Re: [AUCTeX] dvipng is not called by auctex

[David Kastrup]

Faheem Mitha <address@hidden> writes:

> On Wed, 3 Jul 2013, David Kastrup wrote:
>
>> You are obviously in TeX-PDF-mode.  There is no DVI file being
>> generated, so there is nothing that dvipng could be run on.
>> Try C-c C-t C-p to switch off TeX-PDF-mode (if your file actually
>> permits being compiled by normal TeX), then try previewing again.
>
> Yes, you are right. I'm sorry that I missed the obvious. I often end
> up usuing PDF mode for various reasons.
>
> Looking at the compilation output, I see that the creation of the
> preview png snippets seems to be done by ghostscript. It looks like a
> pdf file is first created by TeX and then pdf2dsc is used to create a
> dsc file from that pdf.

The dsc file is not doing much: basically it fakes a PostScript page
directory for the PDF file that then can be processed as if it had been
PostScript to start with.

> I'm not clear what gs uses to create the final png.

Its png16m backend.

> In any case, in terms of speed, is this the best possible option?

Nowadays, it's conceivable that pdftocairo might be faster, but it would
not seem possible to do the kind of demand-based rendering that the
Ghostscript interactive interface does, not with a single process.  If
you are daring, you might want to try writing a backend for that.  At
the time preview-latex was actively developed, there was no reasonable
PDF->png converter available apart from Ghostscript.

-- 
David Kastrup