Add debug save states

Reviewed-on: #5
Co-authored-by: Álex Román Núñez <eirexe@eirteam.moe>

.gitea/workflows/ci.yml

@@ -10,7 +10,7 @@ on:
 jobs:
   build-and-test:
     runs-on: ubuntu-latest
-    timeout-minutes: 15
+    timeout-minutes: 30
     steps:
       - name: Check out source
         uses: actions/checkout@v4

src/debug_tools.rs

@@ -3,16 +3,19 @@
 use std::{collections::HashMap, time::Duration};
 
 use bevy::{
+    input::InputSystems,
     prelude::*,
     settings::{ReflectSettingsGroup, SaveSettingsDeferred, SettingsGroup},
 };
 use bevy_egui::{EguiContexts, EguiPrimaryContextPass, egui};
-use bevy_ggrs::RollbackFrameRate;
+use bevy_ggrs::{RollbackFrameRate, RunGgrsSystems};
 use enum_cycling::EnumCycle;
 use enum_cycling_derive::EnumCycle;
 
 use crate::{AppState, player::Player, replay::StopReplayRecording};
 
+mod save_state;
+
 pub const PLAYER_DEBUG_ROW_COUNT: usize = 6;
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Reflect)]
@@ -114,6 +117,7 @@ enum DebugFlag {
     Hurtboxes,
     Camera,
     DrawThroughGeometry,
+    FrameStepping,
 }
 
 #[derive(Clone, Copy)]
@@ -174,6 +178,10 @@ const WORLD_MENU: &[DebugMenuEntry] = &[
     DebugMenuEntry::GameSpeed {
         label: "Game speed",
     },
+    DebugMenuEntry::Toggle {
+        label: "Frame stepping",
+        flag: DebugFlag::FrameStepping,
+    },
 ];
 
 const DIAGNOSTICS_MENU: &[DebugMenuEntry] = &[DebugMenuEntry::Toggle {
@@ -233,6 +241,8 @@ pub struct DebugSettings {
     selections: Vec<usize>,
     #[reflect(ignore)]
     pub player_rows: HashMap<usize, [FighterDebugRowKind; PLAYER_DEBUG_ROW_COUNT]>,
+    #[reflect(ignore)]
+    pub frame_stepping: bool,
     pub network: bool,
     pub ecb: bool,
     pub stage_collision: bool,
@@ -253,6 +263,7 @@ impl Default for DebugSettings {
             pages: vec![DebugMenuPage::Static(ROOT_MENU)],
             selections: vec![0],
             player_rows: HashMap::new(),
+            frame_stepping: false,
             network: false,
             ecb: false,
             stage_collision: false,
@@ -325,6 +336,7 @@ impl DebugSettings {
             DebugFlag::Hurtboxes => self.hurtboxes,
             DebugFlag::DrawThroughGeometry => self.draw_through_geometry,
             DebugFlag::Camera => self.camera,
+            DebugFlag::FrameStepping => self.frame_stepping,
         }
     }
 
@@ -340,6 +352,7 @@ impl DebugSettings {
                 self.draw_through_geometry = !self.draw_through_geometry
             }
             DebugFlag::Camera => self.camera = !self.camera,
+            DebugFlag::FrameStepping => self.frame_stepping = !self.frame_stepping,
         }
     }
 
@@ -356,9 +369,35 @@ impl DebugSettings {
 
 pub struct DebugToolsPlugin;
 
+#[derive(Resource, Default)]
+struct FrameStepState {
+    requested: bool,
+    time_backup: Option<Time>,
+    last_step_time: Time
+}
+
 impl Plugin for DebugToolsPlugin {
     fn build(&self, app: &mut App) {
         app.init_resource::<DebugSettings>()
+            .init_resource::<FrameStepState>()
+            .init_resource::<save_state::DebugSaveState>()
+            .add_systems(OnEnter(AppState::InMatch), save_state::clear)
+            .add_systems(OnExit(AppState::InMatch), save_state::clear)
+            .add_systems(
+                PreUpdate,
+                prepare_frame_step
+                    .after(InputSystems)
+                    .before(RunGgrsSystems)
+                    .run_if(in_state(AppState::InMatch)),
+            )
+            .add_systems(
+                PreUpdate,
+                save_state::save_or_restore
+                    .after(InputSystems)
+                    .before(RunGgrsSystems)
+                    .run_if(in_state(AppState::InMatch)),
+            )
+            .add_systems(PreUpdate, restore_frame_step_time.after(RunGgrsSystems))
             .add_systems(
                 Update,
                 (handle_palette_input, sync_gizmo_depth_bias)
@@ -391,6 +430,61 @@ fn queue_settings_save(commands: &mut Commands) {
     commands.queue(SaveSettingsDeferred(Duration::from_secs_f32(0.1)));
 }
 
