Netplay: what's in the fork, and playtest feedback here

[easymod0]

This fork is Conker's Bad Fur Day: Recompiled with online multiplayer: every player on their own computer, seeing the match on their own screen. Builds for Windows, Linux and macOS are on the Releases page. You need your own US ROM, and everyone in a match must use the same release.

Playing

In the launcher pick Netplay:

• Quick Match: the first open public room, or a new one if there's none.
• Open matches: the public room list, with how many play and watch. Watch joins as a spectator.
• Room code: a friend hosts (Host tab, Host) and sends you the code.
• On this network: matches on your home or LAN-party network show up by themselves.
• Rejoin last match: back to your place after a drop.

No port forwarding is needed: the server connects everyone, through its relay when it must, and by default nobody sees anyone's address.

What the fork adds

Upstream has the first netplay version (lockstep, mouse and gyro, automatic input delay) behind a build option that's off in its releases. The fork's releases have it on, plus:

Finding and running a match

• Rooms and a relay (no port forwarding), a public room list, Quick Match, LAN discovery
• A waiting room: Ready, Start, Kick and a block list
• A notice when someone's on another release, and a connection test
• A clearer menu: Play, Host and Settings tabs

Matches that hold together

• Desync reports, and recovery: the host sends its game and the match carries on
• A player leaving doesn't end the match, and they can rejoin their place
• Late joining: new players join a match under way
• Rollback, on by default (the host's choice): hides lag by predicting the others' input, with a small input delay that stays steady
• Each player's own input delay, sized for how their inputs reach the others: one bad link doesn't raise everyone's
• A player whose inputs stop for a few seconds is let go of and the others play on; they come back by themselves
• A computer that falls behind catches up, and bursty connections (mobile) cause far fewer catch-ups
• Status on screen: ping, delay, who you're waiting for; Netplay Details (the Esc menu's Netplay tab) shows each player's delay

Spectators

• Up to 8 watch a match, from the start or joining in the middle, without taking a place
• They see everyone's view or one player's, with L and R to switch
• A spectator can take a free place or a leaver's, and the host can swap players and spectators, before the start or during the match
• The host can turn spectators off

Players

• Several players on one computer, playing online with the others
• Swap Sticks in matches
• My view only: each player sees just their own view, full screen

Help wanted

• Playtests over the internet: rollback is on by default now. How does a match feel, on a good connection and a bad one (Wi-Fi, mobile)? Do you see players jump into place, or hear sounds twice? Does a dropout come back cleanly? The log helps: each run writes conker.log next to the game (in your user folder on macOS), and keeps the run before as conker.prev.log (#24).
• macOS: it builds, but nobody has played netplay on a Mac yet.
• Problems: a desync, a crash or a match that won't connect gets an issue with the report template. Anything else (how it plays, ideas, questions) goes here.