ella-math

A dependency-free Geometry and linear algebra library that provides basic vector and matrix calculus operations, written in TypeScript.

Features

Features:

vector addition, subtraction, scalar multiplication, dot product, cross product
calculate vector length
normalize vector
matrix multiplication, determinant, inverse implementations for mat2, mat3, mat4
translation and projection matrices (perspective and orthogonal projection)
matrix vector multiplication
basic geometry shapes

Install and usage

You can either import ella via NPM or directly use it via script tag.

NPM:

First, run: npm i ella-math

import { Vec, Mat, Mat4 } from 'ella-math';

const a = new Vec(1, 2, 3);
const b = new Vec(2, 3, 4);

console.log('a + b = ', a.add(b));
console.log('a dot b = ', a.dot(b));
console.log('a cross b = ', a.cross(b));

// Define a matrix
// heads up: it's the other way round as you would write it down on paper

// prettier-ignore
const m = new Mat([
  1, 2, 3, // column 1
  4, 5, 6, // column 2
  7, 8, 9, // column 3
]);

const mDet = m.determinant(); // 0
const mInv = m.inverse();
console.assert(
  mInv.isFinite() === false,
  'As the determinant of m is 0, there is no inverse of m.'
);

const mA = Mat4.identity();
// create a 4x4 translation matrix
const mB = Mat4.translation(-1, -2, -3);
// create a 4x4 scaling matrix
const mC = Mat4.scaling(2, 4, 6);
// matrix multiplication
const mD = mA.mul(mB);
console.assert(mD.equals(mB), 'mA * mB should equal mB');
const mE = mD.mul(mC);
// matrix division is like multiplication with its inverse
const mF = mE.div(mC);

console.assert(mF.isFinite(), 'mF should be finite.');
console.assert(mF.equals(mD), 'mF should be equal to mD');

// the equality check may sometimes fail in JS due
// to floating point arithmetics (.1+.2 !== .3 issue)
// roughlyEquals checks with a tolerance of 1e-14
console.assert(mF.roughlyEquals(mD), 'mF should be roughly equal to mD');

Directly in the browser

Add this script tag: <script src="https://unpkg.com/ella-math@latest/dist/ella.umd.js"></script>

const { Vec, Mat } = Ella;