Implement root motion into grounded attacks and implement dash attack

src/fighter/baked_animation/runtime.rs

@@ -122,6 +122,10 @@ pub struct FighterBoneMatrices {
     model_matrices: Vec<Option<FixedMat4>>,
     presentation_kind: Option<AnimKind>,
     previous_animation_frame: Option<FighterAnimationFrame>,
+    /// The raw, scaled model-space root translation used as the baseline for
+    /// root-motion extraction.  This is kept separately because the published
+    /// pose has the root translation removed.
+    previous_root_motion_translation: Option<FGVec3>,
     root_motion_delta: crate::math::vec3::FGVec3,
 }
 
@@ -351,6 +355,17 @@ impl FighterBoneMatrices {
         }
         self.local_matrices.clear();
         self.local_matrices.extend_from_slice(local);
+
+        let root_index = if root_motion_bone.is_empty() {
+            None
+        } else {
+            Some(
+                self.bone_names
+                    .iter()
+                    .position(|name| name == root_motion_bone)
+                    .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() {
@@ -365,6 +380,26 @@ impl FighterBoneMatrices {
                 [FGi32::ZERO, FGi32::ZERO, FGi32::ZERO, FGi32::ONE],
             ],
         };
+        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()
+        });
+
+        // Gameplay owns the root's displacement.  Keep rotation and scale in
+        // the animation, but remove its translation before publishing the pose
+        // 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.matrices.clear();
         self.matrices.extend(
             self.model_matrices.iter().map(|matrix| {
@@ -374,15 +409,12 @@ impl FighterBoneMatrices {
         self.root_motion_delta = if advance_history
             && !animation_changed
             && self.previous_animation_frame.is_some()
-            && !root_motion_bone.is_empty()
+            && let (Some(current), Some(previous)) = (
+                raw_root_motion_translation,
+                self.previous_root_motion_translation,
+            )
         {
-            let root_index = self
-                .bone_names
-                .iter()
-                .position(|name| name == root_motion_bone)
-                .expect("configured root motion bone should exist");
-            let mut delta = self.matrices[root_index].get_translation()
-                - self.previous_frame_matrices[root_index].get_translation();
+            let mut delta = current - previous;
             if animation_frame.repeat
                 && self.previous_animation_frame.is_some_and(|previous| {
                     previous.frame.saturating_add(1) == animation_frame.frame
@@ -395,6 +427,7 @@ impl FighterBoneMatrices {
         } else {
             FGVec3::ZERO
         };
+        self.previous_root_motion_translation = raw_root_motion_translation;
         if advance_history {
             self.previous_animation_frame = Some(animation_frame);
         }