Tobias Fischer created PDFBOX-3759:
--------------------------------------
Summary: TTFSubsetter scrambles OpenType ligature table (and
probably others as well)
Key: PDFBOX-3759
URL: https://issues.apache.org/jira/browse/PDFBOX-3759
Project: PDFBox
Issue Type: Bug
Components: FontBox
Affects Versions: 2.0.5
Reporter: Tobias Fischer
Priority: Critical
Attachments:
fontbox-2.0.5-ttfsubsetter_scrambled-OpenType-ligatures.png,
Subset-DejaVuSans_scrambled-OpenType-tables.ttf
When using the TTFSubsetter as standalone software and subsetting an
OpenType/TrueType font, the {{liga}} OpenType ligature table gets scrambled
"randomly".
E.g. when viewing the source font "DejaVuSans.ttf" in FontLab Studio, the
OpenType {{liga}} table is shown as follows:
{code}
feature liga {
script arab;
lookup liga33 {
lookupflag IgnoreMarks RightToLeft;
sub uniFEDF uniFE88 by uniFEF9;
sub uniFEDF uniFE84 by uniFEF7;
sub uniFEDF uniFE82 by uniFEF5;
sub uniFEE0 uniFE88 by uniFEFA;
sub uniFEE0 uniFE84 by uniFEF8;
sub uniFEE0 uniFE82 by uniFEF6;
} liga33;
lookup liga35 {
lookupflag RightToLeft;
sub space uni0652 by uniFE7E;
sub space uni0651 by uniFE7C;
sub space uni0650 by uniFE7A;
sub space uni064F by uniFE78;
sub space uni064E by uniFE76;
sub space uni064D by uniFE74;
sub space uni064C by uniFE72;
sub space uni064B by uniFE70;
sub uni0627 uni0655 by uni0625;
sub uni0627 uni0654 by uni0623;
sub uni0627 uni0653 by uni0622;
sub uni0640 uni0652 by uniFE7F;
sub uni0640 uni0651 by uniFE7D;
sub uni0640 uni0650 by uniFE7B;
sub uni0640 uni064F by uniFE79;
sub uni0640 uni064E by uniFE77;
sub uni0640 uni064B by uniFE71;
sub uni0648 uni0654 by uni0624;
sub uni064A uni0654 by uni0626;
} liga35;
language SND ;
language URD ;
language KUR ;
script latn;
sub f f l by uniFB04;
sub f f i by uniFB03;
sub f l by fl;
sub f i by fi;
sub f f by uniFB00;
language MOL ;
language ROM ;
language ISM ;
language KSM ;
language LSM ;
language NSM ;
language SSM ;
language SKS ;
} liga;
{code}
This ligature table shows for example, in the {{latn}} section, the {{ffl}}
substitution with the ffl ligature {{\uFB04}}.
However, when viewing a subsetted version of the font (like the one attached),
the {{liga}} table is scrambled:
{code}
feature liga {
script arab;
lookup liga33 {
lookupflag IgnoreMarks RightToLeft;
sub _5337 _5250 by _5363;
sub _5337 _5246 by _5361;
sub _5337 _5244 by _5359;
sub _5338 _5250 by _5364;
sub _5338 _5246 by _5362;
sub _5338 _5244 by _5360;
} liga33;
lookup liga35 {
lookupflag RightToLeft;
sub numbersign _1403 by _5240;
sub numbersign _1402 by _5238;
sub numbersign _1401 by _5236;
sub numbersign _1400 by _5234;
sub numbersign _1399 by _5232;
sub numbersign _1398 by _5231;
sub numbersign _1397 by _5229;
sub numbersign _1396 by _5227;
sub _1365 _1406 by _1363;
sub _1365 _1405 by _1361;
sub _1365 _1404 by _1360;
sub _1385 _1403 by _5241;
sub _1385 _1402 by _5239;
sub _1385 _1401 by _5237;
sub _1385 _1400 by _5235;
sub _1385 _1399 by _5233;
sub _1385 _1396 by _5228;
sub _1393 _1405 by _1362;
sub _1395 _1405 by _1364;
} liga35;
language SND ;
language URD ;
language KUR ;
script latn;
sub o o u by _5045;
sub o o r by _5044;
sub o u by _5043;
sub o r by _5042;
sub o o by _5041;
language MOL ;
language ROM ;
language ISM ;
language KSM ;
language LSM ;
language NSM ;
language SSM ;
language SKS ;
} liga;
{code}
The {{liga}} table of the subsetted font now want's to replace "oou" instead of
"ffl".
The result, for example in InDesign, is devastating:
!fontbox-2.0.5-ttfsubsetter_scrambled-OpenType-ligatures.png!
The subsetted font indeed tries to replace "oou" with a non-existing glyph and
scrambles the whole text in the rendering. The font subset is unusable.
I know that it's hard to maintain OpenType features in a font subset, but I
would at least expect that the OpenType tables are kept "as-is"...
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
