Add shifting ECB based on bone positions (melee-like)

src/fighter/state/air.rs

@@ -83,9 +83,7 @@ pub fn apply_air_motion(
     velocity: &FighterVelocity,
     translation: &mut FighterTranslation,
     prev_translation: &mut FighterPreviousTranslation,
-    surface: &mut FighterSurfaceState,
 ) {
-    surface.leave_ground();
     // Vertical velocity should be 0 on the ground
     prev_translation.0 = translation.0;
     translation.0 += velocity.0;
@@ -111,7 +109,6 @@ pub fn update_standard_motion(
         ctx.velocity,
         ctx.translation,
         ctx.prev_translation,
-        ctx.surface,
     );
 }
 
@@ -120,7 +117,12 @@ pub fn collision_interrupt(
     landing_type: LandingType,
 ) -> Option<FighterState> {
     let res = ctx.air_collide_with_stage()?;
-    ctx.translation.0 = res.hit_position - ctx.ecb.get_bottom_point();
+    let diff = res.hit_position - ctx.translation.0;
+    ctx.ecb.bottom -= diff;
+    ctx.ecb.top -= diff;
+    ctx.ecb.left -= diff;
+    ctx.ecb.right -= diff;
+    ctx.translation.0 = res.hit_position;
     ctx.surface.land(res.line_id);
     Some(FighterState::Land(LandingState::create(landing_type)))
 }

src/fighter/state/air_dodge.rs

@@ -38,7 +38,6 @@ impl FighterStateImpl for AirDodgeState {
             state_context.velocity,
             state_context.translation,
             state_context.prev_translation,
-            state_context.surface,
         );
     }
 
@@ -59,6 +58,10 @@ impl FighterStateImpl for AirDodgeState {
     fn is_visually_grounded<'a>(&'a self) -> bool {
         false
     }
+
+    fn surface_policy(&self) -> super::SurfacePolicy {
+        super::SurfacePolicy::Airborne(crate::fighter::surface::EcbLockPolicy::StartOnDetach)
+    }
 }
 
 pub fn check_input(state_context: &InterruptContext) -> Option<FighterState> {

src/fighter/state/fall.rs

@@ -46,5 +46,8 @@ impl FighterStateImpl for FallState {
     ) -> bool {
         false
     }
-}
 
+    fn surface_policy(&self) -> super::SurfacePolicy {
+        super::SurfacePolicy::Airborne(crate::fighter::surface::EcbLockPolicy::StartOnDetach)
+    }
+}

src/fighter/state/ground.rs

@@ -178,7 +178,7 @@ pub fn collide_with_stage_grounded(
     can_walk_off: bool,
 ) -> GroundedMotionResult {
     let translation = &mut state_context.translation;
-    let ecb = state_context.ecb;
+    let ecb = &state_context.ecb;
     let stage_collision = state_context.stage_collision;
 
     let Some(current_line_id) = state_context.surface.line_id() else {
@@ -218,12 +218,18 @@ pub fn collide_with_stage_grounded(
                 GroundedMotionResult::InGround
             }
             GroundedPositionResult::InAir => {
-                state_context.surface.leave_ground();
+                state_context.surface.apply_airborne_policy(
+                    crate::fighter::surface::EcbLockPolicy::StartOnDetach,
+                    state_context.leave_ground_ecb_lock_duration,
+                );
                 GroundedMotionResult::InAir
             }
         }
     } else {
-        state_context.surface.leave_ground();
+        state_context.surface.apply_airborne_policy(
+            crate::fighter::surface::EcbLockPolicy::StartOnDetach,
+            state_context.leave_ground_ecb_lock_duration,
+        );
         GroundedMotionResult::InAir
     }
 }
@@ -363,9 +369,11 @@ mod tests {
         let mut translation = FighterTranslation(FGVec2::lit("11", "0"));
         let previous_translation = FighterPreviousTranslation(translation.0);
         let mut velocity = FighterVelocity::default();
-        let ecb = FighterECB {
-            vertical_half: FGi32::ONE,
-            horizontal_half: FGi32::ONE,
+        let mut ecb = FighterECB {
+            bottom: FGVec2::lit("0.0", "-0.5"),
+            top: FGVec2::lit("0.0", "0.5"),
+            left: FGVec2::lit("-0.5", "0.0"),
+            right: FGVec2::lit("0.5", "0.0"),
         };
         let previous_ecb = FighterPreviousECB::from(ecb);
         let mut context = CollisionContext {
@@ -373,9 +381,10 @@ mod tests {
             prev_translation: &previous_translation,
             velocity: &mut velocity,
             surface: &mut surface,
-            ecb: &ecb,
+            ecb: &mut ecb,
             prev_ecb: &previous_ecb,
             stage_collision: &stage_collision,
+            leave_ground_ecb_lock_duration: 10,
         };
 
