@mhyfritz/vector
v0.1.1
Published
Euclidean (geometric) vectors with a default immutable API
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Readme
vector
Euclidean (geometric) vectors with an immutable and mutable API. Currently, 2D vectors only.
Installation
npm install @mhyfritz/vector
Usage
Node:
const { Vector2d } = require("@mhyfritz/vector");
// or
import { Vector2d } from "@mhyfritz/vector";
Browser:
<!-- import from unpkg -->
<script src="https://unpkg.com/@mhyfritz/vector"></script>
<!-- import from jsdelivr -->
<script src="https://cdn.jsdelivr.net/npm/@mhyfritz/vector"></script>
<!-- usage; module is globally registered as `mhyfritzVector` -->
<script>
const { Vector2d } = mhyfritzVector;
new Vector2d(2, 8);
</script>
API
new Vector2d(x, y)
Creates a new 2D vector.
import { Vector2d } from "@mhyfritz/vector";
new Vector2d(2, 8);
// Vector2d { x: 2, y: 8 }
The "default" (non-prefixed) methods return a new vector and don't mutate the original one, while methods prefixed with $
mutate the caller.
.clone()
Clones a vector.
const a = new Vector2d(2, 8);
const b = a.clone();
// `b` is `Vector2d { x: 2, y: 8 }`
.add(<Vector2d>)
Adds two vectors without mutating the caller.
const a = new Vector2d(2, 8);
const b = new Vector2d(32, 128);
const c = a.add(b);
// `c` is `Vector2d { x: 34, y: 136 }`
// `a` is `Vector2d { x: 2, y: 8 }`
.$add(<Vector2d>)
Adds two vectors and mutates the caller.
const a = new Vector2d(2, 8);
const b = new Vector2d(32, 128);
a.$add(b);
// `a` is `Vector2d { x: 34, y: 136 }`
.sub(<Vector2d>)
Subtracts two vectors without mutating the caller.
const a = new Vector2d(2, 8);
const b = new Vector2d(32, 128);
const c = a.sub(b);
// `c` is `Vector2d { x: -30, y: -120 }`
// `a` is `Vector2d { x: 2, y: 8 }`
.$sub(<Vector2d>)
Subtracts two vectors and mutates the caller.
const a = new Vector2d(2, 8);
const b = new Vector2d(32, 128);
a.$sub(b);
// `a` is `Vector2d { x: -30, y: -120 }`
.mult(<number>)
Performs scalar multiplication without mutating the caller.
const a = new Vector2d(2, 8);
const b = a.mult(2);
// `b` is `Vector2d { x: 4, y: 16 }`
// `a` is `Vector2d { x: 2, y: 8 }`
.$mult(<number>)
Performs scalar multiplication and mutates the caller.
const a = new Vector2d(2, 8);
a.$mult(2);
// `a` is `Vector2d { x: 4, y: 16 }`
.div(<number>)
Performs scalar division without mutating the caller.
const a = new Vector2d(2, 8);
const b = a.div(2);
// `b` is `Vector2d { x: 1, y: 4 }`
// `a` is `Vector2d { x: 2, y: 8 }`
.$div(<number>)
Performs scalar division and mutates the caller.
const a = new Vector2d(2, 8);
a.$div(2);
// `a` is `Vector2d { x: 1, y: 4 }`
.mag()
Returns the magnitude (length) of a vector.
const a = new Vector2d(2, 8);
a.mag();
// 8.246...
.mag(<number>)
Sets the magnitude (length) of a vector without mutating the caller.
const a = new Vector2d(2, 8);
const b = a.mag(10);
// `b` is `Vector2d { x: 2.42..., y: 9.70... }`
// `a` is `Vector2d(2, 8)`
.$mag(<number>)
Sets the magnitude (length) of a vector and mutates the caller.
const a = new Vector2d(2, 8);
a.$mag(10);
// `a` is `Vector2d { x: 2.42..., y: 9.70... }`
.normalize()
Sets the magnitude (length) of a vector to 1 (unit vector) without mutating the caller.
const a = new Vector2d(2, 8);
const b = a.normalize();
// `b` is `Vector2d { x: 0.24..., y: 0.97... }`
// `a` is `Vector2d { x: 2, y: 8 }`
b.mag(); // 1
.$normalize()
Sets the magnitude (length) of a vector to 1 (unit vector) and mutates the caller.
const a = new Vector2d(2, 8);
a.$normalize();
// `a` is `Vector2d { x: 0.24..., y: 0.97... }`
a.mag(); // 1
.limit(<number>)
Limits the magnitude (length) of a vector without mutating the caller.
const a = new Vector2d(2, 8);
a.mag(); // 8.24...
const b = a.limit(5);
// `b` is `Vector2d { x: 1.21..., y: 4.85... }`
// `a` is `Vector2d { x: 2, y: 8 }`
b.mag(); // 5
.$limit(<number>)
Limits the magnitude (length) of a vector and mutates the caller.
const a = new Vector2d(2, 8);
a.$limit(5);
// `a` is `Vector2d { x: 1.21..., y: 4.85... }`
a.mag(); // 5
.direction()
Computes a vector's direction / angle in radians.
const a = new Vector2d(2, 0);
a.direction(); // 0
const b = new Vector2d(2, 2);
b.direction(); // 0.78... radians
(b.direction() / Math.PI) * 180; // 45 degrees
.distance(<Vector2d>)
Computes the Euclidean distance to another vector.
const v = new Vector2d(2, 8);
const w = new Vector2d(32, 128);
v.distance(w); // 123.69...
random()
Static class method that returns a random unit vector.
const a = Vector2d.random();
// Vector2d { x: 0.834182302094392, y: -0.5514887912482904 }
a.mag(); // 1
const b = Vector2d.random();
// Vector2d { x: 0.928078060616885, y: -0.37238570515206604 }
b.mag(); // 1
fromAngle(angle: number, length?: number)
(credits: p5.js)
Static class method that creates a vector from a given angle and length. If no length is specified, a unit vector (length 1) will be produced. Angle has to be specified in radians.
const a = Vector2d.fromAngle(2);
// Vector2d { x: -0.4161468365471424, y: 0.9092974268256817 }
a.mag(); // 1
const b = Vector2d.fromAngle(2, 5);
// Vector2d { x: -2.080734182735712, y: 4.546487134128409 }
b.mag(); // 5
Chaining
Both, immutable and mutable methods are chainable.
const a = new Vector2d(2, 8);
const b = new Vector2d(32, 128);
const c = a.add(b).div(10);
// `c` is `Vector2d { x: 3.4, y: 13.6 }`
// `a` is `Vector2d { x: 2, y: 8 }`
// to avoid unnecessary copies, we can also mix and match
const d = a.add(b).$div(10);
// `d` is `Vector2d { x: 3.4, y: 13.6 }`
// `a` is `Vector2d { x: 2, y: 8 }`
a.$add(b).$div(10);
// `a` is `Vector2d { x: 3.4, y: 13.6 }`
a.$normalize().mag(); // 1
// `a` is `Vector2d { x: 0.24..., y: 0.97... }`