Deduplicate fighter state lifecycle policies

## Summary

- replace the per-fighter received-attack inbox with a typed rollback-registered pending-hit resource
- split combat reaction resolution into its own attack module
- remap entity references during rollback and include pending hits in debug save states

Fixes #21

Reviewed-on: #34
Co-authored-by: Álex Román Núñez <eirexe@eirteam.moe>

.cargo/config.toml

@@ -1,7 +1,7 @@
 # for Linux
 [target.x86_64-unknown-linux-gnu]
 linker = "clang"
-rustflags = ["-C", "link-arg=-fuse-ld=/usr/bin/mold", "-Zshare-generics=y", ]
+rustflags = ["-C", "link-arg=-fuse-ld=/usr/bin/mold", "-Zshare-generics=y", "-D", "warnings", ]
 
 [unstable]
 codegen-backend = true

.gitea/workflows/ci.yml

@@ -25,6 +25,7 @@ jobs:
       - name: Cache Rust dependencies and build artifacts
         uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
+          prefix-key: v1-rust
           shared-key: linux-nightly
           cache-bin: false
 
@@ -45,7 +46,7 @@ jobs:
             pkg-config
 
       - name: Build
-        run: RUSTFLAGS="-D warnings" cargo build --locked -j 4
+        run: cargo build --locked -j 4
 
       - name: Run unit tests
         run: cargo test --locked --lib -j 4

src/debug_tools/save_state.rs

@@ -8,8 +8,8 @@ use crate::{
         FighterVelocity, Grounded,
         animation::FighterAnimationFrame,
         attack::{
-            FighterDamage, FighterKnockbackVelocity, FighterPendingHitReaction,
+            FighterDamage, FighterKnockbackVelocity, FighterPendingHitReaction, FighterPendingHits,
-            FighterReceivedAttacks, FighterSolvedHurtboxes, FighterStaleMoveQueue,
+            FighterSolvedHurtboxes, FighterStaleMoveQueue,
         },
         baked_animation::FighterBoneMatrices,
         state::FighterState,
@@ -28,6 +28,7 @@ pub(super) struct DebugSaveState {
 struct Checkpoint {
     fighters: Vec<FighterCheckpoint>,
     stage_collision: StageCollision,
+    pending_hits: FighterPendingHits,
 }
 
 #[derive(Clone)]
@@ -50,7 +51,6 @@ struct FighterCheckpoint {
     knockback_velocity: FighterKnockbackVelocity,
     stale_moves: FighterStaleMoveQueue,
     hitboxes: FighterHitboxes,
-    received_attacks: FighterReceivedAttacks,
     solved_hurtboxes: FighterSolvedHurtboxes,
     bone_matrices: FighterBoneMatrices,
     grounded: bool,
@@ -97,9 +97,11 @@ pub(super) fn save_or_restore(world: &mut World) {
             };
             checkpoint_fighters.push(checkpoint);
         }
+        let pending_hits = world.resource::<FighterPendingHits>().clone();
         world.resource_mut::<DebugSaveState>().checkpoint = Some(Checkpoint {
             fighters: checkpoint_fighters,
             stage_collision,
+            pending_hits,
         });
         info!("Saved debug game state");
         return;
@@ -147,7 +149,6 @@ pub(super) fn save_or_restore(world: &mut World) {
         entity.insert(saved.knockback_velocity);
         entity.insert(saved.stale_moves.clone());
         entity.insert(saved.hitboxes.clone());
-        entity.insert(saved.received_attacks.clone());
         entity.insert(saved.solved_hurtboxes.clone());
         entity.insert(saved.bone_matrices.clone());
         if saved.grounded {
@@ -156,6 +157,7 @@ pub(super) fn save_or_restore(world: &mut World) {
             entity.remove::<Grounded>();
         }
     }
+    world.insert_resource(checkpoint.pending_hits.clone());
     world.insert_resource(checkpoint.stage_collision);
     for mut match_camera in world.query::<&mut MatchCamera>().iter_mut(world) {
         match_camera.needs_snap = true;
@@ -184,7 +186,6 @@ fn capture_fighter(world: &World, entity: Entity) -> Option<FighterCheckpoint> {
         knockback_velocity: *fighter.get::<FighterKnockbackVelocity>()?,
         stale_moves: fighter.get::<FighterStaleMoveQueue>()?.clone(),
         hitboxes: fighter.get::<FighterHitboxes>()?.clone(),
-        received_attacks: fighter.get::<FighterReceivedAttacks>()?.clone(),
         solved_hurtboxes: fighter.get::<FighterSolvedHurtboxes>()?.clone(),
         bone_matrices: fighter.get::<FighterBoneMatrices>()?.clone(),
         grounded: fighter.contains::<Grounded>(),

src/fighter/attack/mod.rs

@@ -1,18 +1,19 @@
 use std::collections::{HashMap, VecDeque};
 
