Initial work on rollback and refactor

src/fighter/mod.rs

@@ -0,0 +1,86 @@
+//! Everything fighter-shaped: the components that describe a fighter, the
+//! state machine that drives it, and the plugin that schedules it all.
+
+use bevy::prelude::*;
+use bevy_egui::EguiPrimaryContextPass;
+use bevy_ggrs::prelude::*;
+
+pub mod attributes;
+pub mod collision;
+pub mod debug;
+pub mod ecb;
+pub mod motion;
+pub mod state;
+
+// The fighter components are re-exported so the rest of the crate can say
+// `fighter::FighterVelocity` without caring which file it lives in. Named
+// explicitly rather than globbed, so moving a type between submodules can't
+// silently change what this module exports.
+pub use attributes::FighterAttributes;
+pub use ecb::FighterECB;
+pub use motion::{FighterPreviousTranslation, FighterTranslation, FighterVelocity, Grounded};
+
+use crate::schedule::GameplaySet;
+use state::state_interrupt_system;
+
+/// Owns fighter simulation, the rollback registrations for fighter
+/// components, and the fighter debug overlays.
+#[derive(Default)]
+pub struct FighterPlugin;
+
+impl Plugin for FighterPlugin {
+    fn build(&self, app: &mut App) {
+        app
+            // Every state gets a chance to interrupt itself, in priority order.
+            .add_systems(
+                GgrsSchedule,
+                (
+                    state_interrupt_system::<state::wait::WaitState>,
+                    state_interrupt_system::<state::walk::WalkState>,
+                    state_interrupt_system::<state::dash::DashState>,
+                    state_interrupt_system::<state::run::RunState>,
+                )
+                    .chain()
+                    .in_set(GameplaySet::Interrupt),
+            )
+            .add_systems(
+                GgrsSchedule,
+                (
+                    state::wait::wait_update,
+                    state::walk::walk_update,
+                    state::dash::dash_update,
+                    state::run::run_update,
+                )
+                    .chain()
+                    .in_set(GameplaySet::StateUpdate),
+            )
+            .add_systems(
+                GgrsSchedule,
+                (motion::integrate_gravity, motion::apply_motion)
+                    .chain()
+                    .in_set(GameplaySet::Physics),
+            )
+            .add_systems(
+                GgrsSchedule,
+                collision::collide_fighter_with_scene.in_set(GameplaySet::Collision),
+            )
+            .add_observer(state::dash::on_insert_dash)
+            // Rollback registration lives next to the systems that write these
+            // components; a component simulated here but missing from this list
+            // is a desync waiting to happen.
+            .rollback_component_with_copy::<FighterECB>()
+            .rollback_component_with_copy::<FighterVelocity>()
+            .rollback_component_with_copy::<FighterTranslation>()
+            .rollback_component_with_copy::<FighterPreviousTranslation>()
+            .rollback_component_with_copy::<FighterAttributes>()
+            .rollback_component_with_copy::<Grounded>()
+            .rollback_component_with_copy::<state::wait::WaitState>()
+            .rollback_component_with_copy::<state::walk::WalkState>()
+            .rollback_component_with_copy::<state::dash::DashState>()
+            .rollback_component_with_copy::<state::run::RunState>()
+            .checksum_component::<state::dash::DashState>(state::dash::hash_dash_state)
+            // Debug views.
+            .add_systems(FixedPostUpdate, debug::debug_draw_ecb)
+            .add_systems(EguiPrimaryContextPass, debug::fighter_debug);
+    }
+}