Currently, each player buffers their own inputs and sends them to the
host. The host then relays those inputs to everyone else. Every player
waits on inputs from all players to be buffered before continuing. What
this means is all clients run in lockstep, and the total latency of
inputs cannot be lower than the sum of the 2 highest client ping times
in the game (in 3+ player sessions with people across the world, the
latency can be very high).
Host input authority mode changes it so players no longer buffer their
own inputs, and only send them to the host. The host stores only the
most recent input received from a player. The host then sends inputs
for all pads at the SI poll interval, similar to the existing code. If
a player sends inputs to slowly, their last received input is simply
sent again. If they send too quickly, inputs are dropped. This means
that the host has full control over what inputs are actually read by
the game, hence the name of the mode. Also, because the rate at which
inputs are received by SI is decoupled from the rate at which players
are sending inputs, clients are no longer dependent on each other. They
only care what the host is doing. This means that they can set their
buffer individually based on their latency to the host, rather than the
highest latency between any 2 players, allowing someone with lower ping
to the host to have less latency than someone else.
This is a catch to this: as a necessity of how the host's input sending
works, the host has 0 latency. There isn't a good way to fix this, as
input delay is now solely dependent on the real latency to the host's
server. Having differing latency between players would be considered
unfair for competitive play, but for casual play we don't really care.
For this reason though, combined with the potential for a few inputs to
be dropped on a bad connection, the old mode will remain and this new
mode is entirely optional.
Behaviorally, this belongs within the netplay client. The server will
always transmit a known RTC value, so it doesn't even need a global for
this. Given the client receives the packet containing said RTC value, we can
store it as a member variable and provide an accessor for reading that
value.
This removes another global variable within the netplay code.
Most settings which affect determinism will now be synced on NetPlay.
Additionally, there's a strict sync mode which will sync various
enhancements to prevent desync in games that use EFB reads.
This also adds a check for all players having the IPL.bin file, and
doesn't load it for anyone if someone is missing it. This prevents
desyncs caused by mismatched system fonts.
Additionally, the NetPlay window was getting too wide with checkboxes,
so FlowLayout has been introduced to make the checkboxes take up
multiple rows dynamically. However, there's some minor vertical
centering issues I haven't been able to solve, but it's better than a
ridiculously wide window.
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.
This is only ever read from externally, so we can expose a getter that ensures that
immutability, while making the actual instance internal. Given the
filling out of these settings depends on packets received by the client
instance, it makes more sense to make it a part of the client itself.
This trims off one lingering global.
Previously there was only one function under the NetPlay namespace,
which is kind of silly considering we have all of these other types
and functions existing outside of the namespace.
This moves the rest of them into the namespace.
This gets some general names, like Player, for example, out of the global namespace.
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.
Makes the enum values strongly-typed and prevents the identifiers from
polluting the PowerPC namespace. This also cleans up the parameters of
some functions where we were accepting an ambiguous int type and
expecting the correct values to be passed in.
Now those parameters accept a PowerPC::CPUCore type only, making it
immediately obvious which values should be passed in. It also turns out
we were storing these core types into other structures as plain ints,
which have also been corrected.
As this type is used directly with the configuration code, we need to
provide our own overloaded insertion (<<) and extraction (>>) operators
in order to make it compatible with it. These are fairly trivial to
implement, so there's no issue here.
A minor adjustment to TryParse() was required, as our generic function
was doing the following:
N tmp = 0;
which is problematic, as custom types may not be able to have that
assignment performed (e.g. strongly-typed enums), so we change this to:
N tmp;
which is sufficient, as the value is attempted to be initialized
immediately under that statement.
So that it contains the current commit and not an arbitrary date that
may or may not be up-to-date. This will cause tears as people will not
be able to use netplay with one diverging commit that does not touch
anything related. On the other hand, users can’t be trusted.
Replaces them with forward declarations of used types, or removes them entirely if they aren't used at all. This also replaces certain Common headers with less inclusive ones (in terms of definitions they pull in).
Won't work with all games, but provides a nice way to spend extra CPU to make
a variable framerate game faster (e.g. Spyro or The Last Story), or to make
a game use less CPU at the cost of a lower framerate (e.g. Rogue Leader).
