // minMemType42
0x00, 0x00, 0x00, 0x00, // maxMemType42
0x00, 0x00, 0x00, 0x00, // minMemType1
0x00, 0x00, 0x00, 0x00 // maxMemType1
];
this._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]);
//writeToFile(fontData, "/tmp/pdf.js." + fontCount + ".otf");
return fontData;
}
};
var FontsUtils = {
integerToBytes: function fu_integerToBytes(aValue, aBytesCount) {
var bytes = [];
for (var i = 0; i < aBytesCount; i++)
bytes[i] = 0x00;
do {
bytes[--aBytesCount] = (aValue & 0xFF);
aValue = aValue >> 8;
} while (aBytesCount && aValue > 0);
return bytes;
},
bytesToInteger: function(aBytesArray) {
var value = 0;
for (var i = 0; i < aBytesArray.length; i++)
value = (value << 8) + aBytesArray[i];
return value;
},
getMaxPower2: function fu_getMaxPower2(aNumber) {
var maxPower = 0;
var value = aNumber;
while (value >= 2) {
value /= 2;
maxPower++;
}
value = 2;
for (var i = 1; i < maxPower; i++)
value *= 2;
return value;
}
};
/** Implementation dirty logic starts here */
/**
* At the moment TrueType is just a stub that does mostly nothing but in a
* (near?) future this class will rewrite the font to ensure it is well formed
* and valid in the point of view of the sanitizer.
*/
var TrueType = function(aFile) {
var header = this._readOpenTypeHeader(aFile);
var numTables = header.numTables;
// Check that required tables are present
var requiredTables = [
"OS/2",
"cmap",
"head",
"hhea",
"hmtx",
"maxp",
"name",
"post"
];
var tables = [];
for (var i = 0; i < numTables; i++) {
var table = this._readTableEntry(aFile);
var index = requiredTables.indexOf(table.tag);
if (index != -1)
requiredTables.splice(index, 1);
tables.push(table);
}
tables.sort(function(a, b) {
return a.tag > b.tag;
});
// 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") {
OS2 = [
0x00, 0x03, // version
0x02, 0x24, // xAvgCharWidth
0x01, 0xF4, // usWeightClass
0x00, 0x05, // usWidthClass
0x00, 0x00, // fstype
0x02, 0x8A, // ySubscriptXSize
0x02, 0xBB, // ySubscriptYSize
0x00, 0x00, // ySubscriptXOffset
0x00, 0x8C, // ySubscriptYOffset
0x02, 0x8A, // ySuperScriptXSize
0x02, 0xBB, // ySuperScriptYSize
0x00, 0x00, // ySuperScriptXOffset
0x01, 0xDF, // ySuperScriptYOffset
0x00, 0x31, // yStrikeOutSize
0x01, 0x02, // yStrikeOutPosition
0x00, 0x00, // sFamilyClass
0x02, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Panose
0xFF, 0xFF, 0xFF, 0xFF, // ulUnicodeRange1 (Bits 0-31)
0xFF, 0xFF, 0xFF, 0xFF, // ulUnicodeRange1 (Bits 32-63)
0xFF, 0xFF, 0xFF, 0xFF, // ulUnicodeRange1 (Bits 64-95)
0xFF, 0xFF, 0xFF, 0xFF, // ulUnicodeRange1 (Bits 96-127)
0x2A, 0x32, 0x31, 0x2A, // achVendID
0x00, 0x20, // fsSelection
0x00, 0x2D, // usFirstCharIndex
0x00, 0x7A, // usLastCharIndex
0x00, 0x03, // sTypoAscender
0x00, 0x20, // sTypeDescender
0x00, 0x38, // sTypoLineGap
0x00, 0x5A, // usWinAscent
0x02, 0xB4, // usWinDescent
0x00, 0xCE, 0x00, 0x00, // ulCodePageRange1 (Bits 0-31)
0x00, 0x01, 0x00, 0x00, // ulCodePageRange2 (Bits 32-63)
0x00, 0x00, // sxHeight
0x00, 0x00, // sCapHeight
0x00, 0x01, // usDefaultChar
0x00, 0xCD, // usBreakChar
0x00, 0x02 // usMaxContext
];
// Create a new file to hold the new version of our truetype with a new
// header and new offsets
var stream = aFile.stream || aFile;
var ttf = new Uint8Array(stream.length + 16 + OS2.length);
// The new numbers of tables will be the last one plus the num of missing
// tables
var numTables = header.numTables + 1;
// 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: numTables * (4 * 4)
};
// Write the sfnt header with one more table
this._createOpenTypeHeader(ttf, offsets, numTables);
