[NTG-context] (bug?) wrong interline in \placelist[alternative=d] with Pagella italics

[Hans Hagen]

On 3/16/2020 1:27 PM, Wolfgang Schuster wrote:
> Pablo Rodriguez schrieb am 16.03.2020 um 10:01:
>> On 3/15/20 10:56 PM, Wolfgang Schuster wrote:
>>> Pablo Rodriguez schrieb am 15.03.2020 um 20:32:
>>>> [...]
>>>> Everthing is fine when italic fonts aren’t used.
>>>
>>> It can be fixed with a strut option for lists, e.g.
>>> \setuplist[strut=no]. The problem in this case is that the ex-height for
>>> the italic font is larger than the ex-height for the upright font which
>>> pushes the text down because add a strut at the begin and end of the
>>> entries.
>>
>> Many thanks for your reply, Wolfgang.
>>
>> I don’t get \setuplist[strut=no] working in the minimal sample I sent
>> yesterday.
> 
> The key isn't supported yet but it could help to avoid the spacing problem.
> 
>>> Below is a minimal example of the problem, the \setstrut setting changes
>>> the height of the strut for the italic font.
>>
>> I must admit that I don’t understand how to handle struts (I’m not sure
>> I understand what they actually are.)
> 
> The simple answer is that a strut is a invisible vertical line with the 
> height and depth of a line. When you look at the example below you can 
> see the text in the first box touches the top and bottom boundaries.
> 
> When we add a strut at the begin and end of the text we ensure the last 
> line has the depth of a normal line and the first line gets the complete 
> height of a line.
> 
> %%%% begin example
> \starttext
> 
> \ruledvbox{\samplefile{weisman}}
> 
> \blank
> 
> \ruledvbox{\begstrut\samplefile{weisman}\endstrut}
> 
> \stoptext
> %%%% end example
> 
>>> Most fonts (I checked only a small number) don't have such a big
>>> difference between the ex-height of the upright and italic styles which
>>> makes it hard to notice the problem.
>>
>> Yesterday I realized that Pagella was an extreme case, because I tried
>> to report this issue before, but Latin Modern didn’t show the issue (so
>> I thought I was doing something wrong).
> 
> Yes, pagella is a extreme case but when you use bold text the vertical 
> spacing is also messed up. You can avoid this when you use a fixed 
> lineheight (e.g. \setupinterlinespace[line=14pt]) because the default 
> distance is font dependant (default: 2.8 * ex-height).
or one can play with these parameters, that default to:

\setupinterlinespace
   [height=.72,
    depth=.28]

(maybe we should have recomended values for specific fonts)

Hans

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