This adds the functionality of sending the host's save data (raw memory
cards, as well as GCI files and Wii saves with a matching GameID) to
all other clients. The data is compressed using LZO1X to greatly reduce
its size while keeping compression/decompression fast. Save
synchronization is enabled by default, and toggleable with a checkbox
in the NetPlay dialog.
On clicking start, if the option is enabled, game boot will be delayed
until all players have received the save data sent by the host. If any
player fails to receive it properly, boot will be cancelled to prevent
desyncs.
We don't want to write this setting to disk, as SConfig has problems
with leaking settings changed by GameINI into the base configs. The
result of this is that if someone plays an N64 VC game (or other game
where we disable this setting) the branch following option can get
unintentionally disabled globally, which will reduce performance in
many games and cause NetPlay to desync with users who still have it
enabled.
This stops clients randomly deadlocking when a spectator leaves, as the mappings construct is not thread-safe and should not be written while the game is running.
This packet is only used by the host to detect desyncs, and we don't really need to know the exact frame we desynced on (unless you're debugging, but you can just recompile for that), so it's perfectly fine to just send it less often. This makes it so the timebase packet is sent only every 60 frames, rather than every frame, which further cuts back on unnecessary bandwidth consumption.
This should make the NetPlay dialog appear as a separate window in the taskbar on most systems, which makes more sense than a parented dialog as the user will leave it open for an extended period.
We want this setting to invalidate the cache because it may affect the appearance of textures in the rendered scene, therefore one would expect changing it while the game is running to have the expected effect immediately.
This will avoid effects being unexpectedly broken in these games if the user disables the option globally. This list is by no means comprehensive, these are just the games I could confirm use custom mipmaps.
Normally, SI is polled at a rate defined by the game, and we have to send the pad state to other clients on every poll or else we'll desync. This can result in fairly high bandwidth usage, especially with multiple controllers, mostly due to UDP/IP overhead.
This change introduces an option to reduce the SI poll rate to once per frame, which may introduce up to one frame of additional latency, but will reduce bandwidth usage substantially, which is useful for users on very slow internet connections.
Polling SI less frequently than the game asked for did not seem to cause any problems in my testing, so this should be perfectly safe to do.
Selecting Dummy or Memory Card would pass wrong values to EXI::ChangeDevice and not work as expected
Changing path had no effect until device was changed as it didn't call EXI::ChangeDevice at all
Techjar