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

[David Kastrup]

address@hidden writes:

>> YAMAMOTO Mitsuharu <address@hidden> writes:
>>
>>>>> So they are always magnified and look blurry.  This cannot be
>>>>> solved at the Lisp level.
>>>
>>>> That does not make a lot of sense: preview-latex queries the
>>>> resolution of the device and generates images matching the device
>>>> resolution.  If Retina displays are lying about their resolution,
>>>> that is the problem to tackle.
>>>
>>> That's exactly what the OP tried and resulted in failure, i.e., large
>>> blurry images.  Just giving a large resolution value to Ghostscript at
>>> the Lisp level might work on other platforms, but that is not enough
>>> to display images in a non-blurry way on OS X Retina display.
>>
>> Getting the OS X Retina display to display one pixel per image pixel is
>> not a new feature: fixing this (probably requires fixing in the Emacs
>> source rather than in AUCTeX) to get the platform to behave like others
>> is pretty uncontroversial.  I see no non-technical roadblocks there.
>
> What happens when a user moves an Emacs frame from a Retina
> display to a non-Retina display?  The window system on OS X keeps
> the logical (point) size rather than the physical (pixel,
> actually backing store) size.
>
> https://developer.apple.com/library/mac/documentation/GraphicsAnimation/Conceptual/HighResolutionOSX/Explained/Explained.html#//apple_ref/doc/uid/TP40012302-CH4-SW1

Feel free to work out a framework where rerendering for changed geometry
(like for changing the size of a frame's default font) provides benefits
for free operating systems and see how you can fit the specific problems
of MacOSX into such a framework.

It's imaginable to implement such on-demand rerendering with different
resolution/size as a preview-latex-only component, but it certainly
would make sense for Emacs' general image support.

But as long as you are targeting MacOSX-only benefits, the GNU project
is the wrong place to provide them.  That's one of the reasons that
there are several separate feature-enhanced forks for Mac (I haven't
kept track/count of them) and Windows that cater specifically for
features only implemented on those platforms.

-- 
David Kastrup