SDL_CreateWindow fails on Linux when using MSAA GLES2.0

SDL Development
1

I’m having a problem using multisampling with SDL2 on Linux. The SDL error message I’m receiving is “Could not find matching GLX visual”. The code I am using before create window is as follows:

SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, 1);
SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, 4); // or 2, 8, 16, none work

I’m running Ubuntu 16.04 64 bit with the proprietary 381.09 nvidia drivers. My graphics card is a GeForce 750 Ti.

I’ve had this problem in the past on another machine with a previous build of SDL2 and different hardware. What’s the deal?

2

Can you post xdpyinfo and glxinfo for this system?

Have you tried it using straight GL instead of ES?

3

In previous attempts with different hardware create window failed with gl 4 core profile. Here is some output.

xdpyinfo:

glxinfo:

4

Interesting how all the multisample visuals and configs are non-conformant.

Try to match the attributes more closely:

SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 8)
SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 8);
SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8);
SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 8);
SDL_GL_SetAttribute(SDL_GL_BUFFER_SIZE, 32);
SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8); // or 0 if you don't need it.

Do not set SDL_GL_ACCELERATED_VISUAL to anything above -1 or, I think, it will not consider the non-conformant ones.

It looks like it uses the GLX route. Perhaps you have more success with EGL. Set the SDL_OPENGL_ES_DRIVER environment variable to 1 and check if anything changes. I’m not that familiar with the X11 code in SDL, this may not do anything.

1 Like
5

@ChliHug That did it. I removed SDL_GL_ACCELERATED_VISUAL and it works now. Thanks!