+mod reaction;
+
+use bevy::ecs::entity::{EntityMapper, MapEntities};
 use bevy::prelude::*;
-use bevy_ggrs::{Rollback, prelude::GgrsSchedule};
+use bevy_ggrs::{Rollback, RollbackApp, prelude::GgrsSchedule};
-use fixed_math::SinCos;
 use serde::{Deserialize, Serialize};
 
 use crate::{
     fighter::{
-        Fighter, FighterAttributes, FighterFacingDirection, FighterHitboxes, FighterHitstop,
+        Fighter, FighterAttributes, FighterFacingDirection, FighterHitboxes,
         FighterPreviousFacingDirection, FighterPreviousTranslation, FighterRoster,
         FighterTranslation,
         animation::{AnimKind, FighterAnimationFrame},
         baked_animation::{FighterBoneIndexMap, FighterBoneMatrices, FixedMat4},
-        errors::FighterErrors,
         hurtbox::{FixedAffineCapsule, FixedCapsule},
         manifest::FighterManifest,
     },
@@ -432,15 +433,26 @@ pub struct FighterAttackScriptAssets {
 #[derive(Component, Clone, Debug, Default, Hash)]
 pub struct FighterSolvedHurtboxes(pub Vec<FighterSolvedHurtbox>);
 
-#[derive(Component, Clone, Debug, Default, Hash, DerefMut, Deref)]
+#[derive(Clone, Debug, Hash)]
-pub struct FighterReceivedAttacks(
+pub struct FighterHit {
-    pub  Vec<(
+    pub attacker: Entity,
-        /* attacker */ Entity,
+    pub defender: Entity,
-        Handle<FighterAttackScript>,
+    pub attack_script: Handle<FighterAttackScript>,
-        AttackKind,
+    pub attack_kind: AttackKind,
-        /* hitbox_idx */ usize,
+    pub hitbox_index: usize,
-    )>,
+}
-);
+
+#[derive(Resource, Clone, Debug, Default, Hash)]
+pub struct FighterPendingHits(pub Vec<FighterHit>);
+
+impl MapEntities for FighterPendingHits {
+    fn map_entities<M: EntityMapper>(&mut self, entity_mapper: &mut M) {
+        for hit in &mut self.0 {
+            hit.attacker = entity_mapper.get_mapped(hit.attacker);
+            hit.defender = entity_mapper.get_mapped(hit.defender);
+        }
+    }
+}
 
 pub fn solve_hurtboxes(
     mut query: Query<(
@@ -498,19 +510,14 @@ pub fn intersect_attacks_with_hurtboxes(
         &Player,
         &FighterStaleMoveQueue,
     )>,
-    mut query_attacked: Query<(
+    query_attacked: Query<(Entity, &FighterSolvedHurtboxes)>,
-        Entity,
+    mut pending_hits: ResMut<FighterPendingHits>,
-        &FighterSolvedHurtboxes,
-        &Player,
-        &Fighter,
-        &mut FighterReceivedAttacks,
-    )>,
     attack_scripts: Res<Assets<FighterAttackScript>>,
 ) {
+    pending_hits.0.clear();
+
     for &entity_receiving in &roster.0 {
-        let Ok((_, hurtboxes, _, _receiving_fighter, mut received_attacks)) =
+        let Ok((_, hurtboxes)) = query_attacked.get(entity_receiving) else {
-            query_attacked.get_mut(entity_receiving)
-        else {
             continue;
         };
 
@@ -551,12 +558,13 @@ pub fn intersect_attacks_with_hurtboxes(
                 continue;
             };
 
-            received_attacks.push((
+            pending_hits.0.push(FighterHit {
-                entity_hurting,
+                attacker: entity_hurting,
-                active_attack.script.clone(),
+                defender: entity_receiving,
-                active_attack.kind,
+                attack_script: active_attack.script.clone(),
-                hitting_hitbox_idx,
+                attack_kind: active_attack.kind,
-            ));
+                hitbox_index: hitting_hitbox_idx,
+            });
             info!("Hit by hitbox {}!!!!", hitting_hitbox_idx);
 
             active_attack.hit_fighters.push(entity_receiving);
@@ -564,140 +572,21 @@ pub fn intersect_attacks_with_hurtboxes(
     }
 }
 