+fn frame_step_duration(frame_rate: usize) -> Duration {
+    Duration::from_nanos(1_000_000_000u64 / frame_rate as u64)
+}
+
+fn prepare_frame_step(
+    settings: Res<DebugSettings>,
+    gamepads: Query<&Gamepad>,
+    key: Res<ButtonInput<KeyCode>>,
+    mut state: ResMut<FrameStepState>,
+    mut time: ResMut<Time>,
+    frame_rate: Res<RollbackFrameRate>,
+) {
+    if !settings.frame_stepping {
+        state.requested = false;
+        return;
+    }
+
+    let pressed = gamepads
+        .iter()
+        .any(|gamepad| gamepad.pressed(GamepadButton::DPadDown));
+
+    let just_pressed = gamepads
+            .iter()
+            .any(|gamepad| gamepad.just_pressed(GamepadButton::DPadDown));
+
+    let just_pressed = key.just_pressed(KeyCode::F4) || just_pressed;
+    let pressed = key.pressed(KeyCode::F4) || pressed;
+
+    if just_pressed {
+        state.last_step_time = time.clone();
+    }
+
+    let can_repress = pressed && (time.elapsed() - state.last_step_time.elapsed()).as_millis() > 500;
+
+    if !settings.menu_open && (just_pressed || can_repress)
+    {
+        state.requested = true;
+    }
+
+    state.time_backup = Some(*time);
+    let delta = if state.requested {
+        frame_step_duration(**frame_rate)
+    } else {
+        Duration::ZERO
+    };
+    time.advance_by(delta);
+}
+
+fn restore_frame_step_time(mut state: ResMut<FrameStepState>, mut time: ResMut<Time>) {
+    if let Some(backup) = state.time_backup.take() {
+        *time = backup;
+        state.requested = false;
+    }
+}
+
 fn activate_selected(
     settings: &mut DebugSettings,
     page_len: usize,
@@ -408,7 +502,9 @@ fn activate_selected(
             }
             DebugMenuEntry::Toggle { flag, .. } => {
                 settings.toggle_flag(flag);
-                queue_settings_save(commands);
+                if !matches!(flag, DebugFlag::FrameStepping) {
+                    queue_settings_save(commands);
+                }
             }
             DebugMenuEntry::Submenu { entries, .. } => {
                 settings.push_page(DebugMenuPage::Static(entries));
@@ -623,7 +719,9 @@ fn draw_palette(
                                     let mut value = settings.flag(*flag);
                                     if ui.checkbox(&mut value, *label).changed() {
                                         settings.toggle_flag(*flag);
-                                        queue_settings_save(&mut commands);
+                                        if !matches!(flag, DebugFlag::FrameStepping) {
+                                            queue_settings_save(&mut commands);
+                                        }
                                     }
                                 }
                                 DebugMenuEntry::Submenu { label, .. }
@@ -839,6 +937,15 @@ mod tests {
         assert_eq!(GameSpeedDebug::Quarter.frame_rate(), 15);
     }
 
+    #[test]
+    fn frame_stepping_is_disabled_by_default_and_uses_game_speed_timestep() {
+        let settings = DebugSettings::default();
+
+        assert!(!settings.frame_stepping);
+        assert_eq!(frame_step_duration(60), Duration::from_nanos(16_666_666));
+        assert_eq!(frame_step_duration(30), Duration::from_nanos(33_333_333));
+    }
+
     #[test]
     fn empty_player_list_does_not_activate() {
         let mut settings = DebugSettings::default();

