From d724cc0bf6ff6d351319e6fb00f5184a04e16ac0 Mon Sep 17 00:00:00 2001 From: Josh Kingsley Date: Mon, 24 Nov 2025 15:46:22 +0200 Subject: chore: improve dev tasks --- apps/web/src/math/Coord.ts | 23 +++++++++ apps/web/src/math/Ratio.test.ts | 27 +++++++++++ apps/web/src/math/Ratio.ts | 105 ++++++++++++++++++++++++++++++++++++++++ apps/web/src/math/Rect.ts | 104 +++++++++++++++++++++++++++++++++++++++ apps/web/src/math/index.ts | 3 ++ 5 files changed, 262 insertions(+) create mode 100644 apps/web/src/math/Coord.ts create mode 100644 apps/web/src/math/Ratio.test.ts create mode 100644 apps/web/src/math/Ratio.ts create mode 100644 apps/web/src/math/Rect.ts create mode 100644 apps/web/src/math/index.ts (limited to 'apps/web/src/math') diff --git a/apps/web/src/math/Coord.ts b/apps/web/src/math/Coord.ts new file mode 100644 index 0000000..db7ee6d --- /dev/null +++ b/apps/web/src/math/Coord.ts @@ -0,0 +1,23 @@ +/** A coord on a grid whose origin is in the top left. */ +export default class Coord { + private readonly _x: number; + private readonly _y: number; + + constructor(x: number, y: number) { + this._x = x; + this._y = y; + } + + get x(): number { + return this._x; + } + + get y(): number { + return this._y; + } + + /** Get the squared distance of this point from the origin. */ + squaredDistanceFromOrigin(): number { + return this._x * this._x + this._y * this._y; + } +} diff --git a/apps/web/src/math/Ratio.test.ts b/apps/web/src/math/Ratio.test.ts new file mode 100644 index 0000000..da6fef2 --- /dev/null +++ b/apps/web/src/math/Ratio.test.ts @@ -0,0 +1,27 @@ +import { describe, expect, test } from "vitest"; +import Ratio from "./Ratio"; + +describe(Ratio, () => { + describe(Ratio.prototype.add, () => { + test("returns fractions in simplest form", () => { + const a = Ratio.fromInteger(0); + const b = new Ratio(1, 4); + + const c = a.add(b); + expect(c.numerator).toBe(1); + expect(c.denominator).toBe(4); + + const d = c.add(b); + expect(d.numerator).toBe(1); + expect(d.denominator).toBe(2); + + const e = d.add(b); + expect(e.numerator).toBe(3); + expect(e.denominator).toBe(4); + + const f = e.add(b); + expect(f.numerator).toBe(1); + expect(f.denominator).toBe(1); + }); + }); +}); diff --git a/apps/web/src/math/Ratio.ts b/apps/web/src/math/Ratio.ts new file mode 100644 index 0000000..e2a1fbf --- /dev/null +++ b/apps/web/src/math/Ratio.ts @@ -0,0 +1,105 @@ +import { gcd } from "."; + +/** Serializable representation of a ratio. */ +export type RatioData = [numerator: number, denominator: number]; + +/** Representation of a ratio for performing fractional artithmetic. */ +export default class Ratio { + readonly #numerator: number; + readonly #denominator: number; + + get numerator(): number { + return this.#numerator; + } + + get denominator(): number { + return this.#denominator; + } + + constructor(numerator: number, denominator: number) { + if (!Number.isInteger(numerator) || !Number.isInteger(denominator)) { + throw new TypeError( + `Ratio must have integer parts: ${numerator} / ${denominator}`, + ); + } + + if (denominator === 0) { + throw new RangeError("Ratio demnominator cannot be zero"); + } + + const divisor = gcd(numerator, denominator); + + this.#numerator = numerator / divisor; + this.