-pub fn calculate_received_attacks_trajectories(
-    mut attacker: Query<(
-        &mut FighterStaleMoveQueue,
-        &FighterFacingDirection,
-        &FighterHitboxes,
-        &Player,
-        &mut FighterHitstop,
-    )>,
-    receiver: Query<(
-        &mut FighterReceivedAttacks,
-        &mut FighterDamage,
-        &Fighter,
-        &mut FighterPendingHitReaction,
-    )>,
-    attack_scripts: Res<Assets<FighterAttackScript>>,
-    game_settings: Res<GameSettings>,
-    fighter_manifests: Res<Assets<FighterManifest>>,
-) -> Result {
-    for (mut received_attacks, mut receiver_damage, fighter, mut pending_reactions) in receiver {
-        if received_attacks.is_empty() {
-            continue;
-        }
-
-        // we got attacked, time to calculate the total damage
-
-        let damage_data = received_attacks
-            .iter()
-            .filter_map(|(from_entity, attack_script, attack_kind, hitbox_idx)| {
-                let Ok((stale_move_queue, facing_dir, _hitboxes, player, _attacker_hitstop)) =
-                    attacker.get(*from_entity)
-                else {
-                    return None;
-                };
-
-                let Some(attack_script) = attack_scripts.get(attack_script) else {
-                    return None;
-                };
-
-                let hitbox = &attack_script.hitboxes[*hitbox_idx];
-
-                let damage_received =
-                    stale_move_queue.get_attack_damage_multiplier(*attack_kind) * hitbox.damage.0;
-
-                Some((
-                    from_entity,
-                    damage_received,
-                    hitbox,
-                    attack_script,
-                    matches!(facing_dir, FighterFacingDirection::Left),
-                    player.handle,
-                ))
-            })
-            .collect::<Vec<_>>();
-
-        let total_damage_received_this_frame = damage_data
-            .iter()
-            .map(|(_, damage, ..)| damage)
-            .sum::<FGi32>();
-
-        let fighter_manifest = fighter_manifests
-            .get(&fighter.manifest)
-            .ok_or(FighterErrors::FighterManifestNotFound)?;
-
-        let mut reactions = vec![];
-
-        for (attacker_entity, attack_damage, hitbox, _attack_script, facing_left, attacker_slot) in
-            damage_data
-        {
-            let knockback = hitbox.calculate_knockback(
-                &fighter_manifest.attributes,
-                *receiver_damage,
-                FighterDamage(total_damage_received_this_frame),
-                false,
-                false,
-            );
-
-            let angle = match &hitbox.angle {
-                AttackAngle::Normal(angle) => *angle,
-                AttackAngle::Sakurai => FGi32::lit("32.0"),
-            };
-
-            let launch_angle = if facing_left {
-                FGi32::lit("180.0") - angle
-            } else {
-                angle
-            };
-            let (sin, cos) = launch_angle.sin_cos();
-            let launch_direction = FGVec2::new(cos, sin);
-            let hitstop = HitStop::calculate(FighterDamage(attack_damage), false);
-            reactions.push((
-                *attacker_entity,
-                attacker_slot,
-                FighterHitReaction {
-                    launch_velocity: launch_direction * knockback.get_launch_speed(&game_settings),
-                    hitstun_frames: knockback.get_hitstun_frames(&game_settings),
-                    hitstop_frames: hitstop,
-                    kind: HitReactionKind::Flinch,
-                },
-            ));
-        }
-
-        receiver_damage.0 += total_damage_received_this_frame;
-
-        for (attacker_entity, _, reaction) in reactions.iter() {
-            let Ok((.., mut hitstop)) = attacker.get_mut(*attacker_entity) else {
-                continue;
-            };
-
-            hitstop.remaining_frames = reaction.hitstop_frames.max(hitstop.remaining_frames);
-        }
-
-        // Pick attack by port priority
-        pending_reactions.0 = reactions
-            .into_iter()
-            .min_by(|(_, port_a, _), (_, port_b, _)| port_a.cmp(port_b))
-            .map(|(_, _, reaction)| reaction);
-
-        received_attacks.clear();
-    }
-
-    Ok(())
-}
-
 pub struct FighterAttackPlugin;
 
 impl Plugin for FighterAttackPlugin {
     fn build(&self, app: &mut App) {
+        app.init_resource::<FighterPendingHits>()
+            .add_plugins(reaction::FighterReactionPlugin)
+            .rollback_resource_with_clone::<FighterPendingHits>()
+            .update_resource_with_map_entities::<FighterPendingHits>()
+            .checksum_resource_with_hash::<FighterPendingHits>();
         app.add_systems(
             GgrsSchedule,
             (
                 solve_hurtboxes,
                 solve_hitboxes,
                 intersect_attacks_with_hurtboxes,
-                calculate_received_attacks_trajectories,
             )
                 .chain()
                 .after(crate::fighter::baked_animation::update_fighter_bone_matrices)

