Initial work on ledge & improved baking of root motion. (#90)

Reviewed-on: #90
Co-authored-by: Álex Román Núñez <eirexe@eirteam.moe>

src/fighter/state/mod.rs

@@ -20,14 +20,16 @@ use crate::fighter::visual::FighterAnimations;
 use crate::fighter::{
     Fighter, FighterDamage, FighterECB, FighterFacingDirection, FighterHitboxes, FighterHitstop,
     FighterHitstopShake, FighterHitstopShakeKind, FighterHitstopShakeRole,
-    FighterInvulnerabilityState, FighterPendingRespawn, FighterPresentationSnap,
-    FighterPreviousTranslation, FighterSurfaceState, FighterTranslation, FighterVelocity,
+    FighterInvulnerabilityState, FighterLedgeGrabLockout, FighterPendingRespawn,
+    FighterPresentationSnap, FighterPreviousTranslation, FighterSurfaceState, FighterTranslation,
+    FighterVelocity,
 };
 use crate::game_settings::GameSettings;
 use crate::input::FighterInput;
 use crate::match_loading::MatchConfig;
 use crate::match_runtime::MatchState;
 use crate::math::int::FGi32;
+use crate::math::rect::FGRect;
 use crate::math::vec::FGVec2;
 use crate::math::vec3::FGVec3;
 use crate::player::Player;
@@ -52,6 +54,8 @@ pub mod run;
 pub mod turn;
 pub mod wait;
 pub mod walk;
+pub mod ledge_wait;
+pub mod ledge_action;
 
 #[derive(Clone, Copy, Debug, Hash, PartialEq, Eq)]
 pub enum SurfacePolicy {
@@ -135,6 +139,7 @@ pub struct AnimationStatus {
 pub struct InterruptContext<'a> {
     pub input: &'a FighterInput,
     pub facing_direction: &'a mut FighterFacingDirection,
+    pub ledge_grab_lockout: &'a mut FighterLedgeGrabLockout,
     pub game_settings: &'a GameSettings,
     pub fighter_attributes: &'a FighterAttributes,
     pub surface: &'a FighterSurfaceState,
@@ -158,21 +163,38 @@ pub struct EnterContext<'a> {
     pub input: &'a mut FighterInput,
     pub hitboxes: &'a mut FighterHitboxes,
     pub velocity: &'a mut FighterVelocity,
+    pub translation: &'a mut FighterTranslation,
     pub knockback_velocity: &'a mut FighterKnockbackVelocity,
     pub stale_move_queue: &'a mut FighterStaleMoveQueue,
     pub facing_direction: &'a mut FighterFacingDirection,
     pub animation_frame: &'a mut FighterAnimationFrame,
+    pub presentation_snap: &'a mut FighterPresentationSnap,
     pub surface: &'a mut FighterSurfaceState,
     pub vulnerability: &'a mut FighterInvulnerabilityState,
     pub fighter_attributes: &'a FighterAttributes,
     pub attack_script_assets: &'a FighterAttackScriptAssets,
     pub game_settings: &'a GameSettings,
+    pub stage_collision: &'a StageCollision,
+    baked_animations: &'a BakedFighterAnimations,
+    model_scale: FGi32,
 }
 
 impl EnterContext<'_> {
     pub fn play_animation(&mut self, kind: AnimKind, repeat: bool) {
         self.animation_frame.reset(kind, repeat);
     }
+
+    /// World-space root position authored for frame zero of the animation most
+    /// recently selected with [`Self::play_animation`].
+    pub fn initial_animation_root_position(&self) -> Option<FGVec2> {
+        let position = self
+            .baked_animations
+            .initial_root_position(self.animation_frame.kind, self.model_scale)?;
+        Some(
+            self.translation.0
+                + animation_position_to_gameplay(position, self.facing_direction),
+        )
+    }
 }
 
 pub struct ExitContext<'a> {
@@ -195,18 +217,22 @@ pub struct UpdateContext<'a> {
     /// Root motion in the fighter's gameplay plane: X is world-right and Y is
     /// world-up. Animation +Z is forward and is mirrored by facing direction.
     pub animation_root_motion_delta: FGVec2,
+    /// Current world-space root position implied by this animation frame.
+    /// States opt into root motion by assigning this to [`FighterTranslation`].
+    pub animation_root_position: Option<FGVec2>,
     pub animation_frame: u32,
     pub fighter_attributes: &'a FighterAttributes,
     pub attack_scripts: &'a Assets<FighterAttackScript>,
     pub attack_script_assets: &'a FighterAttackScriptAssets,
     pub facing_direction: &'a FighterFacingDirection,
+    pub stage_collision: &'a StageCollision,
 }
 
