[NTG-pdftex] images in formats

David Kastrup dak at gnu.org
Thu Jun 28 12:50:19 CEST 2007

Hans Hagen <pragma at wxs.nl> writes:

> Frank Küster wrote:
>> Hans Hagen <pragma at wxs.nl> wrote:
>>> Thanh Han The wrote:
>>>> dumping an image in pdf mode is rather difficult to get
>>>> right. If in dvi mode an image is "stored" by a reference to
>>>> an external file, then I am afraid the speed gain is not
>>>> that much. There is for sure some comfort by having a dumped
>>>> file reference in the format, but again that can be also
>>>> achieved for pdf mode using some macros IMHO.
>>> to me it looks like a rather useless option to include an image in a 
>>> format, just as we don't embed type 1 fonts in the format either so 
>>> let's not waste energy on it
>> You know that you just said "To me it looks like a rather useless
>> option to include an image in a \savebox in the LaTeX preamble", or
>> "To me it looks like a rather useless option to support
>> preview-latex in PDF mode even for people who use \savebox with
>> images in their preamble"?
> no, i was talking about a 'format' i.e. a \dump'd thing, i have no
> clue what \savebox does, and it may do image trickery as much as it
> likes but in the end the image will not be in the format file

Nor will it be in any output generated by iniTeX.  Do you think we
should turn off PDF/DVI generation completely in iniTeX?  Prohibit
people from generating visible output with it?  If not, then it is
hard to explain why images should be treated differently from other

>>> also, those who generate a format should know what they're
>>> doing/dealing with
>> David knows, but preview-latex just takes the LaTeX preamble which its
>> users have written.
> afaik the problem only occurs when a \dump is done and an option is
> then to \let\dump\end or so

And this will generate a format to be used later just how?

> anyhow, it's a dump related problem, not a macro package related one

mylatex.ltx is a macro package for dumping formats transparently.  It
is not like I have not explained several times that this is done in
preview-latex by default without user intervention, for performance
reasons.  It is also important to fill any repeatedly/globally used
saveboxes in the preamble, since otherwise it will not be possible to
recompile a region (which is done by using the preamble together with
the region, and no code in between).

The WhizzyTeX system also dumps formats more or less at every document
section, in order to provide fast screen updates.  This also is
transparent to the user.

I find it annoying how legitimate concerns and existing _standard_ use
cases and packages are simply brushed aside or ignored.  While there
may be priorities that make it necessary to postpone a proper
implementation, it is not because people putting forward their
concerns and presenting their use cases are idiots or weirdos that can
safely be ignored.

David Kastrup

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