Re: [AUCTeX] Embedded previews in high-DPI?

[Mosè Giordano]

Hi!

2016-05-17 12:40 GMT+02:00 YAMAMOTO Mitsuharu <address@hidden>:
> Spencer Michaels <smichaels <at> g.hmc.edu> writes:
>
>> I'm using AucTeX 11.89.1 + Emacs 24.5 + OSX 10.11.3 on a Retina
>> Macbook, which has a high DPI display. When I generate previews
>> to embed in the TeX document (C-c C-p C-s then C-c C-l), the
>> preview images are rendered at 1/4th the resolution of the
>> surrounding text (their size relative to it is, however,
>> correct). I don't think this is a bug, exactly — it's probably
>> because the parameters passed to Ghostscript take the number of
>> points on the screen (essentially the simulated resolution) as
>> the physical resolution. The way OSX generally handles this is
>> to render images at a multiple of their normal size, usually
>> 2x, then scales the images down to the right physical size. If
>> I specify the right DPI of 227x227 using "preview-resolution,"
>> images are twice as big as they should be but have the right
>> overall number of pixels — can AucTeX render images at a
>> particular DPI but scale them down in size before embedding
>> them in the document? This would support high DPI on the Retina
>> display, I think. I've looked through some of the source but am
>> very new to ELisp, so I haven't found a way so far.
>
> Recently I posted a Retina display support patch for
> preview-latex to the emacs-devel list:
>
>   http://lists.gnu.org/archive/html/emacs-devel/2016-04/msg00890.html
>
> You need Emacs Mac port, which is also mentioned in the above
> post.
>
> It makes Ghostscript generate PDF files instead of PNG ones, and
> let the Mac port render them using the `image-io' image type via
> PDFKit.  So moving an Emacs frame between Retina and non-Retina
> displays works gracefully (the Mac port re-renders PDF
> automatically).  As a bonus, it enables us to use LCD smoothing.
> So it is actually meaningful also on non-Retina displays.

This looks very interesting, but for installing the patch into AUCTeX
I would prefer it to be compatible with vanilla GNU Emacs as well.  Is
it possible to improve it?

Bye,
Mosè