Add support for additional display modes

[falbrechtskirchinger]

Implement additional display modes in SDL2 and WinAPI backends:

• Windowed fullscreen
• Windowed (non-resizable)

Fixes #1512
Closes #1615

To-do:

• Rebase after Replace bool fullscreen parameter with bitset enum #1612.
• Rework options screen and in-game settings window.

Notes and references:

• https://learn.microsoft.com/en-us/windows/win32/winmsg/window-styles
• https://src.chromium.org/viewvc/chrome/trunk/src/ui/views/win/fullscreen_handler.cc

[falbrechtskirchinger]

@Spikeone There you go!

[Flamefire]

This (and the other) PR is old but I'd like to clean the PRs up. I had the conflicts resolved (in a local branch) but am wondering what the intention was. @Spikeone You seem to have been involved too?
I can only imagine 3 modes:

1. Fullscreen
2. Windows w/o resize in full desktop size (aka windowed-fullscreen)
3. Resizeable window.

I'm not sure if we really need option 2 as it looks like it can be done with 3 already. Or am I missing anything?

[Spikeone]

@Flamefire maybe I'm weird but I do play RttR in windowed mode (1920x1080 on a 2560x1440 monitor) but not fullscreen.
Sadly I sometimes fail to click the menu buttons on the bottom, resulting in a resize of the window.
This is annyoing for two reasones:

• You can not change the windowed resolution from our settings, thus you have to change the config.ini everytime
• When you are streaming, this adds either some missing areas on the bottom or a black line (depending on if it became larger or not)

So the case described is exactly what I'd love to have. Funny enough I was looking forward to this and was thinking about taking a look at it since it happened quite often to me recently as I went back into streaming RttR 😅

[Flamefire]

Ok so you basically want a non-resizable window, not a fullscreen window?

Do you remember any other game that has similar options? Especially for changing the windowed size. I'd like to see how their options UI looks.

[Spikeone]

Most other games simply don't support resizing the window, at least older games did not (when they even supported windowed mode at all). Sadly I can not remember any game that I played windowed that prevented resizing at all. So normally you don't have the choice - either its always enabled (so like we do it) or it doesn't work at all (as I'd like it in my case). Only other game I currently know about is my powershellgame where I added that option as well 😅

We do have an option to change the resolution, but it's always fullscreen resolution, even if windowed is enabled.

[Flamefire]

We do have an option to change the resolution, but it's always fullscreen resolution, even if windowed is enabled.

That might be worth changing :) Just switch the label to "Window size" when "windowed" is selected.
And make "Fullscreen" to "Display mode: FullScreen 'Windowed' 'Borderless Window'"

[Spikeone]

That might be worth changing :) Just switch the label to "Window size" when "windowed" is selected.
And make "Fullscreen" to "Display mode: FullScreen 'Windowed' 'Borderless Window'"

would be great - although we discussed this in #889 where, at least I had the feeling, you didn't like the idea. Would be happy to have all the features in any case :)