Borderless Fullscreen doesn't apply when a Vulkan or OpenGL context renders to window on Windows

[Nolram12345]

I'm attempting to integrate borderless fullscreen into my application at the moment, which uses SDL3 for windowing.
When calling the SDL_SetWindowFullscreen function as per the documentation, behaviour appears to change depending on what graphics API is rendering to it. For rendering I currently use the bgfx rendering library, but in this case the issue seems to be more related to the graphics-API owned context rendering to the window. When rendering using D3D11 or 12, SDL_SetWindowFullscreen behaves as one would expect from the documentation, switching to borderless fullscreen when called. However, when rendering to the window from a Vulkan or OpenGL context, the window instead switches into exclusive fullscreen, even when explicitly calling SDL_SetWindowFullscreenMode(sdlWindow, NULL); beforehand.

Is there some way to work around this issue? (Is it even an SDL issue at all or perhaps a driver oddity?)

[Kontrabant]

Duplicate of #12791

Basically, the driver is trying to be clever by doing this, and there doesn't seem to be any easy way to fix it that isn't a horrible hack.

[Nolram12345]

I saw that issue, but thought it may be unrelated since Vulkan and OpenGL drivers are different beasts.
The fact that this issue exists confuses me, since there do seem to be quite an array of GL/VK applications that successfully render into borderless windows?

[playmer]

I've tried looking into this and DXGI layering is the only solution I've seen, though certainly there may be others.

I did start working on DXGI layering a few weeks ago for SDL_Renderer, I'm not sure but I think SDL could do this for you (when writing your own GL/Vk renderer), bur yeah, it's not trivial. Unfortunately I've not gotten very far and have been working on other things, but hopefully I can get back to it and see if we can fix this and a few other issues that require layering to fix. (Smoother resize...maybe?)

[Squall-Leonhart]

Vulkan's native swapchain is a GDI Blit copy, for which there is no capacity to perform borderless fullscreen without invoking DXGI Interop directly, or relying on the driver to do it.

The latter has overhead though.