src/fighter/attack/reaction.rs

@@ -0,0 +1,145 @@
+use bevy::prelude::*;
+use bevy_ggrs::prelude::GgrsSchedule;
+use fixed_math::SinCos;
+
+use super::*;
+use crate::{
+    fighter::{
+        Fighter, FighterFacingDirection, FighterHitboxes, FighterHitstop,
+        FighterPendingHitReaction, FighterStaleMoveQueue, errors::FighterErrors,
+        manifest::FighterManifest,
+    },
+    game_settings::GameSettings,
+    math::{int::FGi32, vec::FGVec2},
+    player::Player,
+    schedule::GameplaySet,
+    scripting::FighterAttackScript,
+};
+
+pub fn resolve_fighter_hits(
+    mut pending_hits: ResMut<FighterPendingHits>,
+    mut attacker: Query<(
+        &FighterStaleMoveQueue,
+        &FighterFacingDirection,
+        &FighterHitboxes,
+        &Player,
+        &mut FighterHitstop,
+    )>,
+    mut receiver: Query<(&mut FighterDamage, &Fighter, &mut FighterPendingHitReaction)>,
+    attack_scripts: Res<Assets<FighterAttackScript>>,
+    game_settings: Res<GameSettings>,
+    fighter_manifests: Res<Assets<FighterManifest>>,
+) -> Result {
+    let hits = std::mem::take(&mut pending_hits.0);
+    let mut hit_offset = 0;
+
+    while hit_offset < hits.len() {
+        let defender = hits[hit_offset].defender;
+        let next_defender = hits[hit_offset..]
+            .iter()
+            .position(|hit| hit.defender != defender)
+            .map_or(hits.len(), |offset| hit_offset + offset);
+
+        let Ok((mut receiver_damage, fighter, mut pending_reaction)) = receiver.get_mut(defender)
+        else {
+            hit_offset = next_defender;
+            continue;
+        };
+
+        let damage_data = hits[hit_offset..next_defender]
+            .iter()
+            .filter_map(|hit| {
+                let Ok((stale_move_queue, facing_dir, _hitboxes, player, _)) =
+                    attacker.get(hit.attacker)
+                else {
+                    return None;
+                };
+                let attack_script = attack_scripts.get(&hit.attack_script)?;
+                let hitbox = attack_script.hitboxes.get(hit.hitbox_index)?;
+                let damage_received = stale_move_queue
+                    .get_attack_damage_multiplier(hit.attack_kind)
+                    * hitbox.damage.0;
+
+                Some((
+                    hit.attacker,
+                    damage_received,
+                    hitbox,
+                    matches!(facing_dir, FighterFacingDirection::Left),
+                    player.handle,
+                ))
+            })
+            .collect::<Vec<_>>();
+
+        let total_damage_received_this_frame = damage_data
+            .iter()
+            .map(|(_, damage, ..)| damage)
+            .sum::<FGi32>();
+        let fighter_manifest = fighter_manifests
+            .get(&fighter.manifest)
+            .ok_or(FighterErrors::FighterManifestNotFound)?;
+        let mut reactions = Vec::with_capacity(damage_data.len());
+
+        for (attacker_entity, attack_damage, hitbox, facing_left, attacker_slot) in damage_data {
+            let knockback = hitbox.calculate_knockback(
+                &fighter_manifest.attributes,
+                *receiver_damage,
+                FighterDamage(total_damage_received_this_frame),
+                false,
+                false,
+            );
+            let angle = match &hitbox.angle {
+                AttackAngle::Normal(angle) => *angle,
+                AttackAngle::Sakurai => FGi32::lit("32.0"),
+            };
+            let launch_angle = if facing_left {
+                FGi32::lit("180.0") - angle
+            } else {
+                angle
+            };
+            let (sin, cos) = launch_angle.sin_cos();
+            let launch_direction = FGVec2::new(cos, sin);
+            let hitstop = HitStop::calculate(FighterDamage(attack_damage), false);
+            reactions.push((
+                attacker_entity,
+                attacker_slot,
+                FighterHitReaction {
+                    launch_velocity: launch_direction * knockback.get_launch_speed(&game_settings),
+                    hitstun_frames: knockback.get_hitstun_frames(&game_settings),
+                    hitstop_frames: hitstop,
+                    kind: HitReactionKind::Flinch,
+                },
+            ));
+        }
+
+        receiver_damage.0 += total_damage_received_this_frame;
+
+        for (attacker_entity, _, reaction) in &reactions {
+            let Ok((.., mut hitstop)) = attacker.get_mut(*attacker_entity) else {
+                continue;
+            };
+            hitstop.remaining_frames = reaction.hitstop_frames.max(hitstop.remaining_frames);
+        }
+
+        pending_reaction.0 = reactions
+            .into_iter()
+            .min_by(|(_, port_a, _), (_, port_b, _)| port_a.cmp(port_b))
+            .map(|(_, _, reaction)| reaction);
+
+        hit_offset = next_defender;
+    }
+
+    Ok(())
+}
+
+pub struct FighterReactionPlugin;
+
+impl Plugin for FighterReactionPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(
+            GgrsSchedule,
+            resolve_fighter_hits
+                .in_set(GameplaySet::Attacks)
+                .after(super::intersect_attacks_with_hurtboxes),
+        );
+    }
+}

src/fighter/mod.rs

@@ -37,8 +37,8 @@ use crate::{
     fighter::{
         attack::{
             AttackKind, FighterAttackPlugin, FighterAttackScriptAssets, FighterDamage,
-            FighterKnockbackVelocity, FighterPendingHitReaction, FighterReceivedAttacks,
+            FighterKnockbackVelocity, FighterPendingHitReaction, FighterSolvedHurtboxes,
-            FighterSolvedHurtboxes, FighterStaleMoveQueue,
+            FighterStaleMoveQueue,
         },
         baked_animation::{FighterBoneIndexMap, FighterBoneMatrices},
         manifest::FighterManifest,
@@ -116,7 +116,6 @@ pub struct FighterVisual;
 
