We'll post something soon comparing all of the options (in our opinion). But as I understand it:
- Supabase Broadcast: one client sends every other client a one-time message
- Supabase Presence: one client tells all other clients that its own state has changed. This is similar to above, except that server keeps track of all the last-state for each client so that new members of the channel can get up to date.
- Supabase Realtime: server tells all clients when server state changes (so you will not get optimistic client-side changes this way)
Supabase’s real-time stuff lets various parts of your system send messages about changes to each other. But when it comes to realtime editing, that’s the easy part!
Reflect is a much higher level abstraction that handles the hard parts:
- maintaining a cache on the device (this alone is annoying hard to get right)
- queuing updates to send to the server reliably
- handling conflicts between different users while preserving the intent of each user, by rebasing histories locally, and choosing the winner on the server
TCR is just a small generalization of what the game industry has been doing for awhile. So in that sense, we are not at all the first.
But I'm honestly not sure why it's not been done on the web yet. To me, it's a really elegant approach. It is harder to implement in a general way (like as a library) because you need to run code on the server. And as others have pointed out, it's harder to make fast.
Perhaps multiplayer is just new enough to the web that there hasn't been time for these approaches to evolve.
I mean, React was also inspired by game techniques that at that time were decades old.