// Insert the missing table
tables.unshift({
tag: "OS/2",
data: OS2
});
// 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]);
this._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;
if (0) {
var data = [];
for (var j = 0; j < tableData.length; j++)
d.push(tableData[j]);
log("data for table: " + table.tag + ": " + data);
}
// 4-byte aligned data
while (offsets.currentOffset & 3)
offsets.currentOffset++;
}
var fontData = [];
for (var i = 0; i < ttf.length; i++)
fontData.push(ttf[i]);
this.data = ttf;
//writeToFile(fontData, "/tmp/pdf.js." + fontCount + ".ttf");
return;
} else if (requiredTables.lenght) {
error("Table " + requiredTables[0] + " is missing from the TruType font");
} else {
this.data = aFile;
}
};
TrueType.prototype = {
_createOpenTypeHeader: function tt_createOpenTypeHeader(aFile, aOffsets, aNumTables) {
// sfnt version (4 bytes)
// XXX if we want to merge this function and the one from the Font class
// XXX this need to be adapted
var version = [0x00, 0x01, 0x00, 0X00];
// numTables (2 bytes)
var numTables = aNumTables;
// searchRange (2 bytes)
var tablesMaxPower2 = FontsUtils.getMaxPower2(numTables);
var searchRange = tablesMaxPower2 * 16;
// entrySelector (2 bytes)
var entrySelector = Math.log(tablesMaxPower2) / Math.log(2);
// rangeShift (2 bytes)
var rangeShift = numTables * 16 - searchRange;
var header = [].concat(version,
FontsUtils.integerToBytes(numTables, 2),
FontsUtils.integerToBytes(searchRange, 2),
FontsUtils.integerToBytes(entrySelector, 2),
FontsUtils.integerToBytes(rangeShift, 2));
aFile.set(header, aOffsets.currentOffset);
aOffsets.currentOffset += header.length;
aOffsets.virtualOffset += header.length;
},
_createTableEntry: function font_createTableEntry(aFile, aOffsets, aTag, aData) {
// tag
var tag = [
aTag.charCodeAt(0),
aTag.charCodeAt(1),
aTag.charCodeAt(2),
aTag.charCodeAt(3)
];
// Per spec tables must be 4-bytes align so add some 0x00 if needed
while (aData.length & 3)
aData.push(0x00);
while (aOffsets.virtualOffset & 3)
aOffsets.virtualOffset++;
// offset
var offset = aOffsets.virtualOffset;
// length
var length = aData.length;
// checksum
var checksum = FontsUtils.bytesToInteger(tag) + offset + length;
var tableEntry = [].concat(tag,
FontsUtils.integerToBytes(checksum, 4),
FontsUtils.integerToBytes(offset, 4),
FontsUtils.integerToBytes(length, 4));
aFile.set(tableEntry, aOffsets.currentOffset);
aOffsets.currentOffset += tableEntry.length;
aOffsets.virtualOffset += aData.length;
},
_readOpenTypeHeader: function tt_readOpenTypeHeader(aFile) {
return {
version: aFile.getBytes(4),
numTables: FontsUtils.bytesToInteger(aFile.getBytes(2)),
searchRange: FontsUtils.bytesToInteger(aFile.getBytes(2)),
entrySelector: FontsUtils.bytesToInteger(aFile.getBytes(2)),
rangeShift: FontsUtils.bytesToInteger(aFile.getBytes(2))
}
},
_readTableEntry: function tt_readTableEntry(aFile) {
// tag
var tag = aFile.getBytes(4);
tag = String.fromCharCode(tag[0]) +
String.fromCharCode(tag[1]) +
String.fromCharCode(tag[2]) +
String.fromCharCode(tag[3]);
var checksum = FontsUtils.bytesToInteger(aFile.getBytes(4));
var offset = FontsUtils.bytesToInteger(aFile.getBytes(4));
var length = FontsUtils.bytesToInteger(aFile.getBytes(4));
// Read the table associated data
var currentPosition = aFile.pos;
aFile.pos = aFile.start + offset;
var data = aFile.getBytes(length);
aFile.pos = currentPosition;
return {
tag: tag,
checksum: checksum,
length: offset,
offset: length,
data: data
}
}
};
/**
* This dictionary holds decoded fonts data.
