Struct HingeConstraint 

pub struct HingeConstraint {
    pub body_a: BodyHandle,
    pub body_b: BodyHandle,
    pub anchor_a: Vec2,
    pub anchor_b: Vec2,
    pub limits: Option<(f32, f32)>,
    pub motor: Option<(f32, f32)>,
    pub compliance: f32,
    /* private fields */
}

Hinge (revolute) joint: two bodies share a common anchor. Allows rotation around the Z-axis. Supports angular limits and a velocity motor.

Fields

body_a: BodyHandle

body_b: BodyHandle

anchor_a: Vec2

anchor_b: Vec2

limits: Option<(f32, f32)>

Angular limits: (min, max) relative angle in radians.

motor: Option<(f32, f32)>

Motor: (target_velocity, max_torque).

compliance: f32

Compliance for soft limits (0 = rigid).

Implementations

impl HingeConstraint

pub fn new( body_a: BodyHandle, anchor_a: Vec2, body_b: BodyHandle, anchor_b: Vec2, ) -> Self

pub fn with_limits(self, min: f32, max: f32) -> Self

Add angular limits in radians (relative angle of B w.r.t. A).

pub fn with_motor(self, target_velocity: f32, max_torque: f32) -> Self

Add a rotational motor.

pub fn with_compliance(self, c: f32) -> Self

Trait Implementations

impl Clone for HingeConstraint

fn clone(&self) -> HingeConstraint

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Constraint for HingeConstraint

fn prepare(&mut self, _bodies: &HashMap<BodyHandle, BodyState>, _dt: f32)

Prepare the constraint for the current step (pre-compute cached values).

fn compute_cdot(&self, bodies: &HashMap<BodyHandle, BodyState>) -> f32

Compute the velocity constraint violation (Cdot = J * v).

fn compute_c(&self, bodies: &HashMap<BodyHandle, BodyState>) -> f32

Compute the position constraint violation (C).

fn get_compliance(&self) -> f32

XPBD compliance (inverse stiffness). 0 = rigid.

fn effective_mass(&self, bodies: &HashMap<BodyHandle, BodyState>) -> f32

Compute effective constraint mass (1 / (J M^-1 J^T)).

fn apply_impulse( &self, bodies: &mut HashMap<BodyHandle, BodyState>, lambda: f32, )

Apply the corrective impulse to body states.

fn solve_velocity( &mut self, bodies: &mut HashMap<BodyHandle, BodyState>, dt: f32, )

Solve velocity constraint (one iteration).

fn solve_position( &mut self, bodies: &mut HashMap<BodyHandle, BodyState>, dt: f32, )

Solve position constraint using XPBD (one sub-step).

fn accumulated_impulse(&self) -> f32

Accumulated impulse for warm starting.

fn reset_accumulated(&mut self)

fn add_accumulated(&mut self, d: f32)

fn body_handles(&self) -> Vec<BodyHandle>

Bodies involved in this constraint.

fn bias(&self, bodies: &HashMap<BodyHandle, BodyState>, dt: f32) -> f32

Baumgarte position bias.

fn impulse_bounds(&self) -> (f32, f32)

Whether this constraint has an upper/lower impulse clamp.

impl Debug for HingeConstraint

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

Formats the value using the given formatter.