Struct geo_buffer::util::Ray

pub struct Ray { /* private fields */ }

This structure conceptullay represents a half-line (which also known as “Ray”).

A ray has a “start vertex” r₀, that is, r₀ is a part of the ray itself, but we cannot make a disk of radius ε which contained in the ray around r₀ for every ε > 0.

If we consider the vectors from r₀ to each point on the ray, then they are all pairwise parallel. Therefore, there exists a “direction vector” v and we can represent each point on ray by the parameterized equation:

r₀ + tv (t ≥ 0),

where t is the parameter which is greater than or equal to zero.

We can also think of a ray as the locus of a moving point at a constant velocity from the starting point r₀ as time passes. In this case, the location of the point after time t (t ≥ 0) is equal to r₀ + tv.

Implementations

impl Ray

pub fn new(src: Coordinate, dst: Coordinate) -> Self

Creates and returns a Ray w.r.t. the given arguments.

Arguments

• src: The starting point of the ray.
• dst: The point for which src is heading.

Return

A Ray that starts from src towards dst with arrival time 1.

Example

use geo_buffer::{Coordinate, Ray};
 
let c1 = (1., 2.).into();
let c2 = (2., 3.).into();
let r1 = Ray::new(c1, c2);
 

pub fn point(&self) -> Coordinate

Returns the “starting point” of the given ray.

Example

use geo_buffer::{Coordinate, Ray};
 
let c1 = (1., 2.).into();
let c2 = (2., 3.).into();
let r1 = Ray::new(c1, c2);
 
assert!(c1.eq(&r1.point()));
 

pub fn point_by_ratio(&self, ratio: f64) -> Coordinate

Returns the value of parameterized equation r₀ + tv by the given ratio t.

Example

use geo_buffer::{Coordinate, Ray};
 
let c1 = (1., 2.).into();
let c2 = (2., 3.).into();
let r1 = Ray::new(c1, c2);
 
assert!(r1.point_by_ratio(2.).eq(&(3., 4.).into()));

pub fn is_contain(&self, rhs: &Coordinate) -> bool

Checks whether self contains the given Cartesian coordinate.

Note that this function considers self as a open-ended line. That is, if the given point lies on the extended line of self, this function returns true.

Return

• true if the given point lies on self,
• false otherwise.

Example

use geo_buffer::{Coordinate, Ray};
 
let c1 = (1., 2.).into();
let c2 = (2., 3.).into();
let r1 = Ray::new(c1, c2);
 
assert!(r1.is_contain(&(3., 4.).into()));

pub fn is_intersect(&self, rhs: &Ray) -> bool

Checks whether the given two rays are intersecting with each other. More precisely, it checks whether they have one or more common points.

Return

• true if the given rays have one or more common points,
• false otherwise.

Example

use geo_buffer::{Coordinate, Ray};
 
let c1 = (1., 2.).into();
let c2 = (2., 3.).into();
let r1 = Ray::new(c1, c2);
 
assert!(r1.is_contain(&(3., 4.).into()));

pub fn intersect(&self, rhs: &Ray) -> Coordinate

Returns a common point of the given rays. If they have more than 2 common points, then returns a middle point of the starting points of the given rays.

Note that this function considers the rays as a open-ended line. That is, if the common point lies on the extended line(s) of them, this function returns the point.

Example

use geo_buffer::{Coordinate, Ray};
 
let c1 = (0., 0.).into();
let c2 = (1., 1.).into();
let c3 = (4., 0.).into();
let c4 = (0., 4.).into();
let r1 = Ray::new(c1, c2);
let r2 = Ray::new(c3, c4);
 
assert!(r1.intersect(&r2).eq(&(2., 2.).into()));
 

pub fn is_parallel(&self, rhs: &Ray) -> bool

Checks whether the given two rays are parallel. If they have more than 2 common points, they are not considered as parallel.

Return

• true if the given rays are parallel,
• false otherwise.

Example

use geo_buffer::{Coordinate, Ray};
 
let c1 = (0., 0.).into();
let c2 = (1., 1.).into();
let c3 = (0., 1.).into();
let c4 = (1., 2.).into();
let r1 = Ray::new(c1, c2);
let r2 = Ray::new(c3, c4);
 
assert!(r1.is_parallel(&r2));

pub fn normalize(&mut self)

Normalizes the given Ray. The magnitude of the ‘velocity’ becomes 1. Does nothing if it is 0.

Example

use geo_buffer::{Coordinate, Ray};
 
let c1 = (0., 0.).into();
let c2 = (3., 4.).into();
let mut r1 = Ray::new(c1, c2);
r1.normalize();
 
assert!(r1.point_by_ratio(1.).eq(&(0.6, 0.8).into()));

pub fn reverse(&self) -> Self

Returns the reversed ray of the given ray. The returned ray has the same starting point and the opposite direction to the given ray.

Trait Implementations

impl Clone for Ray

fn clone(&self) -> Ray

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Ray

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

Formats the value using the given formatter.

impl Default for Ray

fn default() -> Ray

Returns the “default value” for a type.

impl Display for Ray

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

Formats the value using the given formatter.

impl Copy for Ray