[NTG-context] vertical spacing and makeups

[Pablo Rodriguez]

On 04/18/2015 07:15 PM, Wolfgang Schuster wrote:
>> Am 18.04.2015 um 18:43 schrieb Pablo Rodriguez:
>> [...]
>> The first page shows that \setupwhitespace[big] affects to a single line
>> in a makeup. Shouldn’t white space be added only between paragraphs? The
>> second page is right vertically centered. And the third page shows that
>> the white space isn’t added before the first paragraph in a normal page
>> (no makeup).
>>
>> This is the first issue, isn’t it a bug? Or what am I missing?
> 
> TeX inserts the \parskip value which is set by \setupwhitespace
> before your text in the makeup environment. Note that this happens
> only when you have skip before the text (e.g. with the default top=\vss
> setting) at the begin of the environment.
> 
> The following low level example demonstrates this:
> 
> \setuppapersize[A6]
> 
> \starttext
> 
> \dontleavehmode
> \ruledvbox to 3cm{\hsize=4cm text}
> \ruledvbox to 3cm{\hsize=4cm\parskip=2ex\relax text}
> 
> \dontleavehmode
> \ruledvbox to 3cm{\hsize=4cm\vss text\vss}
> \ruledvbox to 3cm{\hsize=4cm\parskip=2ex\relax\vss text\vss}
> 
> \stoptext

Many thanks for your reply, Wolfgang.

So the a workaround would be to use \blank instead of \par or a blank
line, wouldn’t it be?

>> The second issue is about the line height. If I didn’t get it wrong from
>> Hans some days ago, line height is the x-height, plus ascender and
>> descender heights.
> 
> TeX has only a concept for the distance between the baseline of two lines,
> to get a certain line height and depth at the begin and end of your text
> you have to the \strut or \begstrut and \endstrut commands.
> 
> \def\startSlide
>   {\grabbufferdata[SlideContent][startSlide][stopSlide]}
> 
> \def\stopSlide
>   {\startmakeup[standard][align=middle]
>    \begstrut\getbufferdata[SlideContent]\endstrut
>    \stopmakeup}

I tried to use struts with the first issue and I thought they didn’t
work sith makeups.

Many thanks for your code excerpted above. I would have never thought of
this in a decade.

Many thanks for your highly instructive explanation also,


Pablo
-- 
http://www.ousia.tk