Re: Octave 4.0 on Mac OS Yosemite (with gui!)

[Mike Miller]

On Tue, Oct 06, 2015 at 08:41:19 -0400, Ben Abbott wrote:
> I suspect that the OSMesa that accompanies X11 will not play well with 
> Carbon’s OpenGL.

This sounds very similar to the current situation of Linux users with
Nvidia hardware. The standard OSMesa library works well with Mesa
OpenGL, but segfaults when used within Octave with Nvidia's OpenGL.

One workaround that has worked for some is to force Mesa OpenGL to be
preferred at runtime (using LD_PRELOAD) but another may be to ensure
that OSMesa uses its own embedded copy of Mesa OpenGL rather than the
shared OpenGL used by the rest of the system.

> In any event, the possibilities are;
> 
> (1) Use X11 based Qt, OpenGL, and OSMesa
> (2)  Use Carbon based Qt, OpenGL, and Carbon compatible OSMesa
> (3) Use Carbon based Qt, OpenGL, and use Carbon’s offscreen rendering on Mac 
> OS X.
> 
> https://developer.apple.com/library/mac/documentation/GraphicsImaging/Conceptual/OpenGL-MacProgGuide/opengl_offscreen/opengl_offscreen.html
> 
> We are currently struggling with (2). In the least that combination is 
> tricky, but maybe it isn’t feasible?
> 
> Option (3) is most attractive for Mac OS X users. But I don’t know if anyone 
> in the development community has the experience to take that on (I don’t).

You might try using a combination of native OpenGL for on-screen
plotting and Mesa OpenGL with OSMesa for off-screen. I believe this lies
in how OSMesa is configured and built. A recent proposed update of Mesa
[1] for Ubuntu is testing this concept.

[1]: https://launchpad.net/ubuntu/+source/mesa/10.1.3-0ubuntu0.5

-- 
mike