glew to work with pure OpenGL ES only context / Linux ARM

[Smirftsch]

I've got some problem to use glew creating a pure ES context. I am using it in a Linux ARM environment (ODROID-XU4 in Ubuntu 16.04.2 LTS) in combination with SDL2.

The tricky part is, to have hardware acceleration, I need ES, but the 3D driver in this system only works if also initialized with ES too from the begin with, if initialized with GL at first it falls back entirely to Mesa and I am loosing 3D acceleration.
So, if I compile SDL2 with OpenGL and OpenGLES support, it creates (obviously) an initial window with GL and therefor falls back to Mesa even although glew initializes ES properly then, but if I remove OpenGL from SDL2 I get "Missing GL Version" when calling glewInit().
SDL_GL_CONTEXT_MAJOR and MINOR are set, as well as CONTEXT_PROFILE_ES

For this fallback mechanism I have no idea if there is a way to avoid this behavior, but I haven't found any usable docs for that and I am happy to have 3D acceleration working at all there, which is a rare situation in Linux ARM on most dev boards.

So what I need is a way to make a proper, also ES initialized context. I am currently not entirely sure where the problem is, but right now it looks like it is in glew (at least in the end). To reproduce its probably enough to build SDL2 without GL support and init glew then, but need to test this yet on a different platform.

I hope this explanation makes sense and if you need any more information, let me know.

[nigels-com]

Two things to note here:

• GLEW does not support OpenGL ES
• GLEW does not create OpenGL contexts, it works with what's given

-- Nigel

[Smirftsch]

I found some notes in the mailingslists 2011 that someone was working to implement ES in glew and it seems to have no trouble to work with SDL_GL_CONTEXT_PROFILE_ES context in general, so I assumed ES is actually being supported. I also realize that the name of this topic is a bit misleading, so I changed it accordingly. However, if not being supported it's probably making no difference.
Thanks anyway :)

[user1095108]

OpenGL ES compatibility is an OpenGL extension. I have similar problems with SDL2.