Struct RefFrameState 

pub struct RefFrameState {
    pub trans: RefFrameTrans,
    pub rot: RefFrameRot,
}

Combined translational + rotational state of a frame relative to its parent. The untyped storage form used by crate::FrameTree.

Fields

trans: RefFrameTrans

Translational state in parent coordinates.

rot: RefFrameRot

Rotational state (parent → this).

Implementations

impl RefFrameState

pub fn negate(source: &RefFrameState) -> RefFrameState

Negate (invert) a frame state.

If source represents the state of frame B relative to frame A (A->B), the result represents the state of frame A relative to frame B (B->A).

Ported from JEOD ref_frame_state.cc negate method.

Convention:

• trans.position: position of “this” frame’s origin in parent frame coords
• trans.velocity: velocity of “this” frame’s origin in parent frame coords
• rot.t_parent_this: transforms vectors FROM parent TO this frame
• rot.ang_vel_this: angular velocity of this frame relative to parent, in this frame coords

pub fn incr_right(&self, s_bc: &RefFrameState) -> RefFrameState

Compose self (A->B) with s_bc (B->C) to produce A->C.

“Increment right”: given self = S_{A:B} and s_bc = S_{B:C}, compute and return S_{A:C}.

Ported from JEOD ref_frame_state.cc incr_right / compose_state. The identity-rotation fast-path mirrors the Numerical::compare_exact( rot.Q_parent_this.scalar, 1.0) shortcut at models/utils/ref_frames/src/ref_frame_state.cc:267-302 (incr_left, the function JEOD uses in compute_relative_state). When self.rot.q_parent_this is bit-exactly identity, T_{A:B}^T = I and Q_{A:B} is identity, so the quaternion-multiply + normalize + matrix-rebuild round-trip would just reproduce s_bc’s rotation with f64 round-off. Copying instead preserves bits and gives walks through identity hops the hop-count invariance JEOD’s compute_relative_state algorithm assumes (see issue #562 for the case where the absence of this shortcut produced ~30 ULP body-position drift between the 1-hop runner and 2-hop Bevy frame-tree shapes).

Velocity composition retains the omega_{A:B} × x_{B:C} term — this matches JEOD’s incr_left identity branch (:293-295) and our own non-fast-path. JEOD’s separate incr_right identity branch (:376-381) drops that term, but is documented in JEOD as an untested utility “not used in the Reference Frame Model at any point” (:309-311); we don’t propagate that inconsistency.

pub fn incr_left(&mut self, s_ab: &RefFrameState)

Compose s_ab (A->B) with self (B->C) to produce A->C, updating self in place.

“Increment left”: given s_ab = S_{A:B} and self = S_{B:C}, update self to become S_{A:C}.

Same math as incr_right but with different roles.

Trait Implementations

impl Clone for RefFrameState

fn clone(&self) -> RefFrameState

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for RefFrameState

impl Debug for RefFrameState

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for RefFrameState

fn default() -> RefFrameState

Returns the “default value” for a type.

impl PartialEq for RefFrameState

fn eq(&self, other: &RefFrameState) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for RefFrameState