 #[derive(Component)]
 #[require(
-    FighterReceivedAttacks,
     FighterStaleMoveQueue,
     FighterDamage,
     FighterPendingHitReaction,
@@ -199,8 +198,6 @@ impl Plugin for FighterPlugin {
             .checksum_component_with_hash::<FighterHitstop>()
             .rollback_component_with_copy::<FighterKnockbackVelocity>()
             .checksum_component_with_hash::<FighterKnockbackVelocity>()
-            .rollback_component_with_clone::<FighterReceivedAttacks>()
-            .checksum_component_with_hash::<FighterReceivedAttacks>()
             .rollback_resource_with_reflect::<StageCollision>()
             // Debug views.
             .add_systems(

src/fighter/state/air.rs

@@ -1,3 +1,6 @@
+use crate::fighter::state::ground::GroundedStateCommon;
+use crate::fighter::state::land::{LandingState, LandingType};
+use crate::fighter::state::{CollisionContext, FighterState};
 use crate::fighter::*;
 
 pub fn integrate_gravity(velocity: &mut FighterVelocity, attributes: &FighterAttributes) {
@@ -53,6 +56,27 @@ pub fn apply_air_motion(
     translation.0 += velocity.0;
 }
 
+pub fn update_standard_motion(ctx: &mut crate::fighter::state::UpdateContext) {
+    integrate_gravity(ctx.velocity, ctx.fighter_attributes);
+    apply_air_drift(ctx.velocity, ctx.fighter_attributes, ctx.input);
+    apply_air_motion(ctx.velocity, ctx.translation, ctx.prev_translation);
+}
+
+pub fn collision_interrupt(
+    ctx: &mut CollisionContext,
+    landing_type: LandingType,
+) -> Option<FighterState> {
+    let res = ctx.air_collide_with_stage()?;
+    ctx.translation.0 = res.hit_position - ctx.ecb.get_bottom_point();
+    let grounded_common = GroundedStateCommon {
+        current_line_id: res.line_id,
+    };
+    Some(FighterState::Land(LandingState::create(
+        grounded_common,
+        landing_type,
+    )))
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/fighter/state/air_dodge.rs

@@ -3,10 +3,7 @@ use crate::{
         animation::AnimKind,
         state::{
             CollisionContext, EnterContext, FighterState, FighterStateImpl, InterruptContext,
-            UpdateContext, air,
+            UpdateContext, air, fall::FallState, land::LandingType,
-            fall::FallState,
-            ground::GroundedStateCommon,
-            land::{LandingState, LandingType},
         },
     },
     input,
@@ -43,19 +40,7 @@ impl FighterStateImpl for AirDodgeState {
         &mut self,
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
-        if let Some(res) = state_context.air_collide_with_stage() {
+        air::collision_interrupt(state_context, LandingType::Special)
-            // Adjust translation
-            state_context.translation.0 = res.hit_position - state_context.ecb.get_bottom_point();
-            let grounded_common = GroundedStateCommon {
-                current_line_id: res.line_id,
-            };
-            Some(FighterState::Land(LandingState {
-                grounded_common,
-                landing_type: LandingType::Special,
-            }))
-        } else {
-            None
-        }
     }
 
     fn on_enter(&mut self, state_context: &mut EnterContext) {

src/fighter/state/dash.rs

@@ -1,5 +1,3 @@
-use std::hash::Hasher;
-
 use super::{
     CollisionContext, EnterContext, FighterStateImpl, InterruptContext, UpdateContext, ground, run,
     wait, walk,
@@ -7,22 +5,15 @@ use super::{
 use crate::fighter::FighterFacingDirection;
 use crate::fighter::animation::AnimKind;
 use crate::fighter::state::FighterState;
-use crate::fighter::state::fall::FallState;
+use crate::fighter::state::ground::GroundedStateCommon;
-use crate::fighter::state::ground::{GroundedMotionResult, GroundedStateCommon};
 use crate::input::FighterCommands::{SmashMoveLeft, SmashMoveRight};
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Hash)]
 pub struct DashState {
     direction: FighterFacingDirection,
     pub ground_common: GroundedStateCommon,
 }
 
-impl std::hash::Hash for DashState {
-    fn hash<H: Hasher>(&self, state: &mut H) {
-        self.direction.hash(state);
-    }
-}
-
 impl DashState {
     pub fn new(direction: FighterFacingDirection, ground_common: GroundedStateCommon) -> Self {
         Self {
@@ -115,13 +106,7 @@ impl FighterStateImpl for DashState {
         &mut self,
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
-        if let GroundedMotionResult::InAir =
+        ground::collision_interrupt(state_context, &mut self.ground_common, true)
-            ground::collide_with_stage_grounded(state_context, &mut self.ground_common, true)
-        {
-            Some(FighterState::Fall(FallState))
-        } else {
-            None
-        }
     }
 }
 

src/fighter/state/fall.rs

@@ -1,7 +1,5 @@
 use super::{CollisionContext, EnterContext, FighterStateImpl, InterruptContext, UpdateContext};
 use crate::fighter::animation::AnimKind;
-use crate::fighter::state::ground::GroundedStateCommon;
-use crate::fighter::state::land::{LandingState, LandingType};
 use crate::fighter::state::{FighterState, air, jump};
 
