Initial work on rollback and refactor

src/netcode/session.rs

@@ -0,0 +1,48 @@
+//! Bringing up the GGRS session and reporting what it does.
+
+use bevy::prelude::*;
+use bevy_ggrs::{ggrs::UdpNonBlockingSocket, prelude::*};
+
+use crate::args::Args;
+use crate::netcode::GGRSCfg;
+
+pub fn netcode_setup(mut commands: Commands, args: Res<Args>) -> Result {
+    let mut sess_build = SessionBuilder::<GGRSCfg>::new()
+        .with_num_players(args.players)?
+        .with_check_distance(args.check_distance)
+        .with_input_delay(args.input_delay); // (optional) set input delay for the local player
+
+    for i in 0..args.players {
+        sess_build = sess_build.add_player(PlayerType::Local, i)?;
+    }
+
+    if args.synctest {
+        println!("Start synctest!");
+        let sess = sess_build.start_synctest_session()?;
+        commands.insert_resource(Session::SyncTest(sess));
+    } else {
+        println!("Start p2p!");
+        let socket = UdpNonBlockingSocket::bind_to_port(6969)?;
+        let sess = sess_build.start_p2p_session(socket)?;
+        commands.insert_resource(Session::P2P(sess));
+    }
+
+    Ok(())
+}
+
+pub fn print_events_system(mut session: ResMut<Session<GGRSCfg>>) {
+    match session.as_mut() {
+        Session::P2P(s) => {
+            for event in s.events() {
+                match event {
+                    GgrsEvent::Disconnected { .. } | GgrsEvent::NetworkInterrupted { .. } => {
+                        warn!("GGRS event: {event:?}")
+                    }
+                    GgrsEvent::DesyncDetected { .. } => error!("GGRS event: {event:?}"),
+                    _ => info!("GGRS event: {event:?}"),
+                }
+            }
+        }
+        _ => {}
+    }
+}