Fix various runtime shenanigans

## Summary
- add a rollback-tracked `FighterSurfaceState` as the single source of truth for stage contact
- move active stage line ownership out of individual grounded fighter states
- update landing, airborne motion, ledge departure, hit reactions, and debug save states to maintain surface contact
- add tests for contact lifecycle, connected-segment traversal, and ledge departure

Reviewed-on: #60
Co-authored-by: Álex Román Núñez <eirexe@eirteam.moe>

.gitea/workflows/ci.yml

@@ -15,6 +15,27 @@ jobs:
       - name: Check out source
         uses: actions/checkout@v4
 
+      - name: Install Lore CLI
+        run: |
+          scripts/install-lore.sh "$RUNNER_TEMP/lore-bin"
+          echo "$RUNNER_TEMP/lore-bin" >> "$GITHUB_PATH"
+
+      - name: Select Lore asset branch
+        run: |
+          branch=main
+          if [[ "$GITHUB_EVENT_NAME" == pull_request ]]; then
+            branch="$(python3 -c 'import json, os; e=json.load(open(os.environ["GITHUB_EVENT_PATH"], encoding="utf-8")); p=e["pull_request"]; print(p["head"]["ref"] if p["head"]["repo"]["full_name"] == os.environ["GITHUB_REPOSITORY"] else "main")')"
+          fi
+          echo "LORE_BRANCH=$branch" >> "$GITHUB_ENV"
+          echo "Using Lore branch: $branch"
+
+      - name: Fetch assets from Lore
+        env:
+          LORE_CI_USERNAME: ${{ secrets.LORE_CI_USERNAME }}
+          LORE_CI_PASSWORD: ${{ secrets.LORE_CI_PASSWORD }}
+          LORE_AUTH_URL: https://auth.eirexe.moe
+        run: scripts/update-assets.sh "$LORE_BRANCH"
+
       - name: Install Rust toolchain
         run: |
           curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | \
@@ -58,6 +79,27 @@ jobs:
       - name: Check out source
         uses: actions/checkout@v4
 
+      - name: Install Lore CLI
+        run: |
+          scripts/install-lore.sh "$RUNNER_TEMP/lore-bin"
+          echo "$RUNNER_TEMP/lore-bin" >> "$GITHUB_PATH"
+
+      - name: Select Lore asset branch
+        run: |
+          branch=main
+          if [[ "$GITHUB_EVENT_NAME" == pull_request ]]; then
+            branch="$(python3 -c 'import json, os; e=json.load(open(os.environ["GITHUB_EVENT_PATH"], encoding="utf-8")); p=e["pull_request"]; print(p["head"]["ref"] if p["head"]["repo"]["full_name"] == os.environ["GITHUB_REPOSITORY"] else "main")')"
+          fi
+          echo "LORE_BRANCH=$branch" >> "$GITHUB_ENV"
+          echo "Using Lore branch: $branch"
+
+      - name: Fetch assets from Lore
+        env:
+          LORE_CI_USERNAME: ${{ secrets.LORE_CI_USERNAME }}
+          LORE_CI_PASSWORD: ${{ secrets.LORE_CI_PASSWORD }}
+          LORE_AUTH_URL: https://auth.eirexe.moe
+        run: scripts/update-assets.sh "$LORE_BRANCH"
+
       - name: Install Rust toolchain
         run: |
           curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | \
@@ -87,8 +129,11 @@ jobs:
             libusb-1.0-0-dev \
             libwayland-dev \
             libx11-dev \
+            libxfixes3 \
+            libxi6 \
             libxkbcommon-dev \
             libxkbcommon-x11-0 \
+            blender \
             lld-19 \
             llvm-19 \
             mesa-vulkan-drivers \
@@ -99,9 +144,39 @@ jobs:
           echo "/usr/lib/llvm-19/bin" >> "$GITHUB_PATH"
           rm -f "$HOME/.cache/cargo-xwin/clang-cl"
 
+      - name: Install pinned Blender
+        run: |
+          scripts/install-blender.sh "$RUNNER_TEMP/blender"
+          echo "BLENDER=$RUNNER_TEMP/blender/blender" >> "$GITHUB_ENV"
+
       - name: Preprocess assets
         run: cargo run --locked --bin process-assets --no-default-features --features debug_features -j 4
 
+      - name: Verify processed battlefield asset
+        run: |
+          python3 - <<'PY'
+          import json
+          import struct
+
+          path = "imported_assets/Default/stages/battlefield/bf2.blend"
+          with open(path, "rb") as asset:
+              header = asset.read(12)
+              if len(header) != 12:
+                  raise SystemExit(f"processed asset is truncated: {path}")
+              magic, version, length = struct.unpack("<4sII", header)
+              if magic != b"glTF" or version != 2 or length != asset.seek(0, 2):
+                  raise SystemExit(f"processed asset is not a valid GLB: {path}")
+              asset.seek(12)
+              json_length, chunk_type = struct.unpack("<II", asset.read(8))
+              if chunk_type != 0x4E4F534A:
+                  raise SystemExit(f"processed asset has no JSON chunk: {path}")
+              document = json.loads(asset.read(json_length))
+          meshes = document.get("meshes", [])
+          if not meshes:
+              raise SystemExit(f"processed asset contains no meshes: {path}")
+          print(f"{path}: {len(meshes)} meshes, {length} bytes")
+          PY
+
       - name: Build production binary
         run: cargo build --locked --profile production --no-default-features --features debug_features -j 4
 

.gitignore

@@ -1,6 +1,7 @@
 /target
 /.jackdaw
 imported_assets
+/assets/
 
 # Local editor configuration
 **/.vscode/
@@ -10,3 +11,7 @@ imported_assets
 *_old.glb
 /replay.json
 *.replay.tmp
+
+# Python debugger formatter tests
+__pycache__/
+*.pyc

Cargo.toml

@@ -12,7 +12,7 @@ development = ["bevy/dynamic_linking", "bevy/file_watcher"]
 debug_features = ["bevy/free_camera"]
 
 [dependencies]
-bevy = { version = "0.19", features = ["asset_processor", "basis-universal", "bevy_settings"] }
+bevy = { version = "0.19", features = ["asset_processor", "basis-universal", "compressed_image_saver", "bevy_settings"] }
 # Loads the scenes you author in the editor (assets/*.bsn) and builds
 # physics colliders from them. An ordinary dependency; remove it if you
 # stop using authored scenes.

