* LuaTeX has troubles with contextual kern
@ 2013-04-24 9:07 Georg Duffner
2013-04-24 10:46 ` Hans Hagen
0 siblings, 1 reply; 4+ messages in thread
From: Georg Duffner @ 2013-04-24 9:07 UTC (permalink / raw)
To: mailing list for ConTeXt users
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Hi,
in EB Garamond I have some contextual lookups in the kern feature with
which LuaTeX in context standalone (updated today in the morning) seems
to have problems (the issue is not new, I’ve already reported it in
january but perhaps that was a bit too confusing).
The test document is:
\definefontfeature[default][default][mode=base]
\definefontsynonym[ebg][file:EBGaramond12-Regular.otf]
\definefontfeature[ss20][ss20=yes]
\definefontfeature[iota1][cv81=1]
\definefontfeature[iota2][cv81=2]
\definefontfeature[altcirc][cv80=1]
\define\test{Tì αᾟα\par}
\starttext
\definedfont[ebg*default at 12pt]\test
\addfeature{ss20}\test
\addfeature{iota1}\test
\addfeature{iota2}\test
\addfeature{altcirc}\test
\stoptext
The font is at
http://www.georgduffner.at/ebgaramond/fonts/EBGaramond12-Regular.otf
The corresponding lookups in the kern.fea roughly contain
pos T' 145 i.dotless gravecomb;
which increases the right sidebearing of T by 145 before i.dotless
followed by gravecomb
and
pos Eta' <218 0 218 0> uni0345.cap @grk_tlAcc2;
pos Eta' <218 0 418 0> uni0345.cap1 @grk_tlAcc2;
pos Eta' <218 0 558 0> uni0345.cap2 @grk_tlAcc2;
where @grk_tlAcc2 contains the accents attached at the top left of the
glyph and which means that Eta is positioned at 218 inside its bounding
box and the bounding box is expanded by the third value between <>, on
the condition that it’s followed by uni0345.cap* and the said accents.
ss20 does a full decomposition of all composed glyphs so I can replace
any component by an alternate glyph. Their order corresponds to
canonical decomposition.
Attached you find the pdf output and a pdf from a parallel xelatex test
which shows the desired result:
\documentclass[12pt]{minimal}
\usepackage{fontspec}
\setmainfont{EB Garamond}
\newcommand{\test}{Tì αᾟα\par}
\begin{document}
\test
\addfontfeature{RawFeature=+ss20}\test
\addfontfeature{CharacterVariant=81:1}\test
\addfontfeature{CharacterVariant=81:2}\test
\addfontfeature{CharacterVariant=80}\test
\end{document}
Best regards,
Georg
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^ permalink raw reply [flat|nested] 4+ messages in thread* Re: LuaTeX has troubles with contextual kern
2013-04-24 9:07 LuaTeX has troubles with contextual kern Georg Duffner
@ 2013-04-24 10:46 ` Hans Hagen
2013-04-25 6:08 ` Georg Duffner
0 siblings, 1 reply; 4+ messages in thread
From: Hans Hagen @ 2013-04-24 10:46 UTC (permalink / raw)
To: mailing list for ConTeXt users
On 4/24/2013 11:07 AM, Georg Duffner wrote:
> Hi,
>
> in EB Garamond I have some contextual lookups in the kern feature with
> which LuaTeX in context standalone (updated today in the morning) seems
> to have problems (the issue is not new, I’ve already reported it in
> january but perhaps that was a bit too confusing).
>
> The test document is:
>
> \definefontfeature[default][default][mode=base]
you want node mode, so mode=node
> \definefontsynonym[ebg][file:EBGaramond12-Regular.otf]
> \definefontfeature[ss20][ss20=yes]
> \definefontfeature[iota1][cv81=1]
> \definefontfeature[iota2][cv81=2]
> \definefontfeature[altcirc][cv80=1]
> \define\test{Tì αᾟα\par}
> \starttext
> \definedfont[ebg*default at 12pt]\test
> \addfeature{ss20}\test
> \addfeature{iota1}\test
> \addfeature{iota2}\test
> \addfeature{altcirc}\test
> \stoptext
>
> The font is at
> http://www.georgduffner.at/ebgaramond/fonts/EBGaramond12-Regular.otf
>
> The corresponding lookups in the kern.fea roughly contain
>
> pos T' 145 i.dotless gravecomb;
>
> which increases the right sidebearing of T by 145 before i.dotless
> followed by gravecomb
maybe you also need to enable lfbd and rtbd?
> and
>
> pos Eta' <218 0 218 0> uni0345.cap @grk_tlAcc2;
> pos Eta' <218 0 418 0> uni0345.cap1 @grk_tlAcc2;
> pos Eta' <218 0 558 0> uni0345.cap2 @grk_tlAcc2;
>
> where @grk_tlAcc2 contains the accents attached at the top left of the
> glyph and which means that Eta is positioned at 218 inside its bounding
> box and the bounding box is expanded by the third value between <>, on
> the condition that it’s followed by uni0345.cap* and the said accents.
ok, so that is effectively changing the advance width
> ss20 does a full decomposition of all composed glyphs so I can replace
> any component by an alternate glyph. Their order corresponds to
> canonical decomposition.
>
> Attached you find the pdf output and a pdf from a parallel xelatex test
> which shows the desired result:
>
> \documentclass[12pt]{minimal}
> \usepackage{fontspec}
> \setmainfont{EB Garamond}
> \newcommand{\test}{Tì αᾟα\par}
> \begin{document}
> \test
> \addfontfeature{RawFeature=+ss20}\test
> \addfontfeature{CharacterVariant=81:1}\test
> \addfontfeature{CharacterVariant=81:2}\test
> \addfontfeature{CharacterVariant=80}\test
> \end{document}
I don't know what \addfontfeature does in xetex (probably accumulative)
but in context you can best use the \feature command: \feature[+][iota1]
as \addfeature cum suis were somewhat experimental features related to
oriental tex.
