Struct HelixCurve 

pub struct HelixCurve { /* private fields */ }

A helix about its frame’s z, parameterized by turn angle.

The point at t sits at angle t around the axis, radius out along the turned x, risen by pitch·t/2π along z, so one full turn advances exactly one pitch, and a negative pitch winds the other hand. A non-zero taper advances the radius the same way and winds a cone instead. A helix is transcendental: no rational B-spline states it exactly, which is why it is its own type rather than a conversion.

Implementations

impl HelixCurve

pub fn new( frame: Frame, radius: f64, pitch: f64, turns: f64, ) -> OgeomResult<Self>

A helix over turns full revolutions from angle zero.

Errors

OgeomError::Construction if the radius is not finite and positive, the pitch is not finite and non-zero (a zero pitch is a circle, and there is a type for that), or turns is not finite and positive.

pub fn over( frame: Frame, radius: f64, pitch: f64, start: f64, end: f64, ) -> OgeomResult<Self>

A helix over an arbitrary increasing angle interval.

Errors

As HelixCurve::new, with the interval checked instead of the turn count.

pub fn conical( frame: Frame, radius: f64, pitch: f64, taper: f64, start: f64, end: f64, ) -> OgeomResult<Self>

A conical helix: the radius advances by taper per full turn while the point rises by pitch, winding the cone whose half-angle satisfies tan(angle) = taper / pitch. radius is the radius at angle zero, whether or not the interval holds it.

Errors

As HelixCurve::over, and additionally if taper is not finite or the radius runs non-positive anywhere on the interval; past the apex there is no cone to wind.

pub const fn frame(&self) -> &Frame

The frame the helix turns about.

pub const fn radius(&self) -> f64

The radius.

pub const fn pitch(&self) -> f64

The advance along the axis per full turn; negative winds left-handed.

pub const fn taper(&self) -> f64

The radial advance per full turn; zero is the cylindrical helix.

pub const fn is_reversed(&self) -> bool

Whether evaluation runs the domain backwards.

pub fn arc_length(&self, from: f64, to: f64) -> f64

The exact arc length between two parameters: constant speed times the swept angle.

Trait Implementations

impl Clone for HelixCurve

fn clone(&self) -> HelixCurve

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for HelixCurve

impl Curve3d for HelixCurve

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 HelixCurve

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

Formats the value using the given formatter.

impl From<HelixCurve> for Curve

fn from(c: HelixCurve) -> Self

Converts to this type from the input type.

impl PartialEq for HelixCurve

fn eq(&self, other: &HelixCurve) -> 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 HelixCurve