         assert!(matches!(
@@ -411,9 +420,11 @@ mod tests {
         let mut translation = FighterTranslation(FGVec2::lit("11", "0"));
         let previous_translation = FighterPreviousTranslation(translation.0);
         let mut velocity = FighterVelocity::default();
-        let ecb = FighterECB {
-            vertical_half: FGi32::ONE,
-            horizontal_half: FGi32::ONE,
+        let mut ecb = FighterECB {
+            bottom: FGVec2::lit("0.0", "-0.5"),
+            top: FGVec2::lit("0.0", "0.5"),
+            left: FGVec2::lit("-0.5", "0.0"),
+            right: FGVec2::lit("0.5", "0.0"),
         };
         let previous_ecb = FighterPreviousECB::from(ecb);
         let mut context = CollisionContext {
@@ -421,16 +432,17 @@ mod tests {
             prev_translation: &previous_translation,
             velocity: &mut velocity,
             surface: &mut surface,
-            ecb: &ecb,
+            ecb: &mut ecb,
             prev_ecb: &previous_ecb,
             stage_collision: &stage_collision,
+            leave_ground_ecb_lock_duration: 10,
         };
 
         assert!(matches!(
             collide_with_stage_grounded(&mut context, true),
             GroundedMotionResult::InAir
         ));
-        assert_eq!(surface, FighterSurfaceState::Airborne);
+        assert!(matches!(surface, FighterSurfaceState::Airborne { .. }));
     }
 }
 

src/fighter/state/hitstun.rs

@@ -83,7 +83,6 @@ impl FighterStateImpl for HitstunState {
         match self.hitstop_kind {
             HitstopStateKind::Grounded => {}
             HitstopStateKind::Airborne => {
-                ctx.surface.leave_ground();
                 air::integrate_gravity(ctx.velocity, ctx.fighter_attributes, false);
             }
         }
@@ -126,4 +125,13 @@ impl FighterStateImpl for HitstunState {
             HitstopStateKind::Airborne => false,
         }
     }
+
+    fn surface_policy(&self) -> super::SurfacePolicy {
+        match self.hitstop_kind {
+            HitstopStateKind::Grounded => super::SurfacePolicy::Grounded,
+            HitstopStateKind::Airborne => super::SurfacePolicy::Airborne(
+                crate::fighter::surface::EcbLockPolicy::StartOnDetach,
+            ),
+        }
+    }
 }

src/fighter/state/jump.rs

@@ -186,6 +186,16 @@ impl FighterStateImpl for JumpState {
     fn is_visually_grounded<'a>(&'a self) -> bool {
         false
     }
+
+    fn surface_policy(&self) -> super::SurfacePolicy {
+        use crate::fighter::surface::EcbLockPolicy;
+        match self.jump_type {
+            JumpType::DoubleJump => super::SurfacePolicy::Airborne(EcbLockPolicy::Restart),
+            JumpType::ShortHop | JumpType::LongJump => {
+                super::SurfacePolicy::Airborne(EcbLockPolicy::StartOnDetach)
+            }
+        }
+    }
 }
 
 pub fn check_input(state_context: &InterruptContext) -> Option<FighterState> {

src/fighter/state/mod.rs

@@ -21,6 +21,7 @@ use crate::fighter::{
     FighterHitstopShake, FighterHitstopShakeKind, FighterHitstopShakeRole,
     FighterPreviousTranslation, FighterSurfaceState, FighterTranslation, FighterVelocity,
 };
+use crate::fighter::surface::EcbLockPolicy;
 use crate::game_settings::GameSettings;
 use crate::input::FighterInput;
 use crate::math::int::FGi32;
@@ -41,6 +42,12 @@ pub mod turn;
 pub mod wait;
 pub mod walk;
 
+#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq)]
+pub enum SurfacePolicy {
+    Grounded,
+    Airborne(EcbLockPolicy),
+}
+
 macro_rules! fighter_states {
     ($($variant:ident => $ty:ty),* $(,)?) => {
         #[derive(Component, Clone, Debug, Hash)]
@@ -72,6 +79,10 @@ macro_rules! fighter_states {
             pub fn is_visually_grounded(&self) -> bool {
                 match self { $(Self::$variant(s) => s.is_visually_grounded()),* }
             }
+
+            pub fn surface_policy(&self) -> SurfacePolicy {
+                match self { $(Self::$variant(s) => s.surface_policy()),* }
+            }
         }
 