Hans
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___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!
maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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wiki : http://contextgarden.net
___________________________________________________________________________________
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: LuaTeX has troubles with contextual kern
2013-04-24 10:46 ` Hans Hagen
@ 2013-04-25 6:08 ` Georg Duffner
2013-04-25 9:24 ` Hans Hagen
0 siblings, 1 reply; 4+ messages in thread
From: Georg Duffner @ 2013-04-25 6:08 UTC (permalink / raw)
To: mailing list for ConTeXt users
Hi,
Am 2013-04-24 12:46, schrieb Hans Hagen:
> On 4/24/2013 11:07 AM, Georg Duffner wrote:
>> Hi,
>>
>> in EB Garamond I have some contextual lookups in the kern feature with
>> which LuaTeX in context standalone (updated today in the morning) seems
>> to have problems (the issue is not new, I’ve already reported it in
>> january but perhaps that was a bit too confusing).
>>
>> The test document is:
>>
>> \definefontfeature[default][default][mode=base]
>
> you want node mode, so mode=node
I'm sorry, I forgot to mention it, I’ve already tested with mode=node,
the result is exactly the same.
>> \definefontsynonym[ebg][file:EBGaramond12-Regular.otf]
>> \definefontfeature[ss20][ss20=yes]
>> \definefontfeature[iota1][cv81=1]
>> \definefontfeature[iota2][cv81=2]
>> \definefontfeature[altcirc][cv80=1]
>> \define\test{Tì αᾟα\par}
>> \starttext
>> \definedfont[ebg*default at 12pt]\test
>> \addfeature{ss20}\test
>> \addfeature{iota1}\test
>> \addfeature{iota2}\test
>> \addfeature{altcirc}\test
>> \stoptext
>>
>> The font is at
>> http://www.georgduffner.at/ebgaramond/fonts/EBGaramond12-Regular.otf
>>
>> The corresponding lookups in the kern.fea roughly contain
>>
>> pos T' 145 i.dotless gravecomb;
>>
>> which increases the right sidebearing of T by 145 before i.dotless
>> followed by gravecomb
>
> maybe you also need to enable lfbd and rtbd?
lfbd and rtbd don’t make sense here, they are meant to by activated by
opbd and only should affect left and right line-ends. They are the
Opentype equivalents to protrusion settings. This is about "simple"
kerning in the text (btw, there are experimental lfbd and rtbd settings
in the font). This example is a standard kerning lookup (cf.
http://www.adobe.com/devnet/opentype/afdko/topic_feature_file_syntax.html#6.a
http://www.adobe.com/devnet/opentype/afdko/topic_feature_file_syntax.html#6.h
and http://glyphsapp.com/blog/contextual-kerning/ )
>> and
>>
>> pos Eta' <218 0 218 0> uni0345.cap @grk_tlAcc2;
>> pos Eta' <218 0 418 0> uni0345.cap1 @grk_tlAcc2;
>> pos Eta' <218 0 558 0> uni0345.cap2 @grk_tlAcc2;
>>
>> where @grk_tlAcc2 contains the accents attached at the top left of the
>> glyph and which means that Eta is positioned at 218 inside its bounding
>> box and the bounding box is expanded by the third value between <>, on
>> the condition that it’s followed by uni0345.cap* and the said accents.
>
> ok, so that is effectively changing the advance width
Yes.
>> ss20 does a full decomposition of all composed glyphs so I can replace
>> any component by an alternate glyph. Their order corresponds to
>> canonical decomposition.
>>
>> Attached you find the pdf output and a pdf from a parallel xelatex test
>> which shows the desired result:
>>
>> \documentclass[12pt]{minimal}
>> \usepackage{fontspec}
>> \setmainfont{EB Garamond}
>> \newcommand{\test}{Tì αᾟα\par}
>> \begin{document}
>> \test
>> \addfontfeature{RawFeature=+ss20}\test
>> \addfontfeature{CharacterVariant=81:1}\test
>> \addfontfeature{CharacterVariant=81:2}\test
>> \addfontfeature{CharacterVariant=80}\test
>> \end{document}
>
> I don't know what \addfontfeature does in xetex (probably accumulative)
> but in context you can best use the \feature command: \feature[+][iota1]
> as \addfeature cum suis were somewhat experimental features related to
> oriental tex.
I’m a bit confused. As I don’t use context yet (this time I did for
reporting a bug upon which I stumbled when using lualatex) I looked up
the necessary commands in the newly presented "Fonts out of ConTeXt"
where on p. 41 the commands \addfeature and \subtractfeature are used.
In xelatex, \addfontfeature is defined by the package fontspec and does
indeed accumulate features (much like I thought, \addfeature does in
context) but without the need to be defined in the preamble and without
the advantage to define feature sets.
Best regards,
Georg
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!
maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage : http://www.pragma-ade.nl / http://tex.aanhet.net
archive : http://foundry.supelec.fr/projects/contextrev/
wiki : http://contextgarden.net
___________________________________________________________________________________
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2013-04-24 9:07 LuaTeX has troubles with contextual kern Georg Duffner
2013-04-24 10:46 ` Hans Hagen
2013-04-25 6:08 ` Georg Duffner
2013-04-25 9:24 ` Hans Hagen
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