Implement initial display selection

[ivan-mogilko]

Resolve #2280, #2575

1. Engine allows to specify display index in DisplayMode struct. All the code that dealt with getting current display's size or available modes have been adjusted to respect a selected display index.
2. Config has a new option: "[graphics] display = N", where N is a display index.
3. Special handling is done in Direct3D renderer, and Software renderer in case SDL created any of the directx drivers: when switching between exclusive fullscreen and windowed mode they will always set exclusive fullscreen on a display where the window was created (regardless of a initial mode). That's a Direct3D requirement (and possible new DirectX too). This may only be resolved by recreating a device, which in turn requires full recreation of all resources - textures etc, - and that's just too much of a hassle in my opinion.
4. Added a "Display" dropdown list to WinSetup.

TESTING:

• - Display mode selection works normally, with all the fullscreen and windowed mode kinds initializing correctly (this may be tested on default display).
• - Switching windowed/fullscreen works normally.
• - Dragging a window to another display and switching to a non-exclusive fullscreen and back should keep window on that display.
• - Dragging a window to another display and switching to a exclusive fullscreen with Direct3D should init exclusive fullscreen on a display where the window was first created.
• - Winsetup lets select display index. When changing display index, resolution selection will be updated to retrieve available modes from the selected display.

POSSIBLE TODOs:
I noticed in #2280 there's a extra suggestion to add a Editor preference that forces testing on a certain display.

[ivan-mogilko]

I've tested this on two-monitor system, but please test even if you have 1 monitor, to make sure that basic configuration keeps working, because I had to modify several things in graphics mode init.

[ericoporto]

Testing on Windows 11, just using winsetup to change the initial display, it seems it works. I select 0 and get my primary display and I select 1 and get my secondary display. I think it would make more sense if it was 1 and 2, like it shows in Windows multiple displays settings, where the monitors get assigned a number from 1 to how many they are.

About using the feature, the only curious thing is, if there is an application on the secondary display, the AGS game doesn't seem to load in "focus", while on primary display it seems it always loads in "focus" - by focus here I mean it loads the window or fullscreen below the application that is on secondary display, but also not focused so that the game doesn't start until one clicks the game icon in the start bar.

Edit: would it be possible to add a command line parameter to it? It would take a number, like 1 or 2.

Edit2: shouldn't it have the first parameter in winsetup be default, and default would mean like, the primary display or something?

[AlanDrake]

Appears to work as expected.
I have found some unrelated issues though, which I'll write in a new ticket.

EDIT: If I had to nitpick, the default desktop resolution, and available ones, should change when selecting another monitor.

[ivan-mogilko]

EDIT: If I had to nitpick, the default desktop resolution, and available ones, should change when selecting another monitor.

The list of resolutions is supposed to be refilled, is it not? My both displays support same list of resolutions, so I cannot notice the difference.

[AlanDrake]

The list of resolutions is supposed to be refilled, is it not? My both displays support same list of resolutions, so I cannot notice the difference.

I see a repaint when changing Display index, but the availabel select options remain unchanged from what was loaded at start.

[ivan-mogilko]

Pushed a fix, please try again.

[AlanDrake]

Pushed a fix, please try again.

It works now. All good.

[ericoporto]

I had a thinking that once this is merged, the display selection feature is tied to the desktop platforms. While I don't think this will change soon, I wonder if it would be better to have a macro explicitly for this in core/platform.h and then have it set to the AGS desktop macro for now - in this way it would be clear which parts of the code are the way they are because of display selection and not just as a generic desktop thing.

[ericoporto]

Thanks, that's pretty good. I think this looks fine and we will probably only get larger testing once this hits a game in production.