Re: bug? gap appears in columnset

[Hans Hagen <pragma@wxs.nl>]

On 9/17/2013 8:57 PM, Lars Huttar wrote:

> Can you point me to documentation on the constraints that define what
> kind of interlinespace is sane?

the default is 2.8ex which is pretty safe, then there is the ht/dp ratio 
which in some cases has to be adapted to fonts esp when they are 
non-typical

> Also, given the goal that "For using ConTeXt, no TeX programming skills
> and no technical background are needed. Some basic knowledge of
> typography and document design will enable you to use the full power of
> ConTeXt" (http://wiki.contextgarden.net/What_is_ConTeXt), does/could
> ConTeXt issue an error when its assumptions are violated?

well, adapting interlinespace is already beyond basic ... if you have 
specifications from someplace else they are supposed to be experts (ok, 
in many case we get weird specs too, but i always tend to ignore those)

>> \setbox0\hbox{Tg}\the\htdp0,\the\baselineskip
>>
>> gives
>>
>> 10.59601pt,9.3pt
>>
>> so, any line that has a character with ascender and descender will
>> enforce a larger than 9.3pt distance + lineskip and mess up any
>> prediction cq. heuristics
>
> I can't find any reference defining \htdp0, but I'm guessing it means
> the height+depth (where depth means how far descenders extend below the
> baseline) of the "Tg" box.

indeed, \htdp is a convenient macro, you could also add two dimensions 
or use a \dimexpr which is more work

> I'm also confused as to why you're adding 9.3pt + lineskip, when in my
> limited understanding of TeX, I understood lineskip to be *part* of the
> distance between baselines, rather than an additional distance. But
> maybe that's not important to the main issue.

\starttext

\showstruts \strut test \par \strut test

\showstruts \strut \ruledhbox{$\sqrt{test}$} \par \strut test

\stoptext

\lineskip (1pt by default) kicks in when the line distance minus 
baselineskip exceeds \lineskiplimit (0pt by default)

> I'm trying to formulate a rule for knowing whether "interlinespace is sane".
> Is it that interlinespace needs to be more than or equal to the maximum
> of (height + depth + lineskip) of any line in the text?

\setbox0\hbox{()} \the\htdp0

is the minumum and you'd better add one point at least

bodyfont/baseline : 10/12 12/14.4 etc are ok

Hans


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