-fn animation_root_motion_to_gameplay(
-    delta: FGVec3,
+fn animation_position_to_gameplay(
+    position: FGVec3,
     facing_direction: &FighterFacingDirection,
 ) -> FGVec2 {
-    FGVec2::new(delta.z * facing_direction.to_sign(), delta.y)
+    FGVec2::new(position.z * facing_direction.to_sign(), position.y)
 }
 
 impl UpdateContext<'_> {
@@ -226,6 +252,8 @@ pub struct CollisionContext<'a> {
     pub stage_collision: &'a StageCollision,
     pub leave_ground_ecb_lock_duration: u32,
     pub presentation_snap: &'a mut FighterPresentationSnap,
+    pub fighter_ledge_collision_box: FGRect,
+    pub ledge_grab_lockout_active: bool,
     pub downward_stick_threshold: FGi32,
 }
 
@@ -247,6 +275,17 @@ impl CollisionContext<'_> {
             ignore_soft_platforms,
         )
     }
+    pub fn air_collide_with_ledges(
+        &self,
+    ) -> Option<crate::fighter::collision::AirCollisionWithLedgeResult> {
+        if self.ledge_grab_lockout_active {
+            return None;
+        }
+        crate::fighter::collision::air_collide_with_ledges(
+            &self.fighter_ledge_collision_box,
+            self.stage_collision,
+        )
+    }
 }
 
 fighter_states! {
@@ -260,6 +299,8 @@ fighter_states! {
     JumpSquat => jump::JumpSquatState,
     Jump => jump::JumpState,
     Land => land::LandingState,
+    LedgeWait => ledge_wait::LedgeWaitState,
+    LedgeAction => ledge_action::LedgeActionState,
     AirDodge => air_dodge::AirDodgeState,
     Turn => turn::TurnState,
     GroundAttack => ground_attack::GroundAttackState,
@@ -285,6 +326,7 @@ pub struct FighterFrameQuery {
     pub facing_direction: &'static mut FighterFacingDirection,
     pub animation_frame: &'static mut FighterAnimationFrame,
     pub vulnerability: &'static mut FighterInvulnerabilityState,
+    pub ledge_grab_lockout: &'static mut FighterLedgeGrabLockout,
     pub fighter: &'static Fighter,
     pub bone_matrices: &'static FighterBoneMatrices,
 }
@@ -320,6 +362,7 @@ impl<'w, 's> FighterFrameQueryItem<'w, 's> {
         InterruptContext {
             input: &self.input,
             facing_direction: &mut self.facing_direction,
+            ledge_grab_lockout: &mut self.ledge_grab_lockout,
             game_settings,
             fighter_attributes: attributes,
             animation,
@@ -335,20 +378,28 @@ impl<'w, 's> FighterFrameQueryItem<'w, 's> {
         attributes: &'a FighterAttributes,
         attack_script_assets: &'a FighterAttackScriptAssets,
         game_settings: &'a GameSettings,
+        stage_collision: &'a StageCollision,
+        baked_animations: &'a BakedFighterAnimations,
+        model_scale: FGi32,
     ) -> EnterContext<'a> {
         EnterContext {
             input: &mut self.input,
             hitboxes: &mut self.hitboxes,
             velocity: &mut self.velocity,
             knockback_velocity: &mut self.knockback_velocity,
+            translation: &mut self.translation,
             stale_move_queue: &mut self.stale_move_queue,
             facing_direction: &mut self.facing_direction,
             animation_frame: &mut self.animation_frame,
             surface: &mut self.surface,
             vulnerability: &mut self.vulnerability,
+            presentation_snap: &mut self.presentation_snap,
             fighter_attributes: attributes,
             attack_script_assets,
             game_settings,
+            stage_collision,
+            baked_animations,
+            model_scale,
         }
     }
 