 #[derive(Debug, Clone, Copy, Hash)]
@@ -18,36 +16,17 @@ impl FighterStateImpl for FallState {
     }
 
     fn update(&mut self, state_context: &mut UpdateContext) {
-        air::integrate_gravity(state_context.velocity, state_context.fighter_attributes);
+        air::update_standard_motion(state_context);
-        air::apply_air_drift(
-            state_context.velocity,
-            state_context.fighter_attributes,
-            state_context.input,
-        );
-        air::apply_air_motion(
-            state_context.velocity,
-            state_context.translation,
-            state_context.prev_translation,
-        );
     }
 
     fn check_collision_interrupt(
         &mut self,
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
-        if let Some(res) = state_context.air_collide_with_stage() {
+        air::collision_interrupt(
-            // Adjust translation
+            state_context,
-            state_context.translation.0 = res.hit_position - state_context.ecb.get_bottom_point();
+            crate::fighter::state::land::LandingType::Normal,
-            let grounded_common = GroundedStateCommon {
+        )
-                current_line_id: res.line_id,
-            };
-            Some(FighterState::Land(LandingState::create(
-                grounded_common,
-                LandingType::Normal,
-            )))
-        } else {
-            None
-        }
     }
 }
 

src/fighter/state/ground.rs

@@ -3,7 +3,7 @@
 //! bit-for-bit deterministic for rollback.
 
 use crate::fighter::state::{
-    CollisionContext, FighterState, InterruptContext, dash, ground_attack, turn, wait, walk,
+    CollisionContext, FighterState, InterruptContext, dash, fall, ground_attack, turn, wait, walk,
 };
 use crate::fighter::{
     FighterAttributes, FighterPreviousTranslation, FighterTranslation, FighterVelocity,
@@ -163,6 +163,22 @@ pub fn apply_grounded_motion(
     translation.0 += FGVec2::new(velocity.0.x, FGi32::ZERO);
 }
 
+pub fn update_friction_motion(ctx: &mut crate::fighter::state::UpdateContext) {
+    let friction = if ctx.velocity.x.abs() > ctx.fighter_attributes.max_walk_vel {
+        ctx.fighter_attributes.ground_friction
+            * ctx
+                .game_settings
+                .fighter_common
+                .ground_friction_over_walk_speed_multiplier
+    } else {
+        ctx.fighter_attributes.ground_friction
+    };
+
+    let ground_velocity = ctx.velocity.x;
+    ctx.velocity.x += apply_grounded_friction(friction, ground_velocity);
+    apply_grounded_motion(ctx.velocity, ctx.translation, ctx.prev_translation);
+}
+
 pub fn collide_with_stage_grounded(
     state_context: &mut CollisionContext,
     ground_common: &mut GroundedStateCommon,
@@ -210,6 +226,17 @@ pub fn collide_with_stage_grounded(
     }
 }
 
+pub fn collision_interrupt(
+    ctx: &mut CollisionContext,
+    common: &mut GroundedStateCommon,
+    can_walk_off: bool,
+) -> Option<FighterState> {
+    match collide_with_stage_grounded(ctx, common, can_walk_off) {
+        GroundedMotionResult::InGround => None,
+        GroundedMotionResult::InAir => Some(FighterState::Fall(fall::FallState)),
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/fighter/state/hitstun.rs

@@ -6,8 +6,8 @@ use crate::{
             CollisionContext, EnterContext, ExitContext, FighterState, FighterStateImpl,
             InterruptContext, UpdateContext, air,
             fall::FallState,
-            ground::{GroundedMotionResult, GroundedStateCommon, collide_with_stage_grounded},
+            ground::{GroundedStateCommon, collision_interrupt},
-            land::{LandingState, LandingType},
+            land::LandingType,
             wait::WaitState,
         },
     },
@@ -88,29 +88,10 @@ impl FighterStateImpl for HitstunState {
     ) -> Option<FighterState> {
         match &mut self.hitstop_kind {
             HitstopStateKind::Grounded(grounded_state_common) => {
-                if let GroundedMotionResult::InAir =
+                collision_interrupt(state_context, grounded_state_common, true)
-                    collide_with_stage_grounded(state_context, grounded_state_common, true)
-                {
-                    Some(FighterState::Fall(FallState {}))
-                } else {
-                    None
-                }
             }
             HitstopStateKind::Airborne => {
-                if let Some(res) = state_context.air_collide_with_stage() {
+                air::collision_interrupt(state_context, LandingType::Normal)
-                    // Adjust translation
-                    state_context.translation.0 =
-                        res.hit_position - state_context.ecb.get_bottom_point();
-                    let grounded_common = GroundedStateCommon {
-                        current_line_id: res.line_id,
-                    };
-                    Some(FighterState::Land(LandingState::create(
-                        grounded_common,
-                        LandingType::Normal,
-                    )))
-                } else {
-                    None
-                }
             }
         }
     }

