Set OpenGL context 3.3 with SDL2 on mac, not working

Question

I have tried setting the OpenGL context to v3.3 using the following code, it creates a 4.1 context.

SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_FORWARD_COMPATIBLE_FLAG);

Am I doing something wrong or is it a mac problem?

Answer 1

OpenGL does not provide any guarantees that when you ask for an OpenGL X.Y context, that you get exactly an OpenGL X.Y context. It depends on the drivers you use.

• On OS X, if you ask for a core context, you get the highest version supported on your hardware and operating system combination. If you ask for a compatibility context, you get 2.1.

• On my Linux/Mesa system, I always get 3.0 compatibility contexts, and 3.3 core contexts.

• On my Windows/AMD system, I get the exactly the version I ask for.

The 4.1 context should work fine for you if your code assumes that the context is 3.3. Just check that the GL version is >= the version you need, and check that you have a compatibility context if you need it.