README.md

@@ -2,6 +2,15 @@
 
 Fancy heavily advanced platform fighting game
 
+## Debugging fixed-point values with lldb
+
+If using CodeLLDB:
+```json
+"preRunCommands": [
+    "command script import ${workspaceFolder}/tools/lldb_fixed.py"
+]
+```
+
 ## Direct P2P Debugging
 
 ```text
@@ -16,11 +25,6 @@ cargo run -- --debug-match --players 2 --local-port 7001 \
 
 ## Production Build
 
-Production builds use the `production` Cargo profile and do not dynamically
-link Bevy or Rust. Development builds retain Bevy dynamic linking for faster
-iteration. Cargo stores the production profile under `target/production`,
-separate from development artifacts under `target/debug`.
-
 ```sh
 cargo run --locked \
   --bin process-assets --no-default-features --features debug_features
@@ -28,6 +32,19 @@ cargo build --locked \
   --profile production --no-default-features --features debug_features
 ```
 
-The asset preprocessing command must be run from the repository root. It
+## Assets
-populates `imported_assets/Default`, which is then consumed by the production
+
-game without running the asset processor at startup.
+Game assets are managed in Lore rather than Git. Install the Lore CLI, then
+bootstrap or update the local checkout with:
+
+```sh
+scripts/install-lore.sh
+scripts/update-assets.sh
+```
+
+The default Lore branch is `main`; pass another branch explicitly when testing
+coordinated code and asset changes:
+
+```sh
+scripts/update-assets.sh my-feature-branch
+```

assets/fighters/test/scripts/fair.attack.rhai

@@ -1,12 +0,0 @@
-frame(4);
-hitbox(0,
-    "hand_l",
-    damage("5.0"),
-    vec3("0.0", "0.0", "0.0"),
-    fg32("5.0"),
-    angle_sakurai(),
-    knockback_normal(),
-    knockback("10.0"),
-    fg32("1.0")
-);
-frame(8);

assets/fighters/test/scripts/jab.attack.rhai

@@ -1,12 +0,0 @@
-frame(3);
-hitbox(0,
-    "hand_l",
-    damage("5.0"),
-    vec3("0.0", "0.0", "0.0"),
-    fg32("5.0"),
-    angle(fg32("45.0")),
-    knockback_normal(),
-    knockback("18.0"),
-    fg32("140.0")
-);
-frame(8);

assets/fighters/test/scripts/uptilt.attack.rhai

@@ -1,13 +0,0 @@
-frame(9);
-hitbox(0,
-    "hand_l",
-    damage("5.0"),
-    vec3("1.0", "0.0", "0.0"),
-    fg32("7.0"),
-    angle_sakurai(),
-    knockback_normal(),
-    knockback("10.0"),
-    fg32("1.0")
-);
-
-frame(15);

assets/fighters/test/test.fighter.ron

@@ -1,219 +0,0 @@
-(
-    id: TestFighter,
-    model_path: "fighters/test/test_fighter.gltf",
-    model_scale: "10.0",
-    baked_animation_path: "fighters/test/test.fighterbake",
-    icon: (
-        path: "fighters/test/icon.png",
-    ),
-    attributes: (
-        base_walk_accel: "0.1",
-        stick_walk_accel: "0.16",
-        max_walk_vel: "1.0",
-        ground_friction: "0.1",
-        dash_acceleration_duration: 13,
-        dash_duration: 24,
-        base_dash_accel: "0.1",
-        stick_dash_accel: "0.05",
-        max_dash_vel: "2.0",
-        short_hop_vertical_velocity: "1.45",
-        full_jump_vertical_velocity: "2.0",
-        jump_horizontal_velocity: "0.6",
-        air_jump_horizontal_velocity: "0.96",
-        air_jump_multiplier: "1.0",
-        dash_initial_velocity: "1.4",
-        terminal_velocity: "3.0",
-        fast_fall_speed: "3.5",
-        gravity: "0.084",
-        weight: "100.0",
-        jumpsquat_duration: 5,
-        landing_iasa: 4,
-        landing_duration: 30,
-
-        max_air_horizontal_velocity: "2.5",
-        air_drift_max: "1.0",
-        air_acceleration_base: "0.03",
-        air_acceleration_stick: "0.01",
-        air_friction: "0.01",
-
-        air_dodge_duration: 49,
-        air_dodge_velocity: "2.790",
-        air_dodge_decay: "0.9",
-        ecb_vertical_midpoint_offset: "0.0"
-    ),
-    camera: (
-        vertical_origin_offset: "8.0",
-        forward_extent: "25.5",
-        backward_extent: "8.5",
-        upward_extent: "15.0",
-        downward_extent: "5.0",
-        visibility_radius: "5.0",
-    ),
-    animations: {
-        Wait: "Idle_Loop_Game",
-        Walk: "Walk_Loop_IK_Game",
-        Run: "Run_Game",
-        Dash: "Dash_Game",
-        JumpSquat: "Jump_Squat_Game",
-        JumpForward: "Jump_Start_IK_Game",
-        JumpBack: "JumpB_Game",
-        LandingSpecial: "SpecialLand_Game",
-        Landing: "Jump_Land_Game",
-        AirDodge: "Idle_Loop_Game",
-        DoubleJumpForward: "Jump_Start_IK_Game",
-        DoubleJumpBack: "JumpB_Game",
-        Fall: "Fall_Loop_Game",
-        Turn: "Turn_Game",
-
-        FlinchGround: "Air_Hit_Game",
-        FlinchAir: "Air_Hit_Game",
-
-        AttackJab1: "Punch_Jab_Game",
-        AttackUpTilt: "Idle_Loop_Game",
-        AttackForwardTilt: "Idle_Loop_Game",
-        AttackDownTilt: "Idle_Loop_Game"
-    },
-    attack_scripts: {
-        NeutralAir: "fighters/test/scripts/fair.attack.rhai",
-        Jab: "fighters/test/scripts/jab.attack.rhai",
-        UpTilt: "fighters/test/scripts/uptilt.attack.rhai",
-        ForwardTilt: "fighters/test/scripts/uptilt.attack.rhai",
-        DownTilt: "fighters/test/scripts/uptilt.attack.rhai",
-    },
-    hurtboxes: [
-        // center one
-        (
-            bone: "spine_01",
-            offset: (x: "0.0", y: "0.0", z: "0.0"),
-            rotation: FGVec3(x: "0.0", y: "0.0", z: "0.0"),
-            half_length: "0.05",
-            radius: "0.15"
-        ),
-        (
-            bone: "spine_03",
-            offset: (x: "0.0", y: "0.0", z: "0.0"),
-            rotation: FGVec3(x: "0.0", y: "0.0", z: "0.0"),
-            half_length: "0.05",
-            radius: "0.15"
-        ),
-        (
-            bone: "Head",
-            offset: (x: "0.0", y: "0.125", z: "0.0"),
-            rotation: FGVec3(x: "0.0", y: "0.0", z: "0.0"),
-            half_length: "0.05",
-            radius: "0.1"
-        ),
-        (
-            bone: "thigh_r",
-            offset: (x: "0.0", y: "0.15", z: "-0.01"),
-            rotation: FGVec3(x: "0.0", y: "0.0", z: "0.0"),
-            half_length: "0.2",
-            radius: "0.07"
-        ),
-        (
-            bone: "thigh_l",
-            offset: (x: "0.0", y: "0.15", z: "-0.01"),
-            rotation: FGVec3(x: "0.0", y: "0.0", z: "0.0"),
-            half_length: "0.2",
-            radius: "0.07"
-        ),
-        (
-            bone: "calf_l",
-            offset: (x: "0.0", y: "0.15", z: "-0.0"),
-            rotation: FGVec3(x: "0.0", y: "0.0", z: "0.0"),
-            half_length: "0.2",
-            radius: "0.05"
-        ),
-        (
-            bone: "calf_r",
-            offset: (x: "0.0", y: "0.15", z: "-0.0"),
-            rotation: FGVec3(x: "0.0", y: "0.0", z: "0.0"),
-            half_length: "0.2",
-            radius: "0.05"
-        ),
-        (
-            bone: "foot_r",
-            offset: (x: "0.0", y: "0.1", z: "0.01"),
-            rotation: FGVec3(x: "-25.0", y: "0.0", z: "0.0"),
-            half_length: "0.1",
-            radius: "0.04"
-        ),
-        (
-            bone: "foot_l",
-            offset: (x: "0.0", y: "0.1", z: "0.01"),
-            rotation: FGVec3(x: "-25.0", y: "0.0", z: "0.0"),
-            half_length: "0.1",
-            radius: "0.04"
-        ),
-        (
-            bone: "upperarm_l",
-            offset: (x: "0.0", y: "0.09", z: "-0.0"),
-            rotation: FGVec3(x: "0.0", y: "0.0", z: "0.0"),
-            half_length: "0.125",
-            radius: "0.05"
-        ),
-        (
-            bone: "lowerarm_l",
-            offset: (x: "0.0", y: "0.12", z: "-0.0"),
-            rotation: FGVec3(x: "0.0", y: "0.0", z: "0.0"),
-            half_length: "0.115",
-            radius: "0.04"
-        ),
-        (
-            bone: "hand_l",
-            offset: (x: "0.0", y: "0.05", z: "-0.0"),
-            rotation: FGVec3(x: "0.0", y: "0.0", z: "0.0"),
-            half_length: "0.01",
-            radius: "0.04"
-        ),
-        (
-            bone: "upperarm_r",
-            offset: (x: "0.0", y: "0.09", z: "-0.0"),
-            rotation: FGVec3(x: "0.0", y: "0.0", z: "0.0"),
-            half_length: "0.125",
-            radius: "0.05"
-        ),
-        (
-            bone: "lowerarm_r",
-            offset: (x: "0.0", y: "0.12", z: "-0.0"),
-            rotation: FGVec3(x: "0.0", y: "0.0", z: "0.0"),
-            half_length: "0.115",
-            radius: "0.04"
-        ),
-        (
-            bone: "hand_r",
-            offset: (x: "0.0", y: "0.05", z: "-0.0"),
-            rotation: FGVec3(x: "0.0", y: "0.0", z: "0.0"),
-            half_length: "0.01",
-            radius: "0.04"
-        ),
-        /*(
-            bone: "RFootJA",
-            offset: (x: "0.0", y: "0.5", z: "0.0"),
-            rotation: FGVec3(x: "0.0", y: "0.0", z: "90.0"),
-            half_length: "0.5",
-            radius: "1.0"
-        ),
-        (
-            bone: "JOBJ_47",
-            offset: (x: "0.0", y: "0.0", z: "0.0"),
-            rotation: FGVec3(x: "0.0", y: "0.0", z: "90.0"),
-            half_length: "0.5",
-            radius: "1.0"
-        ),
-        (
-            bone: "LFootJA",
-            offset: (x: "0.0", y: "0.5", z: "0.0"),
-            rotation: FGVec3(x: "0.0", y: "0.0", z: "90.0"),
-            half_length: "0.5",
-            radius: "1.0"
-        ),
-        (
-            bone: "JOBJ_41",
-            offset: (x: "0.0", y: "0.0", z: "0.0"),
-            rotation: FGVec3(x: "0.0", y: "0.0", z: "90.0"),
-            half_length: "0.5",
-            radius: "1.0"
-        ),*/
-    ]
-)

assets/fighters/test/test.fighterbake

@@ -1,3 +0,0 @@
-(
-    manifest_path: "fighters/test/test.fighter.ron",
-)

assets/game.stylesheet.ron

@@ -1,128 +0,0 @@
-(
-    cursor: (
-        path: "ui/textures/cursor.png",
-        sampling: Nearest
-    ),
-    css_token: (
-        path: "ui/textures/fighter_select_token.png",
-        sampling: Linear
-    ),
-    player_colors: [
-        Srgba((red: 0.780, green: 0.420, blue: 0.933, alpha: 1.000)),
-        Srgba((red: 0.843, green: 0.227, blue: 0.204, alpha: 1.000)),
-        Srgba((red: 0.333, green: 0.804, blue: 0.078, alpha: 1.000)),
-        Srgba((red: 0.075, green: 0.376, blue: 0.416, alpha: 1.000)),
-        Srgba((red: 0.682, green: 0.878, blue: 0.914, alpha: 1.000))
-    ],
-    button_styles: {
-        MainMenu: (
-            focus_outline_width_px: 4,
-            focus_outline_offset_px: 2,
-            focus_outline_color: Srgba((red: 1.0, green: 1.0, blue: 0.0, alpha: 1.0)),
-            normal: (
-                background_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                border_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                text_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                box_shadow: (),
-            ),
-            press: (
-                background_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                border_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                text_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                box_shadow: (),
-            ),
-            hover: (
-                background_color: Srgba((red: 0.0, green: 1.0, blue: 0.0, alpha: 1.0)),
-                border_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                text_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                box_shadow: (),
-            )
-        ),
-        CharacterSelectCharacter: (
-            focus_outline_width_px: 10,
-            focus_outline_offset_px: 5,
-            focus_outline_color: Srgba((red: 1.0, green: 1.0, blue: 0.0, alpha: 1.0)),
-            normal: (
-                background_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                text_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                box_shadow: (),
-                border_size: 10,
-            ),
-            press: (
-                background_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                text_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                box_shadow: (),
-            ),
-            hover: (
-                background_color: Srgba((red: 0.0, green: 1.0, blue: 0.0, alpha: 1.0)),
-                text_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                box_shadow: (),
-            )
-        ),
-        CharacterSelectStartBanner: (
-            focus_outline_width_px: 10,
-            focus_outline_offset_px: 5,
-            focus_outline_color: Srgba((red: 1.0, green: 1.0, blue: 0.0, alpha: 1.0)),
-            normal: (
-                background_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                text_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                box_shadow: (),
-            ),
-            press: (
-                background_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                text_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                box_shadow: (),
-            ),
-            hover: (
-                background_color: Srgba((red: 0.0, green: 1.0, blue: 0.0, alpha: 1.0)),
-                text_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                box_shadow: (),
-            )
-        ),
-        StageSelectIcon: (
-            focus_outline_width_px: 4,
-            focus_outline_offset_px: 2,
-            focus_outline_color: Srgba((red: 1.0, green: 1.0, blue: 0.0, alpha: 1.0)),
-            normal: (
-                border_color: Srgba((red: 1.0, green: 1.0, blue: 0.0, alpha: 1.0)),
-                background_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 0.0)),
-                text_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                border_size: 10,
-                border_radius: 40.0,
-                box_shadow: (
-                    spread_radius: 5.0,
-                    blur_radius: 5.0,
-                    offset_px_y: 10,
-                    offset_px_x: 10,
-                    color: Srgba((red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0))
-                ),
-            ),
-            press: (
-                background_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                border_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                text_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                border_radius: 40.0,
-                border_size: 10,
-                box_shadow: (
-                    spread_radius: 5.0,
-                    offset_px_y: 10,
-                    offset_px_x: 10,
-                    color: Srgba((red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0))
-                ),
-            ),
-            hover: (
-                background_color: Srgba((red: 0.0, green: 1.0, blue: 0.0, alpha: 1.0)),
-                border_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                border_radius: 40.0,
-                border_size: 10,
-                text_color: Srgba((red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0)),
-                box_shadow: (
-                    spread_radius: 5.0,
-                    offset_px_y: 10,
-                    offset_px_x: 10,
-                    color: Srgba((red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0))
-                ),
-            )
-        ),
-    }
-)

assets/game_settings.ron

@@ -1,36 +0,0 @@
-(   
-    input_common: (
-        stick_deadzone: "0.275",
-        trigger_deadzone: "0.3",
-        smash_input_reset_axis_threshold: "0.25",
-        smash_input_axis_threshold: "0.8",
-        run_stick_threshold: "0.625",
-        smash_input_frame_threshold: 3,
-        input_buffer_size: 3,
-        turn_into_dashback_window: 2,
-    ),
-    fighter_common: (
-        walk_speed_ease: "0.5",
-        ground_max_horizontal_velocity: "3.0",
-        ground_friction_over_walk_speed_multiplier: "2.0",
-        knockback_stacking_window: 2,
-        knockback_decay_per_frame: "0.051",
-        knockback_launch_velocity_multiplier: "0.03",
-        hitstun_frames_per_unit_knockback: "0.4",
-        tumble_bounce_hitstop_threshold: 32,
-        attack_ground_to_airborne_transition_vertical_angle_threshold: "90.0",
-        meteor_angle_threshold: "10.0",
-        visual_shake_frames_per_hitstop_frame: "1.2",
-        visual_shake_table: [
-            -3.0, -1.5, 1.5, 3.0
-        ],
-        attacker_visual_shake_multiplier: 0.4,
-        di_max_angle: "18.0"
-    ),
-    stage_manifest_paths: [
-        "stages/battlefield/test.stage.ron"
-    ],
-    fighter_manifest_paths: [
-        "fighters/test/test.fighter.ron"
-    ]
-)

assets/stages/battlefield/test.stage.ron

@@ -1,139 +0,0 @@
-(
-    id: TestStage,
-    model_path: "stages/battlefield/battlefield.glb#Scene0",
-    icon: (
-        path: "stages/battlefield/icon.png"
-    ),
-
-    // Battlefield
-    /*camera: (
-        left: -200.0,
-        right: 200.0,
-        bottom: -59.0,
-        top: 170.0,
-        origin: (0.0, 44.0),
-        vertical_fov_degrees: 30.0,
-        min_depth: 83.0,
-        max_depth: 1000.0,
-        subject_scale: 1.5,
-        fighter_forward_extent_scale: 1.5,
-        tracking_smoothness: 1.8,
-        vertical_pan_degrees: -10.0,
-        horizontal_pan_degrees_per_unit: 0.1,
-        vertical_pan_degrees_per_unit: 0.1,
-        max_horizontal_pan_degrees: 17.5,
-        max_upward_pan_degrees: 5.0,
-        max_downward_pan_degrees: 7.0,
-    ),*/
-    // Yoshi's story
-
-    /*camera: (
-        left: -180.0,
-        right: 179.0,
-        bottom: -71.0,
-        top: 169.0,
-        origin: (0.0, 44.0),
-        vertical_fov_degrees: 20.0,
-        min_depth: 100.0,
-        max_depth: 1000.0,
-        subject_scale: 1.0,
-        fighter_forward_extent_scale: 1.0,
-        tracking_smoothness: 1.0,
-        vertical_pan_degrees: -10.0,
-        horizontal_pan_degrees_per_unit: 0.05,
-        vertical_pan_degrees_per_unit: 0.15,
-        max_horizontal_pan_degrees: 17.5,
-        max_upward_pan_degrees: 5.0,
-        max_downward_pan_degrees: 7.0,
-    ),*/
-
-    camera: (
-        left: -180.0,
-        right: 179.0,
-        bottom: -71.0,
-        top: 169.0,
-        origin: (0.0, 44.0),
-        vertical_fov_degrees: 20.0,
-        min_depth: 100.0,
-        max_depth: 1000.0,
-        subject_scale: 1.5,
-        fighter_forward_extent_scale: 1.0,
-        tracking_smoothness: 1.0,
-        vertical_pan_degrees: -10.0,
-        horizontal_pan_degrees_per_unit: 0.05,
-        vertical_pan_degrees_per_unit: 0.15,
-        max_horizontal_pan_degrees: 17.5,
-        max_upward_pan_degrees: 5.0,
-        max_downward_pan_degrees: 7.0,
-    ),
-    polygons: [
-        (
-            poly_type: Platform,
-            lines: [
-                (
-                    (x: "-20.0", y: "47.0"),
-                    Floor
-                ),
-                (
-                    (x: "20.0", y: "47.0"),
-                    Floor
-                )
-            ]
-        ),
-        (
-            poly_type: Platform,
-            lines: [
-                (
-                    (x: "-65.0", y: "24.0"),
-                    Floor
-                ),
-                (
-                    (x: "-25.0", y: "24.0"),
-                    Floor
-                )
-            ]
-        ),
-        (
-            poly_type: Platform,
-            lines: [
-                (
-                    (x: "25.0", y: "24.0"),
-                    Floor
-                ),
-                (
-                    (x: "65.0", y: "24.0"),
-                    Floor
-                )
-            ]
-        ),
-        (
-            poly_type: Closed,
-            lines: [
-                (
-                    (x: "-68.0", y: "-3.0"),
-                    Wall
-                ),
-                (
-                    (x: "-68.0", y: "0.0"),
-                    Floor,
-                ),
-                (
-                    (x: "0.0", y: "0.0"),
-                    Floor
-                ),
-                (
-                    (x: "68", y: "0.0"),
-                    Wall
-                ),
-                (
-                    (x: "68.0", y: "-3.0"),
-                    Ceiling
-                ),
-                (
-                    (x: "0.0", y: "-15.0"),
-                    Ceiling
-                ),
-            ]
-        )
-    ]
-)

assets/ui/textures/fighter_select_token.svg

@@ -1,77 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<!-- Created with Inkscape (http://www.inkscape.org/) -->
-
-<svg
-   width="128"
-   height="128"
-   viewBox="0 0 33.866666 33.866666"
-   version="1.1"
-   id="svg1"
-   inkscape:version="1.4.4 (dcaf3e7d9e, 2026-05-05)"
-   sodipodi:docname="cursor.svg"
-   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
-   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
-   xmlns:xlink="http://www.w3.org/1999/xlink"
-   xmlns="http://www.w3.org/2000/svg"
-   xmlns:svg="http://www.w3.org/2000/svg">
-  <sodipodi:namedview
-     id="namedview1"
-     pagecolor="#000000"
-     bordercolor="#000000"
-     borderopacity="0.25"
-     inkscape:showpageshadow="2"
-     inkscape:pageopacity="0.0"
-     inkscape:pagecheckerboard="0"
-     inkscape:deskcolor="#d1d1d1"
-     inkscape:document-units="mm"
-     inkscape:zoom="5.6568542"
-     inkscape:cx="8.6620581"
-     inkscape:cy="67.086756"
-     inkscape:window-width="2560"
-     inkscape:window-height="1006"
-     inkscape:window-x="0"
-     inkscape:window-y="0"
-     inkscape:window-maximized="1"
-     inkscape:current-layer="layer1" />
-  <defs
-     id="defs1">
-    <linearGradient
-       id="linearGradient1"
-       inkscape:collect="always">
-      <stop
-         style="stop-color:#949494;stop-opacity:1;"
-         offset="0"
-         id="stop1" />
-      <stop
-         style="stop-color:#6c6c6c;stop-opacity:1;"
-         offset="0.77473962"
-         id="stop3" />
-      <stop
-         style="stop-color:#9f9f9f;stop-opacity:1;"
-         offset="1"
-         id="stop2" />
-    </linearGradient>
-    <radialGradient
-       inkscape:collect="always"
-       xlink:href="#linearGradient1"
-       id="radialGradient2"
-       cx="16.933332"
-       cy="16.933332"
-       fx="16.933332"
-       fy="16.933332"
-       r="12.733072"
-       gradientUnits="userSpaceOnUse"
-       gradientTransform="matrix(1.2093771,0,0,1.2093771,-3.5454518,-3.5454518)" />
-  </defs>
-  <g
-     inkscape:label="Capa 1"
-     inkscape:groupmode="layer"
-     id="layer1">
-    <circle
-       style="fill:url(#radialGradient2);stroke-width:0.319981"
