[Vm-dev] Ronie's OpenGL work for Mac OS X

[Tobias Pape]

Hi Eliot,


> On 31.01.2018, at 22:26, Eliot Miranda <eliot.miranda at gmail.com> wrote:
> 
> Hi All,
> 
>     what's happened with deleting all of Ronies work on  the OpenGL support in the B3DAcceleratorPlugin on Mac OS X?  It has all been deleted.  That work was necessary in reviving 3D support for Terf on Mac OS X.  Can someone please explain what's going on here.  Why are we regressing to something dating from 2003?

I've been sitting with Fabio over a Bug
	https://github.com/OpenSmalltalk/opensmalltalk-vm/issues/178
we were not able to fix but by reverting Ronies commit:
	https://github.com/OpenSmalltalk/opensmalltalk-vm/commit/275eca83761d0a9aa3e689a7f0c33465c6f160e1

To Quote:
"
This reverts commit bc6e34d and fixes #178.

The vm segfaulted on Travis (#178) because this commit introduced the use of shader and assumed that shader compilation always works (see [1]). As a matter of fact, it does fail on Travis and maybe other macOS systems.

@ronsaldo please provide an updated PR to address the above.

[1] https://github.com/OpenSmalltalk/opensmalltalk-vm/commit/bc6e34d1b2998cb8f3b38a2ce0818eda35a25ce9?diff=unified#diff-7c007173fcbc79b3e9984468210d3d11R369
"

The original commit did not have any commentary besides 
"The B3D plugin is now working again on Mac OS X."

The move from "traditional" OpenGL to doing everything with shaders is quite drastic
and it would be really helpful to comment the commit a bit more extensive. 

The File comment

// Changes: 2017-05-13 Ronie Salgado. Refactored to remove the fixed function pipeline.
// Implemented a layering system to be used in cooperation by the B3DAccelerationPlugin.
// Fixing some graphical glitches that appeared when enabling the double buffering.

Is indeed explanatory, but a lot of code was just commented out and assumptions just made and not checked for.
Also, a fallback is missing for basic, shaderless usage.

-=-=-=-

Please keep in mind that the original issue is that our release-process was stalled; the commit effected SegFaults on Travis, hence making, not producing build artifacts. We cannot guarantee that those segfaults wont happen on user machines.


Best regards
	-Tobias

> 
> _,,,^..^,,,_
> best, Eliot