2D matrix / vector types for HTML Canvas

matrix.ts

import { Vector } from "./vector"

const mi = {
  m11: 0, m12: 1, m13: 2,
  m21: 3, m22: 4, m23: 5,
  m31: 6, m32: 7, m33: 8,
}
export class Matrix {
  constructor(public v: number[]) {
  }
  public static identity(): Matrix {
    return new Matrix([
      1, 0, 0,
      0, 1, 0,
      0, 0, 1
    ])
  }
  public static rotation(r: number): Matrix {
    return new Matrix([
      Math.cos(r),  Math.sin(r), 0,
     -Math.sin(r),  Math.cos(r), 0,
      0,            0,           1
    ])
  }
  public static translate(v: Vector): Matrix {
    return new Matrix([
      1, 0, v.v[0],
      0, 1, v.v[1],
      0, 0, 1
    ])
  }
  public static scale(v: Vector): Matrix {
    return new Matrix([
      v.v[0], 0,      0,
      0,      v.v[1], 0,
      0,      0,      1
    ])
  }
  public static multiply(a: Matrix, b: Matrix): Matrix {
    return new Matrix([
      (((a.v[mi.m11] * b.v[mi.m11]) + (a.v[mi.m12] * b.v[mi.m21])) + (a.v[mi.m13] * b.v[mi.m31])),
      (((a.v[mi.m11] * b.v[mi.m12]) + (a.v[mi.m12] * b.v[mi.m22])) + (a.v[mi.m13] * b.v[mi.m32])),
      (((a.v[mi.m11] * b.v[mi.m13]) + (a.v[mi.m12] * b.v[mi.m23])) + (a.v[mi.m13] * b.v[mi.m33])),
      (((a.v[mi.m21] * b.v[mi.m11]) + (a.v[mi.m22] * b.v[mi.m21])) + (a.v[mi.m23] * b.v[mi.m31])),
      (((a.v[mi.m21] * b.v[mi.m12]) + (a.v[mi.m22] * b.v[mi.m22])) + (a.v[mi.m23] * b.v[mi.m32])),
      (((a.v[mi.m21] * b.v[mi.m13]) + (a.v[mi.m22] * b.v[mi.m23])) + (a.v[mi.m23] * b.v[mi.m33])),
      (((a.v[mi.m31] * b.v[mi.m11]) + (a.v[mi.m32] * b.v[mi.m21])) + (a.v[mi.m33] * b.v[mi.m31])),
      (((a.v[mi.m31] * b.v[mi.m12]) + (a.v[mi.m32] * b.v[mi.m22])) + (a.v[mi.m33] * b.v[mi.m32])),
      (((a.v[mi.m31] * b.v[mi.m13]) + (a.v[mi.m32] * b.v[mi.m23])) + (a.v[mi.m33] * b.v[mi.m33]))
    ])
  }

  public clone(): Matrix {
    return new Matrix(this.v.map(n => n))
  }
}

vector.ts

import { Matrix } from "./matrix"

export class Vector {
  constructor(public v: number[]) {
  }
  public static create(x: number, y: number) {
    return new Vector([x, y])
  }
  public static zero(): Vector {
    return new Vector([0, 0])
  }
  public static add(a: Vector, b: Vector): Vector {
    return new Vector([a.v[0] + b.v[0], a.v[1] + b.v[1]])
  }
  public static sub(a: Vector, b: Vector): Vector {
    return new Vector([a.v[0] - b.v[0], a.v[1] - b.v[1]])
  }
  public static scale(a: Vector, v: number): Vector {
    return new Vector([a.v[0] * v, a.v[1] * v])
  }
  public static mul(a: Vector, b: Vector) {
    return new Vector([a.v[0] * b.v[0], a.v[1] * b.v[1]])
  }
  public static div(a: Vector, b: Vector) {
    return new Vector([a.v[0] / b.v[0], a.v[1] / b.v[1]])
  }
  public static len(a: Vector) {
    return Math.sqrt(a.v[0] * a.v[0] + a.v[1] * a.v[1])
  }
  public static normalize(a: Vector): Vector {
    const length = Vector.len(a)
    return new Vector([a.v[0] / length, a.v[1] / length])
  }
  public static transform(v0: Vector, m0: Matrix): Vector {
    return new Vector([
      (((v0.v[0] * m0.v[0]) + (v0.v[1] * m0.v[1])) + m0.v[2]),
      (((v0.v[0] * m0.v[3]) + (v0.v[1] * m0.v[4])) + m0.v[5])
    ])
  }
  public clone(): Vector {
    return new Vector(this.v.map(n => n))
  }
}