On Wed, Feb 13, 2019 at 4:10 PM Philip Nienhuis <address@hidden
Nicholas Jankowski wrote:
> That is due to OpenGL working with single precision floats. See
> a.o., bugs
> 32980, 33748, and several later duplicates. Indeed an annoying issue.
> these bugs have been around since 2011. My understanding is that OpenGL
> still has no intention to move to general double precision handling
> since most graphics hardware still handles everything in single
> precision (no double benefit for the number and size of pixels our eyes
> are dealing with so far).
> is there a particular hesitancy in working up a scaling fix for this
> problem on the octave side rather than waiting for OpenGL to go double?
AFAIU the Octave devs are waiting for an OpenGL expert to fix this.
From just a little bit of reading, OpenGL is happy working in single precision, as double is slower & more memory intensive with zero benefit for display applications. I think only some of the more advanced GPUs are now starting to handle double precision arithmetic, and those are almost all being designed for GPU computation, not for graphics. In those cases specialized APIs are being used anyway, and those calculations are 'for display', so they still don't have a reason to move display calculations into double precision arithmetic where the hardware will just throw the extra digits away anyway.
I do see the domino effect of patches, though. Maybe a GSOC project?