         $(impl From<$ty> for FighterState {
@@ -99,6 +110,10 @@ pub trait FighterStateImpl: Sized {
     }
 
     fn is_visually_grounded<'a>(&'a self) -> bool;
+
+    fn surface_policy(&self) -> SurfacePolicy {
+        SurfacePolicy::Grounded
+    }
 }
 
 pub struct AnimationStatus {
@@ -173,9 +188,10 @@ pub struct CollisionContext<'a> {
     pub prev_translation: &'a FighterPreviousTranslation,
     pub velocity: &'a mut FighterVelocity,
     pub surface: &'a mut FighterSurfaceState,
-    pub ecb: &'a FighterECB,
+    pub ecb: &'a mut FighterECB,
     pub prev_ecb: &'a FighterPreviousECB,
     pub stage_collision: &'a StageCollision,
+    pub leave_ground_ecb_lock_duration: u32,
 }
 
 impl CollisionContext<'_> {
@@ -218,7 +234,7 @@ pub struct FighterFrameQuery {
     pub surface: &'static mut FighterSurfaceState,
     pub knockback_velocity: &'static mut FighterKnockbackVelocity,
     pub stale_move_queue: &'static mut FighterStaleMoveQueue,
-    pub ecb: &'static FighterECB,
+    pub ecb: &'static mut FighterECB,
     pub prev_ecb: &'static FighterPreviousECB,
     pub facing_direction: &'static mut FighterFacingDirection,
     pub animation_frame: &'static mut FighterAnimationFrame,
@@ -310,15 +326,17 @@ impl<'w, 's> FighterFrameQueryItem<'w, 's> {
     fn collision_context<'a>(
         &'a mut self,
         stage_collision: &'a StageCollision,
+        game_settings: &'a GameSettings,
     ) -> CollisionContext<'a> {
         CollisionContext {
             translation: &mut self.translation,
             prev_translation: &self.prev_translation,
             velocity: &mut self.velocity,
             surface: &mut self.surface,
-            ecb: &self.ecb,
+            ecb: &mut self.ecb,
             prev_ecb: &self.prev_ecb,
             stage_collision,
+            leave_ground_ecb_lock_duration: game_settings.fighter_common.leave_ground_ecb_frame_lock_duration
         }
     }
 }
@@ -373,11 +391,18 @@ fn transition_state(
     frame: &mut FighterFrameQueryItem,
     attributes: &FighterAttributes,
     attack_script_assets: &FighterAttackScriptAssets,
+    game_settings: &GameSettings,
 ) {
     let old_name = current.name();
     let new_name = next.name();
 
     current.on_exit(&mut frame.exit_context());
+    if let SurfacePolicy::Airborne(lock_policy) = next.surface_policy() {
+        frame.surface.apply_airborne_policy(
+            lock_policy,
+            game_settings.fighter_common.leave_ground_ecb_frame_lock_duration,
+        );
+    }
     next.on_enter(&mut frame.enter_context(attributes, attack_script_assets));
     *current = next;
     info!("{} -> {}", old_name, new_name);
@@ -448,10 +473,6 @@ pub fn state_interrupt_system(
                 }
             }
 
-            if matches!(hitstop_kind, hitstun::HitstopStateKind::Airborne) {
-                frame.surface.leave_ground();
-            }
-
             info!("Entering hitstop kind: {:?}", hitstop_kind);
             Some(FighterState::Hitstun(HitstunState::new(
                 reaction,
@@ -475,6 +496,7 @@ pub fn state_interrupt_system(
                 &mut frame,
                 &manifest.attributes,
                 attack_script_assets,
+                &game_settings,
             );
         };
     }
@@ -484,6 +506,7 @@ pub fn state_collision_interrupt_system(
     mut query: Query<StatefulFighterQuery>,
     stage_collision: Res<StageCollision>,
     fighter_manifests: Res<Assets<FighterManifest>>,
+    game_settings: Res<GameSettings>,
 ) {
     for fighter in &mut query {
         let StatefulFighterQueryItem {
@@ -502,7 +525,7 @@ pub fn state_collision_interrupt_system(
             .get(&fighter.manifest)
             .expect("Fighter manifest should be valid");
         let new_state =
-            state.check_collision_interrupt(&mut frame.collision_context(&stage_collision));
+            state.check_collision_interrupt(&mut frame.collision_context(&stage_collision, &game_settings));
         if let Some(new_state) = new_state {
             transition_state(
                 &mut state,
@@ -510,6 +533,7 @@ pub fn state_collision_interrupt_system(
                 &mut frame,
                 &manifest.attributes,
                 &attack_script_assets,
+                &game_settings,
             );
         }
     }