src/fighter/state/jump.rs

@@ -7,9 +7,7 @@ use crate::{
             CollisionContext, EnterContext, FighterState, FighterStateImpl, InterruptContext,
             UpdateContext, air,
             air_dodge::{self, AirDodgeState},
-            fall::FallState,
+            ground::{self, GroundedStateCommon},
-            ground::{self, GroundedMotionResult, GroundedStateCommon},
-            land::{LandingState, LandingType},
         },
     },
     input::FighterCommands,
@@ -84,40 +82,14 @@ impl FighterStateImpl for JumpSquatState {
 
     fn update(&mut self, state_context: &mut UpdateContext) {
         self.duration_counter += 1;
-
+        ground::update_friction_motion(state_context);
-        let friction =
-            if state_context.velocity.x.abs() > state_context.fighter_attributes.max_walk_vel {
-                state_context.fighter_attributes.ground_friction
-                    * state_context
-                        .game_settings
-                        .fighter_common
-                        .ground_friction_over_walk_speed_multiplier
-            } else {
-                state_context.fighter_attributes.ground_friction
-            };
-
-        let ground_velocity = state_context.velocity.x;
-
-        state_context.velocity.x += ground::apply_grounded_friction(friction, ground_velocity);
-
-        ground::apply_grounded_motion(
-            state_context.velocity,
-            state_context.translation,
-            state_context.prev_translation,
-        );
     }
 
     fn check_collision_interrupt(
         &mut self,
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
-        if let GroundedMotionResult::InAir =
+        ground::collision_interrupt(state_context, &mut self.grounded_common, false)
-            ground::collide_with_stage_grounded(state_context, &mut self.grounded_common, false)
-        {
-            Some(FighterState::Fall(FallState))
-        } else {
-            None
-        }
     }
 
     fn on_enter(&mut self, state_context: &mut EnterContext) {
@@ -139,17 +111,7 @@ impl FighterStateImpl for JumpState {
     }
 
     fn update(&mut self, state_context: &mut UpdateContext) {
-        air::integrate_gravity(state_context.velocity, state_context.fighter_attributes);
+        air::update_standard_motion(state_context);
-        air::apply_air_drift(
-            state_context.velocity,
-            state_context.fighter_attributes,
-            state_context.input,
-        );
-        air::apply_air_motion(
-            state_context.velocity,
-            state_context.translation,
-            state_context.prev_translation,
-        );
     }
 
     fn on_enter(&mut self, state_context: &mut EnterContext) {
@@ -207,19 +169,10 @@ impl FighterStateImpl for JumpState {
         &mut self,
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
-        if let Some(res) = state_context.air_collide_with_stage() {
+        air::collision_interrupt(
-            // Adjust translation
+            state_context,
-            state_context.translation.0 = res.hit_position - state_context.ecb.get_bottom_point();
+            crate::fighter::state::land::LandingType::Normal,
-            let grounded_common = GroundedStateCommon {
+        )
-                current_line_id: res.line_id,
-            };
-            Some(FighterState::Land(LandingState::create(
-                grounded_common,
-                LandingType::Normal,
-            )))
-        } else {
-            None
-        }
     }
 }
 

src/fighter/state/land.rs

@@ -3,11 +3,7 @@ use crate::fighter::{
     state::{
         CollisionContext, EnterContext, FighterState, FighterStateImpl, InterruptContext,
         UpdateContext, dash,
-        fall::FallState,
+        ground::{self, GroundedStateCommon, grounded_movement_standstill_common_interrupts},
-        ground::{
-            self, GroundedMotionResult, GroundedStateCommon,
-            grounded_movement_standstill_common_interrupts,
-        },
         walk,
     },
 };
@@ -53,39 +49,14 @@ impl FighterStateImpl for LandingState {
     }
 
     fn update(&mut self, state_context: &mut UpdateContext) {
-        let friction =
+        ground::update_friction_motion(state_context);
-            if state_context.velocity.x.abs() > state_context.fighter_attributes.max_walk_vel {
-                state_context.fighter_attributes.ground_friction
-                    * state_context
-                        .game_settings
-                        .fighter_common
-                        .ground_friction_over_walk_speed_multiplier
-            } else {
-                state_context.fighter_attributes.ground_friction
-            };
-
-        let ground_velocity = state_context.velocity.x;
-
-        state_context.velocity.x += ground::apply_grounded_friction(friction, ground_velocity);
-
-        ground::apply_grounded_motion(
-            state_context.velocity,
-            state_context.translation,
-            state_context.prev_translation,
-        );
     }
 
     fn check_collision_interrupt(
         &mut self,
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
-        if let GroundedMotionResult::InAir =
+        ground::collision_interrupt(state_context, &mut self.grounded_common, true)
-            ground::collide_with_stage_grounded(state_context, &mut self.grounded_common, true)
-        {
-            Some(FighterState::Fall(FallState))
-        } else {
-            None
-        }
     }
 
     fn on_enter(&mut self, state_context: &mut EnterContext) {

src/fighter/state/run.rs

@@ -6,9 +6,7 @@ use super::{
 };
 use crate::fighter::animation::AnimKind;
 use crate::fighter::state::FighterState;
-use crate::fighter::state::fall::FallState;
+use crate::fighter::state::ground::GroundedStateCommon;
-use crate::fighter::state::ground::{GroundedMotionResult, GroundedStateCommon};
-use crate::math::int::FGi32;
 