*/
var PSFonts = new Dict();
var Stack = function(aStackSize) {
var innerStack = new Array(aStackSize || 0);
this.push = function(aOperand) {
innerStack.push(aOperand);
};
this.pop = function() {
if (!this.count())
throw new Error("stackunderflow");
return innerStack.pop();
};
this.peek = function() {
if (!this.count())
return null;
return innerStack[innerStack.length - 1];
};
this.get = function(aIndex) {
return innerStack[aIndex];
};
this.clear = function() {
innerStack = [];
};
this.count = function() {
return innerStack.length;
};
this.dump = function() {
for (var i = 0; i < this.length; i++)
log(innerStack[i]);
};
this.clone = function() {
return innerStack.slice();
};
};
var Type1Parser = function() {
// Turn on this flag for additional debugging logs
var debug = false;
var dump = function(aData) {
if (debug)
log(aData);
};
/*
* 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(aStream, aKey, aDiscardNumber, aByteArray) {
var start = Date.now();
var r = aKey, c1 = 52845, c2 = 22719;
var decryptedString = [];
var value = "";
var count = aStream.length;
for (var i = 0; i < count; i++) {
value = aStream.getByte();
if (aByteArray)
decryptedString[i] = value ^ (r >> 8);
else
decryptedString[i] = String.fromCharCode(value ^ (r >> 8));
r = ((value + r) * c1 + c2) & ((1 << 16) - 1);
}
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
* 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",
"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": "hvcurveto"
};
function decodeCharString(aStream) {
var start = Date.now();
var charString = [];
var value = "";
var count = aStream.length;
for (var i = 0; i < count; i++) {
value = aStream.getByte();
if (value < 32) {
if (value == 12) {
value = charStringDictionary["12"][aStream.getByte()];
i++;
} else {
value = charStringDictionary[value];
}
} else if (value <= 246) {
value = parseInt(value) - 139;
} else if (value <= 250) {
value = ((value - 247) * 256) + parseInt(aStream.getByte()) + 108;
i++;
} else if (value <= 254) {
value = -((value - 251) * 256) - parseInt(aStream.getByte()) - 108;
i++;
} else {
var byte = aStream.getByte();
var high = (byte >> 1);
value = (byte - high) << 24 | aStream.getByte() << 16 |
aStream.getByte() << 8 | aStream.getByte();
i += 4;
}
charString.push(value);
}
var end = Date.now();
dump("Time to decode charString of length " + count + " is " + (end - start));
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
*/
this.extractFontInfo = function(aStream) {
var eexecString = decrypt(new Stream(aStream), kEexecEncryptionKey, 4, true);
var subrs = [], glyphs = [];
var inSubrs = inGlyphs = false;
var glyph = "";
var token = "";
var index = 0;
var length = 0;
var count = eexecString.length;
var c = "";
for (var i = 0; i < count; i++) {
var c = eexecString[i];
if (inSubrs && c == 0x52) {
length = parseInt(length);
var stream = new Stream(eexecString.slice(i + 3, i + 3 + length));
var encodedSubr = decrypt(stream, kCharStringsEncryptionKey, 4).join("");
var subr = decodeCharString(new StringStream(encodedSubr));
subrs.push(subr);
i += 3 + length;
} else if (inGlyphs && c == 0x52) {
length = parseInt(length);
var stream = new Stream(eexecString.slice(i + 3, i + 3 + length));
var encodedCharstring = decrypt(stream, kCharStringsEncryptionKey, 4).join("");
var subr = decodeCharString(new StringStream(encodedCharstring));
glyphs.push({
glyph: glyph,
data: subr
});
i += 3 + length;
} else if (inGlyphs && c == 0x2F) {
token = "";
glyph = "";
while ((c = eexecString[++i]) != 0x20 && i < count)
glyph += String.fromCharCode(c);
} else if (c == 0x2F && eexecString[i+1] == 0x53 && !inGlyphs && !inSubrs) {
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
}
};
/*
* 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, aSubrs) {
operandStack.clear();
executionStack.clear();
executionStack.push(aCharstring.slice());
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();
var leftSidebearing = operandStack.pop();
operandStack.push(charWidthVector);
if (leftSidebearing) {
operandStack.push(leftSidebearing);
operandStack.push("hmoveto");
}
break;
case "div":
var num2 = operandStack.pop();
var num1 = operandStack.pop();
operandStack.push(num2 / num1);
break;
case "setcurrentpoint":
case "dotsection":
case "seac":
case "sbw":
error(obj + " parsing is not implemented (yet)");
break;
case "closepath":
case "return":
break;
case "vstem3":
case "vstem":
operandStack.push("vstem");
break;
case "hstem":
case "hstem3":
operandStack.push("hstem");
break;
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 "endchar":
operandStack.push("endchar");
return operandStack.clone();
case "pop":
operandStack.pop();
break;
default:
operandStack.push(obj);
break;
}
}
}
}
};
var CFF = function(aFontName, aFontBBox, aFontFile) {
var start = Date.now();
// Get the data block containing glyphs and subrs informations
var length1 = aFontFile.dict.get("Length1");
var length2 = aFontFile.dict.get("Length2");
aFontFile.skip(length1);
var eexecBlock = aFontFile.getBytes(length2);
// Extract informations from it
var parser = new Type1Parser();
var fontInfo = parser.extractFontInfo(eexecBlock);
fontInfo.name = aFontName;
fontInfo.bbox = aFontBBox;
// XXX
this.glyphs = fontInfo.charstrings;
this.data = this.convertToCFF(fontInfo);
var end = Date.now();
//log("Time to parse font is:" + (end - start));
};
CFF.prototype = {
createCFFIndexHeader: function(aObjects, aIsByte) {
var data = [];
// First 2 bytes contains the number of objects contained into this index
var count = aObjects.length;
if (count ==0)
return [0x00, 0x00, 0x00];
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 (aObjects[i])
relativeOffset += aObjects[i].length;
}
for (var i =0; i < count; i++) {
for (var j = 0; j < aObjects[i].length; j++)
data.push(aIsByte ? aObjects[i][j] : aObjects[i].charCodeAt(j));
}
return data;
},
encodeNumber: function(aValue) {
var x = 0;
// XXX we don't really care about Type2 optimization here...
