Re: [NTG-context] fitting a picture to the available space

12 Sep 2008


      On Thu, Sep 11, 2008 at 11:50 PM, Thomas A. Schmitz
 wrote:
...
On Sep 11, 2008, at 7:59 PM, Thomas A. Schmitz wrote:
...
On Sep 11, 2008, at 6:20 PM, Thomas A. Schmitz wrote:
...
...
\starttext
\start
\setbox\scratchbox\vbox{\externalfigure[mill]}
\dimen0=\wd\scratchbox
\dimen2=\ht\scratchbox
\framed[frame=on,strut=no,width=8cm,height=2cm]
{\dimen1=\hsize \divide\dimen1 by \dimen0
\dimen3=\vsize \divide\dimen3 by \dimen2
\ifdim\dimen1>\dimen3
  \externalfigure[mill][height=\vsize]
\else
  \externalfigure[mill][width=\hsize]
\fi}
\framed[frame=on,strut=no,width=2cm,height=8cm]
{\dimen1=\hsize \divide\dimen1 by \dimen0
\dimen3=\vsize \divide\dimen3 by \dimen2
\ifdim\dimen1>\dimen3
  \externalfigure[mill][height=\vsize]
\else
  \externalfigure[mill][width=\hsize]
\fi}
\stop
\stoptext
Wolfgang
Wolfgang,
as always, you're a source of wisdom and knowledge... Just I
understand this correctly and can adapt it to my macro: \dimen1=
\hsize: here \hsize refers to the size of the \framed inside which
we're operating, right?
And another question: I get an error "! Illegal unit of measure (pt
inserted)." Is it really possible to divide a dimension by another
dimension? Not according to what I read here: http://www.tug.org/utilities/plain/cseq.html#divide-rp
 "must be a nonzero integer." See, I'm far from being a native
speaker of TeX...
I now have something along these lines (ugly code ahead!):
\setbox\scratchbox\vbox{\externalfigure[mill]%
       \dimen0=\wd\scratchbox%
       \def\@WD{\withoutpt{\the\dimen0}}%
       \def\@@WD{\integerrounding{\@WD}}%
       \dimen4=\textwidth \divide\dimen4 by \@@WD%
       \dimen2=\ht\scratchbox%
       \def\@HT{\withoutpt{\the\dimen2}}%
       \def\@@HT{\integerrounding{\@HT}}%
       \dimen6=\textheight \divide\dimen6 by \@@HT%
       \ifdim\dimen4>\dimen6%
         \def\Myheight{\textheight}\def\Mywidth{}%
       \else%
         \def\Mywidth{\textwidth}\def\Myheight{}%
       \fi
and then use height=\Myheight,width=\Mywidth. Bu there's still a
problem... Anyway, does it make sense in general?
You should close the box before you want to get it's dimensions.

\unprotect

\def\????bf{@@@@bf}

\presetlocalframed[\????bf]

\def\boxfigure[#1][#2]%
  {\bgroup
   \setbox\scratchbox\hbox{\externalfigure[#1]}%
   \!!dimena\wd\scratchbox
   \!!dimenb\ht\scratchbox
   \localframed
     [\????bf]
     [\c!strut=\v!no,
      \c!width=8cm,
      \c!height=6cm,
      #2]
     \bgroup
     \!!dimena\dimexpr\hsize/\!!dimena\relax
     \!!dimenb\dimexpr\vsize/\!!dimenb\relax
     \ifdim\!!dimena>\!!dimenb
       \externalfigure[mill][height=\vsize]
     \else
       \externalfigure[mill][width=\hsize]
     \fi
     \egroup
   \egroup}

\protect

\starttext

\boxfigure[mill][width=8cm,height=2cm]

\boxfigure[mill][width=2cm,height=8cm]

\stoptext

Wolfgang

Re: [NTG-context] fitting a picture to the available space

Wolfgang Schuster