src/debug_tools/save_state.rs

@@ -0,0 +1,196 @@
+use bevy::prelude::*;
+
+use crate::{
+    camera::MatchCamera,
+    fighter::{
+        FighterECB, FighterFacingDirection, FighterHitboxes, FighterHitstop,
+        FighterPreviousFacingDirection, FighterPreviousTranslation, FighterTranslation,
+        FighterVelocity, Grounded,
+        animation::FighterAnimationFrame,
+        attack::{
+            FighterDamage, FighterKnockbackVelocity, FighterPendingHitReaction,
+            FighterReceivedAttacks, FighterSolvedHurtboxes, FighterStaleMoveQueue,
+        },
+        baked_animation::FighterBoneMatrices,
+        state::FighterState,
+    },
+    input::FighterInput,
+    player::Player,
+    stage::line::StageCollision,
+};
+
+#[derive(Resource, Default)]
+pub(super) struct DebugSaveState {
+    checkpoint: Option<Checkpoint>,
+}
+
+#[derive(Clone)]
+struct Checkpoint {
+    fighters: Vec<FighterCheckpoint>,
+    stage_collision: StageCollision,
+}
+
+#[derive(Clone)]
+struct FighterCheckpoint {
+    entity: Entity,
+    handle: usize,
+    ecb: FighterECB,
+    previous_ecb: crate::fighter::ecb::FighterPreviousECB,
+    velocity: FighterVelocity,
+    translation: FighterTranslation,
+    previous_translation: FighterPreviousTranslation,
+    facing: FighterFacingDirection,
+    previous_facing: FighterPreviousFacingDirection,
+    animation: FighterAnimationFrame,
+    state: FighterState,
+    input: FighterInput,
+    damage: FighterDamage,
+    pending_hit_reaction: FighterPendingHitReaction,
+    hitstop: FighterHitstop,
+    knockback_velocity: FighterKnockbackVelocity,
+    stale_moves: FighterStaleMoveQueue,
+    hitboxes: FighterHitboxes,
+    received_attacks: FighterReceivedAttacks,
+    solved_hurtboxes: FighterSolvedHurtboxes,
+    bone_matrices: FighterBoneMatrices,
+    grounded: bool,
+}
+
+pub(super) fn save_or_restore(world: &mut World) {
+    if world.resource::<super::DebugSettings>().menu_open {
+        return;
+    }
+
+    let left = world
+        .query::<&Gamepad>()
+        .iter(world)
+        .any(|gamepad| gamepad.just_pressed(GamepadButton::DPadLeft));
+    let right = world
+        .query::<&Gamepad>()
+        .iter(world)
+        .any(|gamepad| gamepad.just_pressed(GamepadButton::DPadRight));
+
+    if left == right {
+        return;
+    }
+
+    let Some(roster) = world
+        .get_resource::<crate::fighter::FighterRoster>()
+        .map(|roster| roster.0.clone())
+    else {
+        return;
+    };
+    if roster.len() != 1 {
+        warn!("Save states are only available in single-player matches");
+        return;
+    }
+
+    if left {
+        let Some(stage_collision) = world.get_resource::<StageCollision>().cloned() else {
+            return;
+        };
+        let mut checkpoint_fighters = Vec::with_capacity(roster.len());
+        for entity in roster.iter().copied() {
+            let Some(checkpoint) = capture_fighter(world, entity) else {
+                warn!("Could not save the current fighter state");
+                return;
+            };
+            checkpoint_fighters.push(checkpoint);
+        }
+        world.resource_mut::<DebugSaveState>().checkpoint = Some(Checkpoint {
+            fighters: checkpoint_fighters,
+            stage_collision,
+        });
+        info!("Saved debug game state");
+        return;
+    }
+
+    let Some(checkpoint) = world.resource::<DebugSaveState>().checkpoint.clone() else {
+        warn!("No debug game state has been saved");
+        return;
+    };
+    if checkpoint.fighters.len() != roster.len()
+        || checkpoint
+            .fighters
+            .iter()
+            .zip(roster.iter())
+            .any(|(saved, current)| saved.entity != *current)
+    {
+        warn!("Saved debug game state belongs to another match");
+        return;
+    }
+
+    for saved in &checkpoint.fighters {
+        let Some(player) = world.entity(saved.entity).get::<Player>() else {
+            warn!("Could not restore the saved fighter state");
+            return;
+        };
+        if player.handle != saved.handle {
+            warn!("Saved debug game state belongs to another match");
+            return;
+        }
+
+        let mut entity = world.entity_mut(saved.entity);
+        entity.insert(saved.ecb);
+        entity.insert(saved.previous_ecb);
+        entity.insert(saved.velocity);
+        entity.insert(saved.translation);
+        entity.insert(saved.previous_translation);
+        entity.insert(saved.facing);
+        entity.insert(saved.previous_facing);
+        entity.insert(saved.animation);
+        entity.insert(saved.state.clone());
+        entity.insert(saved.input);
+        entity.insert(saved.damage);
+        entity.insert(saved.pending_hit_reaction.clone());
+        entity.insert(saved.hitstop);
+        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 {
+            entity.insert(Grounded);
+        } else {
+            entity.remove::<Grounded>();
+        }
+    }
+    world.insert_resource(checkpoint.stage_collision);
+    for mut match_camera in world.query::<&mut MatchCamera>().iter_mut(world) {
+        match_camera.needs_snap = true;
+    }
+    info!("Restored debug game state");
+}
+
+fn capture_fighter(world: &World, entity: Entity) -> Option<FighterCheckpoint> {
+    let fighter = world.entity(entity);
+    Some(FighterCheckpoint {
+        entity,
+        handle: fighter.get::<Player>()?.handle,
+        ecb: *fighter.get::<FighterECB>()?,
+        previous_ecb: *fighter.get::<crate::fighter::ecb::FighterPreviousECB>()?,
+        velocity: *fighter.get::<FighterVelocity>()?,
+        translation: *fighter.get::<FighterTranslation>()?,
+        previous_translation: *fighter.get::<FighterPreviousTranslation>()?,
+        facing: *fighter.get::<FighterFacingDirection>()?,
+        previous_facing: *fighter.get::<FighterPreviousFacingDirection>()?,
+        animation: *fighter.get::<FighterAnimationFrame>()?,
+        state: fighter.get::<FighterState>()?.clone(),
+        input: *fighter.get::<FighterInput>()?,
+        damage: *fighter.get::<FighterDamage>()?,
+        pending_hit_reaction: fighter.get::<FighterPendingHitReaction>()?.clone(),
+        hitstop: *fighter.get::<FighterHitstop>()?,
+        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>(),
+    })
+}
+
+pub(super) fn clear(mut save_state: ResMut<DebugSaveState>) {
+    save_state.checkpoint = None;
+}