[Gimp-developer] Can we conclude Gimp on Mac/OS X with retina displays does not work at 100% view?

[Marius Kjeldahl <marius kjeldahl gmail com>]

Periodically I've been trying to get Gimp to work correctly on an iMac
5K the last couple of years. I've tried many times (and versions)
without success. I've tried the latest version 2.8.16 (which runs
outside X11) still without success. The program "runs" just fine, but
anything I touch with when I try to edit at "100% view" gets
pixellated.

I know it's related to how Mac's retina displays work. Take a
screenshot using Gimp on Mac and it immediately appears at twice the
resolution. Take a screenshot using Preview, everything looks fine.

But here's the kicker. Open that "fine" screenshot in Gimp, and it's
still twice the resolution. I haven't found any way to "work" with an
image in it's native resolution (where a pixel is a pixel).

For comparison I've set up a Linux VM (Lubuntu) and configured it so
that it's not "DPI confused" (basically tell VirtualBox not to scale
anything and modify the DPI setting on the X server to have some sane
values for DPI so at least text looks somewhat normal - icons are
still tiny though).

I've merged a screenshot with "Mac native" Gimp on the left and "Linux
VM" Gimp to the right, and told Gimp to load the same screenshot and
display it at 100% on both.

http://imgur.com/a/XOLop

A couple of observations; If I display the image at 200% on the Linux
VM, it looks identical to the native Mac version. But I have found no
way to do the opposite (have Mac native Gimp display an image at 100%
resolution and get it to display at the proper size similar to the
Linux VM version).

I've mucked around with the DPI settings in Preferences on the Mac
native Gimp as well. It doesn't seem to do anything noticeable to the
image being edited; it mostly seems to affect the Gimp GUI itself
(text).

Googling around there are all kinds of "fixes", which basically
involve downscaling the image in Gimp to get it at the proper size.
The problem is that this actually removes halves the pixels and make
everything look blurry.

Based on this I've concluded there is no way to edit images with the
current Mac release of Gimp at 100% size on retina displays (where a
pixel is a pixel).

Am I wrong, and if so, any hints on what I should be doing differently?

Thanks,

Marius K.