[dviout] [tex-live] dviout: color specials in the are not page independent

[Hironobu Yamashita]

Hi Igor,

First, please also keep cc to the list.
(This topic is not directly related to TeX Live, so moved the list
from tex-live to dviout.)


2018-04-20 7:15 GMT+09:00 Igor Ya. Spectorsky <i.spectorsky at gmail.com>:
> Hi,
>
> Thanks for clarifying. I think I use color only for hyperref to paint
> reference. Even after dviout modifies the dvi-file, all colors remain; I
> don't see any difference.
> Anycase, it is not very difficult to press Ok after the first calling
> dviout.
>
> By the way, is it possible to make dviout scroll pages continuously? It is
> not very convenient to do some separate manipulations to go to the
> next/previous page while scrolling with mouse wheel. Of course, there is the
> second scrollbar to switch to any page, but it would be better to switch to
> the next or previous page just with scrolling wheel.

I'm not familiar with all of dviout features, but I don't think that's
supported.


>
> Thanks for help
>
>
> 19.04.2018 19:13, Hironobu Yamashita пише:
>
>> Hi Igor,
>>
>>> When dvi file is opened by dviout, some strange message appears:
>>> dviout color specials in the are not page independent. When I agree
>>> for modifying the file, everything works. However, what is there in
>>> my file that dviout dislikes?
>>> Within MiKteX (there is  dvi-viewer yap) no warning appears like that.
>>
>> dviout checks page-independency and shows a warning,
>> and yap does not; that is all what differs.
>>
>> A DVI file is a sequence of commands which form "a machine-like language".
>> In the simplest situation, the appearance of a page can be determined
>> from commands encapsulated in that single page. Therefore, when
>> a DVI viewer is going to display a single page from a multipage DVI file,
>> the viewer is required to parse only that single page. This is true in
>> most case, because a DVI file is
>>
>> * (always) page-independent if no \special commands are involved
>> * (sometimes) page-independent if \special commands appears
>>
>> However, the real world is not so simple as expected; there is a
>> possibility
>> that the commands in preceeding page affect the page appearance.
>> It occurs when \special's are involved, like page color, text color etc.
>> MWE (the first and second pages should be in red):
>>
>> \documentclass{article}
>> \usepackage{color}
>> \begin{document}
>> \pagecolor{red}
>> first,\newpage second
>> \end{document}
>>
>> To handle this situation, dviout correctly parses throughout a DVI file,
>> from the start page (with a help of a program dvispc.exe background).
>> I guess dviout is calling a user's attention for safety in this complex
>> situation.
>>
>> I don't know much about yap, but if the second page of MWE above
>> is shown in red, yap should be doing similar too (without showing any
>> warnings to user).
>>
>> Hironobu Yamashita
>>
>>
>
>
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Hironobu Yamashita