-       id="path1"
-       cx="16.933332"
-       cy="16.933332"
-       r="15.399086" />
-  </g>
-</svg>

scripts/install-blender.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+version="5.2.2"
+sha256="84098912789dc450e95697c4184fb8a90acbe5111c2ba4aede3fecb57806a168"
+install_dir="${1:-${BLENDER_INSTALL_DIR:-${HOME}/.local/blender-${version}}}"
+
+if [[ "$(uname -s)" != Linux || "$(uname -m)" != x86_64 ]]; then
+    echo "error: this installer currently supports Linux x86_64 only" >&2
+    exit 1
+fi
+
+if [[ -x "$install_dir/blender" ]]; then
+    "$install_dir/blender" --version | head -n 1
+    exit 0
+fi
+
+mkdir -p "$(dirname "$install_dir")"
+tmp_dir="$(mktemp -d)"
+trap 'rm -rf "$tmp_dir"' EXIT
+
+archive="blender-${version}-linux-x64.tar.xz"
+url="https://download.blender.org/release/Blender5.2/${archive}"
+
+curl --fail --location --silent --show-error --output "$tmp_dir/$archive" "$url"
+printf '%s  %s\n' "$sha256" "$tmp_dir/$archive" | sha256sum --check --status
+tar --extract --xz --file "$tmp_dir/$archive" --directory "$tmp_dir"
+mv "$tmp_dir/blender-${version}-linux-x64" "$install_dir"
+
+"$install_dir/blender" --version | head -n 1

scripts/install-lore.sh

@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+version="v0.10.0"
+sha256="0d1633b71e44081c6a3ca57ad5be3df7a9563698827638838939c3c832e87351"
+install_dir="${1:-${LORE_INSTALL_DIR:-${HOME}/.local/bin}}"
+
+if [[ "$(uname -s)" != Linux || "$(uname -m)" != x86_64 ]]; then
+    echo "error: this installer currently supports Linux x86_64 only" >&2
+    exit 1
+fi
+
+mkdir -p "$install_dir"
+tmp_dir="$(mktemp -d)"
+trap 'rm -rf "$tmp_dir"' EXIT
+
+archive="lore-${version}-x86_64-unknown-linux-gnu.tar.gz"
+url="https://github.com/EpicGames/lore/releases/download/${version}/${archive}"
+
+curl --fail --location --silent --show-error --output "$tmp_dir/$archive" "$url"
+printf '%s  %s\n' "$sha256" "$tmp_dir/$archive" | sha256sum --check --status
+tar --extract --gzip --file "$tmp_dir/$archive" --directory "$tmp_dir"
+
+binary="$(find "$tmp_dir" -type f -name lore -print -quit)"
+if [[ -z "$binary" ]]; then
+    echo "error: Lore archive did not contain a lore binary" >&2
+    exit 1
+fi
+
+install -m 0755 "$binary" "$install_dir/lore"
+"$install_dir/lore" --version

scripts/update-assets.sh

@@ -0,0 +1,111 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+readonly lore_url="${LORE_REPOSITORY_URL:-lore://lore.eirexe.moe/shinespark}"
+readonly default_branch="${LORE_DEFAULT_BRANCH:-main}"
+readonly assets_dir="${LORE_ASSETS_DIR:-assets}"
+branch="${1:-${LORE_BRANCH:-$default_branch}}"
+
+case "$branch" in
+    ""|*[!A-Za-z0-9._/-]*)
+        echo "error: invalid Lore branch name: $branch" >&2
+        exit 2
+        ;;
+esac
+
+if [[ -n "${LORE_IDENTITY_TOKEN:-}" ]]; then
+    lore_args=(--identity-token "$LORE_IDENTITY_TOKEN")
+elif [[ -n "${LORE_CI_USERNAME:-}" || -n "${LORE_CI_PASSWORD:-}" ]]; then
+    if [[ -z "${LORE_CI_USERNAME:-}" || -z "${LORE_CI_PASSWORD:-}" ]]; then
+        echo "error: LORE_CI_USERNAME and LORE_CI_PASSWORD must be provided together" >&2
+        exit 2
+    fi
+    : "${LORE_AUTH_URL:=https://auth.eirexe.moe}"
+    export LORE_AUTH_URL
+    token="$(python3 - <<'PY'
+import json
+import os
+import sys
+import urllib.error
+import urllib.request
+
+request = urllib.request.Request(
+    os.environ["LORE_AUTH_URL"].rstrip("/") + "/auth/login",
+    data=json.dumps({
+        "username": os.environ["LORE_CI_USERNAME"],
+        "password": os.environ["LORE_CI_PASSWORD"],
+    }).encode(),
+    headers={"Content-Type": "application/json"},
+    method="POST",
+)
+try:
+    with urllib.request.urlopen(request) as response:
+        payload = json.load(response)
+except urllib.error.HTTPError as error:
+    print(f"Lore authentication failed with HTTP {error.code}", file=sys.stderr)
+    sys.exit(1)
+
+token = payload.get("token")
+if not isinstance(token, str) or not token:
+    print("Lore authentication response did not contain a token", file=sys.stderr)
+    sys.exit(1)
+print(token)
+PY
+    )"
+    if [[ -n "${GITHUB_ENV:-}" ]]; then
+        echo "::add-mask::$token"
+    fi
+    lore_args=(--identity-token "$token")
+else
+    lore_args=()
+fi
+
+if [[ -e "$assets_dir" && ! -d "$assets_dir" ]]; then
+    echo "error: $assets_dir exists but is not a directory" >&2
+    exit 1
+fi
+
+if [[ -d "$assets_dir/.lore" ]]; then
+    if ! lore "${lore_args[@]}" --repository "$assets_dir" repository info >/dev/null; then
+        echo "error: $assets_dir is not a usable Lore checkout" >&2
+        exit 1
+    fi
+    if ! lore "${lore_args[@]}" --repository "$assets_dir" branch list --no-pager \
+        | grep -Fqx "  $branch"; then
+        if [[ "$branch" != "$default_branch" ]]; then
+            echo "warning: Lore branch does not exist: $branch; using $default_branch" >&2
+            branch="$default_branch"
+        else
+            echo "error: Lore branch does not exist: $branch" >&2
+            exit 1
+        fi
+    fi
+    lore "${lore_args[@]}" --repository "$assets_dir" sync "$branch@LATEST"
+    exit 0
+fi
+
+if [[ -d "$assets_dir" && -n "$(find "$assets_dir" -mindepth 1 -maxdepth 1 -print -quit)" ]]; then
+    echo "error: refusing to overwrite non-Lore directory: $assets_dir" >&2
+    exit 1
+fi
+
+metadata_dir="$(mktemp -d)"
+trap 'rm -rf "$metadata_dir"' EXIT
+lore "${lore_args[@]}" --non-interactive clone --bare "$lore_url" "$metadata_dir"
+
+if ! lore "${lore_args[@]}" --repository "$metadata_dir" branch list --no-pager \
+    | grep -Fqx "  $branch"; then
+    if [[ "$branch" != "$default_branch" ]]; then
+        echo "warning: Lore branch does not exist: $branch; using $default_branch" >&2
+        branch="$default_branch"
+    else
+        echo "error: Lore branch does not exist: $branch" >&2
+        echo "available branches:" >&2
+        lore "${lore_args[@]}" --repository "$metadata_dir" branch list --no-pager >&2
+        exit 1
+    fi
+fi
+
+rm -rf "$assets_dir"
+lore "${lore_args[@]}" --non-interactive clone --branch "$branch" "$lore_url" "$assets_dir"
+lore "${lore_args[@]}" --repository "$assets_dir" status --revision-only --no-pager

src/blend_asset.rs

@@ -0,0 +1,394 @@
+//! Blender `.blend` source processing.
+//!
+//! Blender is used as an offline importer. The processed result is a normal
+//! GLB, so the runtime continues to use Bevy's built-in glTF loader.
+
+use bevy::{
+    asset::{
+        AssetLoader, AssetPath, AsyncWriteExt, LoadContext,
+        io::{Reader, Writer},
+        processor::LoadTransformAndSave,
+        saver::{AssetSaver, SavedAsset},
+        transformer::{AssetTransformer, TransformedAsset},
+    },
+    gltf::GltfLoader,
+    prelude::*,
+    reflect::TypePath,
+};
+use serde::Deserialize;
+use std::{
+    collections::HashMap,
+    fs, io,
+    path::{Path, PathBuf},
+    process::Command,
+    time::{SystemTime, UNIX_EPOCH},
+};
+
+use crate::fighter::animation::AnimKind;
+
+const EXPORT_SCRIPT: &str = include_str!("blend_asset/export.py");
+
+#[derive(Asset, TypePath)]
+struct BlendSource {
+    glb: Vec<u8>,
+}
+
+#[derive(Default, TypePath)]
+struct BlendSourceLoader;
+
+#[derive(Debug, Deserialize)]
+struct ExportManifest {
+    dependencies: Vec<String>,
+}
+
+#[derive(Debug, Deserialize)]
+struct AnimationManifest {
+    animations: HashMap<AnimKind, String>,
+}
+
+impl AssetLoader for BlendSourceLoader {
+    type Asset = BlendSource;
+    type Settings = ();
+    type Error = io::Error;
+
+    async fn load(
+        &self,
+        reader: &mut dyn Reader,
+        _: &Self::Settings,
+        load_context: &mut LoadContext<'_>,
+    ) -> Result<Self::Asset, Self::Error> {
+        let mut source_bytes = Vec::new();
+        reader.read_to_end(&mut source_bytes).await?;
+
+        let temp = TempDir::new()?;
+        let source_path = locate_source(load_context.path().path());
+        let blend_path = if let Some(path) = source_path.as_deref() {
+            path.to_path_buf()
+        } else {
+            let path = temp.path().join("source.blend");
+            fs::write(&path, source_bytes)?;
+            path
+        };
+        let output = temp.path().join("export.gltf");
+        let script = temp.path().join("export.py");
+        let actions = referenced_actions(load_context, &asset_root()).await?;
+        let actions_path = temp.path().join("actions.json");
+        fs::write(
+            &actions_path,
+            serde_json::to_vec(&actions).map_err(io::Error::other)?,
+        )?;
+        fs::write(&script, EXPORT_SCRIPT)?;
+
+        let result = Command::new(std::env::var_os("BLENDER").unwrap_or_else(|| "blender".into()))
+            .arg("--background")
+            .arg(&blend_path)
+            .arg("--python")
+            .arg(&script)
+            .arg("--")
+            .arg(&output)
+            .arg(&actions_path)
+            .arg(&blend_path)
+            .output()
+            .map_err(|error| io::Error::other(format!("failed to start Blender: {error}")))?;
+        if !result.status.success() {
+            return Err(io::Error::other(format!(
+                "Blender export failed with {}:\n{}\n{}",
+                result.status,
+                String::from_utf8_lossy(&result.stdout),
+                String::from_utf8_lossy(&result.stderr)
+            )));
+        }
+
+        let manifest: ExportManifest =
+            serde_json::from_slice(&fs::read(temp.path().join("export-manifest.json"))?)
+                .map_err(|error| io::Error::new(io::ErrorKind::InvalidData, error))?;
+
+        let asset_root = asset_root();
+        let mut dependencies = manifest.dependencies;
+        let document: serde_json::Value = serde_json::from_slice(&fs::read(&output)?)
+            .map_err(|error| io::Error::new(io::ErrorKind::InvalidData, error))?;
+        validate_export(&document, &output)?;
+        if let Some(images) = document.get("images").and_then(serde_json::Value::as_array) {
+            for image in images {
+                if let Some(uri) = image.get("uri").and_then(serde_json::Value::as_str) {
+                    let path = temp.path().join(uri);
+                    dependencies.push(path.to_string_lossy().into_owned());
+                }
+            }
+        }
+
+        let mut seen = std::collections::HashSet::new();
+        for dependency in dependencies {
+            let physical = PathBuf::from(&dependency);
+            let Some(asset_path) = physical_to_asset_path(&physical, &asset_root) else {
+                continue;
+            };
+            if seen.insert(asset_path.clone()) {
+                // This read is intentionally discarded: it registers the file and
+                // its processed hash as a processor dependency.
+                load_context
+                    .read_asset_bytes(asset_path)
+                    .await
+                    .map_err(|error| {
+                        io::Error::other(format!("failed to read blend dependency: {error}"))
+                    })?;
+            }
+        }
+
+        let glb = make_glb(&output, &temp, load_context.path().path(), &asset_root)?;
+        Ok(BlendSource { glb })
+    }
+
+    fn extensions(&self) -> &[&str] {
+        &["blend"]
+    }
+}
+
+fn validate_export(document: &serde_json::Value, output: &Path) -> io::Result<()> {
+    for key in ["scenes", "nodes", "meshes"] {
+        let count = document
+            .get(key)
+            .and_then(serde_json::Value::as_array)
+            .map_or(0, Vec::len);
+        if count == 0 {
+            return Err(io::Error::new(
+                io::ErrorKind::InvalidData,
+                format!("Blender export {} contains no {key}", output.display()),
+            ));
+        }
+    }
+    Ok(())
+}
+
+async fn referenced_actions(
+    load_context: &mut LoadContext<'_>,
+    root: &Path,
+) -> io::Result<Vec<String>> {
+    let model_path = load_context.path().path();
+    let Some(stem) = model_path.file_stem().and_then(|stem| stem.to_str()) else {
+        return Ok(Vec::new());
+    };
+    let manifest_path = model_path
+        .parent()
+        .unwrap_or_else(|| Path::new(""))
+        .join(format!("{stem}.fighter.ron"));
+    if !root.join(&manifest_path).is_file() {
+        return Ok(Vec::new());
+    }
+    let bytes = load_context
+        .read_asset_bytes(manifest_path)
+        .await
+        .map_err(|error| io::Error::other(error.to_string()))?;
+    let manifest: AnimationManifest = ron::de::from_bytes(&bytes)
+        .map_err(|error| io::Error::new(io::ErrorKind::InvalidData, error))?;
+    Ok(manifest.animations.into_values().collect())
+}
+
+#[derive(Asset, TypePath)]
+struct ProcessedBlend {
+    bytes: Vec<u8>,
+}
+
+#[derive(Default, TypePath)]
+struct BlendTransformer;
+
+impl AssetTransformer for BlendTransformer {
+    type AssetInput = BlendSource;
+    type AssetOutput = ProcessedBlend;
+    type Settings = ();
+    type Error = io::Error;
+
+    async fn transform<'a>(
+        &'a self,
+        source: TransformedAsset<Self::AssetInput>,
+        _: &'a Self::Settings,
+    ) -> Result<TransformedAsset<Self::AssetOutput>, Self::Error> {
+        let bytes = source.glb.clone();
+        Ok(source.replace_asset(ProcessedBlend { bytes }))
+    }
+}
+
+#[derive(Default, TypePath)]
+struct BlendSaver;
+
+impl AssetSaver for BlendSaver {
+    type Asset = ProcessedBlend;
+    type Settings = ();
+    type OutputLoader = GltfLoader;
+    type Error = io::Error;
+
+    async fn save(
+        &self,
+        writer: &mut Writer,
+        asset: SavedAsset<'_, '_, Self::Asset>,
+        _: &Self::Settings,
+        _: AssetPath<'_>,
+    ) -> Result<<Self::OutputLoader as AssetLoader>::Settings, Self::Error> {
+        writer.write_all(&asset.bytes).await?;
+        Ok(default())
+    }
+}
+
+type BlendProcessor = LoadTransformAndSave<BlendSourceLoader, BlendTransformer, BlendSaver>;
+
+pub struct BlendAssetProcessingPlugin;
+
+impl Plugin for BlendAssetProcessingPlugin {
+    fn build(&self, app: &mut App) {
+        app.init_asset::<BlendSource>()
+            .init_asset::<ProcessedBlend>()
+            .register_asset_loader(BlendSourceLoader)
+            .register_asset_processor(BlendProcessor::new(BlendTransformer, BlendSaver))
+            .set_default_asset_processor::<BlendProcessor>("blend");
+    }
+}
+
+struct TempDir(PathBuf);
+
+impl TempDir {
+    fn new() -> io::Result<Self> {
+        let stamp = SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .unwrap_or_default()
+            .as_nanos();
+        let path =
+            std::env::temp_dir().join(format!("shinespark-blend-{}-{stamp}", std::process::id()));
+        fs::create_dir_all(&path)?;
+        Ok(Self(path))
+    }
+    fn path(&self) -> &Path {
+        &self.0
+    }
+}
+
+impl Drop for TempDir {
+    fn drop(&mut self) {
+        let _ = fs::remove_dir_all(&self.0);
+    }
+}
+
+fn asset_root() -> PathBuf {
+    std::env::var_os("BEVY_ASSET_ROOT")
+        .map(PathBuf::from)
+        .unwrap_or_else(|| std::env::current_dir().unwrap_or_default().join("assets"))
+}
+
+fn locate_source(path: &Path) -> Option<PathBuf> {
+    let root = asset_root();
+    [root.join(path), PathBuf::from(path)]
+        .into_iter()
+        .find(|candidate| candidate.is_file())
+}
+
+fn physical_to_asset_path(path: &Path, root: &Path) -> Option<String> {
+    let canonical = fs::canonicalize(path).ok()?;
+    let root = fs::canonicalize(root).ok()?;
+    let relative = canonical.strip_prefix(root).ok()?;
+    Some(relative.to_string_lossy().replace('\\', "/"))
+}
+
+fn make_glb(
+    gltf_path: &Path,
+    temp: &TempDir,
+    model_asset_path: &Path,
+    asset_root: &Path,
+) -> io::Result<Vec<u8>> {
+    let mut json: serde_json::Value = serde_json::from_slice(&fs::read(gltf_path)?)
+        .map_err(|error| io::Error::new(io::ErrorKind::InvalidData, error))?;
+    let bin_name = json["buffers"][0]["uri"].as_str().ok_or_else(|| {
+        io::Error::new(io::ErrorKind::InvalidData, "glTF has no binary buffer URI")
+    })?;
+    let mut bin = fs::read(temp.path().join(bin_name))?;
+    let model_parent = model_asset_path.parent().unwrap_or_else(|| Path::new(""));
+    let image_count = json["images"].as_array().map_or(0, Vec::len);
+    if image_count > 0 && !json["bufferViews"].is_array() {
+        return Err(io::Error::new(
+            io::ErrorKind::InvalidData,
+            "glTF bufferViews are not an array",
+        ));
+    }
+    for index in 0..image_count {
+        let uri = json["images"][index]
+            .get("uri")
+            .and_then(serde_json::Value::as_str)
+            .map(str::to_owned);
+        let Some(uri) = uri else { continue };
+        if uri.starts_with("data:") {
+            continue;
+        }
+        let uri_path = temp.path().join(uri);
+        if let Some(asset_path) = physical_to_asset_path(&uri_path, asset_root) {
+            json["images"][index]["uri"] =
+                serde_json::Value::String(relative_uri(model_parent, Path::new(&asset_path)));
+        } else {
+            let bytes = fs::read(&uri_path)?;
+            while bin.len() % 4 != 0 {
+                bin.push(0);
+            }
+            let offset = bin.len();
+            bin.extend_from_slice(&bytes);
+            let mime = mime_type(&uri_path);
+            let view = json["bufferViews"].as_array().unwrap().len();
+            json["bufferViews"]
+                .as_array_mut()
+                .unwrap()
+                .push(serde_json::json!({
+                    "buffer": 0,
+                    "byteOffset": offset,
+                    "byteLength": bytes.len(),
+                }));
+            json["images"][index].as_object_mut().unwrap().remove("uri");
+            json["images"][index]["bufferView"] = serde_json::Value::from(view);
+            json["images"][index]["mimeType"] = serde_json::Value::String(mime.to_owned());
+        }
+    }
+    json["buffers"][0]["byteLength"] = serde_json::Value::from(bin.len());
+    json["buffers"][0].as_object_mut().unwrap().remove("uri");
+    let mut json_bytes = serde_json::to_vec(&json).map_err(io::Error::other)?;
+    while json_bytes.len() % 4 != 0 {
+        json_bytes.push(b' ');
+    }
+    while bin.len() % 4 != 0 {
+        bin.push(0);
+    }
+    let length = 12 + 8 + json_bytes.len() + 8 + bin.len();
+    let mut glb = Vec::with_capacity(length);
+    glb.extend_from_slice(b"glTF");
+    glb.extend_from_slice(&2u32.to_le_bytes());
+    glb.extend_from_slice(&(length as u32).to_le_bytes());
+    glb.extend_from_slice(&(json_bytes.len() as u32).to_le_bytes());
+    glb.extend_from_slice(b"JSON");
+    glb.extend_from_slice(&json_bytes);
+    glb.extend_from_slice(&(bin.len() as u32).to_le_bytes());
+    glb.extend_from_slice(b"BIN\0");
+    glb.extend_from_slice(&bin);
+    Ok(glb)
+}
+
+fn relative_uri(from: &Path, to: &Path) -> String {
+    let from: Vec<_> = from.components().collect();
+    let to: Vec<_> = to.components().collect();
+    let common = from.iter().zip(&to).take_while(|(a, b)| a == b).count();
+    let mut result = PathBuf::new();
+    for _ in common..from.len() {
+        result.push("..");
+    }
+    for component in &to[common..] {
+        result.push(component.as_os_str());
+    }
+    result.to_string_lossy().replace('\\', "/")
+}
+
+fn mime_type(path: &Path) -> &'static str {
+    match path
+        .extension()
+        .and_then(|e| e.to_str())
+        .unwrap_or_default()
+        .to_ascii_lowercase()
+        .as_str()
+    {
+        "jpg" | "jpeg" => "image/jpeg",
+        "webp" => "image/webp",
+        _ => "image/png",
+    }
+}

src/blend_asset/export.py

@@ -0,0 +1,80 @@
+import bpy
+import json
+import os
+import sys
+
+
+def main():
+    output = sys.argv[sys.argv.index("--") + 1]
+    actions_path = sys.argv[sys.argv.index("--") + 2]
+    source_path = sys.argv[sys.argv.index("--") + 3]
+    loaded_path = os.path.realpath(bpy.data.filepath)
+    expected_path = os.path.realpath(source_path)
+    if loaded_path != expected_path:
+        raise RuntimeError(
+            f"Blender loaded {loaded_path!r} instead of {expected_path!r}"
+        )
+    if not bpy.data.objects or not bpy.data.meshes:
+        raise RuntimeError("Blender loaded an empty scene")
+    with open(actions_path) as file:
+        actions_to_keep = set(json.load(file))
+
+    for obj in bpy.data.objects:
+        if not obj.animation_data:
+            continue
+        for track in list(obj.animation_data.nla_tracks):
+            if track.name.startswith("[Action Stash]"):
+                obj.animation_data.nla_tracks.remove(track)
+
+    nla_tracks = [
+        track
+        for obj in bpy.data.objects
+        if obj.animation_data
+        for track in obj.animation_data.nla_tracks
+    ]
+    use_nla_tracks = bool(nla_tracks)
+
+    # For blends without NLA tracks, use the actions referenced by the fighter
+    # manifest instead of sampling every source action.
+    if not use_nla_tracks and actions_to_keep:
+        from io_scene_gltf2 import GLTF2_filter_action
+
+        if not hasattr(bpy.types.Scene, "gltf_action_filter"):
+            bpy.types.Scene.gltf_action_filter = bpy.props.CollectionProperty(
+                type=GLTF2_filter_action
+            )
+        scene = bpy.context.scene
+        scene.gltf_action_filter.clear()
+        for action in bpy.data.actions:
+            item = scene.gltf_action_filter.add()
+            item.action = action
+            item.keep = action.name in actions_to_keep
+
+    bpy.ops.export_scene.gltf(
+        filepath=output,
+        export_format="GLTF_SEPARATE",
+        export_keep_originals=True,
+        export_extras=True,
+        export_animations=True,
+        export_skins=True,
+        export_morph=True,
+        export_yup=True,
+        export_def_bones=True,
+        export_action_filter=False,
+        export_animation_mode="NLA_TRACKS" if use_nla_tracks else "ACTIONS",
+    )
+
+    dependencies = []
+    for image in bpy.data.images:
+        if image.source not in {"FILE", "TILED"}:
+            continue
+        path = image.filepath_raw or image.filepath
+        if path and not image.packed_file:
+            dependencies.append(bpy.path.abspath(path))
+
+    with open(os.path.join(os.path.dirname(output), "export-manifest.json"), "w") as file:
+        json.dump({"dependencies": sorted(set(dependencies))}, file)
+
+
+if __name__ == "__main__":
+    main()

src/debug_tools.rs

@@ -3,11 +3,9 @@
 use std::{collections::HashMap, time::Duration};
 
 use bevy::{
-    input::InputSystems,
