Implement land from below, fix attacks not lifting fighters off the ground (#96)

Reviewed-on: #96
Co-authored-by: Álex Román Núñez <eirexe@eirteam.moe>

src/fighter/state/hitstun.rs

@@ -1,8 +1,6 @@
 use crate::{
     fighter::{
-        animation::AnimKind,
-        attack::{self, FighterHitReaction},
-        state::{
+        FighterVelocity, animation::AnimKind, attack::{self, FighterHitReaction}, state::{
             CollisionContext, EnterContext, ExitContext, FighterState, FighterStateImpl,
             InterruptContext, UpdateContext,
             air::{self, AirborneStateCommon},
@@ -40,6 +38,30 @@ impl HitstunState {
 impl FighterStateImpl for HitstunState {
     const NAME: &'static str = "Hitstun";
 
+    fn check_interrupt(&self, state_context: &mut InterruptContext) -> Option<FighterState> {
+        if state_context.get_current_animation_frame() > self.hit_reaction.hitstun_frames {
+            match &self.hitstop_kind {
+                HitstopStateKind::Grounded => Some(FighterState::Wait(WaitState)),
+                HitstopStateKind::Airborne => Some(FighterState::Fall(FallState::new(
+                    AirborneStateCommon::default(),
+                ))),
+            }
+        } else {
+            None
+        }
+    }
+
+    fn on_enter(&mut self, state_context: &mut EnterContext) {
+        let animation = match self.hitstop_kind {
+            HitstopStateKind::Grounded => AnimKind::FlinchGround,
+            HitstopStateKind::Airborne => AnimKind::FlinchAir,
+        };
+        state_context.play_animation(animation, false);
+        state_context.velocity.0 = FGVec2::ZERO;
+    }
+
+    fn on_exit(&mut self, _state_context: &mut ExitContext) {}
+
     fn name(&self) -> String {
         let hitstop_kind = match self.hitstop_kind {
             HitstopStateKind::Grounded => "Grounded",
@@ -54,19 +76,6 @@ impl FighterStateImpl for HitstunState {
         format!("Hitstun ({hitstop_kind}, {hit_reaction_type})")
     }
 
-    fn check_interrupt(&self, state_context: &mut InterruptContext) -> Option<FighterState> {
-        if state_context.get_current_animation_frame() > self.hit_reaction.hitstun_frames {
-            match &self.hitstop_kind {
-                HitstopStateKind::Grounded => Some(FighterState::Wait(WaitState)),
-                HitstopStateKind::Airborne => Some(FighterState::Fall(FallState::new(
-                    AirborneStateCommon::default(),
-                ))),
-            }
-        } else {
-            None
-        }
-    }
-
     fn update(&mut self, ctx: &mut UpdateContext) {
         if !self.knockback_applied {
             let launch_direction = attack::directional_influence::apply_directional_influence(
@@ -83,6 +92,8 @@ impl FighterStateImpl for HitstunState {
             HitstopStateKind::Grounded => {}
             HitstopStateKind::Airborne => {
                 air::integrate_gravity(ctx.velocity, ctx.fighter_attributes, false);
+                let vel_with_kb = FighterVelocity(ctx.velocity.0 + ctx.knockback_velocity.0);
+                air::apply_air_motion(&vel_with_kb, ctx.translation, ctx.prev_translation);
             }
         }
 
@@ -92,21 +103,8 @@ impl FighterStateImpl for HitstunState {
             .max(FGi32::ZERO);
 
         ctx.knockback_velocity.0 = ctx.knockback_velocity.normalize_or_zero() * next_speed;
-
-        ctx.translation.0 += ctx.velocity.0 + ctx.knockback_velocity.0;
     }
 
-    fn on_enter(&mut self, state_context: &mut EnterContext) {
-        let animation = match self.hitstop_kind {
-            HitstopStateKind::Grounded => AnimKind::FlinchGround,
-            HitstopStateKind::Airborne => AnimKind::FlinchAir,
-        };
-        state_context.play_animation(animation, false);
-        state_context.velocity.0 = FGVec2::ZERO;
-    }
-
-    fn on_exit(&mut self, _state_context: &mut ExitContext) {}
-
     fn check_collision_interrupt(
         &mut self,
         state_context: &mut CollisionContext,
@@ -114,7 +112,7 @@ impl FighterStateImpl for HitstunState {
         match &mut self.hitstop_kind {
             HitstopStateKind::Grounded => collision_interrupt(state_context, true),
             HitstopStateKind::Airborne => {
-                air::collision_interrupt(state_context, LandingType::Normal, false)
+                air::collision_interrupt(state_context, LandingType::Normal, Default::default())
             }
         }
     }