if (aValue >= -32768 && aValue <= 32767) {
return [
28,
FontsUtils.integerToBytes(aValue >> 8, 1),
FontsUtils.integerToBytes(aValue, 1)
];
} else if (aValue >= (-2147483647-1) && aValue <= 2147483647) {
return [
0xFF,
FontsUtils.integerToBytes(aValue >> 24, 1),
FontsUtils.integerToBytes(aValue >> 16, 1),
FontsUtils.integerToBytes(aValue >> 8, 1),
FontsUtils.integerToBytes(aValue, 1)
];
} else {
error("Value: " + aValue + " is not allowed");
}
},
getOrderedCharStrings: function(aGlyphs) {
var charstrings = [];
for (var i = 0; i < aGlyphs.length; i++) {
var glyph = aGlyphs[i].glyph;
var unicode = GlyphsUnicode[glyph];
if (!unicode) {
if (glyph != ".notdef")
warn(glyph + " does not have an entry in the glyphs unicode dictionary");
} else {
var b1 = parseInt("0x" + unicode[0] + unicode[1]);
var b2 = parseInt("0x" + unicode[2] + unicode[3]);
unicode = FontsUtils.bytesToInteger([b1, b2]);
charstrings.push({
glyph: glyph,
unicode: unicode,
charstring: aGlyphs[i].data.slice()
});
}
};
charstrings.sort(function(a, b) {
return a.unicode > b.unicode;
});
return charstrings;
},
convertToCFF: function(aFontInfo) {
var debug = false;
function dump(aMsg) {
if (debug)
log(aMsg);
};
var charstrings = this.getOrderedCharStrings(aFontInfo.charstrings);
var charstringsCount = 0;
var charstringsDataLength = 0;
var glyphs = [];
var glyphsChecker = {};
var subrs = aFontInfo.subrs;
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);
glyphs.push(flattened);
charstringsCount++;
charstringsDataLength += flattened.length;
}
dump("There is " + charstringsCount + " glyphs (size: " + charstringsDataLength + ")");
// 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([aFontInfo.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]);
}
// 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,
};
// Encode the glyph and add it to the FUX
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(c);
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);
}
for (var k = 0; k < bytes.length; k++)
charstring.push(bytes[k]);
}
}
r.push(charstring);
}
var charstringsIndex = this.createCFFIndexHeader(r, 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 = aFontInfo.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(" ");
// Top Dict Index
cff.set(topDictIndex, currentOffset);
currentOffset += topDictIndex.length;
// Strings Index
cff.set(stringsIndex, currentOffset);
currentOffset += stringsIndex.length;
// Global Subrs Index
cff.set(globalSubrsIndex, currentOffset);
currentOffset += globalSubrsIndex.length;
// Charset Index
cff.set(charset, currentOffset);
currentOffset += charset.length;
// Fill charstrings data
cff.set(charstringsIndex, currentOffset);
currentOffset += charstringsIndex.length;
// Private Data
var defaultWidth = this.encodeNumber(0);
var privateData = [].concat(
defaultWidth, [20],
defaultWidth, [21],
[
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;
dump("==================== debug ====================");
//var file = new Uint8Array(cff, 0, currentOffset);
//var parser = new Type2Parser();
//parser.parse(new Stream(file));
var fontData = [];
for (var i = 0; i < currentOffset; i++)
fontData.push(cff[i]);
//log("== write to file");
//writeToFile(fontData, "/tmp/pdf.js." + fontCount + ".cff");
return fontData;
}
};