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Merge pull request #4423 from chriskr/font-aliases

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Treat fonts with the same font descriptor and encoding as aliases
This commit is contained in:
Brendan Dahl 2014-04-09 10:26:09 -07:00
commit a6e5f31ca1
6 changed files with 245 additions and 10 deletions
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94
src/core/evaluator.js
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@ -17,11 +17,11 @@
/* globals assert, assertWellFormed, ColorSpace, DecodeStream, Dict, Encodings,
error, ErrorFont, Font, FONT_IDENTITY_MATRIX, fontCharsToUnicode,
FontFlags, ImageKind, info, isArray, isCmd, isDict, isEOF, isName,
isNum, isStream, isString, JpegStream, Lexer, Metrics, Name, Parser,
Pattern, PDFImage, PDFJS, serifFonts, stdFontMap, symbolsFonts,
getTilingPatternIR, warn, Util, Promise, LegacyPromise,
RefSetCache, isRef, TextRenderingMode, CMapFactory, OPS,
UNSUPPORTED_FEATURES, UnsupportedManager */
isNum, isStream, isString, JpegStream, Lexer, Metrics,
MurmurHash3_64, Name, Parser, Pattern, PDFImage, PDFJS, serifFonts,
stdFontMap, symbolsFonts, getTilingPatternIR, warn, Util, Promise,
LegacyPromise, RefSetCache, isRef, TextRenderingMode, CMapFactory,
OPS, UNSUPPORTED_FEATURES, UnsupportedManager */
'use strict';
@ -413,6 +413,36 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
if (!isDict(font)) {
return errorFont();
}
var preEvaluatedFont = this.preEvaluateFont(font, xref);
var descriptor = preEvaluatedFont.descriptor;
var fontID = fontRef.num + '_' + fontRef.gen;
if (isDict(descriptor)) {
if (!descriptor.fontAliases) {
descriptor.fontAliases = Object.create(null);
}
var fontAliases = descriptor.fontAliases;
var hash = preEvaluatedFont.hash;
if (fontAliases[hash]) {
var aliasFontRef = fontAliases[hash].aliasRef;
if (aliasFontRef && this.fontCache.has(aliasFontRef)) {
this.fontCache.putAlias(fontRef, aliasFontRef);
var cachedFont = this.fontCache.get(fontRef);
return cachedFont;
}
}
if (!fontAliases[hash]) {
fontAliases[hash] = {
fontID: Font.getFontID()
};
}
fontAliases[hash].aliasRef = fontRef;
fontID = fontAliases[hash].fontID;
}
// Workaround for bad PDF generators that don't reference fonts
// properly, i.e. by not using an object identifier.
// Check if the fontRef is a Dict (as opposed to a standard object),
@ -426,12 +456,12 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
// Keep track of each font we translated so the caller can
// load them asynchronously before calling display on a page.
font.loadedName = 'g_font_' + (fontRefIsDict ?
fontName.replace(/\W/g, '') : (fontRef.num + '_' + fontRef.gen));
fontName.replace(/\W/g, '') : fontID);
if (!font.translated) {
var translated;
try {
translated = this.translateFont(font, xref);
translated = this.translateFont(preEvaluatedFont, xref);
} catch (e) {
UnsupportedManager.notify(UNSUPPORTED_FEATURES.font);
translated = new ErrorFont(e instanceof Error ? e.message : e);
@ -1127,7 +1157,7 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
return widths;
},
translateFont: function PartialEvaluator_translateFont(dict, xref) {
preEvaluateFont: function PartialEvaluator_preEvaluateFont(dict, xref) {
var baseDict = dict;
var type = dict.get('Subtype');
assertWellFormed(isName(type), 'invalid font Subtype');
@ -1148,9 +1178,55 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
assertWellFormed(isName(type), 'invalid font Subtype');
composite = true;
}
var maxCharIndex = (composite ? 0xFFFF : 0xFF);
var descriptor = dict.get('FontDescriptor');
if (descriptor) {
var hash = new MurmurHash3_64();
var encoding = baseDict.getRaw('Encoding');
if (isName(encoding)) {
hash.update(encoding.name);
} else if (isRef(encoding)) {
hash.update(encoding.num + '_' + encoding.gen);
}
var toUnicode = dict.get('ToUnicode') || baseDict.get('ToUnicode');
if (isStream(toUnicode)) {
var stream = toUnicode.str || toUnicode;
var uint8array = stream.buffer ?
new Uint8Array(stream.buffer.buffer, 0, stream.bufferLength) :
new Uint8Array(stream.bytes.buffer,
stream.start, stream.end - stream.start);
hash.update(uint8array);
} else if (isName(toUnicode)) {
hash.update(toUnicode.name);
}
var widths = dict.get('Widths') || baseDict.get('Widths');
if (widths) {
var uint8array = new Uint8Array(new Uint32Array(widths).buffer);
hash.update(uint8array);
}
}
return {
descriptor: descriptor,
dict: dict,
baseDict: baseDict,
composite: composite,
hash: hash ? hash.hexdigest() : ''
};
},
translateFont: function PartialEvaluator_translateFont(preEvaluatedFont,
xref) {
var baseDict = preEvaluatedFont.baseDict;
var dict = preEvaluatedFont.dict;
var composite = preEvaluatedFont.composite;
var descriptor = preEvaluatedFont.descriptor;
var type = dict.get('Subtype');
var maxCharIndex = (composite ? 0xFFFF : 0xFF);
if (!descriptor) {
if (type.name == 'Type3') {
// FontDescriptor is only required for Type3 fonts when the document