+    camera::{CameraOutputMode, visibility::RenderLayers}, input::InputSystems, prelude::*, render::render_resource::BlendState, settings::{ReflectSettingsGroup, SaveSettingsDeferred, SettingsGroup},
-    prelude::*,
-    settings::{ReflectSettingsGroup, SaveSettingsDeferred, SettingsGroup},
 };
-use bevy_egui::{EguiContexts, EguiPrimaryContextPass, egui};
+use bevy_egui::{EguiContexts, EguiGlobalSettings, EguiPrimaryContextPass, PrimaryEguiContext, egui};
 use bevy_ggrs::{RollbackFrameRate, RunGgrsSystems};
 use enum_cycling::EnumCycle;
 use enum_cycling_derive::EnumCycle;
@@ -397,6 +395,7 @@ impl Plugin for DebugToolsPlugin {
                     .before(RunGgrsSystems)
                     .run_if(in_state(AppState::InMatch)),
             )
+            .add_systems(Startup, spawn_egui_camera)
             .add_systems(PreUpdate, restore_frame_step_time.after(RunGgrsSystems))
             .add_systems(
                 Update,
@@ -408,6 +407,26 @@ impl Plugin for DebugToolsPlugin {
     }
 }
 
+pub fn spawn_egui_camera(mut commands: Commands, mut egui_global_settings: ResMut<EguiGlobalSettings>,) {
+    egui_global_settings.auto_create_primary_context = false;
+    commands.spawn((
+        // The `PrimaryEguiContext` component requires everything needed to render a primary context.
+        PrimaryEguiContext,
+        Camera2d,
+        // Setting RenderLayers to none makes sure we won't render anything apart from the UI.
+        RenderLayers::none(),
+        Camera {
+            order: 2,
+            output_mode: CameraOutputMode::Write {
+                blend_state: Some(BlendState::ALPHA_BLENDING),
+                clear_color: ClearColorConfig::None,
+            },
+            clear_color: ClearColorConfig::Custom(Color::NONE),
+            ..default()
+        },
+    ));
+}
+
 fn player_handles(players: &Query<&Player>) -> Vec<usize> {
     let mut handles = players
         .iter()

src/debug_tools/save_state.rs

@@ -1,12 +1,22 @@
 use bevy::prelude::*;
 
 use crate::{
-    camera::MatchCamera, fighter::{
+    camera::MatchCamera,
-        FighterECB, FighterFacingDirection, FighterHitboxes, FighterHitstop, FighterHitstopShake, FighterPreviousFacingDirection, FighterPreviousTranslation, FighterTranslation, FighterVelocity, Grounded, animation::FighterAnimationFrame, attack::{
+    fighter::{
+        FighterECB, FighterFacingDirection, FighterHitboxes, FighterHitstop, FighterHitstopShake,
+        FighterPreviousFacingDirection, FighterPreviousTranslation, FighterSurfaceState,
+        FighterTranslation, FighterVelocity,
+        animation::FighterAnimationFrame,
+        attack::{
             FighterDamage, FighterKnockbackVelocity, FighterPendingHitReaction, FighterPendingHits,
             FighterSolvedHurtboxes, FighterStaleMoveQueue,
-        }, baked_animation::FighterBoneMatrices, state::FighterState,
+        },
-    }, input::FighterInput, player::Player, stage::line::StageCollision,
+        baked_animation::FighterBoneMatrices,
+        state::FighterState,
+    },
+    input::FighterInput,
+    player::Player,
+    stage::line::StageCollision,
 };
 
 #[derive(Resource, Default)]
@@ -44,7 +54,7 @@ struct FighterCheckpoint {
     hitboxes: FighterHitboxes,
     solved_hurtboxes: FighterSolvedHurtboxes,
     bone_matrices: FighterBoneMatrices,
-    grounded: bool,
+    surface: FighterSurfaceState,
 }
 
 pub(super) fn save_or_restore(world: &mut World) {
@@ -143,11 +153,7 @@ pub(super) fn save_or_restore(world: &mut World) {
         entity.insert(saved.hitboxes.clone());
         entity.insert(saved.solved_hurtboxes.clone());
         entity.insert(saved.bone_matrices.clone());
-        if saved.grounded {
+        entity.insert(saved.surface);
-            entity.insert(Grounded);
-        } else {
-            entity.remove::<Grounded>();
-        }
     }
     world.insert_resource(checkpoint.pending_hits.clone());
     world.insert_resource(checkpoint.stage_collision);
@@ -181,7 +187,7 @@ fn capture_fighter(world: &World, entity: Entity) -> Option<FighterCheckpoint> {
         hitboxes: fighter.get::<FighterHitboxes>()?.clone(),
         solved_hurtboxes: fighter.get::<FighterSolvedHurtboxes>()?.clone(),
         bone_matrices: fighter.get::<FighterBoneMatrices>()?.clone(),
-        grounded: fighter.contains::<Grounded>(),
+        surface: *fighter.get::<FighterSurfaceState>()?,
     })
 }
 

src/fighter/attack/mod.rs

@@ -605,7 +605,6 @@ impl Plugin for FighterAttackPlugin {
                 intersect_attacks_with_hurtboxes,
             )
                 .chain()
-                .after(crate::fighter::baked_animation::update_fighter_bone_matrices)
                 .in_set(GameplaySet::Attacks),
         );
     }

src/fighter/baked_animation/asset_baking.rs

@@ -2,8 +2,8 @@ use super::{
     BAKED_ANIMATION_FPS,
     runtime::{BakedAnimationClip, BakedFighterAnimations},
 };
-use crate::math::fixed_transform::FixedMat4;
 use crate::fighter::{animation::AnimKind, manifest::FighterManifest};
+use crate::math::fixed_transform::FixedMat4;
 use bevy::{
     asset::{
         AssetLoader, AssetPath, AsyncWriteExt, LoadContext,
@@ -51,6 +51,9 @@ impl AssetLoader for FighterBakeSourceLoader {
             .map_err(|error| io::Error::other(error.to_string()))?;
         let manifest: FighterManifest = ron::de::from_bytes(&manifest_bytes)
             .map_err(|error| io::Error::new(io::ErrorKind::InvalidData, error))?;
+        // `read_asset_bytes` uses the processor's processed asset source. This
+        // deliberately allows `model_path` to point at a `.blend`: the blend
+        // processor has already converted it to a hybrid GLB by this point.
         let model_bytes = load_context
             .read_asset_bytes(&manifest.model_path)
             .await

src/fighter/baked_animation/mod.rs

@@ -4,8 +4,8 @@ mod asset_baking;
 mod runtime;
 mod visual_binding;
 
-pub use asset_baking::{BakedAnimationAssetProcessingPlugin, BakedAnimationPlugin};
 pub use crate::math::fixed_transform::FixedMat4;
+pub use asset_baking::{BakedAnimationAssetProcessingPlugin, BakedAnimationPlugin};
 pub use runtime::{
     BakedAnimationClip, BakedFighterAnimations, FighterBoneIndexMap, FighterBoneMatrices,
     update_fighter_bone_matrices,
@@ -21,6 +21,7 @@ mod tests {
     use asset_baking::{
         Channel, ChannelValues, bake_gltf_document, baked_frame_count, sample_vec3,
     };
+    use serde_json::json;
     use std::collections::HashMap;
 
     #[test]
@@ -29,11 +30,7 @@ mod tests {
             "../../../assets/fighters/test/test.fighter.ron"
         ))
         .unwrap();
-        let (document, buffers, _) = gltf::import(concat!(
+        let (document, buffers) = test_gltf(&manifest.animations);
-            env!("CARGO_MANIFEST_DIR"),
-            "/assets/fighters/test/test_fighter.gltf"
-        ))
-        .unwrap();
         let baked = bake_gltf_document(document, buffers, &manifest.animations).unwrap();
 
         assert_eq!(baked.frame_rate, BAKED_ANIMATION_FPS);
@@ -51,6 +48,104 @@ mod tests {
         assert_eq!(baked.parents.len(), baked.bone_names.len());
     }
 
+    /// Builds the smallest glTF document that still exercises the complete
+    /// animation-baking path. Keeping this fixture in memory avoids making
+    /// unit tests depend on the production Blender asset or Blender itself.
+    fn test_gltf(
+        animations: &HashMap<AnimKind, String>,
+    ) -> (gltf::Document, Vec<gltf::buffer::Data>) {
+        let mut names: Vec<_> = animations.values().cloned().collect();
+        names.sort();
+        names.dedup();
+
+        let mut data = Vec::new();
+        let mut buffer_views = Vec::new();
+        let mut accessors = Vec::new();
+        let mut gltf_animations = Vec::new();
+
+        for name in names {
+            let duration: f32 = match name.as_str() {
+                "Idle_Loop_Game" => 2.0,
+                "Walk_Loop_IK_Game" | "Run_Game" => 0.533333361,
+                "Dash_Game" => 0.333333343,
+                "Jump_Land_Game" => 0.133333340,
+                "JumpB_Game" => 56.0 / 60.0,
+                _ => 0.0,
+            };
+            let input_offset = data.len();
+            data.extend_from_slice(&0.0_f32.to_le_bytes());
+            data.extend_from_slice(&duration.to_le_bytes());
+            let output_offset = data.len();
+            data.extend_from_slice(
+                &[0.0_f32, 0.0, 0.0]
+                    .into_iter()
+                    .flat_map(f32::to_le_bytes)
+                    .collect::<Vec<_>>(),
+            );
+            data.extend_from_slice(
+                &[1.0_f32, 0.0, 0.0]
+                    .into_iter()
+                    .flat_map(f32::to_le_bytes)
+                    .collect::<Vec<_>>(),
+            );
+
+            let input_view = buffer_views.len();
+            buffer_views.push(json!({
+                "buffer": 0,
+                "byteOffset": input_offset,
+                "byteLength": 8
+            }));
+            let output_view = buffer_views.len();
+            buffer_views.push(json!({
+                "buffer": 0,
+                "byteOffset": output_offset,
+                "byteLength": 24
+            }));
+            let input_accessor = accessors.len();
+            accessors.push(json!({
+                "bufferView": input_view,
+                "componentType": 5126,
+                "count": 2,
+                "type": "SCALAR",
+                "min": [0.0],
+                "max": [duration]
+            }));
+            let output_accessor = accessors.len();
+            accessors.push(json!({
+                "bufferView": output_view,
+                "componentType": 5126,
+                "count": 2,
+                "type": "VEC3"
+            }));
+            gltf_animations.push(json!({
+                "name": name,
+                "samplers": [{
+                    "input": input_accessor,
+                    "output": output_accessor,
+                    "interpolation": "LINEAR"
+                }],
+                "channels": [{
+                    "sampler": 0,
+                    "target": { "node": 0, "path": "translation" }
+                }]
+            }));
+        }
+
+        let document = json!({
+            "asset": { "version": "2.0" },
+            "scene": 0,
+            "scenes": [{ "nodes": [0] }],
+            "nodes": [{ "name": "root", "children": [1] }, { "name": "hand" }],
+            "buffers": [{ "byteLength": data.len() }],
+            "bufferViews": buffer_views,
+            "accessors": accessors,
+            "animations": gltf_animations
+        });
+        let bytes = serde_json::to_vec(&document).unwrap();
+        let gltf = gltf::Gltf::from_slice(&bytes).unwrap();
+        (gltf.document, vec![gltf::buffer::Data(data)])
+    }
+
     #[test]
     fn pose_sampling_wraps_repeating_frames_and_clamps_finished_frames() {
         let first = FixedMat4::IDENTITY;
@@ -124,6 +219,7 @@ mod tests {
         second.translate(FGVec3::lit("0", "3", "0"));
         let mut matrices = FighterBoneMatrices::default();
         matrices.set_pose(
+            AnimKind::Wait,
             &["root".into(), "hand".into()],
             &[None, Some(0)],
             &[first, second],
@@ -144,6 +240,7 @@ mod tests {
         hand.translate(FGVec3::lit("0", "3", "0"));
         let mut matrices = FighterBoneMatrices::default();
         matrices.set_pose(
+            AnimKind::Wait,
             &["root".into(), "hand".into()],
             &[None, Some(0)],
             &[root, hand],
@@ -164,6 +261,20 @@ mod tests {
         );
     }
 
+    #[test]
+    fn repeated_pose_updates_reuse_scratch_and_output_buffers() {
+        let mut matrices = FighterBoneMatrices::default();
+        let names = ["root".into(), "hand".into()];
+        let parents = [None, Some(0)];
+        let pose = [FixedMat4::IDENTITY, FixedMat4::IDENTITY];
+
+        matrices.set_pose(AnimKind::Wait, &names, &parents, &pose, FGi32::ONE);
+        let capacities = matrices.buffer_capacities();
+        matrices.set_pose(AnimKind::Wait, &names, &parents, &pose, FGi32::ONE);
+
+        assert_eq!(capacities, matrices.buffer_capacities());
+    }
+
     #[test]
     fn model_scale_affects_gameplay_bones_without_changing_visual_locals() {
         let mut root = FixedMat4::IDENTITY;
@@ -172,6 +283,7 @@ mod tests {
         hand.translate(FGVec3::lit("0", "2", "0"));
         let mut matrices = FighterBoneMatrices::default();
         matrices.set_pose(
+            AnimKind::Wait,
             &["root".into(), "hand".into()],
             &[None, Some(0)],
             &[root, hand],

src/fighter/baked_animation/runtime.rs

@@ -3,7 +3,7 @@ use std::collections::HashMap;
 use bevy::prelude::*;
 use serde::{Deserialize, Serialize};
 
-use super::{BAKED_ANIMATION_FPS};
+use super::BAKED_ANIMATION_FPS;
 
 use crate::{
     fighter::{
@@ -12,8 +12,8 @@ use crate::{
         manifest::FighterManifest,
         visual::FighterAnimations,
     },
+    math::fixed_transform::FixedMat4,
     math::int::FGi32,
-    math::fixed_transform::FixedMat4
 };
 
 #[derive(Clone, Debug, Serialize, Deserialize)]
@@ -70,12 +70,31 @@ pub struct FighterBoneMatrices {
     previous_frame_matrices: Vec<FixedMat4>,
     local_matrices: Vec<FixedMat4>,
     previous_local_matrices: Vec<FixedMat4>,
+    model_matrices: Vec<Option<FixedMat4>>,
+    presentation_kind: Option<AnimKind>,
 }
 
 #[derive(Component, Clone, Debug, Default)]
 pub struct FighterBoneIndexMap(pub HashMap<String, usize>);
 
 impl FighterBoneMatrices {
+    #[cfg(test)]
+    pub(super) fn buffer_capacities(&self) -> [usize; 5] {
+        [
+            self.matrices.capacity(),
+            self.local_matrices.capacity(),
+            self.previous_frame_matrices.capacity(),
+            self.previous_local_matrices.capacity(),
+            self.model_matrices.capacity(),
+        ]
+    }
+
+    pub fn get_by_idx(&self, index: usize) -> Option<(FixedMat4, FixedMat4)> {
+        Some((
+            *self.previous_frame_matrices.get(index)?,
+            *self.matrices.get(index)?,
+        ))
+    }
     pub fn get(&self, bone: &str) -> Option<(FixedMat4, FixedMat4)> {
         let index = self.bone_names.iter().position(|name| name == bone)?;
         Some((
@@ -120,6 +139,7 @@ impl FighterBoneMatrices {
     }
     pub(super) fn set_pose(
         &mut self,
+        kind: AnimKind,
         bone_names: &[String],
         parents: &[Option<usize>],
         local: &[FixedMat4],
@@ -142,13 +162,20 @@ impl FighterBoneMatrices {
             assert_eq!(self.bone_names, bone_names, "baked bone names changed");
             assert_eq!(self.parents, parents, "baked bone parents changed");
         }
+        self.matrices.reserve(local.len());
+        self.previous_frame_matrices.reserve(local.len());
+        self.local_matrices.reserve(local.len());
+        self.previous_local_matrices.reserve(local.len());
+        self.model_matrices.reserve(local.len());
         std::mem::swap(&mut self.matrices, &mut self.previous_frame_matrices);
+        let animation_changed = self.presentation_kind != Some(kind);
         std::mem::swap(&mut self.local_matrices, &mut self.previous_local_matrices);
         self.local_matrices.clear();
         self.local_matrices.extend_from_slice(local);
-        let mut model = vec![None; local.len()];
+        self.model_matrices.resize(local.len(), None);
+        self.model_matrices.fill(None);
         for index in 0..local.len() {
-            resolve_model_transform(index, parents, local, &mut model)
+            resolve_model_transform(index, parents, local, &mut self.model_matrices)
                 .expect("baked bone hierarchy should be valid");
         }
         let model_scale = FixedMat4 {
@@ -159,10 +186,20 @@ impl FighterBoneMatrices {
                 [FGi32::ZERO, FGi32::ZERO, FGi32::ZERO, FGi32::ONE],
             ],
         };
-        self.matrices = model
+        self.matrices.clear();
-            .into_iter()
+        self.matrices.extend(
-            .map(|matrix| model_scale.mul(matrix.expect("baked bone hierarchy should be valid")))
+            self.model_matrices.iter().map(|matrix| {
-            .collect();
+                model_scale.mul(matrix.expect("baked bone hierarchy should be valid"))
+            }),
+        );
+        // A state transition is a discontinuity, not an animation frame to
+        // interpolate from the previous clip.  Keep the presentation pose at
+        // the new clip's first/current frame immediately.
+        if animation_changed {
+            self.previous_local_matrices
+                .clone_from(&self.local_matrices);
+        }
+        self.presentation_kind = Some(kind);
     }
 }
 
@@ -192,6 +229,7 @@ pub fn update_fighter_bone_matrices(
             .get(&fighter.manifest)
             .expect("fighter manifest should be loaded before the match starts");
         matrices.set_pose(
+            frame.kind,
             &baked.bone_names,
             &baked.parents,
             pose,

src/fighter/collision.rs

@@ -50,11 +50,13 @@ pub fn air_collide_with_stage(
         translation.0 + ecb.get_bottom_point(),
     );
 
-    let mut intersect_results = vec![];
+    stage_collision
-
+        .stage_polys
-    for (poly_idx, poly) in stage_collision.stage_polys.iter().enumerate() {
+        .iter()
-        if let Some(intersect_result) = poly.intersect_ray(ray_segment) {
+        .enumerate()
-            intersect_results.push((
+        .filter_map(|(poly_idx, poly)| {
+            poly.intersect_ray(ray_segment).map(|intersect_result| {
+                (
                     AirCollisionWithStageResult {
                         line_id: {
                             StageLineID {
@@ -68,13 +70,9 @@ pub fn air_collide_with_stage(
                     intersect_result
                         .position
                         .distance_squared(ray_segment.point2()),
-            ));
+                )
-        }
+            })
-    }
+        })
-    intersect_results.sort_by(|(_, a), (_, b)| a.cmp(b));
+        .max_by(|(_, a), (_, b)| a.cmp(b))
-
+        .map(|(result, _)| result)
-    intersect_results
-        .iter()
-        .last()
-        .map(|(val, _)| val.to_owned().clone())
 }

src/fighter/debug.rs

@@ -27,6 +27,7 @@ use crate::game_settings::GameSettings;
 use crate::input::FighterInput;
 use crate::math::int::FGi32;
 use crate::math::vec::FGVec2;
+use crate::math::vec3::FGVec3;
 use crate::player::Player;
 
 pub fn debug_draw_ecb(
@@ -39,6 +40,12 @@ pub fn debug_draw_ecb(
     mut gizmos: Gizmos,
 ) {
     for (ecb, trf, ecb_prev, trf_prev) in ecbs {
+        gizmos.cross(
+            FGVec3::new(trf.0.x, trf.0.y, FGi32::ZERO).to_vec3(),
+            2.0,
+            bevy::color::palettes::css::BLUE,
+        );
+
         let transformed =
             ecb.to_3d_lineloop(Transform::from_xyz(trf.x.to_num(), trf.y.to_num(), 0.0));
         gizmos.lineloop(transformed, YELLOW);
@@ -153,10 +160,17 @@ pub fn fighter_debug(
     Ok(())
 }
 
-pub fn animation_debug(query: Query<(&GlobalTransform, &FighterBoneMatrices)>, mut gizmos: Gizmos) {
+pub fn animation_debug(
-    for (global_transform, matrices) in query {
+    query: Query<(
-        let (_, rotation, translation) = global_transform.to_scale_rotation_translation();
+        &FighterTranslation,
-        let marker_transform = Transform::from_translation(translation).with_rotation(rotation);
+        &FighterFacingDirection,
+        &FighterBoneMatrices,
+    )>,
+    mut gizmos: Gizmos,
+) {
+    for (global_transform, facing_dir, matrices) in query {
+        let global_transform = global_transform.get_3d_transform(facing_dir);
+        let marker_transform = global_transform.to_mat4();
         for (_, matrix) in matrices.iter() {
             let pos = marker_transform.transform_point(Vec3::new(
                 matrix.cols[3][0].to_num(),

src/fighter/ecb.rs

@@ -1,28 +1,44 @@
 use bevy::prelude::*;
 
-use crate::math::{int::FGi32, vec::FGVec2};
+use crate::{
+    fighter::{
+        FighterFacingDirection, FighterSurfaceState, FighterTranslation,
+        baked_animation::FighterBoneMatrices,
+    }, math::{int::FGi32, vec::FGVec2},
+};
 
 /// Environment collision box: the diamond used to resolve a fighter against
 /// the stage. Purely geometry — the collision response lives in
 /// [`super::collision`].
-#[derive(Component, Debug, Clone, Copy, Hash)]
+#[derive(Component, Debug, Clone, Copy, Hash, Default)]
 #[require(FighterPreviousECB)]
 pub struct FighterECB {
-    pub vertical_half: FGi32,
+    pub top: FGVec2,
-    pub horizontal_half: FGi32,
+    pub bottom: FGVec2,
+    pub left: FGVec2,
+    pub right: FGVec2,
+}
+
+#[derive(Component, Debug, Clone)]
+pub struct FighterECBBoneIndices {
+    pub indices: Vec<usize>,
 }
 
 #[derive(Component, Debug, Clone, Copy, Default, Hash)]
 pub struct FighterPreviousECB {
-    pub vertical_half: FGi32,
+    pub top: FGVec2,
-    pub horizontal_half: FGi32,
+    pub bottom: FGVec2,
+    pub left: FGVec2,
+    pub right: FGVec2,
 }
 
 impl From<FighterECB> for FighterPreviousECB {
     fn from(ecb: FighterECB) -> Self {
         Self {
-            vertical_half: ecb.vertical_half,
+            top: ecb.top,
-            horizontal_half: ecb.horizontal_half,
+            bottom: ecb.bottom,
+            left: ecb.left,
+            right: ecb.right,
         }
     }
 }
@@ -35,53 +51,84 @@ pub fn snapshot_fighter_ecb(fighters: Query<(&FighterECB, &mut FighterPreviousEC
 
 impl FighterECB {
     pub fn to_3d_lineloop(&self, trf: Transform) -> [Vec3; 4] {
-        let rel_up = trf.transform_point(Vec3::new(
+        [self.top, self.right, self.bottom, self.left]
-            0.0,
+            .map(|point| trf.transform_point(Vec3::new(point.x.to_num(), point.y.to_num(), 0.0)))
-            (self.vertical_half + self.vertical_half).to_num(),
-            0.0,
-        ));
-        let rel_down = trf.transform_point(Vec3::new(0.0, 0.0, 0.0));
-        let rel_left = trf.transform_point(Vec3::new(
-            (-self.horizontal_half).to_num(),
-            self.vertical_half.to_num(),
-            0.0,
-        ));
-        let rel_right = trf.transform_point(Vec3::new(
-            self.horizontal_half.to_num(),
-            self.vertical_half.to_num(),
-            0.0,
-        ));
-        [rel_up, rel_right, rel_down, rel_left]
     }
 
     pub fn get_bottom_point(&self) -> FGVec2 {
-        FGVec2::new(FGi32::ZERO, FGi32::ZERO)
+        self.bottom
     }
 }
 
 impl FighterPreviousECB {
