From f401a64eb2ef0485bec074b67d74d3a60fdcfc9c Mon Sep 17 00:00:00 2001
From: notmasteryet <async.processingjs@yahoo.com>
Date: Sun, 18 Sep 2011 21:25:05 -0500
Subject: [PATCH] Sanitize 'loca' font table: some fonts have first glyph with
length 10
---
fonts.js | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 53 insertions(+), 1 deletion(-)
diff --git a/fonts.js b/fonts.js
index 874048532..b17549091 100644
--- a/fonts.js
+++ b/fonts.js
@@ -1053,6 +1053,49 @@ var Font = (function Font() {
}
};
+ function sanitizeGlyphLocations(loca, glyf, numGlyphs,
+ isGlyphLocationsLong) {
+ var itemSize, itemDecode, itemEncode;
+ if (isGlyphLocationsLong) {
+ itemSize = 4;
+ itemDecode = function(data, offset) {
+ return (data[offset] << 24) | (data[offset + 1] << 16) |
+ (data[offset + 2] << 8) | data[offset + 3];
+ };
+ itemEncode = function(data, offset, value) {
+ data[offset] = (value >>> 24) & 0xFF;
+ data[offset + 1] = (value >> 16) & 0xFF;
+ data[offset + 2] = (value >> 8) & 0xFF;
+ data[offset + 3] = value & 0xFF;
+ };
+ } else {
+ itemSize = 2;
+ itemDecode = function(data, offset) {
+ return (data[offset] << 8) | data[offset + 1];
+ };
+ itemEncode = function(data, offset, value) {
+ data[offset] = (value >> 8) & 0xFF;
+ data[offset + 1] = value & 0xFF;
+ };
+ }
+ var locaData = loca.data;
+ var startOffset = itemDecode(locaData, 0);
+ var firstOffset = itemDecode(locaData, itemSize);
+ if (firstOffset - startOffset < 12 || startOffset > 0) {
+ // removing first glyph
+ glyf.data = glyf.data.subarray(firstOffset);
+ glyf.length -= firstOffset;
+
+ itemEncode(locaData, 0, 0);
+ var i, pos = itemSize;
+ for (i = 1; i <= numGlyphs; ++i) {
+ itemEncode(locaData, pos,
+ itemDecode(locaData, pos) - firstOffset);
+ pos += itemSize;
+ }
+ }
+ }
+
// Check that required tables are present
var requiredTables = ['OS/2', 'cmap', 'head', 'hhea',
'hmtx', 'maxp', 'name', 'post'];
@@ -1060,7 +1103,7 @@ var Font = (function Font() {
var header = readOpenTypeHeader(font);
var numTables = header.numTables;
- var cmap, maxp, hhea, hmtx, vhea, vmtx, head;
+ var cmap, maxp, hhea, hmtx, vhea, vmtx, head, loca, glyf;
var tables = [];
for (var i = 0; i < numTables; i++) {
var table = readTableEntry(font);
@@ -1083,6 +1126,10 @@ var Font = (function Font() {
vmtx = table;
else if (table.tag == 'vhea')
vhea = table;
+ else if (table.tag == 'loca')
+ loca = table;
+ else if (table.tag == 'glyf')
+ glyf = table;
}
tables.push(table);
}
@@ -1127,6 +1174,11 @@ var Font = (function Font() {
sanitizeMetrics(font, hhea, hmtx, numGlyphs);
sanitizeMetrics(font, vhea, vmtx, numGlyphs);
+ if (head && loca && glyf) {
+ var isGlyphLocationsLong = int16([head.data[50], head.data[51]]);
+ sanitizeGlyphLocations(loca, glyf, numGlyphs, isGlyphLocationsLong);
+ }
+
// Sanitizer reduces the glyph advanceWidth to the maxAdvanceWidth
// Sometimes it's 0. That needs to be fixed
if (hhea.data[10] == 0 && hhea.data[11] == 0) {