Document the application freeze during window drag/resize on Windows using SDL_main with internal loops

[daninsky1]

There is this historic issue: #1059

This problem is like the "how to quit Vim" of SDL — it happens to many users, but the information about it is scattered across GitHub issues, Reddit threads, Stack Overflow, etc.

It would be very helpful to have official documentation explaining when this happens, why this happens, and how to solve it. Without proper documentation, new users are likely to get confused or assume SDL is bad designed.
Please consider adding this to the SDL3 documentation or wiki. It would save time and frustration for a lot of developers.

Here's an example of a relevant solution in SDL3: using the new callback system:
#12972 (comment)

But at the same time, the current documentation doesn't strongly recommend using the new callback system:
https://wiki.libsdl.org/SDL3/README-main-functions#main-callbacks-in-sdl3
And many developers aim to support Windows. So, this can easily lead to app freeze.

[slouken]

The problem is that there isn't a great place to document this. Please feel free to create a PR that makes sense to you. It should include both callback and non-callback solutions.

[icculus]

The problem is that there isn't a great place to document this.

I think we amend the paragraph here...

SDL/include/SDL3/SDL_events.h

Lines 1240 to 1242 in 89a8cf2

	* SDL_PollEvent() is the favored way of receiving system events since it can
	* be done from the main loop and does not suspend the main loop while waiting
	* on an event to be posted.

...to say something like "Note that there's a quirk about how Windows handles events while dragging/resizing a window, please read wiki.libsdl.org/SDL3/WindowsHangsDuringDrag for technical details."

And then we talk as much as we want on that wiki page.

I'm going to assign this to me, to do once I catch up.

[icculus]

(Whatever else we do, I think having this specific thing on a Wiki page, where search engines will find it and we can trivially link to it on forums/discord/etc, is super-useful.)

[nfries88]

A workaround to this I've seen other frameworks start doing is what SDL already does to work around other problems on some other systems: start a new thread to call SDL_main on and proxy all UI calls to the real main thread