     pub fn to_3d_lineloop(&self, trf: Transform) -> [Vec3; 4] {
-        let rel_up = trf.transform_point(Vec3::new(
+        [self.top, self.right, self.bottom, self.left]
-            0.0,
+            .map(|point| trf.transform_point(Vec3::new(point.x.to_num(), point.y.to_num(), 0.0)))
-            (self.vertical_half + self.vertical_half).to_num(),
-            0.0,
-        ));
-        let rel_down = trf.transform_point(Vec3::new(0.0, 0.0, 0.0));
-        let rel_left = trf.transform_point(Vec3::new(
-            (-self.horizontal_half).to_num(),
-            self.vertical_half.to_num(),
-            0.0,
-        ));
-        let rel_right = trf.transform_point(Vec3::new(
-            self.horizontal_half.to_num(),
-            self.vertical_half.to_num(),
-            0.0,
-        ));
-        [rel_up, rel_right, rel_down, rel_left]
     }
 
     pub fn get_bottom_point(&self) -> FGVec2 {
-        FGVec2::new(FGi32::ZERO, FGi32::ZERO)
+        self.bottom
+    }
+}
+
+pub fn update_ecb(
+    query: Query<(
+        &mut FighterECB,
+        &FighterSurfaceState,
+        &FighterECBBoneIndices,
+        &FighterBoneMatrices,
+        &FighterTranslation,
+        &FighterFacingDirection,
+    )>,
+) {
+    for (mut ecb, surface_state, bone_indices, bone_matrices, translation, facing_dir) in query {
+        let trf = translation.get_3d_transform(facing_dir);
+
+        let transformed_ecb_bones = bone_indices.indices.iter().filter_map(|idx| {
+            let Some((_, bone_matrix)) = bone_matrices.get_by_idx(*idx) else {
+                return None;
+            };
+
+            let pt = trf.transform_point(bone_matrix.get_translation());
+
+            Some(FGVec2::new(pt.x, pt.y) - translation.0)
+        }).collect::<Vec<_>>();
+
+        let max_x = transformed_ecb_bones.iter().max_by(|a, b| a.x.cmp(&b.x)).map(|final_val| final_val.x).unwrap_or(FGi32::lit("0.5"));
+        let min_x = transformed_ecb_bones.iter().min_by(|a, b| a.x.cmp(&b.x)).map(|final_val| final_val.x).unwrap_or(FGi32::lit("-0.5"));
+        let max_y = transformed_ecb_bones.iter().max_by(|a, b| a.y.cmp(&b.y)).map(|final_val| final_val.y).unwrap_or(FGi32::lit("0.5"));
+        let min_y = transformed_ecb_bones.iter().min_by(|a, b| a.y.cmp(&b.y)).map(|final_val| final_val.y).unwrap_or(FGi32::lit("-0.5"));
+
+        let midpoint_height = (max_y + min_y) / FGi32::lit("2.0");
+        let top = FGVec2::new(FGi32::ZERO, max_y);
+        let bottom = FGVec2::new(FGi32::ZERO, min_y);
+        let left = FGVec2::new(min_x, midpoint_height);
+        let right = FGVec2::new(max_x, midpoint_height);
+
+        let ecb_lock_frames_remaining = if let FighterSurfaceState::Airborne { ecb_lock_frames_remaining } = *surface_state {
+            ecb_lock_frames_remaining
+        } else {
+            0
+        };
+
+        ecb.top = top;
+
+        if ecb_lock_frames_remaining == 0 {
+            ecb.bottom = bottom;
+        }
+
+        ecb.left = left;
+        ecb.right = right;
+
+        if surface_state.is_grounded() {
+            ecb.bottom = FGVec2::ZERO;
+        }
+    }
+}
+
+pub fn decrement_ecb_lockout(surface_states: Query<&mut FighterSurfaceState>) {
+    for mut state in surface_states {
+        state.tick_ecb_lock();
     }
 }
 
@@ -92,12 +139,16 @@ mod tests {
     #[test]
     fn previous_ecb_copies_current_dimensions() {
         let current = FighterECB {
-            vertical_half: FGi32::lit("0.5"),
+            bottom: FGVec2::lit("0.0", "-0.5"),
-            horizontal_half: FGi32::lit("0.25"),
+            top: FGVec2::lit("0.0", "0.5"),
+            left: FGVec2::lit("-0.5", "0.0"),
+            right: FGVec2::lit("0.5", "0.0"),
         };
         let previous = FighterPreviousECB::from(current);
 
-        assert_eq!(previous.vertical_half, current.vertical_half);
+        assert_eq!(previous.top, current.top);
-        assert_eq!(previous.horizontal_half, current.horizontal_half);
+        assert_eq!(previous.bottom, current.bottom);
+        assert_eq!(previous.left, current.left);
+        assert_eq!(previous.right, current.right);
     }
 }

src/fighter/manifest.rs

@@ -65,6 +65,7 @@ pub struct FighterManifest {
     pub animations: HashMap<AnimKind, String>,
     pub attack_scripts: HashMap<AttackKind, String>,
     pub hurtboxes: Vec<FighterHurtbox>,
+    pub ecb_bones: Vec<String>,
 }
 
 #[derive(Resource)]

src/fighter/mod.rs

@@ -18,6 +18,7 @@ pub mod hurtbox;
 pub mod manifest;
 pub mod motion;
 pub mod state;
+pub mod surface;
 pub mod visual;
 
 // The fighter components are re-exported so the rest of the crate can say
@@ -28,9 +29,9 @@ pub use attributes::FighterAttributes;
 pub use ecb::FighterECB;
 pub use manifest::FighterId;
 pub use motion::{
-    FighterPreviousFacingDirection, FighterPreviousTranslation, FighterTranslation,
+    FighterPreviousFacingDirection, FighterPreviousTranslation, FighterTranslation, FighterVelocity,
-    FighterVelocity, Grounded,
 };
+pub use surface::FighterSurfaceState;
 
 use crate::{
     AppState, fighter::{
@@ -38,7 +39,7 @@ use crate::{
             AttackKind, FighterAttackPlugin, FighterAttackScriptAssets, FighterDamage,
             FighterKnockbackVelocity, FighterPendingHitReaction, FighterSolvedHurtboxes,
             FighterStaleMoveQueue,
-        }, baked_animation::{FighterBoneIndexMap, FighterBoneMatrices}, manifest::FighterManifest, state::{FighterState, air::AirborneStateCommon, fall::FallState}, visual::FighterAnimations,
+        }, baked_animation::{FighterBoneIndexMap, FighterBoneMatrices}, ecb::FighterECBBoneIndices, manifest::FighterManifest, state::{FighterState, air::AirborneStateCommon, fall::FallState}, visual::FighterAnimations,
     }, input::FighterInput, math::{int::FGi32, vec::FGVec2}, player::Player, schedule::GameplaySet, scripting::FighterAttackScript, stage::line::StageCollision,
 };
 use state::state_interrupt_system;
@@ -58,14 +59,14 @@ pub enum FighterFacingDirection {
 pub enum FighterHitstopShakeKind {
     #[default]
     Horizontal,
-    Vertical
+    Vertical,
 }
 
 #[derive(Component, Copy, Clone, Hash, Debug, PartialEq, Reflect, Default)]
 pub enum FighterHitstopShakeRole {
     #[default]
     Attacker,
-    Receiver
+    Receiver,
 }
 
 #[derive(Component, Default, Copy, Clone, Hash)]
@@ -73,7 +74,7 @@ pub struct FighterHitstopShake {
     pub remaining_frames: u32,
     pub total_frames: u32,
     pub kind: FighterHitstopShakeKind,
-    pub role: FighterHitstopShakeRole
+    pub role: FighterHitstopShakeRole,
 }
 
 #[derive(Component, Default, Copy, Clone, Hash)]
@@ -133,7 +134,7 @@ pub struct FighterVisual;
     FighterPendingHitReaction,
     FighterHitstop,
     FighterKnockbackVelocity,
-    FighterTranslation,
+    FighterTranslation
 )]
 pub struct Fighter {
     pub manifest: Handle<FighterManifest>,
@@ -170,10 +171,15 @@ impl Plugin for FighterPlugin {
             )*/
             .add_systems(
                 GgrsSchedule,
-                state::state_collision_interrupt_system.in_set(GameplaySet::Collision),
+                (
+                    (ecb::update_ecb, ecb::decrement_ecb_lockout, state::state_collision_interrupt_system).chain(),
+                    baked_animation::update_fighter_bone_matrices,
+                )
+                    .chain()
+                    .in_set(GameplaySet::Collision),
             )
             .add_systems(
-                Update,
+                PostUpdate,
                 (
                     motion::apply_fighter_translation_to_visuals,
                     animation::apply_animation,
@@ -200,8 +206,8 @@ impl Plugin for FighterPlugin {
             .checksum_component_with_hash::<FighterPreviousFacingDirection>()
             .rollback_component_with_copy::<animation::FighterAnimationFrame>()
             .checksum_component_with_hash::<animation::FighterAnimationFrame>()
-            .rollback_component_with_copy::<Grounded>()
+            .rollback_component_with_copy::<FighterSurfaceState>()
-            .checksum_component_with_hash::<Grounded>()
+            .checksum_component_with_hash::<FighterSurfaceState>()
             .rollback_component_with_copy::<FighterFacingDirection>()
             .rollback_component_with_copy::<FighterDamage>()
             .checksum_component_with_hash::<FighterDamage>()
@@ -259,7 +265,7 @@ pub struct FighterActiveAttack {
     pub active_hitboxes: Vec<usize>,
     pub solved_hitboxes: Vec<attack::FighterSolvedHitbox>,
     pub hit_fighters: Vec<Entity>,
-    pub stalled: bool
+    pub stalled: bool,
 }
 
 #[derive(Component, Clone, Debug, Default, Hash)]
@@ -274,6 +280,7 @@ pub fn spawn_fighter(
     animations: FighterAnimations,
     attack_scripts: FighterAttackScriptAssets,
     visual_root: WorldAssetRoot,
+    ecb_bone_indices: Vec<usize>,
 ) -> Entity {
     commands
         .spawn((
@@ -284,13 +291,14 @@ pub fn spawn_fighter(
             Fighter { manifest: manifest },
             FighterFacingDirection::Right,
             FighterPreviousFacingDirection(FighterFacingDirection::Right),
+            FighterSurfaceState::default(),
             Transform::from_scale(Vec3::splat(model_scale.to_num())),
             (
-                FighterECB {
+                FighterECB::default(),
-                    vertical_half: FGi32::lit("5.0"),
-                    horizontal_half: FGi32::lit("2.5"),
-                },
                 FighterHitboxes::default(),
+                FighterECBBoneIndices {
+                    indices: ecb_bone_indices
+                }
             ),
             (
                 FighterVelocity::default(),

src/fighter/motion.rs

@@ -5,19 +5,16 @@ use bevy::prelude::*;
 use bevy_ggrs::GgrsFrameTiming;
 
 use crate::debug_tools::PresentationMotionMode;
-use crate::fighter::{FighterHitstopShake};
+use crate::fighter::FighterHitstopShake;
 use crate::game_settings::GameSettings;
 use crate::{
-    fighter::{FighterECB, FighterFacingDirection, baked_animation::FixedMat4},
+    fighter::{FighterFacingDirection, baked_animation::FixedMat4},
     math::{int::FGi32, vec::FGVec2, vec3::FGVec3},
 };
 
 #[derive(Component, Clone, Copy, Hash)]
 pub struct FighterPreviousFacingDirection(pub FighterFacingDirection);
 
-#[derive(Component, Clone, Copy, Hash)]
-pub struct Grounded;
-
 #[derive(Component, Deref, DerefMut, Default, Debug, Clone, Copy, Hash)]
 pub struct FighterVelocity(pub FGVec2);
 
@@ -59,7 +56,6 @@ pub fn apply_fighter_translation_to_visuals(
     query: Query<(
         &FighterTranslation,
         &FighterPreviousTranslation,
-        &FighterECB,
         &FighterHitstopShake,
         &mut Transform,
     )>,
@@ -68,33 +64,42 @@ pub fn apply_fighter_translation_to_visuals(
     game_settings: Res<GameSettings>,
 ) {
     let overstep_fraction = timing.overstep_fraction();
-    for (translation, previous_translation, ecb, hitstop_shake, mut transform) in query {
+    for (translation, previous_translation, hitstop_shake, mut transform) in query {
         let translation = sample_presentation_translation(
             *previous_translation,
             *translation,
             overstep_fraction,
             debug_settings.motion_sampling,
         );
-        let bottom = ecb.get_bottom_point();
         transform.translation = Vec3::new(
-            translation.x + bottom.x.to_num::<f32>(),
+            translation.x,
-            translation.y + bottom.y.to_num::<f32>(),
+            translation.y,
             0.0,
         );
 
-        if hitstop_shake.remaining_frames > 0 && hitstop_shake.total_frames > 0 && !game_settings.fighter_common.visual_shake_table.is_empty() {
+        if hitstop_shake.remaining_frames > 0
+            && hitstop_shake.total_frames > 0
+            && !game_settings.fighter_common.visual_shake_table.is_empty()
+        {
             let total = hitstop_shake.total_frames as f32;
             let curr = hitstop_shake.remaining_frames as f32;
             let elapsed = 1.0 - curr / total;
 
-            
+            let access_index = (hitstop_shake.remaining_frames as usize)
-            let access_index = (hitstop_shake.remaining_frames as usize) % game_settings.fighter_common.visual_shake_table.len();
+                % game_settings.fighter_common.visual_shake_table.len();
             let shake_multiplier = match hitstop_shake.role {
-                super::FighterHitstopShakeRole::Attacker => game_settings.fighter_common.attacker_visual_shake_multiplier,
+                super::FighterHitstopShakeRole::Attacker => {
+                    game_settings
+                        .fighter_common
+                        .attacker_visual_shake_multiplier
+                }
                 super::FighterHitstopShakeRole::Receiver => 1.0,
             };
-            let shake_amount: f32 = 1.0 - EaseFunction::QuinticIn.sample(elapsed).unwrap_or_default();
+            let shake_amount: f32 =
-            let shake_amount = game_settings.fighter_common.visual_shake_table[access_index] * shake_amount * shake_multiplier;
+                1.0 - EaseFunction::QuinticIn.sample(elapsed).unwrap_or_default();
+            let shake_amount = game_settings.fighter_common.visual_shake_table[access_index]
+                * shake_amount
+                * shake_multiplier;
 
             let shake_offset = match hitstop_shake.kind {
                 super::FighterHitstopShakeKind::Horizontal => Vec3::new(shake_amount, 0.0, 0.0),

src/fighter/state/air.rs

@@ -1,4 +1,3 @@
-use crate::fighter::state::ground::GroundedStateCommon;
 use crate::fighter::state::land::{LandingState, LandingType};
 use crate::fighter::state::{CollisionContext, FighterState};
 use crate::fighter::*;
@@ -30,7 +29,7 @@ pub fn process_fast_fall(
 pub fn integrate_gravity(
     velocity: &mut FighterVelocity,
     attributes: &FighterAttributes,
-    fast_fall: bool
+    fast_fall: bool,
 ) {
     velocity.y -= attributes.gravity;
 
@@ -94,10 +93,23 @@ pub fn update_standard_motion(
     ctx: &mut crate::fighter::state::UpdateContext,
     airborne_common: &mut AirborneStateCommon,
 ) {
-    process_fast_fall(airborne_common, ctx.input, &mut ctx.velocity, ctx.fighter_attributes);
+    process_fast_fall(
-    integrate_gravity(ctx.velocity, ctx.fighter_attributes, airborne_common.is_fast_falling);
+        airborne_common,
+        ctx.input,
+        &mut ctx.velocity,
+        ctx.fighter_attributes,
+    );
+    integrate_gravity(
+        ctx.velocity,
+        ctx.fighter_attributes,
+        airborne_common.is_fast_falling,
+    );
     apply_air_drift(ctx.velocity, ctx.fighter_attributes, ctx.input);
-    apply_air_motion(ctx.velocity, ctx.translation, ctx.prev_translation);
+    apply_air_motion(
+        ctx.velocity,
+        ctx.translation,
+        ctx.prev_translation,
+    );
 }
 
 pub fn collision_interrupt(
@@ -105,14 +117,14 @@ 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;
-    let grounded_common = GroundedStateCommon {
+    ctx.ecb.bottom -= diff;
-        current_line_id: res.line_id,
+    ctx.ecb.top -= diff;
-    };
+    ctx.ecb.left -= diff;
-    Some(FighterState::Land(LandingState::create(
+    ctx.ecb.right -= diff;
-        grounded_common,
+    ctx.translation.0 = res.hit_position;
-        landing_type,
+    ctx.surface.land(res.line_id);
-    )))
+    Some(FighterState::Land(LandingState::create(landing_type)))
 }
 
 #[cfg(test)]

src/fighter/state/air_dodge.rs

@@ -1,9 +1,16 @@
 use crate::{
     fighter::{
-        animation::AnimKind, state::{
+        animation::AnimKind,
-            CollisionContext, EnterContext, FighterState, FighterStateImpl, InterruptContext, UpdateContext, air::{self, AirborneStateCommon}, fall::FallState, land::LandingType,
+        state::{
+            CollisionContext, EnterContext, FighterState, FighterStateImpl, InterruptContext,
+            UpdateContext,
+            air::{self, AirborneStateCommon},
+            fall::FallState,
+            land::LandingType,
         },
-    }, input, math::vec::FGVec2,
+    },
+    input,
+    math::vec::FGVec2,
 };
 
 #[derive(Debug, Clone, Hash)]
@@ -16,7 +23,9 @@ impl FighterStateImpl for AirDodgeState {
 
     fn check_interrupt(&self, state_context: &mut InterruptContext) -> Option<FighterState> {
         if state_context.is_current_animation_finished() {
-            Some(FighterState::Fall(FallState::new(AirborneStateCommon::default())))
+            Some(FighterState::Fall(FallState::new(
+                AirborneStateCommon::default(),
+            )))
         } else {
             None
         }
@@ -46,11 +55,13 @@ impl FighterStateImpl for AirDodgeState {
             self.direction * state_context.fighter_attributes.air_dodge_velocity;
     }
 
-    fn is_visually_grounded<'a>(
+    fn is_visually_grounded<'a>(&'a self) -> bool {
-        &'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/dash.rs

@@ -5,52 +5,43 @@ use super::{
 use crate::fighter::FighterFacingDirection;
 use crate::fighter::animation::AnimKind;
 use crate::fighter::state::FighterState;
-use crate::fighter::state::ground::GroundedStateCommon;
 use crate::input::FighterCommands::{SmashMoveLeft, SmashMoveRight};
 
 #[derive(Debug, Clone, Hash)]
 pub struct DashState {
     direction: FighterFacingDirection,
-    pub ground_common: GroundedStateCommon,
 }
 
 impl DashState {
-    pub fn new(direction: FighterFacingDirection, ground_common: GroundedStateCommon) -> Self {
+    pub fn new(direction: FighterFacingDirection) -> Self {
-        Self {
+        Self { direction }
-            direction,
-            ground_common,
-        }
     }
 }
 
 impl FighterStateImpl for DashState {
     const NAME: &'static str = "Dash";
     fn check_interrupt(&self, ctx: &mut InterruptContext) -> Option<FighterState> {
-        let ground = &self.ground_common;
         let attributes = ctx.fighter_attributes;
 
         // A reverse dash can interrupt before IASA
         if let Some(direction) =
             check_smash_input_with_dir(ctx).filter(|direction| *direction != self.direction)
         {
-            return Some(FighterState::Dash(DashState::new(
+            return Some(FighterState::Dash(DashState::new(direction)));
-                direction,
-                ground.clone(),
-            )));
         }
 
-        if let Some(state) = ground::grounded_movement_common_interrupts(ctx, ground) {
+        if let Some(state) = ground::grounded_movement_common_interrupts(ctx) {
             return Some(state);
         }
 
         if ctx.is_current_animation_finished() {
-            return run::check_input(ctx, ground)
+            return run::check_input(ctx)
-                .or_else(|| walk::check_input(ctx, ground))
+                .or_else(|| walk::check_input(ctx))
-                .or_else(|| wait::check_input(ctx, ground));
+                .or_else(|| wait::check_input(ctx));
         }
 
         if ctx.get_current_animation_frame() > attributes.dash_acceleration_duration {
-            return run::check_input(ctx, ground);
+            return run::check_input(ctx);
         }
 
         None
@@ -106,12 +97,10 @@ impl FighterStateImpl for DashState {
         &mut self,
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
-        ground::collision_interrupt(state_context, &mut self.ground_common, true)
+        ground::collision_interrupt(state_context, true)
     }
 
-    fn is_visually_grounded<'a>(
+    fn is_visually_grounded<'a>(&'a self) -> bool {
-        &'a self,
-    ) -> bool {
         true
     }
 }
@@ -126,10 +115,6 @@ fn check_smash_input_with_dir(state_context: &InterruptContext) -> Option<Fighte
     }
 }
 
-pub fn check_input(
+pub fn check_input(state_context: &InterruptContext) -> Option<FighterState> {
-    state_context: &InterruptContext,
+    check_smash_input_with_dir(state_context).map(|dir| FighterState::Dash(DashState::new(dir)))
-    ground_common: &GroundedStateCommon,
-) -> Option<FighterState> {
-    check_smash_input_with_dir(state_context)
-        .map(|dir| FighterState::Dash(DashState::new(dir, ground_common.clone())))
 }

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

@@ -3,7 +3,8 @@
 //! bit-for-bit deterministic for rollback.
 
 use crate::fighter::state::{
-    CollisionContext, FighterState, InterruptContext, air, dash, fall, ground_attack, turn, wait, walk,
+    CollisionContext, FighterState, InterruptContext, air, dash, fall, ground_attack, turn, wait,
+    walk,
 };
 use crate::fighter::{
     FighterAttributes, FighterPreviousTranslation, FighterTranslation, FighterVelocity,
@@ -13,13 +14,6 @@ use crate::math::int::{FGWide, FGi32};
 use crate::math::vec::FGVec2;
 use crate::stage::line::{StageLineID, StagePoly, StagePolyLineSegment, StagePolyLineSegmentType};
 
-use bevy::prelude::*;
-
-#[derive(Reflect, Hash, Clone, Debug)]
-pub struct GroundedStateCommon {
-    pub current_line_id: StageLineID,
-}
-
 pub fn apply_grounded_friction(friction: FGi32, ground_vel: FGi32) -> FGi32 {
     if friction.abs() > ground_vel.abs() {
         -ground_vel
@@ -181,22 +175,23 @@ pub fn update_friction_motion(ctx: &mut crate::fighter::state::UpdateContext) {
 
 pub fn collide_with_stage_grounded(
     state_context: &mut CollisionContext,
-    ground_common: &mut GroundedStateCommon,
     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 stage_poly = stage_collision
+    let Some(current_line_id) = state_context.surface.line_id() else {
-        .stage_polys
+        return GroundedMotionResult::InAir;
-        .get(ground_common.current_line_id.polygon);
+    };
+
+    let stage_poly = stage_collision.stage_polys.get(current_line_id.polygon);
 
     if let Some(stage_poly) = stage_poly {
         let ecb_bottom_pos = translation.0 + ecb.get_bottom_point();
         match resolve_grounded_position(
             stage_poly,
-            ground_common.current_line_id.segment,
+            current_line_id.segment,
             ecb_bottom_pos,
             can_walk_off,
         ) {
@@ -216,30 +211,43 @@ pub fn collide_with_stage_grounded(
                             .0
                             .project_onto_normalized(current_segment.normal)
                 };
-                ground_common.current_line_id.segment = segment_idx;
+                state_context.surface.land(StageLineID {
+                    polygon: current_line_id.polygon,
+                    segment: segment_idx,
+                });
                 GroundedMotionResult::InGround
             }
-            GroundedPositionResult::InAir => GroundedMotionResult::InAir,
+            GroundedPositionResult::InAir => {
+                state_context.surface.apply_airborne_policy(
