Optimize rollback sync-test performance (#86)

## Summary

- remove immutable stage geometry and derived animation/collision data from rollback snapshots
- avoid a duplicate full skeletal hierarchy traversal during root-motion sampling
- cache root-motion cycle deltas per animation clip
- optimize the game crate in development builds
- make Tracy profiling opt-in via the `tracy` feature

Reviewed-on: #86
Co-authored-by: Álex Román Núñez <eirexe@eirteam.moe>

src/fighter/baked_animation/runtime.rs

@@ -127,6 +127,8 @@ pub struct FighterBoneMatrices {
     /// pose has the root translation removed.
     previous_root_motion_translation: Option<FGVec3>,
     root_motion_delta: crate::math::vec3::FGVec3,
+    cached_root_motion_kind: Option<AnimKind>,
+    cached_root_motion_cycle_delta: FGVec3,
 }
 
 #[derive(Component, Clone, Debug, Default)]
@@ -366,12 +368,6 @@ impl FighterBoneMatrices {
                     .expect("configured root motion bone should exist"),
             )
         };
-        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 self.model_matrices)
-                .expect("baked bone hierarchy should be valid");
-        }
         let model_scale = FixedMat4 {
             cols: [
                 [model_scale, FGi32::ZERO, FGi32::ZERO, FGi32::ZERO],
@@ -380,13 +376,16 @@ impl FighterBoneMatrices {
                 [FGi32::ZERO, FGi32::ZERO, FGi32::ZERO, FGi32::ONE],
             ],
         };
+        // Root motion only needs the configured bone's model transform. Resolve
+        // that ancestry first, then do the normal full-pose pass once below.
+        // Previously the complete hierarchy was resolved once before removing
+        // root translation and once afterwards.
         let raw_root_motion_translation = root_index.map(|root_index| {
-            model_scale
-                .mul(
-                    self.model_matrices[root_index]
-                        .expect("baked bone hierarchy should be valid"),
-                )
-                .get_translation()
+            self.model_matrices.resize(local.len(), None);
+            self.model_matrices.fill(None);
+            let root = resolve_model_transform(root_index, parents, local, &mut self.model_matrices)
+                .expect("baked bone hierarchy should be valid");
+            model_scale.mul(root).get_translation()
         });
 
         // Gameplay owns the root's displacement.  Keep rotation and scale in
@@ -394,11 +393,12 @@ impl FighterBoneMatrices {
         // used by visuals and gameplay volumes.
         if let Some(root_index) = root_index {
             self.local_matrices[root_index].translate(FGVec3::ZERO);
-            self.model_matrices.fill(None);
-            for index in 0..local.len() {
-                resolve_model_transform(index, parents, &self.local_matrices, &mut self.model_matrices)
-                    .expect("baked bone hierarchy should be valid");
-            }
+        }
+        self.model_matrices.resize(local.len(), None);
+        self.model_matrices.fill(None);
+        for index in 0..local.len() {
+            resolve_model_transform(index, parents, &self.local_matrices, &mut self.model_matrices)
+                .expect("baked bone hierarchy should be valid");
         }
         self.matrices.clear();
         self.matrices.extend(
@@ -517,9 +517,16 @@ fn sample_fighter_bone_matrices(
     let manifest = manifests
         .get(&fighter.manifest)
         .expect("fighter manifest should be loaded before the match starts");
-    let root_motion_cycle_delta = baked
-        .root_motion_cycle_delta(frame.kind, &manifest.root_motion_bone, manifest.model_scale)
-        .unwrap_or(FGVec3::ZERO);
+    let root_motion_cycle_delta = if matrices.cached_root_motion_kind == Some(frame.kind) {
+        matrices.cached_root_motion_cycle_delta
+    } else {
+        let delta = baked
+            .root_motion_cycle_delta(frame.kind, &manifest.root_motion_bone, manifest.model_scale)
+            .unwrap_or(FGVec3::ZERO);
+        matrices.cached_root_motion_kind = Some(frame.kind);
+        matrices.cached_root_motion_cycle_delta = delta;
+        delta
+    };
     let root_motion_loop_frame_count = baked
         .frame_count(frame.kind)
         .map(|count| count.saturating_sub(1).max(1));