[REQUEST] Multiplayer support

[the-smartest-cat]

Describe the feature you'd like to propose.

It would be nice to have a custom block that can distinguish between different controllers/players connected to the device. Basically just a custom block that allows local multiplayer.
I don't think this would work for handhelds like the 3DS and PS vita though, considering that the controller is built in.

Device(s)

No response

Additional context

Maybe it could look something like this?

Pre-submission Checks

• I have checked that the roadmap doesn't already contain this feature.
• I have searched existing issues and confirmed this feature has not been requested before.

[gradylink]

This would definitely be handled by the Gamepad custom extension.

[childishbeat]

Both systems (and other handheld devices, including their predecessors) can do local wireless multiplayer, and some with built-in controls can work with external controllers directly. Whether that would need Bluetooth, local Wi-Fi or some proprietary standard or something, I'm sure it can be done.

[TheVogels]

Both systems (and other handheld devices, including their predecessors) can do local wireless multiplayer, and some with built-in controls can work with external controllers directly. Whether that would need Bluetooth, local Wi-Fi or some proprietary standard or something, I'm sure it can be done.

Local Multiplayer would probably need to use Cloud Variables or something, there isn't an easy way to synchronize something without issues.

[childishbeat]

What about custom extensions, or is Scratch or Scratch Everywhere! structured in such a way that one would need to massively restructure first to make things reliable for either solution?

Either way, I suppose technically local multiplayer on the same device is possible (like if two players use WASD and the arrow keys on the same keyboard respectively) and with special setups depending on platform, multiple controllers is doable, even if that's at the expense of players' available inputs and/or convenience.

[TheVogels]

Sorry I meant to synchronize a project without cloud variables to have multiplayer, Cloud Variables would be easier.

[childishbeat]

Ah, gotcha. I was just throwing everything out there.

[CST1229]

Both systems (and other handheld devices, including their predecessors) can do local wireless multiplayer, and some with built-in controls can work with external controllers directly. Whether that would need Bluetooth, local Wi-Fi or some proprietary standard or something, I'm sure it can be done.

Local Multiplayer would probably need to use Cloud Variables or something, there isn't an easy way to synchronize something without issues.

the 'surest' way would be to make the runtime deterministic (e.g no randomness and consistent time-related stuff, make sure it runs the same on every device), then synchronize only inputs from each player each frame (AKA lockstep netcode)

[childishbeat]

That sounds good and all, but obviously the (pick random) block would still need to work. It also says in this Springer article that Scratch is not deterministic, and I'm not sure SE! will make the switch or at least have a mode for it. https://link.springer.com/article/10.1007/s10664-022-10255-x

[OceanIsEndless]

Local Multiplayer would probably need to use Cloud Variables or something, there isn't an easy way to synchronize something without issues.

the 'surest' way would be to make the runtime deterministic (e.g no randomness and consistent time-related stuff, make sure it runs the same on every device), then synchronize only inputs from each player each frame (AKA lockstep netcode)

That sounds good and all, but obviously the (pick random) block would still need to work. It also says in this Springer article that Scratch is not deterministic, and I'm not sure SE! will make the switch or at least have a mode for it. https://link.springer.com/article/10.1007/s10664-022-10255-x

Whoa, that article is very interesting, but surely this wouldn't be necessary for supporting multiplayer? Couldn't it just update all the controller blocks once before each frame? What is the issue with synchronization?

[namenamenam]

Wouldn't local multiplayer just be multiple controllers connected to the a single device running one instance of a project? How did cloud variables and synchronization get involved here? That's not what OP was talking about at all.

[gradylink]

Transferred to lua extension repo as this is more relevant for the the gamepad extension