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Merge pull request #482 from ironymark/master

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FIxed Ascent and Descent in OS/2 table
This commit is contained in:
vingtetun 2011-09-16 17:41:09 -07:00
commit 82745def0a
2 changed files with 46 additions and 8 deletions
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1
LICENSE
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@ -8,6 +8,7 @@
Justin D'Arcangelo <justindarc@gmail.com>
Yury Delendik
Kalervo Kujala
Adil Allawi <@ironymark>
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),

53
fonts.js
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@ -12,6 +12,9 @@ var kMaxWaitForFontFace = 1000;
// Unicode Private Use Area
var kCmapGlyphOffset = 0xE000;
// PDF Glyph Space Units are one Thousandth of a TextSpace Unit except for Type 3 fonts
var kPDFGlyphSpaceUnits = 1000;
// Until hinting is fully supported this constant can be used
var kHintingEnabled = false;
@ -534,6 +537,10 @@ var Font = (function Font() {
};
function createOpenTypeHeader(sfnt, file, numTables) {
// Windows hates the Mac TrueType sfnt version number
if (sfnt == 'true')
sfnt = string32(0x00010000);
// sfnt version (4 bytes)
var header = sfnt;
@ -663,7 +670,9 @@ var Font = (function Font() {
format314);
};
function createOS2Table(properties) {
function createOS2Table(properties, override) {
var override = override || {};
var ulUnicodeRange1 = 0;
var ulUnicodeRange2 = 0;
var ulUnicodeRange3 = 0;
@ -694,6 +703,21 @@ var Font = (function Font() {
}
}
var unitsPerEm = override.unitsPerEm || kPDFGlyphSpaceUnits;
var typoAscent = override.ascent || properties.ascent;
var typoDescent = override.descent || properties.descent;
var winAscent = override.yMax || typoAscent;
var winDescent = -override.yMin || -typoDescent;
// if there is a units per em value but no other override then scale the calculated ascent
if (unitsPerEm != kPDFGlyphSpaceUnits && 'undefined' == typeof(override.ascent)) {
// if the font units differ to the PDF glyph space units then scale up the values
typoAscent = Math.round(typoAscent * unitsPerEm / kPDFGlyphSpaceUnits);
typoDescent = Math.round(typoDescent * unitsPerEm / kPDFGlyphSpaceUnits);
winAscent = typoAscent;
winDescent = -typoDescent;
}
return '\x00\x03' + // version
'\x02\x24' + // xAvgCharWidth
'\x01\xF4' + // usWeightClass
@ -722,11 +746,11 @@ var Font = (function Font() {
string16(firstCharIndex ||
properties.firstChar) + // usFirstCharIndex
string16(lastCharIndex || properties.lastChar) + // usLastCharIndex
string16(properties.ascent) + // sTypoAscender
string16(properties.descent) + // sTypoDescender
string16(typoAscent) + // sTypoAscender
string16(typoDescent) + // sTypoDescender
'\x00\x64' + // sTypoLineGap (7%-10% of the unitsPerEM value)
string16(properties.ascent) + // usWinAscent
string16(-properties.descent) + // usWinDescent
string16(winAscent) + // usWinAscent
string16(winDescent) + // usWinDescent
'\x00\x00\x00\x00' + // ulCodePageRange1 (Bits 0-31)
'\x00\x00\x00\x00' + // ulCodePageRange2 (Bits 32-63)
string16(properties.xHeight) + // sxHeight
@ -833,9 +857,11 @@ var Font = (function Font() {
var data = file.getBytes(length);
file.pos = previousPosition;
if (tag == 'head')
if (tag == 'head') {
// clearing checksum adjustment
data[8] = data[9] = data[10] = data[11] = 0;
data[17] |= 0x20; //Set font optimized for cleartype flag
}
return {
tag: tag,
@ -1008,7 +1034,7 @@ var Font = (function Font() {
var header = readOpenTypeHeader(font);
var numTables = header.numTables;
var cmap, maxp, hhea, hmtx, vhea, vmtx;
var cmap, maxp, hhea, hmtx, vhea, vmtx, head;
var tables = [];
for (var i = 0; i < numTables; i++) {
var table = readTableEntry(font);
@ -1022,6 +1048,8 @@ var Font = (function Font() {
hhea = table;
else if (table.tag == 'hmtx')
hmtx = table;
else if (table.tag == 'head')
head = table;
requiredTables.splice(index, 1);
} else {
@ -1048,9 +1076,18 @@ var Font = (function Font() {
createOpenTypeHeader(header.version, ttf, numTables);
if (requiredTables.indexOf('OS/2') != -1) {
//extract some more font properties from the OpenType head and hhea tables
var override = {
unitsPerEm: int16([head.data[18], head.data[19]]),
yMax: int16([head.data[42], head.data[43]]),
yMin: int16([head.data[38], head.data[39]]) - 0x10000, //always negative
ascent: int16([hhea.data[4], hhea.data[5]]),
descent: int16([hhea.data[6], hhea.data[7]]) - 0x10000 //always negative
}
tables.push({
tag: 'OS/2',
data: stringToArray(createOS2Table(properties))
data: stringToArray(createOS2Table(properties, override))
});
}