@@ -367,7 +418,16 @@ impl<'w, 's> FighterFrameQueryItem<'w, 's> {
         attributes: &'a FighterAttributes,
         attack_scripts: &'a Assets<FighterAttackScript>,
         attack_script_assets: &'a FighterAttackScriptAssets,
+        stage_collision: &'a StageCollision,
     ) -> UpdateContext<'a> {
+        let animation_root_motion_delta = animation_position_to_gameplay(
+            self.bone_matrices.root_motion_delta(),
+            &self.facing_direction,
+        );
+        let animation_root_position = self
+            .bone_matrices
+            .root_motion_position()
+            .map(|_| self.translation.0 + animation_root_motion_delta);
         UpdateContext {
             translation: &mut self.translation,
             prev_translation: &mut self.prev_translation,
@@ -377,24 +437,28 @@ impl<'w, 's> FighterFrameQueryItem<'w, 's> {
             surface: &mut self.surface,
             knockback_velocity: &mut self.knockback_velocity,
             game_settings,
-            animation_root_motion_delta: animation_root_motion_to_gameplay(
-                self.bone_matrices.root_motion_delta(),
-                &self.facing_direction,
-            ),
+            animation_root_motion_delta,
+            animation_root_position,
             animation_frame: self.animation_frame.frame,
             vulnerability: &mut self.vulnerability,
             fighter_attributes: attributes,
             attack_scripts,
             attack_script_assets,
             facing_direction: &self.facing_direction,
+            stage_collision: &stage_collision,
         }
     }
 
     fn collision_context<'a>(
         &'a mut self,
         stage_collision: &'a StageCollision,
+        fighter_manifest: &'a FighterManifest,
         game_settings: &'a GameSettings,
     ) -> CollisionContext<'a> {
+        let fighter_ledge_collision_box = FGRect {
+            origin: self.translation.0 + fighter_manifest.ledge_grab_box_start,
+            end: self.translation.0 + fighter_manifest.ledge_grab_box_end,
+        };
         CollisionContext {
             translation: &mut self.translation,
             prev_translation: &self.prev_translation,
@@ -409,6 +473,8 @@ impl<'w, 's> FighterFrameQueryItem<'w, 's> {
                 .fighter_common
                 .leave_ground_ecb_frame_lock_duration,
             downward_stick_threshold: game_settings.input_common.run_stick_threshold,
+            fighter_ledge_collision_box,
+            ledge_grab_lockout_active: self.ledge_grab_lockout.is_active(),
         }
     }
 }
@@ -432,6 +498,7 @@ pub struct StatefulFighterQuery {
 pub fn state_update_system(
     mut query: Query<StatefulFighterQuery>,
     game_settings: Res<GameSettings>,
+    stage_collision: Res<StageCollision>,
     attack_scripts: Res<Assets<FighterAttackScript>>,
     manifests: Res<Assets<FighterManifest>>,
 ) {
@@ -455,6 +522,7 @@ pub fn state_update_system(
             &manifest.attributes,
             &attack_scripts,
             &fighter.attack_script_assets,
+            &stage_collision,
         );
         state.update(&mut update_ctx);
     }
@@ -466,7 +534,10 @@ fn transition_state(
     frame: &mut FighterFrameQueryItem,
     attributes: &FighterAttributes,
     attack_script_assets: &FighterAttackScriptAssets,
+    stage_collision: &StageCollision,
     game_settings: &GameSettings,
+    baked_animations: &BakedFighterAnimations,
+    model_scale: FGi32,
 ) {
     let old_name = current.name();
     let new_name = next.name();
@@ -480,7 +551,14 @@ fn transition_state(
                 .leave_ground_ecb_frame_lock_duration,
         );
     }
-    next.on_enter(&mut frame.enter_context(attributes, attack_script_assets, game_settings));
+    next.on_enter(&mut frame.enter_context(
+        attributes,
+        attack_script_assets,
+        game_settings,
+        stage_collision,
+        baked_animations,
+        model_scale,
+    ));
     *current = next;
     info!("{} -> {}", old_name, new_name);
 }
@@ -508,6 +586,9 @@ pub fn state_interrupt_system(
         let manifest = fighter_manifests
             .get(&fighter.manifest)
             .expect("Fighter manifest should be valid");
+        let baked = baked_animations
+            .get(&animations.baked)
+            .expect("Animation should exist");
 
