Add virtual joypad buttons for semantic "yes"/"no"

[Grublady]

This PR adds "virtual" joypad buttons which correspond to semantic inputs rather than physical inputs.

These virtual button events can be mapped to actions as usual, allowing interface actions such as "confirm" or "cancel" to use any supported controller's native semantics.

For example, although the A buttons on Xbox and Switch controllers send JoyButton::A and JoyButton::B respectively, both inputs would now also send JoyButton::SEMANTIC_YES as well.

Tested on macOS 15.3 with Switch Pro Controller and Switch Joy-Cons, needs testing on other platforms/controllers.

Motivation

Previously, joypad face button events were identified strictly by position (ie top, bottom, left, right).
This is typically desirable for gameplay, as the control layout can be designed once and keep the same ergonomics across controllers.

However, this system created a problem when accounting for controller layouts whose face button semantics are reversed:
For example, Xbox controllers use the bottom (A) button for "yes," "confirm," or "select" in menu navigation, whereas Switch controllers use the right (A) button for these purposes.
Thus, mapping one of these face button positions to menu navigation is always unintuitive for some controllers.

The goal of this PR is to allow developers to easily implement semantically-correct interaction.
This is relevant to most games, so I believe it makes sense as an engine feature.

[JoNax97]

Isn't mapping physical inputs to semantic ones the whole point of actions?
I'm not opposed to the underlying idea, I just feel we're reinventing the wheel and mixing comcerns here

[Grublady]

Isn't mapping physical inputs to semantic ones the whole point of actions?

Yes, and in most cases this is sufficient.

The issue arises when the same physical input means something different depending on which controller is in use.

Specifically, Xbox controller users expect the bottom face button to act as "yes," whereas Nintendo controller users expect it to act as "no." (And vice versa for the right face button.)

[JoNax97]

I ser your point now. I feel this might be addressed in a way that's more in line with the current way input works, by allowing defining a different physical input to an action based on controller type.

So for example, you create an accept action bound to Nintendo A and Xbox A, instead of mapping to generic "button 1". I imagine this would work similarly to choosing between physical and vs keycode when adding a keyboard input.

This way the semantics stay on the side of the action, while allowing different configurations for each platform.

How does that sound?

[Grublady]

I ser your point now. I feel this might be addressed in a way that's more in line with the current way input works, by allowing defining a different physical input to an action based on controller type.

That might be another possibility, though I worry it may be a bit over-engineered.

Really the only scenario this PR currently seeks to address is the discrepancy in A & B buttons, and I think the complexity of providing per-controller-type events would be overkill for this case.

Is there another use case you have in mind for segregated input events?

[JoNax97]

I don't have a use case right now, but it makes me wonder how common it would be for games to map input differently per-console.

For example the convention for jumping being different between switch and playstation (making this up)

[Grublady]

I don't have a use case right now, but it makes me wonder how common it would be for games to map input differently per-console.

As far as I'm aware, all other controls are typically mapped to the same physical position.

I checked some popular games from other engines to see how they handle it:

• Hollow Knight (Unity) maps all gameplay controls positionally but uses the expected A/B mappings for menu actions on each console.
• Fortnite (Unreal) similarly seems to map all gameplay controls positionally but use the native A/B menu actions.
• Minecraft Bedrock Ed. (custom C++ engine) maps everything positionally except for A/B, which it maps according to platform (for both menu and gameplay actions).

Even if we were to find another common case of differing conventions, it should be fairly trivial to extend it from this PR.
I don't foresee a significant number of these (if any), so I don't think it makes sense to preemptively accommodate them.

[JoNax97]

Makes sense to me

[Calinou]

This will fail to detect third-party Switch controllers.

See #89193 which aims to be more reliable in controller type detection.

[Grublady]

Nice catch, I'll rebase and update to use that PR's detection

[Grublady]

Now based on #89193 and its controller type detection

[ThatBlockyPenguin]

Would love to see this added in some way!
Glad to see there's work on it. :)

[Nintorch]

Another possible candidate for the base of this PR: #112680 :D (well, when it's ready, that is...)