strange stretching with \blank[...]

strange stretching with \blank[...]

[Peter Münster]

Hello,

please consider the following example file:

\setupalign[line]
\starttext
\input knuth
\blank[big]
\input knuth
\blank[2*big] % 2*big is much smaller than simple big !
\input knuth
\placetable{bla}{\vbox to 18cm{bla}}
\stoptext

But \blank[big,big] is working right.

It seems, that we should replace all "2*big" by "big,big" in core-sec.tex

Cheers, Peter

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http://pmrb.free.fr/contact/

Re: strange stretching with \blank[...]

[Taco Hoekwater]

Hi,

Peter Münster wrote:
> But \blank[big,big] is working right.
> 
> It seems, that we should replace all "2*big" by "big,big" in core-sec.tex

I regard this a bug in the definition of 2*big. I'm not sure
how many old documents will break if it is fixed, though. The
correct definition is:

  \defineblankmethod
      [2*big]
      {\addblankskip+{\bigskipamount}{\openlineheight}%
       \addblankskip+{\bigskipamount}{\openlineheight}}

The current definition is:

  \defineblankmethod
      [2*big]
      {\addblankskip+{2\bigskipamount}{2\openlineheight}}%

but that does not copy the stretch and shrink parts.

TeX is a bit stupid come to skip assignments, after

   \skip0=5pt plus 10pt minus 10pt
   \skip1=2\skip0

\skip0 will be *exactly* 10pt, without any glue components.

Cheers, Taco

Re: strange stretching with \blank[...]

[Hans Hagen]

� wrote:

>Hello,
>
>please consider the following example file:
>
>\setupalign[line]
>\starttext
>\input knuth
>\blank[big]
>\input knuth
>\blank[2*big] % 2*big is much smaller than simple big !
>\input knuth
>\placetable{bla}{\vbox to 18cm{bla}}
>\stoptext
>
>But \blank[big,big] is working right.
>
>It seems, that we should replace all "2*big" by "big,big" in core-sec.tex
>  
>
no, this is a bug! (qualifies for stupid bug of the year)

in core-spa you will find:

% happens often, so we speed this up:

\defineblankmethod    [2*\v!line] 
{\addblankskip+{2\openlineheight}{2\openlineheight}}
\defineblankmethod     [2*\v!big] {\addblankskip+{2\bigskipamount 
}{2\openlineheight}}

comment those two lines!  multiplication makes the stretch/shrink 
disappear (this is a tex feature and i should have know better)

you can test the current situation with:

\def\addblankskip#1#2#3%
  {before:\the\blankskip\endgraf
   \global\advance\blankskip#1\ifgridsnapping#3\else#2\fi
   after:\the\blankskip\endgraf}

test \blank[big]
test \blank[big,big]
test \blank[2*big]

I'll patch it.

Hans

Re: strange stretching with \blank[...]

[Hans Hagen]

Taco Hoekwater wrote:

> Hi,
>
> Peter M�nster wrote:
>
>> But \blank[big,big] is working right.
>>
>> It seems, that we should replace all "2*big" by "big,big" in 
>> core-sec.tex
>
>
> I regard this a bug in the definition of 2*big. I'm not sure
> how many old documents will break if it is fixed, though. The
> correct definition is:
>
>  \defineblankmethod
>      [2*big]
>      {\addblankskip+{\bigskipamount}{\openlineheight}%
>       \addblankskip+{\bigskipamount}{\openlineheight}}

ah, that's a nice one i hadn't though tof, thanks

Hans