 #[derive(Component, Debug, Clone, Hash)]
 pub struct RunState {
@@ -64,13 +62,7 @@ impl FighterStateImpl for RunState {
         &mut self,
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
-        if let GroundedMotionResult::InAir =
+        ground::collision_interrupt(state_context, &mut self.grounded_common, true)
-            ground::collide_with_stage_grounded(state_context, &mut self.grounded_common, false)
-        {
-            Some(FighterState::Fall(FallState))
-        } else {
-            None
-        }
     }
 }
 

src/fighter/state/turn.rs

@@ -1,7 +1,6 @@
 use super::{CollisionContext, EnterContext, FighterStateImpl, InterruptContext, UpdateContext};
 use crate::fighter::animation::AnimKind;
-use crate::fighter::state::fall::FallState;
+use crate::fighter::state::ground::{self, GroundedStateCommon};
-use crate::fighter::state::ground::{self, GroundedMotionResult, GroundedStateCommon};
 use crate::fighter::state::{FighterState, dash, jump, wait, walk};
 use crate::input::FighterCommands;
 
@@ -48,39 +47,14 @@ impl FighterStateImpl for TurnState {
     }
 
     fn update(&mut self, state_context: &mut UpdateContext) {
-        let friction =
+        ground::update_friction_motion(state_context);
-            if state_context.velocity.x.abs() > state_context.fighter_attributes.max_walk_vel {
-                state_context.fighter_attributes.ground_friction
-                    * state_context
-                        .game_settings
-                        .fighter_common
-                        .ground_friction_over_walk_speed_multiplier
-            } else {
-                state_context.fighter_attributes.ground_friction
-            };
-
-        let ground_velocity = state_context.velocity.x;
-
-        state_context.velocity.x += ground::apply_grounded_friction(friction, ground_velocity);
-
-        ground::apply_grounded_motion(
-            state_context.velocity,
-            state_context.translation,
-            state_context.prev_translation,
-        );
     }
 
     fn check_collision_interrupt(
         &mut self,
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
-        if let GroundedMotionResult::InAir =
+        ground::collision_interrupt(state_context, &mut self.grounded_common, false)
-            ground::collide_with_stage_grounded(state_context, &mut self.grounded_common, false)
-        {
-            Some(FighterState::Fall(FallState))
-        } else {
-            None
-        }
     }
 }
 

src/fighter/state/wait.rs

@@ -3,8 +3,7 @@ use super::{
 };
 use crate::fighter::animation::AnimKind;
 use crate::fighter::state::FighterState;
-use crate::fighter::state::fall::FallState;
+use crate::fighter::state::ground::GroundedStateCommon;
-use crate::fighter::state::ground::{GroundedMotionResult, GroundedStateCommon};
 
 #[derive(Debug, Clone, Hash)]
 pub struct WaitState {
@@ -38,39 +37,14 @@ impl FighterStateImpl for WaitState {
     }
 
     fn update(&mut self, state_context: &mut UpdateContext) {
-        let friction =
+        ground::update_friction_motion(state_context);
-            if state_context.velocity.x.abs() > state_context.fighter_attributes.max_walk_vel {
-                state_context.fighter_attributes.ground_friction
-                    * state_context
-                        .game_settings
-                        .fighter_common
-                        .ground_friction_over_walk_speed_multiplier
-            } else {
-                state_context.fighter_attributes.ground_friction
-            };
-
-        let ground_velocity = state_context.velocity.x;
-
-        state_context.velocity.x += ground::apply_grounded_friction(friction, ground_velocity);
-
-        ground::apply_grounded_motion(
-            state_context.velocity,
-            state_context.translation,
-            state_context.prev_translation,
-        );
     }
 
     fn check_collision_interrupt(
         &mut self,
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
-        if let GroundedMotionResult::InAir =
+        ground::collision_interrupt(state_context, &mut self.grounded_common, false)
-            ground::collide_with_stage_grounded(state_context, &mut self.grounded_common, false)
-        {
-            Some(FighterState::Fall(FallState))
-        } else {
-            None
-        }
     }
 }
 

src/fighter/state/walk.rs

@@ -4,8 +4,7 @@ use super::{
 };
 use crate::fighter::animation::AnimKind;
 use crate::fighter::state::FighterState;
-use crate::fighter::state::fall::FallState;
+use crate::fighter::state::ground::GroundedStateCommon;
-use crate::fighter::state::ground::{GroundedMotionResult, GroundedStateCommon};
 
 #[derive(Debug, Clone, Hash)]
 pub struct WalkState {
@@ -55,13 +54,7 @@ impl FighterStateImpl for WalkState {
         &mut self,
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
-        if let GroundedMotionResult::InAir =
+        ground::collision_interrupt(state_context, &mut self.grounded_common, false)
-            ground::collide_with_stage_grounded(state_context, &mut self.grounded_common, false)
-        {
-            Some(FighterState::Fall(FallState))
-        } else {
-            None
-        }
     }
 }