+                    crate::fighter::surface::EcbLockPolicy::StartOnDetach,
+                    state_context.leave_ground_ecb_lock_duration,
+                );
+                GroundedMotionResult::InAir
+            }
         }
     } else {
+        state_context.surface.apply_airborne_policy(
+            crate::fighter::surface::EcbLockPolicy::StartOnDetach,
+            state_context.leave_ground_ecb_lock_duration,
+        );
         GroundedMotionResult::InAir
     }
 }
 
-pub fn collision_interrupt(
+pub fn collision_interrupt(ctx: &mut CollisionContext, can_walk_off: bool) -> Option<FighterState> {
-    ctx: &mut CollisionContext,
+    match collide_with_stage_grounded(ctx, can_walk_off) {
-    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::new(air::AirborneStateCommon::default()))),
+        GroundedMotionResult::InAir => Some(FighterState::Fall(fall::FallState::new(
+            air::AirborneStateCommon::default(),
+        ))),
     }
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::fighter::ecb::FighterPreviousECB;
+    use crate::fighter::{FighterECB, FighterSurfaceState};
     use crate::stage::line::StagePolyType;
 
     fn two_segment_floor() -> StagePoly {
@@ -346,28 +354,116 @@ mod tests {
             GroundedPositionResult::InAir
         ));
     }
+
+    #[test]
+    fn grounded_collision_updates_surface_segment() {
+        let stage_collision = crate::stage::line::StageCollision {
+            stage_polys: vec![two_segment_floor()],
+        };
+        let mut surface = FighterSurfaceState::Grounded {
+            line_id: StageLineID {
+                polygon: 0,
+                segment: 0,
+            },
+        };
+        let mut translation = FighterTranslation(FGVec2::lit("11", "0"));
+        let previous_translation = FighterPreviousTranslation(translation.0);
+        let mut velocity = FighterVelocity::default();
+        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 {
+            translation: &mut translation,
+            prev_translation: &previous_translation,
+            velocity: &mut velocity,
+            surface: &mut surface,
+            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::InGround
+        ));
+        assert_eq!(
+            surface.line_id(),
+            Some(StageLineID {
+                polygon: 0,
+                segment: 1,
+            })
+        );
+    }
+
+    #[test]
+    fn walking_off_edge_clears_surface_contact() {
+        let stage_collision = crate::stage::line::StageCollision {
+            stage_polys: vec![StagePoly::build(
+                StagePolyType::Platform,
+                &[
+                    (FGVec2::lit("0", "0"), StagePolyLineSegmentType::Floor),
+                    (FGVec2::lit("10", "0"), StagePolyLineSegmentType::Floor),
+                ],
+            )],
+        };
+        let mut surface = FighterSurfaceState::Grounded {
+            line_id: StageLineID {
+                polygon: 0,
+                segment: 0,
+            },
+        };
+        let mut translation = FighterTranslation(FGVec2::lit("11", "0"));
+        let previous_translation = FighterPreviousTranslation(translation.0);
+        let mut velocity = FighterVelocity::default();
+        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 {
+            translation: &mut translation,
+            prev_translation: &previous_translation,
+            velocity: &mut velocity,
+            surface: &mut surface,
+            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!(matches!(surface, FighterSurfaceState::Airborne { .. }));
+    }
 }
 
 pub fn grounded_movement_common_interrupts(
     state_context: &InterruptContext,
-    ground_common: &GroundedStateCommon,
 ) -> Option<FighterState> {
-    super::jump::check_input(state_context, ground_common)
+    super::jump::check_input(state_context)
 }
 
 pub fn grounded_movement_standstill_common_interrupts(
     state_context: &InterruptContext,
-    ground_common: &GroundedStateCommon,
 ) -> Option<FighterState> {
-    if let Some(state) = ground_attack::check_interrupt(state_context, &ground_common) {
+    if let Some(state) = ground_attack::check_interrupt(state_context) {
         Some(state)
-    } else if let Some(state) = dash::check_input(state_context, &ground_common) {
+    } else if let Some(state) = dash::check_input(state_context) {
         Some(state)
-    } else if let Some(state) = turn::check_input(state_context, &ground_common) {
+    } else if let Some(state) = turn::check_input(state_context) {
         Some(state)
-    } else if let Some(state) = walk::check_input(state_context, &ground_common) {
+    } else if let Some(state) = walk::check_input(state_context) {
         Some(state)
-    } else if let Some(state) = wait::check_input(state_context, &ground_common) {
+    } else if let Some(state) = wait::check_input(state_context) {
         Some(state)
     } else {
         None

src/fighter/state/ground_attack.rs

@@ -2,14 +2,13 @@ use crate::fighter::{
     attack::{AttackKind, update_active_hitbox_list},
     state::{
         CollisionContext, EnterContext, ExitContext, FighterState, FighterStateImpl,
-        InterruptContext, UpdateContext, ground::GroundedStateCommon, wait::WaitState,
+        InterruptContext, UpdateContext, wait::WaitState,
     },
 };
 
 #[derive(Clone, Debug, Hash)]
 pub struct GroundAttackState {
     pub attack_kind: AttackKind,
-    pub grounded_common: GroundedStateCommon,
 }
 
 impl FighterStateImpl for GroundAttackState {
@@ -17,9 +16,7 @@ impl FighterStateImpl for GroundAttackState {
 
     fn check_interrupt(&self, state_context: &mut InterruptContext) -> Option<FighterState> {
         if state_context.is_current_animation_finished() {
-            Some(FighterState::Wait(WaitState {
+            Some(FighterState::Wait(WaitState))
-                grounded_common: self.grounded_common.clone(),
-            }))
         } else {
             None
         }
@@ -53,7 +50,7 @@ impl FighterStateImpl for GroundAttackState {
             active_hitboxes: Vec::new(),
             solved_hitboxes: Vec::new(),
             hit_fighters: Vec::new(),
-            stalled: false
+            stalled: false,
         });
     }
 
@@ -68,17 +65,12 @@ impl FighterStateImpl for GroundAttackState {
         None
     }
 
-    fn is_visually_grounded<'a>(
+    fn is_visually_grounded<'a>(&'a self) -> bool {
-        &'a self,
-    ) -> bool {
         true
     }
 }
 
-pub fn check_interrupt(
+pub fn check_interrupt(state_context: &InterruptContext) -> Option<FighterState> {
-    state_context: &InterruptContext,
-    grounded_common: &GroundedStateCommon,
-) -> Option<FighterState> {
     if state_context
         .input
         .has_command(crate::input::FighterCommands::Attack)
@@ -89,7 +81,6 @@ pub fn check_interrupt(
             .to_attack_kind_grounded();
         Some(FighterState::GroundAttack(GroundAttackState {
             attack_kind,
-            grounded_common: grounded_common.clone(),
         }))
     } else {
         None

src/fighter/state/hitstun.rs

@@ -7,7 +7,7 @@ use crate::{
             InterruptContext, UpdateContext,
             air::{self, AirborneStateCommon},
             fall::FallState,
-            ground::{GroundedStateCommon, collision_interrupt},
+            ground::collision_interrupt,
             land::LandingType,
             wait::WaitState,
         },
@@ -17,7 +17,7 @@ use crate::{
 
 #[derive(Clone, Debug, Hash)]
 pub enum HitstopStateKind {
-    Grounded(GroundedStateCommon),
+    Grounded,
     Airborne,
 }
 
@@ -43,7 +43,7 @@ impl FighterStateImpl for HitstunState {
 
     fn name(&self) -> String {
         let hitstop_kind = match self.hitstop_kind {
-            HitstopStateKind::Grounded(_) => "Grounded",
+            HitstopStateKind::Grounded => "Grounded",
             HitstopStateKind::Airborne => "Airborne",
         };
 
@@ -58,14 +58,10 @@ impl FighterStateImpl for HitstunState {
     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(grounded_state_common) => {
+                HitstopStateKind::Grounded => Some(FighterState::Wait(WaitState)),
-                    Some(FighterState::Wait(WaitState {
+                HitstopStateKind::Airborne => Some(FighterState::Fall(FallState::new(
-                        grounded_common: grounded_state_common.clone(),
+                    AirborneStateCommon::default(),
-                    }))
+                ))),
-                }
-                HitstopStateKind::Airborne => {
-                    Some(FighterState::Fall(FallState::new(AirborneStateCommon::default())))
-                }
             }
         } else {
             None
@@ -85,7 +81,7 @@ impl FighterStateImpl for HitstunState {
         }
 
         match self.hitstop_kind {
-            HitstopStateKind::Grounded(_) => {}
+            HitstopStateKind::Grounded => {}
             HitstopStateKind::Airborne => {
                 air::integrate_gravity(ctx.velocity, ctx.fighter_attributes, false);
             }
@@ -103,7 +99,7 @@ impl FighterStateImpl for HitstunState {
 
     fn on_enter(&mut self, state_context: &mut EnterContext) {
         let animation = match self.hitstop_kind {
-            HitstopStateKind::Grounded(_) => AnimKind::FlinchGround,
+            HitstopStateKind::Grounded => AnimKind::FlinchGround,
             HitstopStateKind::Airborne => AnimKind::FlinchAir,
         };
         state_context.play_animation(animation, false);
@@ -116,9 +112,7 @@ impl FighterStateImpl for HitstunState {
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
         match &mut self.hitstop_kind {
-            HitstopStateKind::Grounded(grounded_state_common) => {
+            HitstopStateKind::Grounded => collision_interrupt(state_context, true),
-                collision_interrupt(state_context, grounded_state_common, true)
-            }
             HitstopStateKind::Airborne => {
                 air::collision_interrupt(state_context, LandingType::Normal)
             }
@@ -127,8 +121,17 @@ impl FighterStateImpl for HitstunState {
 
     fn is_visually_grounded<'a>(&'a self) -> bool {
         match self.hitstop_kind {
-            HitstopStateKind::Grounded(_) => true,
+            HitstopStateKind::Grounded => true,
             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

@@ -2,10 +2,17 @@ use bevy::prelude::*;
 
 use crate::{
     fighter::{
-        animation::AnimKind, state::{
+        animation::AnimKind,
-            CollisionContext, EnterContext, FighterState, FighterStateImpl, InterruptContext, UpdateContext, air::{self, AirborneStateCommon}, air_dodge::{self, AirDodgeState}, ground::{self, GroundedStateCommon},
+        state::{
+            CollisionContext, EnterContext, FighterState, FighterStateImpl, InterruptContext,
+            UpdateContext,
+            air::{self, AirborneStateCommon},
+            air_dodge::{self, AirDodgeState},
+            ground,
         },
-    }, input::FighterCommands, math::{int::FGi32, vec::FGVec2},
+    },
+    input::FighterCommands,
+    math::{int::FGi32, vec::FGVec2},
 };
 #[derive(Debug, Hash, Clone, Copy)]
 pub enum JumpType {
@@ -22,14 +29,12 @@ pub struct JumpState {
 
 #[derive(Debug, Clone, Hash)]
 pub struct JumpSquatState {
-    pub grounded_common: GroundedStateCommon,
     pub duration_counter: u32,
 }
 
 impl JumpSquatState {
-    pub fn create(grounded_common: GroundedStateCommon) -> Self {
+    pub fn create() -> Self {
         Self {
-            grounded_common,
             duration_counter: 0,
         }
     }
@@ -69,7 +74,10 @@ impl FighterStateImpl for JumpSquatState {
             } else {
                 JumpType::ShortHop
             };
-            Some(FighterState::Jump(JumpState { jump_type, airborne_state_common: AirborneStateCommon::default() }))
+            Some(FighterState::Jump(JumpState {
+                jump_type,
+                airborne_state_common: AirborneStateCommon::default(),
+            }))
         } else {
             None
         }
@@ -84,7 +92,7 @@ impl FighterStateImpl for JumpSquatState {
         &mut self,
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
-        ground::collision_interrupt(state_context, &mut self.grounded_common, false)
+        ground::collision_interrupt(state_context, false)
     }
 
     fn on_enter(&mut self, state_context: &mut EnterContext) {
@@ -92,9 +100,7 @@ impl FighterStateImpl for JumpSquatState {
         state_context.input.clear_command(FighterCommands::Jump);
     }
 
-    fn is_visually_grounded<'a>(
+    fn is_visually_grounded<'a>(&'a self) -> bool {
-        &'a self,
-    ) -> bool {
         true
     }
 }
@@ -105,7 +111,7 @@ impl FighterStateImpl for JumpState {
         if state_context.input.has_command(FighterCommands::Jump) {
             Some(FighterState::Jump(JumpState {
                 jump_type: JumpType::DoubleJump,
-                airborne_state_common: AirborneStateCommon::default()
+                airborne_state_common: AirborneStateCommon::default(),
             }))
         } else {
             air_dodge::check_input(state_context)
@@ -177,21 +183,26 @@ impl FighterStateImpl for JumpState {
         )
     }
 
-    fn is_visually_grounded<'a>(
+    fn is_visually_grounded<'a>(&'a self) -> bool {
-        &'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(
+pub fn check_input(state_context: &InterruptContext) -> Option<FighterState> {
-    state_context: &InterruptContext,
-    ground_common: &GroundedStateCommon,
-) -> Option<FighterState> {
     state_context
         .input
         .has_command(FighterCommands::Jump)
-        .then(|| FighterState::JumpSquat(JumpSquatState::create(ground_common.clone())))
+        .then(|| FighterState::JumpSquat(JumpSquatState::create()))
 }
 
 pub fn check_input_double_jump(state_context: &InterruptContext) -> Option<FighterState> {
@@ -201,7 +212,7 @@ pub fn check_input_double_jump(state_context: &InterruptContext) -> Option<Fight
         .then(|| {
             FighterState::Jump(JumpState {
                 jump_type: JumpType::DoubleJump,
-                airborne_state_common: AirborneStateCommon::default()
+                airborne_state_common: AirborneStateCommon::default(),
             })
         })
 }

src/fighter/state/land.rs

@@ -3,7 +3,7 @@ use crate::fighter::{
     state::{
         CollisionContext, EnterContext, FighterState, FighterStateImpl, InterruptContext,
         UpdateContext, dash,
-        ground::{self, GroundedStateCommon, grounded_movement_standstill_common_interrupts},
+        ground::{self, grounded_movement_standstill_common_interrupts},
         walk,
     },
 };
@@ -16,16 +16,12 @@ pub enum LandingType {
 
 #[derive(Debug, Clone, Hash)]
 pub struct LandingState {
-    pub grounded_common: GroundedStateCommon,
     pub landing_type: LandingType,
 }
 
 impl LandingState {
-    pub fn create(grounded_common: GroundedStateCommon, landing_type: LandingType) -> Self {
+    pub fn create(landing_type: LandingType) -> Self {
-        Self {
+        Self { landing_type }
-            grounded_common,
-            landing_type,
-        }
     }
 }
 
@@ -34,14 +30,14 @@ impl FighterStateImpl for LandingState {
 
     fn check_interrupt(&self, state_context: &mut InterruptContext) -> Option<FighterState> {
         if state_context.is_current_animation_finished() {
-            grounded_movement_standstill_common_interrupts(state_context, &self.grounded_common)
+            grounded_movement_standstill_common_interrupts(state_context)
         } else if state_context.get_current_animation_frame()
             >= state_context.fighter_attributes.landing_iasa
             && let LandingType::Normal = self.landing_type
         {
-            dash::check_input(state_context, &self.grounded_common).or_else(|| {
+            dash::check_input(state_context).or_else(|| {
-                ground::grounded_movement_common_interrupts(state_context, &self.grounded_common)
+                ground::grounded_movement_common_interrupts(state_context)
-                    .or_else(|| walk::check_input(state_context, &self.grounded_common))
+                    .or_else(|| walk::check_input(state_context))
             })
         } else {
             None
@@ -56,7 +52,7 @@ impl FighterStateImpl for LandingState {
         &mut self,
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
-        ground::collision_interrupt(state_context, &mut self.grounded_common, true)
+        ground::collision_interrupt(state_context, true)
     }
 
     fn on_enter(&mut self, state_context: &mut EnterContext) {
@@ -70,9 +66,7 @@ impl FighterStateImpl for LandingState {
         };
     }
 
-    fn is_visually_grounded<'a>(
+    fn is_visually_grounded<'a>(&'a self) -> bool {
-        &'a self,
-    ) -> bool {
         true
     }
 }

src/fighter/state/mod.rs

@@ -7,7 +7,8 @@ use bevy::prelude::*;
 
 use crate::fighter::animation::{AnimKind, FighterAnimationFrame};
 use crate::fighter::attack::{
-    FighterAttackScriptAssets, FighterKnockbackVelocity, FighterPendingHitReaction, FighterStaleMoveQueue, HitStop,
+    FighterAttackScriptAssets, FighterKnockbackVelocity, FighterPendingHitReaction,
+    FighterStaleMoveQueue, HitStop,
 };
 use crate::fighter::attributes::FighterAttributes;
 use crate::fighter::baked_animation::BakedFighterAnimations;
@@ -16,8 +17,11 @@ use crate::fighter::manifest::FighterManifest;
 use crate::fighter::state::hitstun::HitstunState;
 use crate::fighter::visual::FighterAnimations;
 use crate::fighter::{
-    Fighter, FighterECB, FighterFacingDirection, FighterHitboxes, FighterHitstop, FighterHitstopShake, FighterHitstopShakeKind, FighterHitstopShakeRole, FighterPreviousTranslation, FighterTranslation, FighterVelocity,
+    Fighter, FighterECB, FighterFacingDirection, FighterHitboxes, FighterHitstop,
+    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;
@@ -38,6 +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)]
@@ -69,6 +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 {
@@ -95,9 +109,11 @@ pub trait FighterStateImpl: Sized {
         None
     }
 
-    fn is_visually_grounded<'a>(
+    fn is_visually_grounded<'a>(&'a self) -> bool;
-        &'a self,
+
-    ) -> bool;
+    fn surface_policy(&self) -> SurfacePolicy {
+        SurfacePolicy::Grounded
+    }
 }
 
 pub struct AnimationStatus {
@@ -151,6 +167,7 @@ pub struct UpdateContext<'a> {
     pub input: &'a mut FighterInput,
     pub hitboxes: &'a mut FighterHitboxes,
     pub velocity: &'a mut FighterVelocity,
+    pub surface: &'a mut FighterSurfaceState,
     pub knockback_velocity: &'a mut FighterKnockbackVelocity,
     pub game_settings: &'a GameSettings,
     pub animation_frame: u32,
@@ -170,9 +187,11 @@ pub struct CollisionContext<'a> {
     pub translation: &'a mut FighterTranslation,
     pub prev_translation: &'a FighterPreviousTranslation,
     pub velocity: &'a mut FighterVelocity,
-    pub ecb: &'a FighterECB,
+    pub surface: &'a mut FighterSurfaceState,
+    pub ecb: &'a mut FighterECB,
     pub prev_ecb: &'a FighterPreviousECB,
     pub stage_collision: &'a StageCollision,
+    pub leave_ground_ecb_lock_duration: u32,
 }
 
 impl CollisionContext<'_> {
@@ -212,9 +231,10 @@ pub struct FighterFrameQuery {
     pub input: &'static mut FighterInput,
     pub hitboxes: &'static mut FighterHitboxes,
     pub velocity: &'static mut FighterVelocity,
+    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,
@@ -292,27 +312,31 @@ impl<'w, 's> FighterFrameQueryItem<'w, 's> {
             input: &mut self.input,
             hitboxes: &mut self.hitboxes,
             velocity: &mut self.velocity,
+            surface: &mut self.surface,
             knockback_velocity: &mut self.knockback_velocity,
             game_settings,
             animation_frame: self.animation_frame.frame,
             fighter_attributes: attributes,
             attack_scripts,
             attack_script_assets,
-            facing_direction: &self.facing_direction
+            facing_direction: &self.facing_direction,
         }
     }
 
     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,
-            ecb: &self.ecb,
+            surface: &mut self.surface,
+            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
         }
     }
 }
@@ -367,11 +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);
@@ -400,7 +431,9 @@ pub fn state_interrupt_system(
 
         let new_state = if let Some(reaction) = pending_hit_reaction.take() {
             hitstop.remaining_frames = *reaction.hitstop_frames;
-            let shake_frames = reaction.hitstop_frames.calculate_shake_frames(&game_settings);
+            let shake_frames = reaction
+                .hitstop_frames
+                .calculate_shake_frames(&game_settings);
             hitstop_shake.role = FighterHitstopShakeRole::Receiver;
             hitstop_shake.total_frames = shake_frames;
             hitstop_shake.remaining_frames = shake_frames;
@@ -410,34 +443,24 @@ pub fn state_interrupt_system(
                 FighterHitstopShakeKind::Vertical
             };
 
-            let mut hitstop_kind = match &*state {
+            let mut hitstop_kind = if frame.surface.is_grounded() {
-                FighterState::Wait(value) => {
+                hitstun::HitstopStateKind::Grounded
-                    hitstun::HitstopStateKind::Grounded(value.grounded_common.clone())
+            } else {
-                }
+                hitstun::HitstopStateKind::Airborne
-                FighterState::Walk(value) => {
-                    hitstun::HitstopStateKind::Grounded(value.grounded_common.clone())
-                }
-                FighterState::Dash(value) => {
-                    hitstun::HitstopStateKind::Grounded(value.ground_common.clone())
-                }
-                FighterState::Run(value) => {
-                    hitstun::HitstopStateKind::Grounded(value.grounded_common.clone())
-                }
-                FighterState::Turn(value) => {
-                    hitstun::HitstopStateKind::Grounded(value.grounded_common.clone())
-                }
-                FighterState::GroundAttack(value) => {
-                    hitstun::HitstopStateKind::Grounded(value.grounded_common.clone())
-                }
-                _ => hitstun::HitstopStateKind::Airborne,
             };
 
-            if let hitstun::HitstopStateKind::Grounded(_) = hitstop_kind {
+            if let hitstun::HitstopStateKind::Grounded = hitstop_kind {
                 let straight_up_angle = FGi32::lit("90.0");
