SDL+OpenGL context, glitchy window with integrated graphics

SDL Development
21

I assumed you were using the GL context created by SDL_Renderer.

Anyway, this is getting off topic and doesn’t really help the OP. Going by the code they posted, they’re doing all rendering on their own and aren’t using SDL_Renderer at all.

22

Just as I am, for 3D graphics and shader programming. I hoped it might be helpful to know that everything works for me, using a similar Intel integrated GPU, even if I explicitly select OpenGL 3.x.

23

So even when explicitly asking for 8 alpha bits you only get 2? That sounds broken.
(Which is not that surprising, as Intel isn’t exactly known for having great GPU drivers on Windows, and certainly not for a great OpenGL implementation)