[NTG-pdftex] PDF inclusion with annotations

Hans Hagen pragma@wxs.nl
Sat, 12 Jul 2003 19:22:07 +0200


At 14:01 10/07/2003 +0200, Martin Schroeder wrote:

>I must confess I have not cared for annotations yet so I just
>hope that this is correct (it certainly sounds so) and leave that
>to the experts.

an option is to support this under user control:

\pdfmergeannots=0 : not enabled
\pdfmergeannots=1 : enabled

defaulting to 0 (not enabled)

that way macro packages can control it

also, it will need some extensive testing, esp for user annotations which 
may have object references, resources etc; since this would involve parsing 
of content, it's also a dangerous excersise (hard to make foolproof); this 
means that we should be able to control this at the annotation level:

- links
- widgets
- etc

so, we should need something

\pdfmergelinkannots=1
etc

as well

> > Another important this which happens within the function out_image,
> > is the calculation to the new coordinates of the annotation's /Rect.
> > There are no big problems if an images is scaled with the help of
> > <rule spec> of \pdfximage. But their are a lot of problems if
> > macro packages do something like \pdfliteral{.5 0 0 .5 0 0 cm}
> > for scaling and similar things for rotating images. To calculate
> > the coordinates of /Rect, pdftex must know exactly which coordinate
> > transformations are actually taking place. So I introduced two
> > new primitives: \pdfsetctm and \pdfresetctm.
>
>This I find much more interesting.

this problem is more general, since it also concerns normal (not xpdf 
related) code; i remember discussing this with thanh a few years a go but 
forgot about the implications, but for out_image situations it sounds ok to 
me

>[...]
>
> > Since TeX does not have a function to scan floating-point numbers,
> > I used scan_dimen as a work around to scan the arguments of \pdfsetctm.
> > That's why you must write
> >
> >    \pdfsetctm 0bp 1bp -1bp 0bp 0bp
> >
> > so far. It should be no problem to change this in the future.
>
>This could be added.

i don't like the unit; we could use numbers here and assume that they are 
scaled points (as happened in some dvi postprocessors); an alternative is 
to make it a token list
\pdfsetctm{....} and treat each component as what it is: floating point or 
dimension.

Hans
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