README

Vec2

An intuitive, lightweight 2d vector library with built-in canvas support.

Installation

Install using yarn or npm:

yarn add @felixgro/vec2
# or
npm i @felixgro/vec2

Import in Javascript or Typescript file:

import Vec2 from '@felixgro/vec2';

API

Vector Properties

Property	Type	Description
x	number	x-Coordinate
y	number	y-Coordinate
pos	[number, number]	Coordinates as array [x, y] to enable usage of spread operator.
length	number	absolute length of vector
lengthSquared	number	squared length of vector

Instantiation Methods

Basic instantiation:

const vecA = new Vec2();     // x: 0, y: 0
const vecB = new Vec2(1, 5); // x: 1, y: 5

Static instantiation methods:

Vec2.random();
Vec2.fromAngle(radians: number, length: number);

Vec2.up(); 	   	// x: 0, y: -1
Vec2.down();  	// x: 0, y: 1
Vec2.right();   // x: 1, y: 0
Vec2.left();  	// x: -1, y: 0

Operation Methods

vec.add(vec: Vec2 | number): Vec2;
vec.subtract(vec: Vec2 | number): Vec2;
vec.multiply(vec: Vec2 | number): Vec2;
vec.divide(vec: Vec2 | number): Vec2;

Other Methods

vec.normalize(): Vec2;
vec.inverse(): Vec2;
vec.clone(): Vec2;

vec.rotate(radians: number, clockwise?: boolean): Vec2;
vec.setMagnitude(magnitude: number): Vec2;
vec.clampMagnitude(min: number, max: number): Vec2;

vec.dot(vec: Vec2): number;
vec.cross(vec: Vec2): number;

vec.angleTo(vec: Vec2): number;
vec.distanceTo(vec: Vec2): number;
vec.equals(vec: Vec2): boolean;

Helpers

renderOnCanvas

Renders one or multiple vectors on 2d canvas using it's rendering context.

import Vec2, { renderOnCanvas } from '@felixgro/vec2';

// get canvas drawing context
const ctx = someCanvas.getContext('2d');

// draw vector
renderOnCanvas(vecA, ctx);

// ..or draw many vectors at once
renderOnCanvas([vecA, vecB, vecC], ctx);

You may pass an additional options object as third parameter:

// default options:
const options = {
    origin: new Vec2(),
    color: '#000',
    width: 3,
    arrow: true,
};

renderOnCanvas(vec: Vec2 | Vec2[], ctx: CanvasRenderingContext2D, options: DrawOptions);

lerp

Linear interpolation between two vectors.

import Vec2, { lerp } from '@felixgro/vec2';

const vecA = new Vec2(1, 1);
const vecB = new Vec2(-1, -1);

const vecC = lerp(vecA, vecB, 0.5); // x: 0, y: 0

randomBetween

Create a random vector between two vectors.

import Vec2, { randomBetween } from '@felixgro/vec2';

const vecA = new Vec2(100, 100);
const vecB = new Vec2(200, 200);

const vecC = randomBetween(vecA, vecB); // 100 < x,y < 200

Usage no npm install needed!