Re: (bug?) wrong hyphenation with external fonts

[Hans Hagen <pragma@wxs.nl>]

On 2/4/2016 9:27 PM, Pablo Rodriguez wrote:
> On 02/03/2016 02:18 PM, Hans Hagen wrote:
>> On 2/2/2016 12:28 PM, Pablo Rodriguez wrote:
>>> Dear list,
>>> [...]
>>> Hyphenation is wrong with fonts that don’t come with the ConTeXt
>>> distribution. TeX Gyre Pagella is hyphenated right, but MinionPro or
>>> even TeX Gyre Pagella Math are wrong hyphenated.
>>>
>>> I’m afraid it may be a bug. Could anyone confirm it?
>>
>> to what extend hyphenation is supported depends on the interaction
>> between ligature building / kerning / trickery and possible hyohenation
>> points; the font handler tries to do its best
>
> Many thanks for your reply, Hans.
>
> I reported the issue in the opposite way it happens:
>
>      \definefontfamily[mainface][rm][MinionPro]
>      \definefontfamily[anotherface][rm][TeX Gyre Pagella]
>      \setupbodyfont[mainface]
>
>      \starttext
>      \startTEXpage[offset=1em]
>      \hyphenatedword{LibreOffice libre office}
>
>      \setupbodyfont[anotherface]%
>      \hyphenatedword{LibreOffice libre office}
>      \stopTEXpage
>      \stoptext
>
> The ff-ligature prevents hyphenation with TeX Gyre Pagella, but not with
> MinionPro. (This is the opposite of what I reported before.)

it depends on the complexity of the ligature .. ff is not so much an 
issue but you can have ff + i = ffi etc and we need to deal with kerning 
too (it depends a bit on how the opentype features are applied and we 
can handle quite some weird ligature implementations)

the latest mechanism in context can deal with quite some situations but 
at some point has to make decisions (in order not to loose for instance 
kerns; double chained ligatures would result in way more overhead and is 
not worth the trouble)

one might wonder if we never had these  f[fil] ligatures of if ancient 
technology had provides hundreds of them combining upto 4 characters etc 
etc.

Hans

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                                           Hans Hagen | PRAGMA ADE
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