Consider using `WS_EX_NOREDIRECTIONBITMAP`

[smoogipoo]

As mentioned in https://learn.microsoft.com/en-us/archive/msdn-magazine/2014/june/windows-with-c-high-performance-window-layering-using-the-windows-composition-engine, using WS_EX_NOREDIRECTIONBITMAP eliminates some GPU->GPU or GPU->CPU copies.

Tasks:

• Add the WS_EX style to SDL. It looks like SDL2 doesn't use CreateWindowEx, but SDL3 does, so it might be easier to wait for SDL3 rather than try to upstream WS_EX styles into SDL2.
• Potentially change Veldrid to use FlipSequential. The article mentions only this presentation mode is supported, but will have to check on the effect of this.

Usages in the wild: https://grep.app/search?q=WS_EX_NOREDIRECTIONBITMAP

[Susko3]

Better to upstream and wait for SDL3, it's releasing soon so the API will be stabilised. I've also been working on getting "SDL3-CS" bindings automatically generated.