Enum Curve 

pub enum Curve {
    Line(LineCurve),
    Circle(CircleCurve),
    Ellipse(EllipseCurve),
    Hyperbola(HyperbolaCurve),
    Parabola(ParabolaCurve),
    BSpline(BSplineCurve),
    Helix(HelixCurve),
    Trimmed(Box<TrimmedCurve>),
    Offset(Box<OffsetCurve>),
    OnSurface(Box<CurveOnSurface>),
}

A curve in space.

Variants

Line(LineCurve)

A straight line.

Circle(CircleCurve)

A circle or arc.

Ellipse(EllipseCurve)

An ellipse or arc.

Hyperbola(HyperbolaCurve)

One branch of a hyperbola.

Parabola(ParabolaCurve)

A parabola.

BSpline(BSplineCurve)

A polynomial or rational B-spline.

Helix(HelixCurve)

A helix about an axis, the one transcendental the vocabulary keeps.

Trimmed(Box<TrimmedCurve>)

Another curve restricted to a sub-interval.

Offset(Box<OffsetCurve>)

A curve at a constant distance from another, offset in the plane perpendicular to a reference direction.

OnSurface(Box<CurveOnSurface>)

A surface curve: a pcurve composed with the surface it is drawn on.

Implementations

impl Curve

pub fn to_bspline(&self, tol: Tolerances) -> OgeomResult<BSplineCurve>

This curve as a B-spline, exactly, over [0, 1].

Exact rather than fitted: the result passes through the same points as the original at corresponding parameters, to rounding. The correspondence is not the identity; see the module documentation for why it cannot be.

Errors

OgeomError::Construction if the curve’s range is degenerate or its geometry cannot be evaluated.

pub fn to_bspline_over( &self, range: (f64, f64), tol: Tolerances, ) -> OgeomResult<BSplineCurve>

This curve as a B-spline over part of its range.

The span is what gets converted, rather than the whole curve being converted and then trimmed. For a conic those differ: trimming a rational quadratic needs knot insertion at a parameter that has to be solved for, while building the arc directly is a closed form.

Errors

As Curve::to_bspline.

impl Curve

A spline over [0, 1], whatever it was over.

pub fn fitted_bspline_over( &self, range: (f64, f64), tolerance: f64, tol: Tolerances, ) -> OgeomResult<Fitted<BSplineCurve>>

This curve as a B-spline fitted over range to a stated tolerance, at the curve’s own parameters.

The approximation Curve::to_bspline refuses to make silently: a helix, an offset curve, a curve on a surface (anything with no exact rational form) is sampled at its own parameters and fitted through them, the fit measured against the curve between the samples as well as at them, and the sampling doubled until the tolerance is met or the budget runs out. The result is same-parameter with the curve, so every chart already speaking the curve’s parameter still does, and its error is what was measured, not what was asked.

Errors

OgeomError::Construction if the range is empty or the tolerance is not a distance; as fit::fit_points_at.

impl Curve

pub fn general_transformed( &self, t: &GeneralTransform, tol: Tolerances, ) -> OgeomResult<BSplineCurve>

This curve carried through a general affine transform.

A shear or an uneven scale is not a placement: it carries a circle to an ellipse, and an ellipse to a conic with no analytic name here. So the curve is converted to its exact B-spline form first and the control points are moved, which an affine map does exactly: a B-spline is an affine combination of its control points, so transforming them and transforming every point of the curve are the same thing.

The result is a B-spline whatever went in, and its parameterization is the converted one rather than the original. That is the price of a transform the analytic types cannot express, and it is why transformed takes only a Transform: a placement keeps the type, and only this does not.

Errors

As Curve::to_bspline, plus OgeomError::Construction if the transform collapses the curve to a point.

Trait Implementations

impl Clone for Curve

fn clone(&self) -> Curve

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Curve3d for Curve

fn domain(&self) -> (f64, f64)

The parameter interval over which the curve is defined.

fn point_at(&self, u: f64, tol: Tolerances) -> OgeomResult<Point>

The point at u.

fn d1_at(&self, u: f64, tol: Tolerances) -> OgeomResult<Vector>

The first derivative at u.

fn derivatives_at( &self, u: f64, n: usize, tol: Tolerances, ) -> OgeomResult<Vec<Vector>>

Derivatives up to order n, with result[0] the point itself.

fn kind(&self) -> CurveKind

What kind of curve this is.

fn continuity(&self) -> Continuity

How smooth the curve is across its domain.

fn is_closed(&self, tol: Tolerances) -> bool

Whether the curve’s ends meet.

fn is_periodic(&self) -> bool

Whether the curve continues past its domain by repeating.

fn tangent_at(&self, u: f64, tol: Tolerances) -> OgeomResult<Direction>

The unit tangent at u.

fn curvature_at(&self, u: f64, tol: Tolerances) -> OgeomResult<f64>

The curvature at u.

fn start(&self, tol: Tolerances) -> OgeomResult<Point>

The start point.

fn end(&self, tol: Tolerances) -> OgeomResult<Point>

The end point.

fn normalize_parameter(&self, u: f64, tol: Tolerances) -> OgeomResult<f64>

Bring u into the domain, wrapping if the curve is periodic.

impl Debug for Curve

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

Formats the value using the given formatter.

impl From<BSplineCurve> for Curve

fn from(c: BSplineCurve) -> Self

Converts to this type from the input type.

impl From<CircleCurve> for Curve

fn from(c: CircleCurve) -> Self

Converts to this type from the input type.

impl From<EllipseCurve> for Curve

fn from(c: EllipseCurve) -> Self

Converts to this type from the input type.

impl From<HelixCurve> for Curve

fn from(c: HelixCurve) -> Self

Converts to this type from the input type.

impl From<HyperbolaCurve> for Curve

fn from(c: HyperbolaCurve) -> Self

Converts to this type from the input type.

impl From<LineCurve> for Curve

fn from(c: LineCurve) -> Self

Converts to this type from the input type.

impl From<ParabolaCurve> for Curve

fn from(c: ParabolaCurve) -> Self

Converts to this type from the input type.

impl From<TrimmedCurve> for Curve

fn from(c: TrimmedCurve) -> Self

Converts to this type from the input type.

impl PartialEq for Curve

fn eq(&self, other: &Curve) -> 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 Reversible for Curve

fn reversed(&self) -> Self

This geometry with its parameter direction reversed.

impl StructuralPartialEq for Curve

impl Transformable for Curve

fn transformed(&self, t: &Transform, tol: Tolerances) -> OgeomResult<Self>

This geometry moved by t.