Trait VelocitySource

pub trait VelocitySource:
    QueryData
    + Send
    + Sync
    + 'static {
    type Previous: Component;
    type Current: Component;

    // Required methods
    fn previous(start: &Self::Previous) -> Vec3;
    fn current(end: &Self::Current) -> Vec3;
}

A QueryData type for specifying the components that store velocity for easing. Required for TransformExtrapolationPlugin and TransformHermiteEasingPlugin.

Example

use bevy::{ecs::query::QueryData, prelude::*};
use bevy_transform_interpolation::VelocitySource;

// Velocity components

#[derive(Component)]
struct LinearVelocity(Vec3);

#[derive(Component)]
struct PreviousLinearVelocity(Vec3);

#[derive(Component)]
struct AngularVelocity(Vec3);

#[derive(Component)]
struct PreviousAngularVelocity(Vec3);

// Velocity source for easing that uses linear velocity
#[derive(QueryData)]
struct LinVelSource;

impl VelocitySource for LinVelSource {
    type Previous = PreviousLinearVelocity;
    type Current = LinearVelocity;

    fn previous(previous: &Self::Previous) -> Vec3 {
        previous.0
    }

    fn current(current: &Self::Current) -> Vec3 {
        current.0
    }
}

// Velocity source for easing that uses angular velocity
#[derive(QueryData)]
struct AngVelSource;

impl VelocitySource for AngVelSource {
    type Previous = PreviousAngularVelocity;
    type Current = AngularVelocity;

    fn previous(previous: &Self::Previous) -> Vec3 {
        previous.0
    }

    fn current(current: &Self::Current) -> Vec3 {
        current.0
    }
}

Some forms of easing such as extrapolation may not require the previous velocity. In such cases, the Previous component can be set to (), and previous can simply return Vec3::ZERO.

Required Associated Types

type Previous: Component

The component that stores the previous velocity.

This is not required for all easing backends, such as extrapolation. In such cases, this can be set to ().

type Current: Component

The component that stores the current velocity.

Required Methods

fn previous(start: &Self::Previous) -> Vec3

Returns the previous velocity.

This is not required for all easing backends, such as extrapolation. In such cases, this can return Vec3::ZERO.

fn current(end: &Self::Current) -> Vec3

Returns the current velocity.

Object Safety

This trait is not object safe.

Implementations on Foreign Types

impl VelocitySource for ()

type Previous = DummyComponent

type Current = DummyComponent

fn previous(_: &Self::Previous) -> Vec3

fn current(_: &Self::Current) -> Vec3

Implementors