One of the open-source software projects which has often fascinated me, is called OGRE, which stands for Open-Source Graphics Rendering Engine. It’s a very powerful set of libraries, that allows good coders to design 3D graphics applications, which take full advantage of hardware-accelerated – i.e., GPU-based – rendering, of virtual 3D scenes designed by such users, into simulated 2D camera views, within the same scene. This is one of the most common modes in which 3D Graphics is operated.
One of the things that OGRE is not, is a full-fledged game engine unto itself. This is due to:
- Lack of sound implementation (Additionally linking applications to the SDL Library may solve that),
- Lack of scripting support, without some sort of add-on. I think I compiled it with Python support, which would supply scripting, if my coding was good enough.
Modern builds of OGRE break with the past, in that they no longer use ‘OIS’ as their input system. Instead, at least their Sample Browser uses the ‘SDL library’ to do the same.
One of the feats which I have now accomplished on the computer named ‘Phosphene’, which is a Debian / Stretch, Debian 9 system, was to compile version 1.11.5 of this engine because I’m curious about Game Design, which I have been for a long time. And one of the reasons I feel that this software is stable on Phosphene, is due to the information which I already provided in This past posting. The past posting announced observations which I made, when this same hardware was called the computer ‘Plato’, but already running Debian Stretch.
What my observation essentially suggests is, that running 3D, OpenGL applications can in fact break the compositor because they suspend it, but that there is a work-around.
(Updated 2/20/2019, 19h00 … )
(As of earlier, the same day:)
‘Good applications’ will use the same mechanism, to suspend compositing while they run. The OGRE Sample Browser is an example of such a ‘good application’.
The workaround seems to be, to go into ‘System Settings -> Display And Monitor -> Compositor’ and to Un-check ‘Allow applications to block compositing.’ If the compositing has already been compromised, then a Log-Out followed by a Log-In is next required.
(Update 2/20/2019, 19h00 : )
One fact which puzzles me, is that I have myself written a blog posting according to which this compositing malfunction was supposedly fixed. This seems to form a startling contradiction to what I found today.
But there is a possible explanation for this. It may be that at the time the patch was released, to the Wayland / X-server compositing, I still had the Open-Source Mesa graphics drivers installed on ‘Plato’, that also include the Nouveau Drivers.
Later in the evolution of ‘Plato’ I had switched it to the proprietary NVIDIA Drivers. I must have also changed the setting in the Settings Panel back at that point, forgetting about some of my existing blog postings on the subject.
This hardware, now running as the computer ‘Phosphene’, has had the proprietary drivers installed from the beginning, as one of the earliest things I installed on it.