Struct bevy::prelude::CubicCurve

pub struct CubicCurve<P>
where
    P: VectorSpace,
{ /* private fields */ }

A collection of CubicSegments chained into a single parametric curve. Has domain [0, N) where N is the number of attached segments.

Use any struct that implements the CubicGenerator trait to create a new curve, such as CubicBezier.

Implementations

impl<P> CubicCurve<P>

where P: VectorSpace,

pub fn position(&self, t: f32) -> P

Compute the position of a point on the cubic curve at the parametric value t.

Note that t varies from 0..=(n_points - 3).

Examples found in repository

examples/animation/color_animation.rs (line 108)

fn animate_curve<T: CurveColor>(
    time: Res<Time>,
    mut query: Query<(&mut Transform, &mut Sprite, &Curve<T>)>,
) {
    let t = (time.elapsed_seconds().sin() + 1.) / 2.;

    for (mut transform, mut sprite, cubic_curve) in &mut query {
        // position takes a point from the curve where 0 is the initial point
        // and 1 is the last point
        sprite.color = cubic_curve.0.position(t).into();
        transform.translation.x = 600. * (t - 0.5);
    }
}

examples/animation/cubic_curve.rs (line 84)

fn animate_cube(time: Res<Time>, mut query: Query<(&mut Transform, &Curve)>, mut gizmos: Gizmos) {
    let t = (time.elapsed_seconds().sin() + 1.) / 2.;

    for (mut transform, cubic_curve) in &mut query {
        // Draw the curve
        gizmos.linestrip(cubic_curve.0.iter_positions(50), WHITE);
        // position takes a point from the curve where 0 is the initial point
        // and 1 is the last point
        transform.translation = cubic_curve.0.position(t);
    }
}

pub fn velocity(&self, t: f32) -> P

Compute the first derivative with respect to t at t. This is the instantaneous velocity of a point on the cubic curve at t.

Note that t varies from 0..=(n_points - 3).

pub fn acceleration(&self, t: f32) -> P

Compute the second derivative with respect to t at t. This is the instantaneous acceleration of a point on the cubic curve at t.

Note that t varies from 0..=(n_points - 3).

pub fn iter_samples<'a, 'b>( &'b self, subdivisions: usize, sample_function: impl FnMut(&CubicCurve<P>, f32) -> P + 'a ) -> impl Iterator<Item = P> + 'a

where 'b: 'a,

A flexible iterator used to sample curves with arbitrary functions.

This splits the curve into subdivisions of evenly spaced t values across the length of the curve from start (t = 0) to end (t = n), where n = self.segment_count(), returning an iterator evaluating the curve with the supplied sample_function at each t.

For subdivisions = 2, this will split the curve into two lines, or three points, and return an iterator with 3 items, the three points, one at the start, middle, and end.

pub fn segments(&self) -> &[CubicSegment<P>]

The list of segments contained in this CubicCurve.

This spline’s global t value is equal to how many segments it has.

All method accepting t on CubicCurve depends on the global t. When sampling over the entire curve, you should either use one of the iter_* methods or account for the segment count using curve.segments().len().

pub fn iter_positions(&self, subdivisions: usize) -> impl Iterator<Item = P>

Iterate over the curve split into subdivisions, sampling the position at each step.

Examples found in repository

examples/animation/cubic_curve.rs (line 81)

fn animate_cube(time: Res<Time>, mut query: Query<(&mut Transform, &Curve)>, mut gizmos: Gizmos) {
    let t = (time.elapsed_seconds().sin() + 1.) / 2.;

    for (mut transform, cubic_curve) in &mut query {
        // Draw the curve
        gizmos.linestrip(cubic_curve.0.iter_positions(50), WHITE);
        // position takes a point from the curve where 0 is the initial point
        // and 1 is the last point
        transform.translation = cubic_curve.0.position(t);
    }
}

pub fn iter_velocities(&self, subdivisions: usize) -> impl Iterator<Item = P>

Iterate over the curve split into subdivisions, sampling the velocity at each step.

pub fn iter_accelerations(&self, subdivisions: usize) -> impl Iterator<Item = P>

Iterate over the curve split into subdivisions, sampling the acceleration at each step.

pub fn push_segment(&mut self, segment: CubicSegment<P>)

Adds a segment to the curve

Trait Implementations

impl<P> Clone for CubicCurve<P>

where P: Clone + VectorSpace,

fn clone(&self) -> CubicCurve<P>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<P> Debug for CubicCurve<P>

where P: Debug + VectorSpace,

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

Formats the value using the given formatter.

impl<P> Extend<CubicSegment<P>> for CubicCurve<P>

where P: VectorSpace,

fn extend<T>(&mut self, iter: T)

where T: IntoIterator<Item = CubicSegment<P>>,

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl<P> From<CubicCurve<P>> for RationalCurve<P>

where P: VectorSpace,

fn from(value: CubicCurve<P>) -> RationalCurve<P>

Converts to this type from the input type.

impl<P> IntoIterator for CubicCurve<P>

where P: VectorSpace,

type IntoIter = <Vec<CubicSegment<P>> as IntoIterator>::IntoIter

Which kind of iterator are we turning this into?

type Item = CubicSegment<P>

The type of the elements being iterated over.

fn into_iter(self) -> <CubicCurve<P> as IntoIterator>::IntoIter

Creates an iterator from a value.

impl<P> PartialEq for CubicCurve<P>

where P: PartialEq + VectorSpace,

fn eq(&self, other: &CubicCurve<P>) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

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

impl<P> StructuralPartialEq for CubicCurve<P>

where P: VectorSpace,