Figure out missing display handle implementations about raw-window-handle

[notgull]

For Win32, there isn't really a concept of a display. Some structures are thread local, but overall there is very little context for the windows. Leaving it empty is probably the right choice. I am not familiar with WinRT.

Web stuff is generally contextualized by the window/document, which is often cached. But given that it can be derived from anywhere it might not be worth it.

I don't know other platforms well enough to comment on them.

[kchibisov]

The documentation, as far as I could find it, says that you're allowed to pass EGL_DEFAULT_DISPLAY (i.e. a null-ptr) on Wayland too? So why are we restricting that?

you could try, but it'll fail.

[kchibisov]

Everything which is not implemented is not needed or doesn't exist as a concept. I remember discussing it with you on #matrix and I told that it's more about platforms having a concept of multiple display servers, so they need a way to distinguish between them, which is only an issue on platforms with the freedom to choose the display server.

[madsmtm]

I do remember too, I was just unsure if we were still missing something.

I guess I'll reword that section at some point then, and then close this issue.

[madsmtm]

The documentation, as far as I could find it, says that you're allowed to pass EGL_DEFAULT_DISPLAY (i.e. a null-ptr) on Wayland too? So why are we restricting that?

[madsmtm]

And it seems like HaikuOS just got the ability to pass a handle as well, although that doesn't really sound stable yet.