[Fontinst] Kerning of the dotlessi

[Lars Hellström]

Plamen Tanovski skrev:
> Hi,
> 
> I had to typeset some turkish last days and I've realized, that there
> is no kerning regarding the dotlessi, so "Y\i lmaz" looks suboptimal.
> The files in the latinmtx folder don't have any kerning commands for
> the dotlessi.

Funny -- before your mail I could have sworn latin.mtx did

\setleftrightkerning{dotlessi}{i}{1000}

(it does this with all sorts of other letters, so why not dotlessi?), 
but perhaps it was dotlessI that clouded my memory.

However, after searching through several hierarchies of 
fontinst-related files for dotlessi, I have encountered several 
\setkerns for it, so maybe it has been considered a letter already 
kerned by the foundry. Or maybe it was never used that much by fontinst 
authors...

> My first suggestion was: let the dotlessi kern on its left and right
> like a "n". 

On the left hand side that should work fine. On the right hand side one 
could imagine there being e.g. n-u kerns that are inappropriate for 
dotlessi-u, though.

> MinionPro have e.g.:
> 
> KPX Y dotlessi -90
> KPX Y n -90
> KPX Y u -99
> 
> The problem with this is, that there are no many kerning pairs with
> "n" in the most fonts. For example, Adobe Stempel Garamond Roman
> doesn't have a kerning pair Y-n. 

Sådan Ynkedom! :-)

> All the Y- pairs are:
> 
> KPX Y A -74
> KPX Y a -74
> KPX Y colon -92
> KPX Y comma -111
> KPX Y e -74
> KPX Y hyphen -92
> KPX Y i -37
> KPX Y o -74
> KPX Y p -74
> KPX Y period -111
> KPX Y q -74
> KPX Y semicolon -92
> KPX Y u -74
> KPX Y v -55
> 
> Since Y-dotlessi seems to be a very common pair in turkish, maybe
> llbuild.mtx should include something like:
> 
> \ifiskern{Y}{n}\then
>   \setkern{Y}{dotlessi}{\kerning{Y}{n}}
> \Else
>   \setkern{Y}{dotlessi}{\kerning{Y}{u}}

The Y-p kern could also be taken as template.

> \Fi
> 
> \setleftkerning{dotlessi}{n}{1000}
> \setrightkerning{dotlessi}{n}{1000}

Hmm... it should be easy to create a command 
\ifhasleftkerning{<glyph>}\then to test if kerning exists. Many 
\set(left|right)kerning commands should probably be conditionalised 
that way.

> This lets me to the idea to maybe introduce language-specific mtx-files,
> where people can put the desired kerning adjustment for their language.

Not a bad idea, but it depends on people making contributions. 
Development has been slow the last couple of years.

Lars Hellström