Re: Xlib, (GLX or EGL), OpenGL. Stuck at double buffering not working properly.

[Olivier Henley <olivier.henley@gmail.com>]

> X11 seems to have a single event queue so event processing can occur on any task. 

ok. I will investigate the possibilities.

> The GLFW maintainer explains a bit how all the platform do their event and window management in #5 at https://discourse.glfw.org/t/multithreading-glfw/573/5

Thank you for this nice discussion. The OP is quite in line with what I was envisioning for an Ada replacement. 

> I'm not sure how you can get tearing. Do you still get it when you explicitly set swap interval to 1?

No, it's not tearing per se. I wanted to picture a frame, rendered, but with different black damaged portions. I either get that of full black frames.

> Is there a particular reason you're trying this on X11?

- It's still ubiquitous
- Ubuntu 18.04 LTS has it by default
- Low hanging fruit. Many code examples here and there around the web.

> I've been thinking a lot about a GLFW replacement written in Ada, because GLFW tries to maintain too many backends (X11 and macOS are dead platforms for gaming/3D IMO) and development is slow. 

Not just that, installing for Ada, on Windows is tricky and quite frustrating.

> A replacement that just supports WGL+win32 and Wayland+EGL would be nice and feasible. 

Nice to know you would be satisfied with just that. I was wondering about Apple dropping OpenGL. If you say, we do not care, for now at least, it reassures me.

> Also, I would like to have more control over the frame latency via accurate frame presentation feedback (presentation-time Wayland protocol)

Could you elaborate? I bought the Wayland online book and I am almost done but never 'touched' any code yet. Do you mean that using Wayland, we can 'drive' precise refresh presentation with guaranteed full-frames?

> Have you considered putting your code under some OSS license? 

Will do.

> It would be nice if we could team up to make this happen :)

That is perfect because Orka was exactly the client I wanted to fulfill the needs. I'll get in touch then.