-                if reaction.hitstop_frames >= HitStop::new(game_settings.fighter_common.tumble_bounce_hitstop_threshold) {
+                if reaction.hitstop_frames
+                    >= HitStop::new(game_settings.fighter_common.tumble_bounce_hitstop_threshold)
+                {
                     hitstop_kind = hitstun::HitstopStateKind::Airborne;
                 // TODO: Use floor normal here
-                } else if reaction.launch_angle.abs_diff(straight_up_angle) < game_settings.fighter_common.attack_ground_to_airborne_transition_vertical_angle_threshold {
+                } else if reaction.launch_angle.abs_diff(straight_up_angle)
+                    < game_settings
+                        .fighter_common
+                        .attack_ground_to_airborne_transition_vertical_angle_threshold
+                {
                     hitstop_kind = hitstun::HitstopStateKind::Airborne;
                 } else {
                     // straight down is 270
@@ -473,6 +496,7 @@ pub fn state_interrupt_system(
                 &mut frame,
                 &manifest.attributes,
                 attack_script_assets,
+                &game_settings,
             );
         };
     }
@@ -482,6 +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 {
@@ -500,7 +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,
@@ -508,6 +533,7 @@ pub fn state_collision_interrupt_system(
                 &mut frame,
                 &manifest.attributes,
                 &attack_script_assets,
+                &game_settings,
             );
         }
     }

src/fighter/state/run.rs

@@ -6,19 +6,14 @@ use super::{
 };
 use crate::fighter::animation::AnimKind;
 use crate::fighter::state::FighterState;
-use crate::fighter::state::ground::GroundedStateCommon;
 
 #[derive(Component, Debug, Clone, Hash)]
-pub struct RunState {
+pub struct RunState;
-    pub grounded_common: GroundedStateCommon,
-}
 
 impl FighterStateImpl for RunState {
     const NAME: &'static str = "Run";
     fn check_interrupt(&self, state_context: &mut InterruptContext) -> Option<FighterState> {
-        if let Some(state) =
+        if let Some(state) = ground::grounded_movement_common_interrupts(state_context) {
-            ground::grounded_movement_common_interrupts(state_context, &self.grounded_common)
-        {
             return Some(state);
         }
 
@@ -28,8 +23,7 @@ impl FighterStateImpl for RunState {
         {
             None
         } else {
-            walk::check_input(state_context, &self.grounded_common)
+            walk::check_input(state_context).or_else(|| wait::check_input(state_context))
-                .or_else(|| wait::check_input(state_context, &self.grounded_common))
         }
     }
 
@@ -62,26 +56,19 @@ impl FighterStateImpl for RunState {
         &mut self,
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
-        ground::collision_interrupt(state_context, &mut self.grounded_common, true)
+        ground::collision_interrupt(state_context, true)
     }
 
-    fn is_visually_grounded<'a>(
+    fn is_visually_grounded<'a>(&'a self) -> bool {
-        &'a self,
-    ) -> bool {
         true
     }
 }
 
-pub fn check_input(
+pub fn check_input(state_context: &InterruptContext) -> Option<FighterState> {
-    state_context: &InterruptContext,
-    ground_state_common: &GroundedStateCommon,
-) -> Option<FighterState> {
     let input_frame = state_context.input.get_last_frame();
     if input_frame.movement.x.abs() >= state_context.game_settings.input_common.run_stick_threshold
     {
-        return Some(FighterState::Run(RunState {
+        return Some(FighterState::Run(RunState));
-            grounded_common: ground_state_common.clone(),
-        }));
     }
     None
 }

src/fighter/state/turn.rs

@@ -1,13 +1,11 @@
 use super::{CollisionContext, EnterContext, FighterStateImpl, InterruptContext, UpdateContext};
 use crate::fighter::animation::AnimKind;
-use crate::fighter::state::ground::{self, GroundedStateCommon};
+use crate::fighter::state::ground;
 use crate::fighter::state::{FighterState, dash, jump, wait, walk};
 use crate::input::FighterCommands;
 
 #[derive(Debug, Clone, Hash)]
-pub struct TurnState {
+pub struct TurnState;
-    pub grounded_common: GroundedStateCommon,
-}
 
 impl FighterStateImpl for TurnState {
     const NAME: &'static str = "Turn";
@@ -19,19 +17,19 @@ impl FighterStateImpl for TurnState {
                 .input_common
                 .turn_into_dashback_window as u32
         {
-            if let Some(state) = dash::check_input(state_context, &self.grounded_common) {
+            if let Some(state) = dash::check_input(state_context) {
                 return Some(state);
             }
         }
-        if let Some(state) = jump::check_input(state_context, &self.grounded_common) {
+        if let Some(state) = jump::check_input(state_context) {
             *state_context.facing_direction = state_context.facing_direction.reverse();
             Some(state)
         } else if state_context.is_current_animation_finished() {
-            if let Some(state) = dash::check_input(state_context, &self.grounded_common) {
+            if let Some(state) = dash::check_input(state_context) {
                 Some(state)
-            } else if let Some(state) = walk::check_input(state_context, &self.grounded_common) {
+            } else if let Some(state) = walk::check_input(state_context) {
                 Some(state)
-            } else if let Some(state) = wait::check_input(state_context, &self.grounded_common) {
+            } else if let Some(state) = wait::check_input(state_context) {
                 Some(state)
             } else {
                 None
@@ -54,20 +52,15 @@ impl FighterStateImpl for TurnState {
         &mut self,
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
-        ground::collision_interrupt(state_context, &mut self.grounded_common, false)
+        ground::collision_interrupt(state_context, false)
     }
 
-    fn is_visually_grounded<'a>(
+    fn is_visually_grounded<'a>(&'a self) -> bool {
-        &'a self,
-    ) -> bool {
         true
     }
 }
 
-pub fn check_input(
+pub fn check_input(state_context: &InterruptContext) -> Option<FighterState> {
-    state_context: &InterruptContext,
-    grounded_common: &GroundedStateCommon,
-) -> Option<FighterState> {
     let input_frame = state_context.input.get_last_frame();
 
     let has_smash_input = state_context
@@ -81,9 +74,7 @@ pub fn check_input(
         && input_frame.movement.x.signum() != state_context.facing_direction.to_sign()
         && !has_smash_input
     {
-        return Some(FighterState::Turn(TurnState {
+        return Some(FighterState::Turn(TurnState));
-            grounded_common: grounded_common.clone(),
-        }));
     }
     None
 }

src/fighter/state/wait.rs

@@ -3,24 +3,18 @@ use super::{
 };
 use crate::fighter::animation::AnimKind;
 use crate::fighter::state::FighterState;
-use crate::fighter::state::ground::GroundedStateCommon;
 
 #[derive(Debug, Clone, Hash)]
-pub struct WaitState {
+pub struct WaitState;
-    pub grounded_common: GroundedStateCommon,
-}
 
 impl FighterStateImpl for WaitState {
     const NAME: &'static str = "Wait";
     fn check_interrupt(&self, state_context: &mut InterruptContext) -> Option<FighterState> {
-        if let Some(state) =
+        if let Some(state) = ground::grounded_movement_common_interrupts(state_context) {
-            ground::grounded_movement_common_interrupts(state_context, &self.grounded_common)
-        {
             Some(state)
-        } else if let Some(state) = ground::grounded_movement_standstill_common_interrupts(
+        } else if let Some(state) =
-            state_context,
+            ground::grounded_movement_standstill_common_interrupts(state_context)
-            &self.grounded_common,
+        {
-        ) {
             // Don't transition into yourself
             if let FighterState::Wait(_) = state {
                 None
@@ -44,26 +38,19 @@ impl FighterStateImpl for WaitState {
         &mut self,
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
-        ground::collision_interrupt(state_context, &mut self.grounded_common, false)
+        ground::collision_interrupt(state_context, false)
     }
 
-    fn is_visually_grounded<'a>(
+    fn is_visually_grounded<'a>(&'a self) -> bool {
-        &'a self,
-    ) -> bool {
         true
     }
 }
 
-pub fn check_input(
+pub fn check_input(state_context: &InterruptContext) -> Option<FighterState> {
-    state_context: &InterruptContext,
-    ground_state_common: &GroundedStateCommon,
-) -> Option<FighterState> {
     let input_frame = state_context.input.get_last_frame();
 
     if input_frame.movement.x.abs() < state_context.game_settings.input_common.stick_deadzone {
-        return Some(FighterState::Wait(WaitState {
+        return Some(FighterState::Wait(WaitState));
-            grounded_common: ground_state_common.clone(),
-        }));
     }
     None
 }

src/fighter/state/walk.rs

@@ -4,23 +4,17 @@ use super::{
 };
 use crate::fighter::animation::AnimKind;
 use crate::fighter::state::FighterState;
-use crate::fighter::state::ground::GroundedStateCommon;
 
 #[derive(Debug, Clone, Hash)]
-pub struct WalkState {
+pub struct WalkState;
-    pub grounded_common: GroundedStateCommon,
-}
 
 impl FighterStateImpl for WalkState {
     const NAME: &'static str = "Walk";
     fn check_interrupt(&self, state_context: &mut InterruptContext) -> Option<FighterState> {
-        if let Some(state) =
+        if let Some(state) = ground::grounded_movement_common_interrupts(state_context) {
-            ground::grounded_movement_common_interrupts(state_context, &self.grounded_common)
-        {
             return Some(state);
         }
-        wait::check_input(state_context, &self.grounded_common)
+        wait::check_input(state_context).or_else(|| dash::check_input(state_context))
-            .or_else(|| dash::check_input(state_context, &self.grounded_common))
     }
 
     fn on_enter(&mut self, state_context: &mut EnterContext) {
@@ -54,26 +48,19 @@ impl FighterStateImpl for WalkState {
         &mut self,
         state_context: &mut CollisionContext,
     ) -> Option<FighterState> {
-        ground::collision_interrupt(state_context, &mut self.grounded_common, false)
+        ground::collision_interrupt(state_context, false)
     }
 
-    fn is_visually_grounded<'a>(
+    fn is_visually_grounded<'a>(&'a self) -> bool {
-        &'a self,
-    ) -> bool {
         true
     }
 }
 
-pub fn check_input(
+pub fn check_input(state_context: &InterruptContext) -> Option<FighterState> {
-    state_context: &InterruptContext,
-    ground_state_common: &GroundedStateCommon,
-) -> Option<FighterState> {
     let input_frame = state_context.input.get_last_frame();
 
     if !input_frame.movement.x.is_zero() {
-        return Some(FighterState::Walk(WalkState {
+        return Some(FighterState::Walk(WalkState));
-            grounded_common: ground_state_common.clone(),
-        }));
     }
 
     None

src/fighter/surface.rs

@@ -0,0 +1,130 @@
+use bevy::prelude::*;
+
+use crate::{stage::line::StageLineID};
+
+#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq)]
+pub enum EcbLockPolicy {
+    StartOnDetach,
+    Restart,
+    Preserve,
+    Clear,
+}
+
+/// The stage surface currently supporting a fighter.
+///
+/// This is physics state rather than fighter-state-machine state. Keeping it
+/// separate means grounded, landing, and hitstun states all share one source
+/// of truth for stage contact.
+#[derive(Component, Clone, Copy, Debug, Hash, PartialEq, Eq)]
+pub enum FighterSurfaceState {
+    Airborne {
+        ecb_lock_frames_remaining: u32
+    },
+    Grounded {
+        line_id: StageLineID,
+    },
+}
+
+impl Default for FighterSurfaceState {
+    fn default() -> Self {
+        Self::Airborne {
+            ecb_lock_frames_remaining: 0
+        }
+    }
+}
+
+impl FighterSurfaceState {
+    pub fn is_grounded(self) -> bool {
+        matches!(self, Self::Grounded { .. })
+    }
+
+    pub fn line_id(self) -> Option<StageLineID> {
+        match self {
+            Self::Airborne { .. } => None,
+            Self::Grounded { line_id } => Some(line_id),
+        }
+    }
+
+    pub(crate) fn land(&mut self, line_id: StageLineID) {
+        *self = Self::Grounded { line_id };
+    }
+
+    pub(crate) fn apply_airborne_policy(
+        &mut self,
+        policy: EcbLockPolicy,
+        ecb_lock_duration: u32,
+    ) {
+        let current_lock = match *self {
+            Self::Airborne { ecb_lock_frames_remaining } => ecb_lock_frames_remaining,
+            Self::Grounded { .. } => 0,
+        };
+        let ecb_lock_frames_remaining = match policy {
+            EcbLockPolicy::StartOnDetach if self.is_grounded() => ecb_lock_duration,
+            EcbLockPolicy::StartOnDetach => current_lock,
+            EcbLockPolicy::Restart => ecb_lock_duration,
+            EcbLockPolicy::Preserve => current_lock,
+            EcbLockPolicy::Clear => 0,
+        };
+        *self = Self::Airborne { ecb_lock_frames_remaining };
+    }
+
+    pub(crate) fn tick_ecb_lock(&mut self) {
+        if let Self::Airborne { ecb_lock_frames_remaining } = self {
+            *ecb_lock_frames_remaining = ecb_lock_frames_remaining.saturating_sub(1);
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn contact_lifecycle_has_one_source_of_truth() {
+        let mut surface = FighterSurfaceState::default();
+        assert!(!surface.is_grounded());
+        assert_eq!(surface.line_id(), None);
+
+        let line_id = StageLineID {
+            polygon: 2,
+            segment: 3,
+        };
+        surface.land(line_id);
+        assert!(surface.is_grounded());
+        assert_eq!(surface.line_id(), Some(line_id));
+
+        surface.apply_airborne_policy(EcbLockPolicy::Clear, 0);
+        assert!(!surface.is_grounded());
+        assert_eq!(surface.line_id(), None);
+    }
+
+    #[test]
+    fn start_on_detach_does_not_reset_an_existing_lock() {
+        let mut surface = FighterSurfaceState::default();
+        surface.apply_airborne_policy(EcbLockPolicy::Restart, 5);
+        surface.tick_ecb_lock();
+        surface.apply_airborne_policy(EcbLockPolicy::StartOnDetach, 5);
+
+        assert_eq!(
+            surface,
+            FighterSurfaceState::Airborne {
+                ecb_lock_frames_remaining: 4,
+            }
+        );
+    }
+
+    #[test]
+    fn restart_retriggers_an_existing_lock() {
+        let mut surface = FighterSurfaceState::default();
+        surface.apply_airborne_policy(EcbLockPolicy::Restart, 5);
+        surface.tick_ecb_lock();
+        surface.apply_airborne_policy(EcbLockPolicy::Restart, 5);
+
+        assert_eq!(
+            surface,
+            FighterSurfaceState::Airborne {
+                ecb_lock_frames_remaining: 5,
+            }
+        );
+    }
+}

src/game_settings.rs

@@ -39,6 +39,7 @@ pub struct FighterSettingsCommon {
     
     /// Maximum angle changed caused by directional influence
     pub di_max_angle: FGi32,
+    pub leave_ground_ecb_frame_lock_duration: u32
 }
 #[derive(Reflect, Serialize, Deserialize, Clone)]
 #[reflect(opaque)]

src/input/gamecube/poll.rs

@@ -1,6 +1,8 @@
 use std::panic::{self, AssertUnwindSafe};
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, Mutex};
+use std::thread::JoinHandle;
+use std::time::{Duration, Instant};
 
 use bevy::prelude::*;
 use gc_adapter_neo::{Controller, GcAdapter};
@@ -55,10 +57,11 @@ impl GcPortState {
 /// Shared, `Send + Sync` handle to the latest snapshot from the poll
 /// thread. Safe to store as an ordinary [`Resource`] (no `NonSend` needed)
 /// because the `GcAdapter` itself never leaves its thread.
-#[derive(Resource, Clone)]
+#[derive(Resource)]
 pub struct GcAdapterSnapshot {
     ports: Arc<Mutex<[GcPortState; 4]>>,
     shutdown: Arc<AtomicBool>,
+    poll_thread: Option<JoinHandle<()>>,
 }
 
 impl GcAdapterSnapshot {
@@ -69,13 +72,37 @@ impl GcAdapterSnapshot {
 
 impl Drop for GcAdapterSnapshot {
     fn drop(&mut self) {
-        // Only actually signals shutdown once the last clone (this resource
+        self.shutdown.store(true, Ordering::Release);
-        // is never cloned in practice, but be defensive) is dropped.
+
-        if Arc::strong_count(&self.shutdown) <= 1 {
+        if let Some(poll_thread) = self.poll_thread.take() {
-            self.shutdown.store(true, Ordering::Relaxed);
+            if let Err(payload) = poll_thread.join() {
+                error!(
+                    "GameCube Controller Adapter poll thread panicked during shutdown: {payload:?}"
+                );
             }
         }
     }
+}
+
+const INITIAL_ERROR_BACKOFF: Duration = Duration::from_millis(1);
+const MAX_ERROR_BACKOFF: Duration = Duration::from_millis(100);
+
+fn next_error_backoff(backoff: Duration) -> Duration {
+    backoff.saturating_mul(2).min(MAX_ERROR_BACKOFF)
+}
+
+/// Wait for a retry while still allowing the owner to shut the poll thread down promptly.
+fn wait_for_retry(shutdown: &AtomicBool, delay: Duration) -> bool {
+    let deadline = Instant::now() + delay;
+    while !shutdown.load(Ordering::Acquire) {
+        let remaining = deadline.saturating_duration_since(Instant::now());
+        if remaining.is_zero() {
+            return true;
+        }
+        std::thread::sleep(remaining.min(Duration::from_millis(10)));
+    }
+    false
+}
 
 /// Connects to the first GameCube adapter found on the USB bus and starts
 /// polling it on a dedicated thread. Returns `None` (after logging a
@@ -94,7 +121,7 @@ pub fn spawn_poll_thread() -> Result<GcAdapterSnapshot, gc_adapter_neo::UsbError
 
     let thread_ports = ports.clone();
     let thread_shutdown = shutdown.clone();
-    std::thread::Builder::new()
+    let poll_thread = std::thread::Builder::new()
         .name("gc-adapter-poll".into())
         .spawn(move || {
             // Flush whatever the adapter had buffered before we started
@@ -107,17 +134,27 @@ pub fn spawn_poll_thread() -> Result<GcAdapterSnapshot, gc_adapter_neo::UsbError
             let mut rate_window_start = std::time::Instant::now();
             #[cfg(debug_assertions)]
             let mut rate_window_count: u32 = 0;
+            let mut error_backoff = INITIAL_ERROR_BACKOFF;
 
-            while !thread_shutdown.load(Ordering::Relaxed) {
+            while !thread_shutdown.load(Ordering::Acquire) {
                 let result = panic::catch_unwind(AssertUnwindSafe(|| adapter.read_controllers()));
 
                 let controllers = match result {
-                    Ok(Ok(controllers)) => controllers,
+                    Ok(Ok(controllers)) => {
+                        error_backoff = INITIAL_ERROR_BACKOFF;
+                        controllers
+                    }
                     // Ignore this, for some reason we get a bunch of these when we start reading
                     Ok(Err(
                         gc_adapter_neo::AdapterError::Parse(_)
                         | gc_adapter_neo::AdapterError::ShortRead(_),
-                    )) => continue,
+                    )) => {
+                        if !wait_for_retry(&thread_shutdown, error_backoff) {
+                            break;
+                        }
+                        error_backoff = next_error_backoff(error_backoff);
+                        continue;
+                    }
                     Ok(Err(gc_adapter_neo::AdapterError::Usb(err))) => {
                         error!(
                             "GameCube Controller Adapter USB read failed ({err:?}); stopping \
@@ -160,5 +197,32 @@ pub fn spawn_poll_thread() -> Result<GcAdapterSnapshot, gc_adapter_neo::UsbError
         })
         .expect("failed to spawn gc-adapter poll thread");
 
-    Ok(GcAdapterSnapshot { ports, shutdown })
+    Ok(GcAdapterSnapshot {
+        ports,
+        shutdown,
+        poll_thread: Some(poll_thread),
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn error_backoff_is_capped() {
+        let mut backoff = INITIAL_ERROR_BACKOFF;
+        for _ in 0..16 {
+            backoff = next_error_backoff(backoff);
+        }
+
+        assert_eq!(backoff, MAX_ERROR_BACKOFF);
+        assert_eq!(next_error_backoff(MAX_ERROR_BACKOFF), MAX_ERROR_BACKOFF);
+    }
+
+    #[test]
+    fn retry_wait_stops_when_shutdown_is_requested() {
+        let shutdown = AtomicBool::new(true);
+
+        assert!(!wait_for_retry(&shutdown, Duration::from_secs(1)));
+    }
 }

src/lib.rs

@@ -38,6 +38,7 @@ use crate::{
 };
 
 mod args;
+pub mod blend_asset;
 pub mod camera;
 pub mod debug_tools;
 pub mod fighter;
@@ -89,6 +90,7 @@ pub struct GameAssetPlugin;
 impl Plugin for GameAssetPlugin {
     fn build(&self, app: &mut App) {
         app.add_plugins((
+            blend_asset::BlendAssetProcessingPlugin,
             RonAssetPlugin::<FighterManifest>::create("fighter.ron"),
             RonAssetPlugin::<StageManifest>::create("stage.ron"),
             RonAssetPlugin::<GameSettings>::create("ron"),

src/main.rs

@@ -1,6 +1,7 @@
 use bevy::asset::AssetMode::Processed;
 #[cfg(feature = "debug_features")]
 use bevy::camera_controller::free_camera::FreeCameraPlugin;
+use bevy::gltf::GltfPlugin;
 use bevy::image::{ImageAddressMode, ImagePlugin, ImageSamplerDescriptor};
 use bevy::prelude::*;
 #[cfg(feature = "debug_features")]
@@ -12,14 +13,18 @@ fn main() -> AppExit {
     // A `Repeat` sampler so the tileable materials authored in the
     // editor render the same way at runtime; Bevy's default
     // `ClampToEdge` smears texture edges on brush geometry.
+    let default_sampler = ImageSamplerDescriptor::linear()
+        .set_address_mode(ImageAddressMode::Repeat)
+        .set_anisotropic_filter(16)
+        .clone();
+
     let default_plugins = DefaultPlugins
         .set(ImagePlugin {
-            default_sampler: ImageSamplerDescriptor {
+            default_sampler: default_sampler.clone(),
-                address_mode_u: ImageAddressMode::Repeat,
+        })
-                address_mode_v: ImageAddressMode::Repeat,
+        .set(GltfPlugin {
-                address_mode_w: ImageAddressMode::Repeat,
+            default_sampler,
-                ..ImageSamplerDescriptor::linear()
+            ..default()
-            },
         })
         .set(AssetPlugin {
             mode: Processed,

src/match_loading.rs

@@ -336,6 +336,15 @@ pub fn prepare_match(
             );
             return;
         }
+
+        let ecb_bone_indices = baked.bone_names.iter().enumerate().filter_map(|(idx, name)| {
+            if manifest.ecb_bones.contains(name) {
+                Some(idx)