         let new_state = if let Some(reaction) = pending_hit_reaction.take() {
             hitstop.remaining_frames = *reaction.victim_hitstop_frames;
@@ -579,7 +660,10 @@ pub fn state_interrupt_system(
                 &mut frame,
                 &manifest.attributes,
                 attack_script_assets,
+                &stage_collision,
                 &game_settings,
+                baked,
+                manifest.model_scale,
             );
         };
     }
@@ -594,6 +678,7 @@ pub fn state_collision_interrupt_system(
     mut match_state: ResMut<MatchState>,
     stage_registry: Res<StageManifestRegistry>,
     stage_manifests: Res<Assets<StageManifest>>,
+    baked_animations: Res<Assets<BakedFighterAnimations>>,
 ) {
     let Some(stage_manifest_handle) = stage_registry.get(match_config.stage) else {
         return;
@@ -608,6 +693,7 @@ pub fn state_collision_interrupt_system(
             mut state,
             mut frame,
             fighter,
+            animations,
             attack_script_assets,
             mut hitstop,
             mut pending_respawn,
@@ -619,6 +705,9 @@ pub fn state_collision_interrupt_system(
         let manifest = fighter_manifests
             .get(&fighter.manifest)
             .expect("Fighter manifest should be valid");
+        let baked = baked_animations
+            .get(&animations.baked)
+            .expect("Animation should exist");
 
         if pending_respawn.0 {
             **pending_respawn = false;
@@ -665,7 +754,10 @@ pub fn state_collision_interrupt_system(
                 &mut frame,
                 &manifest.attributes,
                 attack_script_assets,
+                &stage_collision,
                 &game_settings,
+                baked,
+                manifest.model_scale,
             );
             continue;
         }
@@ -675,7 +767,7 @@ pub fn state_collision_interrupt_system(
         }
 
         let new_state = state.check_collision_interrupt(
-            &mut frame.collision_context(&stage_collision, &game_settings),
+            &mut frame.collision_context(&stage_collision, manifest, &game_settings),
         );
         if let Some(new_state) = new_state {
             transition_state(
@@ -684,8 +776,81 @@ pub fn state_collision_interrupt_system(
                 &mut frame,
                 &manifest.attributes,
                 &attack_script_assets,
+                &stage_collision,
                 &game_settings,
+                baked,
+                manifest.model_scale,
             );
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::fighter::ecb::FighterPreviousECB;
+    use crate::stage::line::{StageLedge, StageLedgeSide, StageVertexID};
+
+    #[test]
+    fn animation_positions_map_forward_to_facing_and_preserve_height() {
+        let position = FGVec3::lit("99", "3", "5");
+
+        assert_eq!(
+            animation_position_to_gameplay(position, &FighterFacingDirection::Right),
+            FGVec2::lit("5", "3")
+        );
+        assert_eq!(
+            animation_position_to_gameplay(position, &FighterFacingDirection::Left),
+            FGVec2::lit("-5", "3")
+        );
+    }
+
+    #[test]
+    fn ledge_lockout_suppresses_ledge_collision() {
+        let ledge_id = StageVertexID {
+            polygon: 0,
+            vertex: 0,
+        };
+        let stage_collision = StageCollision {
+            ledges: vec![StageLedge {
+                id: ledge_id,
+                position: FGVec2::ZERO,
+                hang_side: StageLedgeSide::Left,
+            }],
+            ..default()
+        };
+        let previous_translation = FighterPreviousTranslation::default();
+        let input = FighterInput::default();
+        let mut translation = FighterTranslation::default();
+        let mut velocity = FighterVelocity::default();
+        let mut surface = FighterSurfaceState::default();
+        let mut ecb = FighterECB::default();
+        let previous_ecb = FighterPreviousECB::from(ecb);
+        let mut presentation_snap = FighterPresentationSnap::default();
+        let mut context = CollisionContext {
+            translation: &mut translation,
+            prev_translation: &previous_translation,
+            input: &input,
+            velocity: &mut velocity,
+            surface: &mut surface,
+            ecb: &mut ecb,
+            prev_ecb: &previous_ecb,
+            stage_collision: &stage_collision,
+            leave_ground_ecb_lock_duration: 0,
+            presentation_snap: &mut presentation_snap,
+            fighter_ledge_collision_box: FGRect {
+                origin: FGVec2::lit("-1", "1"),
+                end: FGVec2::lit("1", "-1"),
+            },
+            ledge_grab_lockout_active: true,
+            downward_stick_threshold: FGi32::ONE,
+        };
+
+        assert!(context.air_collide_with_ledges().is_none());
+        context.ledge_grab_lockout_active = false;
+        assert_eq!(
+            context.air_collide_with_ledges().map(|result| result.ledge),
+            Some(ledge_id)
+        );
+    }
+}