+            } else {
+                None
+            }
+        }).collect::<Vec<_>>();
+
         if let Err(error) = manifest.attributes.validate() {
             fail_match(
                 &mut next_state,
@@ -436,6 +445,7 @@ pub fn prepare_match(
             attack_scripts,
             manifest_handle,
             manifest.model_scale,
+            ecb_bone_indices,
         ));
     }
 
@@ -477,7 +487,7 @@ pub fn prepare_match(
     );
 
     let mut fighter_roster = Vec::with_capacity(config.players.len());
-    for (index, (player, (scene, animations, attack_scripts, manifest_handle, model_scale))) in
+    for (index, (player, (scene, animations, attack_scripts, manifest_handle, model_scale, ecb_bone_indices))) in
         config.players.iter().zip(prepared).enumerate()
     {
         let spawn_x = (index as i32 * 2 + 1 - config.players.len() as i32) * 5;
@@ -490,6 +500,7 @@ pub fn prepare_match(
             animations,
             attack_scripts,
             WorldAssetRoot(scene),
+            ecb_bone_indices
         ));
     }
 

src/math/vec.rs

@@ -2,7 +2,7 @@ use bevy::math::Vec2;
 use bevy::prelude::*;
 use fixed::types::I32F32;
 use serde::{Deserialize, Serialize};
-use std::ops::{Add, AddAssign, Div, Mul, MulAssign, Sub};
+use std::ops::{Add, AddAssign, Div, Mul, MulAssign, Sub, SubAssign};
 
 use super::int::{FGWide, FGi32};
 
@@ -227,6 +227,15 @@ impl AddAssign for FGVec2 {
     }
 }
 
+impl SubAssign for FGVec2 {
+    fn sub_assign(&mut self, rhs: Self) {
+        *self = Self {
+            x: self.x - rhs.x,
+            y: self.y - rhs.y,
+        }
+    }
+}
+
 impl MulAssign for FGVec2 {
     fn mul_assign(&mut self, rhs: Self) {
         *self = Self {

src/menus/character_select/mod.rs

@@ -1,19 +1,8 @@
 use bevy::{picking::pointer::PointerId, prelude::*};
 
 use crate::{
-    AppState,
+    AppState, fighter::manifest::{FighterManifest, FighterManifestRegistry}, game_settings::CommonAssets, input::{LocalInputAssignments, LocalInputSource}, menus::{
-    fighter::manifest::{FighterManifest, FighterManifestRegistry},
+        MenuCameraMarker, MenuMarker, button::FGUiButton, character_select::{character_box::CharacterBox, token::CharacterSelectToken}, cursor::{FGMenuCursor, MenuCursorInputSource}, errors::MenuErrors::FighterManifestNotFound, match_config::{MenuMatchConfig, MenuMatchPlayerSlot}, scaling, spawn_menu, style::{FGUiButtonType, FGUiStyle},
-    game_settings::CommonAssets,
-    input::{LocalInputAssignments, LocalInputSource},
-    menus::{
-        MenuMarker,
-        button::FGUiButton,
-        character_select::{character_box::CharacterBox, token::CharacterSelectToken},
-        cursor::{FGMenuCursor, MenuCursorInputSource},
-        errors::MenuErrors::FighterManifestNotFound,
-        match_config::{MenuMatchConfig, MenuMatchPlayerSlot},
-        scaling, spawn_menu,
-        style::{FGUiButtonType, FGUiStyle},
     },
 };
 
@@ -241,7 +230,7 @@ pub fn copy_cursor_transform_to_token(
     character_boxes: Query<(&CharacterBox, &ComputedNode, &UiGlobalTransform)>,
     match_config: Res<MenuMatchConfig>,
     cursors: Query<&UiGlobalTransform, With<FGMenuCursor>>,
-    cam: Single<&Camera, With<IsDefaultUiCamera>>,
+    cam: Single<&Camera, With<MenuCameraMarker>>,
     ui_scale: Res<UiScale>,
 ) -> Result {
     let camera = cam.into_inner();

src/menus/cursor.rs

@@ -9,11 +9,8 @@ use bevy::{
 };
 
 use crate::{
-    input::{LocalInputAssignments, LocalInputSource},
+    input::{LocalInputAssignments, LocalInputSource}, menus::{
-    menus::{
+        MenuCameraMarker, input::{MenuInput, MenuInputState}, scaling, style::FGUiStyle,
-        input::{MenuInput, MenuInputState},
-        scaling,
-        style::FGUiStyle,
     },
 };
 
@@ -181,7 +178,7 @@ pub fn cursor_input(
 }
 
 pub fn update_cursor_transform(
-    camera: Single<&Camera, With<IsDefaultUiCamera>>,
+    camera: Single<&Camera, With<MenuCameraMarker>>,
     query: Query<(&mut Node, &PointerLocation), With<FGMenuCursor>>,
     ui_scale: Res<UiScale>,
 ) {

src/menus/mod.rs

@@ -25,6 +25,8 @@ pub mod style;
 
 #[derive(Component, Clone, Default)]
 pub struct MenuMarker {}
+#[derive(Component, Clone, Default)]
+pub struct MenuCameraMarker {}
 
 pub struct MenuPlugin;
 
@@ -38,6 +40,7 @@ pub fn wrap_menu(menu: impl Scene) -> impl Scene {
     bsn! {
         #MenuRoot
         MenuMarker
+        Transform
         Node {
             width: percent(100),
             height: percent(100),
@@ -46,6 +49,12 @@ pub fn wrap_menu(menu: impl Scene) -> impl Scene {
             flex_direction: FlexDirection::Column,
         }
         Children [
+            (
+                #MenuCamera
+                Camera
+                Camera2d
+                MenuCameraMarker
+            ),
             (
                 #MenuContainer
                 Node {
@@ -70,10 +79,9 @@ pub fn despawn_menu(
     if let Some(entity) = existing_menu {
         commands
             .entity(entity.into_inner())
-            .remove::<Camera2d>()
-            .remove::<Camera>()
             .despawn();
     }
+
 }
 
 pub fn spawn_menu(
@@ -84,8 +92,6 @@ pub fn spawn_menu(
     if let Some(entity) = existing_menu {
         commands
             .entity(entity.into_inner())
-            .remove::<Camera2d>()
-            .remove::<Camera>()
             .despawn();
     }
     commands.queue_spawn_scene(wrap_menu(menu));
@@ -113,16 +119,7 @@ impl Plugin for MenuPlugin {
     fn build(&self, app: &mut App) {
         app.add_systems(
             OnEnter(AppState::MainMenu),
-            (build_menu::<MainMenu>, |mut commands: Commands| {
+            build_menu::<MainMenu>,
-                commands.spawn((Camera2d, IsDefaultUiCamera));
-                commands.spawn((
-                    Camera2d,
-                    Camera {
-                        order: 1,
-                        ..default()
-                    },
-                ));
-            }),
         )
         .add_message::<character_select::PlayerSlotAssigned>()
         .init_resource::<navigation::UINavigationActionState>()

src/replay.rs

@@ -152,6 +152,20 @@ fn validate(replay: &Replay) -> Result<(), String> {
     {
         return Err("replay frames must be strictly ordered".into());
     }
+    if replay
+        .frames
+        .windows(2)
+        .any(|frames| frames[0].frame.checked_add(1) != Some(frames[1].frame))
+    {
+        return Err("replay frames must be contiguous".into());
+    }
+    if replay
+        .checksums
+        .windows(2)
+        .any(|checksums| checksums[0].frame >= checksums[1].frame)
+    {
+        return Err("replay checksums must be strictly ordered".into());
+    }
     if replay
         .frames
         .iter()
@@ -173,6 +187,21 @@ impl Replay {
         handles.sort_unstable();
         handles != (0..handles.len()).collect::<Vec<_>>()
     }
+
+    fn frame(&self, frame: i32) -> Option<&ReplayFrame> {
+        let first_frame = self.frames.first()?.frame;
+        let index = frame.checked_sub(first_frame)? as usize;
+        self.frames
+            .get(index)
+            .filter(|recorded| recorded.frame == frame)
+    }
+
+    fn checksum(&self, frame: i32) -> Option<u128> {
+        self.checksums
+            .binary_search_by_key(&frame, |checksum| checksum.frame)
+            .ok()
+            .map(|index| self.checksums[index].checksum)
+    }
 }
 
 fn start_replay(mut commands: Commands, args: Res<Args>, loaded: Option<Res<LoadedReplay>>) {
@@ -210,11 +239,7 @@ fn replay_inputs(
                 .insert(frame.0, inputs.iter().map(|(input, _)| *input).collect());
         }
         ReplayMode::Playback { replay, mismatch } if !*mismatch => {
-            let Some(recorded) = replay
+            let Some(recorded) = replay.frame(frame.0) else {
-                .frames
-                .iter()
-                .find(|recorded| recorded.frame == frame.0)
-            else {
                 error!("Replay has no input for frame {}", frame.0);
                 *mismatch = true;
                 return;
@@ -235,14 +260,10 @@ fn record_checksum(
     let Some(mut runtime) = runtime else { return };
     if matches!(&runtime.mode, ReplayMode::Record { .. }) {
         runtime.checksums.insert(frame.0, checksum.0);
-    } else if let ReplayMode::Playback { replay, mismatch } = &mut runtime.mode {
+    } else if let ReplayMode::Playback { replay, mismatch } = &mut runtime.mode
-        if let Some(expected) = replay
+        && let Some(expected) = replay.checksum(frame.0)
-            .checksums
+        && expected != checksum.0
-            .iter()
-            .find(|value| value.frame == frame.0)
-            .map(|value| value.checksum)
     {
-            if expected != checksum.0 {
         error!(
             "Replay desync at frame {}: expected {:X}, got {:X}",
             frame.0, expected, checksum.0
@@ -250,8 +271,6 @@ fn record_checksum(
         *mismatch = true;
     }
 }
-    }
-}
 
 fn stop_recording(
     mut commands: Commands,
@@ -407,4 +426,41 @@ mod tests {
             "unsupported replay version 1"
         );
     }
+
+    #[test]
+    fn playback_lookups_use_frame_offsets_and_support_sparse_checksums() {
+        let mut replay = sample();
+        replay.frames[0].frame = 10;
+        replay.frames.push(ReplayFrame {
+            frame: 11,
+            inputs: replay.frames[0].inputs.clone(),
+        });
+        replay.checksums.push(ReplayChecksum {
+            frame: 11,
+            checksum: 84,
+        });
+        replay.checksums[0].frame = 10;
+        validate(&replay).unwrap();
+
+        assert_eq!(replay.frame(10).unwrap().frame, 10);
+        assert_eq!(replay.frame(11).unwrap().frame, 11);
+        assert!(replay.frame(9).is_none());
+        assert_eq!(replay.checksum(10), Some(42));
+        assert_eq!(replay.checksum(11), Some(84));
+        assert_eq!(replay.checksum(12), None);
+    }
+
+    #[test]
+    fn noncontiguous_input_frames_are_rejected() {
+        let mut replay = sample();
+        replay.frames.push(ReplayFrame {
+            frame: 3,
+            inputs: replay.frames[0].inputs.clone(),
+        });
+
+        assert_eq!(
+            validate(&replay).unwrap_err(),
+            "replay frames must be contiguous"
+        );
+    }
 }

src/schedule.rs

@@ -19,10 +19,10 @@ pub enum GameplaySet {
     StateUpdate,
     /// Integrate velocities into positions.
     Physics,
-    /// Solve collision boxes
-    Animation,
     /// Resolve the integrated positions against the stage.
     Collision,
+    /// Solve collision boxes
+    Animation,
     /// Resolve attacks
     Attacks,
 }
@@ -40,8 +40,8 @@ impl Plugin for GameplaySchedulePlugin {
                 GameplaySet::Interrupt,
                 GameplaySet::StateUpdate,
                 GameplaySet::Physics,
-                GameplaySet::Collision,
                 GameplaySet::Animation,
+                GameplaySet::Collision,
                 GameplaySet::Attacks,
             )
                 .chain(),

src/stage/line.rs

@@ -26,7 +26,7 @@ pub enum StagePolyType {
     Platform,
 }
 
-#[derive(Reflect, Hash, Debug, Clone, Copy, Default)]
+#[derive(Reflect, Hash, Debug, Clone, Copy, Default, PartialEq, Eq)]
 pub struct StageLineID {
     pub polygon: usize,
     pub segment: usize,

src/ui/fighter_info.rs

@@ -1,13 +1,17 @@
 use bevy::prelude::*;
 
-use crate::{fighter::{attack::FighterDamage, manifest::{FighterManifest}}, match_loading::MatchPlayer, player::Player};
+use crate::{
+    fighter::{attack::FighterDamage, manifest::FighterManifest}, match_loading::{MatchPlayer}, match_runtime::MatchState, player::Player, ui::stock_icon::BattleUIStockIcon,
+};
 
 #[derive(Component, FromTemplate)]
 pub struct FighterInfoUI {
     percentage_text: Entity,
+    stock_icon_container: Entity,
     _name_text: Entity,
     player_handle: usize,
     visible_damage: FighterDamage,
+    visible_stocks: u8,
 }
 
 impl FighterInfoUI {
@@ -16,6 +20,7 @@ impl FighterInfoUI {
         bsn! {
             FighterInfoUI {
                 percentage_text: #PercentageText,
+                stock_icon_container: #StockIconContainer,
                 _name_text: #NameText,
                 player_handle: {match_player.handle}
             }
@@ -25,6 +30,10 @@ impl FighterInfoUI {
                 justify_content: JustifyContent::Center,
             }
             Children [
+                (
+                    #StockIconContainer
+                    Node
+                )
                 (
                     #PercentageText
                     Text("0.00%")
@@ -41,17 +50,54 @@ impl FighterInfoUI {
     }
 }
 
-pub fn update_fighter_info_damage(fighters: Query<(&Player, &FighterDamage)>, ui_elements: Query<&mut FighterInfoUI>, mut commands: Commands) {
+pub fn update_fighter_info_damage(
+    fighters: Query<(&Player, &FighterDamage)>,
+    ui_elements: Query<&mut FighterInfoUI>,
+    mut commands: Commands,
+) {
     for mut ui_element in ui_elements {
-        let Some((_, damage)) = fighters.iter().find(|(player, _)| {
+        let Some((_, damage)) = fighters
-            player.handle == ui_element.player_handle
+            .iter()
-        }) else {
+            .find(|(player, _)| player.handle == ui_element.player_handle)
+        else {
             continue;
         };
 
         if *damage != ui_element.visible_damage {
-            commands.entity(ui_element.percentage_text).insert(Text(format!("{}%", damage)));
+            commands
+                .entity(ui_element.percentage_text)
+                .insert(Text(format!("{}%", damage)));
             ui_element.visible_damage = damage.clone();
         }
     }
 }
+
+pub fn update_fighter_info_stocks(
+    match_state: Res<MatchState>,
+    ui_elements: Query<&mut FighterInfoUI>,
+    mut commands: Commands,
+) {
+
+    for mut ui_element in ui_elements {
+        let handle = ui_element.player_handle;
+        let Some(match_player) = match_state.players.get(handle) else {
+            continue;
+        };
+
+        let Some(stocks) = match_player.stocks_remaining else {
+            continue;
+        };
+
+        if stocks != ui_element.visible_stocks {
+            commands
+                .entity(ui_element.stock_icon_container)
+                .despawn_children()
+                .with_children(|spawner| {
+                    for _ in 0..stocks {
+                        spawner.spawn_empty().apply_scene(BattleUIStockIcon::scene());
+                    }
+                });
+            ui_element.visible_stocks = stocks;
+        }
+    }
+}

src/ui/mod.rs

@@ -1,10 +1,15 @@
 use bevy::prelude::*;
 
-use crate::AppState;
+use crate::{
+    AppState,
+    match_loading::{MatchConfig, MatchRules},
+    match_runtime::MatchState,
+};
 
 pub mod battle_ui;
 pub mod errors;
 pub mod fighter_info;
+pub mod stock_icon;
 
 #[derive(Default)]
 pub struct InGameUIPlugin;
@@ -13,6 +18,20 @@ impl Plugin for InGameUIPlugin {
     fn build(&self, app: &mut App) {
         app.add_systems(OnEnter(AppState::InMatch), battle_ui::spawn_battle_ui)
             .add_systems(OnExit(AppState::InMatch), battle_ui::cleanup_battle_ui)
-            .add_systems(PostUpdate, fighter_info::update_fighter_info_damage);
+            .add_systems(PostUpdate, fighter_info::update_fighter_info_damage)
+            .add_systems(
+                PostUpdate,
+                fighter_info::update_fighter_info_stocks.run_if(
+                    resource_exists::<MatchState>
+                        .and_then(resource_exists::<MatchConfig>)
+                        .and_then(|match_config: Res<MatchConfig>| {
+                            if let MatchRules::Stock { .. } = match_config.rules {
+                                true
+                            } else {
+                                false
+                            }
+                        }),
+                ),
+            );
     }
 }

src/ui/stock_icon.rs

@@ -0,0 +1,17 @@
+use bevy::prelude::*;
+
+#[derive(SceneComponent, Clone, FromTemplate)]
+pub struct BattleUIStockIcon;
+
+impl BattleUIStockIcon {
+    pub fn scene() -> impl Scene {
+        bsn! {
+            Node {
+                width: px(32),
+                height: px(32),
+                border_radius: BorderRadius::MAX,
+            }
+            BackgroundColor({bevy::color::palettes::css::RED})
+        }
+    }
+}

tools/lldb_fixed.py

@@ -0,0 +1,123 @@
+"""LLDB summaries for Rust's `fixed` crate.
+
+Load this file from LLDB with:
+
+    command script import /path/to/shinespark/tools/lldb_fixed.py
+
+The implementation does not use floating-point arithmetic, so displayed values
+are exact even for FixedI128/FixedU128 values.
+"""
+
+import re
+
+try:
+    import lldb
+except ImportError:
+    # Keep the pure parsing and formatting helpers testable without LLDB.
+    lldb = None
+
+
+_FIXED_TYPE_RE = re.compile(r"(?:^|::)Fixed([IU])(8|16|32|64|128)<(.+)>$")
+_DIRECT_TYPENUM_RE = re.compile(r"(?:^|::)U(\d+)$")
+_TYPENUM_BIT_RE = re.compile(r"(?:^|::)B([01])(?=\s*[,>])")
+
+
+def parse_fixed_type(type_name):
+    """Return (signed, storage_bits, fractional_bits), or None."""
+    if not type_name:
+        return None
+
+    match = _FIXED_TYPE_RE.search(type_name.replace(" ", ""))
+    if match is None:
+        return None
+
+    signed = match.group(1) == "I"
+    storage_bits = int(match.group(2))
+    fractional_type = match.group(3)
+
+    direct = _DIRECT_TYPENUM_RE.search(fractional_type)
+    if direct is not None:
+        fractional_bits = int(direct.group(1))
+    else:
+        # typenum represents UInt<N, B> as a binary tree. Its textual Rust
+        # type lists the bits from most significant to least significant.
+        digits = _TYPENUM_BIT_RE.findall(fractional_type)
+        if not digits:
+            return None
+        fractional_bits = int("".join(digits), 2)
+
+    if fractional_bits > storage_bits:
+        return None
+    return signed, storage_bits, fractional_bits
+
+
+def normalize_bits(raw_bits, signed, storage_bits):
+    """Interpret a possibly unsigned LLDB integer using the fixed type's width."""
+    mask = (1 << storage_bits) - 1
+    raw_bits &= mask
+    if signed and raw_bits >= 1 << (storage_bits - 1):
+        raw_bits -= 1 << storage_bits
+    return raw_bits
+
+
+def format_fixed(raw_bits, fractional_bits):
+    """Format a scaled integer exactly as a decimal string."""
+    if fractional_bits == 0:
+        return str(raw_bits)
+
+    negative = raw_bits < 0
+    magnitude = -raw_bits if negative else raw_bits
+    whole = magnitude >> fractional_bits
+    remainder = magnitude & ((1 << fractional_bits) - 1)
+
+    if remainder == 0:
+        result = str(whole)
+    else:
+        # remainder / 2^n == (remainder * 5^n) / 10^n, which gives a finite,
+        # exact decimal representation without converting through a float.
+        decimal = str(remainder * 5**fractional_bits).zfill(fractional_bits)
+        result = f"{whole}.{decimal.rstrip('0')}"
+
+    return f"-{result}" if negative else result
+
+
+def _parse_lldb_integer(value):
+    text = value.GetValue()
+    if text is not None:
+        try:
+            return int(text, 0)
+        except ValueError:
+            pass
+
+    # GetValueAsUnsigned is also useful on LLDB versions that do not render
+    # primitive values through GetValue. It is sufficient for all <= 64-bit
+    # fixed types; current LLDB versions render i128/u128 through GetValue.
+    return value.GetValueAsUnsigned()
+
+
+def fixed_summary(value, _internal_dict):
+    layout = parse_fixed_type(value.GetTypeName())
+    if layout is None:
+        return None
+
+    signed, storage_bits, fractional_bits = layout
+    bits = value.GetChildMemberWithName("bits")
+    if not bits.IsValid():
+        return None
+
+    raw_bits = _parse_lldb_integer(bits)
+    raw_bits = normalize_bits(raw_bits, signed, storage_bits)
+    return format_fixed(raw_bits, fractional_bits)
+
+
+def __lldb_init_module(debugger, _internal_dict):
+    # LLDB's type-name regex sees the concrete fixed type rather than project
+    # aliases such as FGi32 and FGWide.
+    debugger.HandleCommand(
+        "type summary add --python-function lldb_fixed.fixed_summary "
+        "--category Shinespark --regex "
+        "'^fixed::Fixed(I|U)(8|16|32|64|128)<.+>$'"
+    )
+    # A dedicated category makes the formatter work even when CodeLLDB has not
+    # enabled rustc's standard `Rust` formatter category yet.
+    debugger.HandleCommand("type category enable Shinespark")

tools/test_lldb_fixed.py

@@ -0,0 +1,58 @@
+import unittest
+
+import lldb_fixed
+
+
+class ParseFixedTypeTests(unittest.TestCase):
+    def test_direct_typenum_alias(self):
+        self.assertEqual(
+            lldb_fixed.parse_fixed_type("fixed::FixedI32<typenum::uint::U16>"),
+            (True, 32, 16),
+        )
+
+    def test_expanded_typenum(self):
+        type_name = (
+            "fixed::FixedI32<"
+            "typenum::uint::UInt<"
+            "typenum::uint::UInt<"
+            "typenum::uint::UInt<"
+            "typenum::uint::UInt<"
+            "typenum::uint::UInt<typenum::uint::UTerm, typenum::bit::B1>, "
+            "typenum::bit::B0>, typenum::bit::B0>, typenum::bit::B0>, "
+            "typenum::bit::B0>>"
+        )
+        self.assertEqual(lldb_fixed.parse_fixed_type(type_name), (True, 32, 16))
+
+    def test_unsigned_type(self):
+        self.assertEqual(
+            lldb_fixed.parse_fixed_type("fixed::FixedU64<typenum::uint::U24>"),
+            (False, 64, 24),
+        )
+
+    def test_unrelated_type(self):
+        self.assertIsNone(lldb_fixed.parse_fixed_type("core::primitive::i32"))
+
+
+class FormatFixedTests(unittest.TestCase):
+    def test_q16_16(self):
+        self.assertEqual(lldb_fixed.format_fixed(3 << 15, 16), "1.5")
+        self.assertEqual(lldb_fixed.format_fixed(-(3 << 15), 16), "-1.5")
+        self.assertEqual(lldb_fixed.format_fixed(1, 16), "0.0000152587890625")
+
+    def test_integer_value_has_no_decimal_suffix(self):
+        self.assertEqual(lldb_fixed.format_fixed(12 << 16, 16), "12")
+
+    def test_q96_32(self):
+        raw = (1 << 100) + (1 << 31)
+        self.assertEqual(
+            lldb_fixed.format_fixed(raw, 32),
+            "295147905179352825856.5",
+        )
+
+    def test_twos_complement_normalization(self):
+        self.assertEqual(lldb_fixed.normalize_bits(0xFFFF8000, True, 32), -32768)
+        self.assertEqual(lldb_fixed.normalize_bits(0xFFFF8000, False, 32), 0xFFFF8000)
+
+
+if __name__ == "__main__":
+    unittest.main()