#denominator = denominator / divisor; + } + + multiplyRatio(other: Ratio): Ratio { + return new Ratio( + this.numerator * other.numerator, + this.denominator * other.denominator, + ); + } + + divideRatio(other: Ratio): Ratio { + return new Ratio( + this.numerator * other.denominator, + this.denominator * other.numerator, + ); + } + + add(other: Ratio): Ratio { + return new Ratio( + this.numerator * other.denominator + other.numerator * this.denominator, + this.denominator * other.denominator, + ); + } + + subtract(other: Ratio): Ratio { + return new Ratio( + this.numerator * other.denominator - other.numerator * this.denominator, + this.denominator * other.denominator, + ); + } + + compare(other: Ratio): number { + const left = this.numerator * other.denominator; + const right = other.numerator * this.denominator; + return left < right ? -1 : left > right ? 1 : 0; + } + + equals(other: Ratio): boolean { + return this.compare(other) === 0; + } + + toNumber(): number { + return this.numerator / this.denominator; + } + + toString(): string { + return `${this.numerator}/${this.denominator}`; + } + + [Symbol.for("nodejs.util.inspect.custom")](): string { + return `Ratio { ${this.numerator}/${this.denominator} }`; + } + + static fromInteger(n: number): Ratio { + return new Ratio(n, 1); + } + + toData(): RatioData { + return [this.numerator, this.denominator]; + } + + static fromData(ratio: RatioData): Ratio { + return new Ratio(ratio[0], ratio[1]); + } + + static min(...ratios: Ratio[]): Ratio { + return ratios.reduce((a, b) => (a.compare(b) <= 0 ? a : b)); + } + + static max(...ratios: Ratio[]): Ratio { + return ratios.reduce((a, b) => (a.compare(b) >= 0 ? a : b)); + } +} diff --git a/apps/web/src/math/Rect.ts b/apps/web/src/math/Rect.ts new file mode 100644 index 0000000..f52a2f7 --- /dev/null +++ b/apps/web/src/math/Rect.ts @@ -0,0 +1,104 @@ +import Coord from "./Coord"; + +/** A rectangle on a grid whose origin is in the top left. */ +export default class Rect { + private readonly _topLeft: Coord; + private readonly _width: number; + private readonly _height: number; + + constructor( + topLeftX: number, + topLeftY: number, + width: number, + height: number, + ) { + this._topLeft = new Coord(topLeftX, topLeftY); + this._width = width; + this._height = height; + } + + /** Width of this rectangle. */ + get width(): number { + return this._width; + } + + /** Height of this rectangle. */ + get height(): number { + return this._height; + } + + /** Coord of the top-left point of this rectangle. */ + get topLeft(): Coord { + return this._topLeft; + } + + /** Coord of the bottom-right point of this rectangle. */ + get bottomRight(): Coord { + return new Coord( + this._topLeft.x + this._width, + this._topLeft.y + this._height, + ); + } + + get center(): Coord { + return new Coord( + this.topLeft.x + (this.bottomRight.x - this.topLeft.x) / 2, + this.topLeft.y + (this.bottomRight.y - this.topLeft.y) / 2, + ); + } + + /** Determine if this rectangle contains the point at `coord`. */ + containsCoord(coord: Coord): boolean { + return ( + this.topLeft.x <= coord.x && + coord.x <= this.bottomRight.x && + this.topLeft.y <= coord.y && + coord.y <= this.bottomRight.y + ); + } + + verticallyContainsCoord(coord: Coord): boolean { + return this.topLeft.y <= coord.y && coord.y <= this.bottomRight.y; + } + + horizontallyContainsCoord(coord: Coord): boolean { + return this.topLeft.x <= coord.x && coord.x <= this.bottomRight.x; + } + + extend(other: Rect): Rect { + const topLeftX = Math.min( + this.topLeft.x, + this.bottomRight.x, + other.topLeft.x, + other.bottomRight.x, + ); + + const topLeftY = Math.min( + this.topLeft.y, + this.bottomRight.y, + other.topLeft.y, + other.bottomRight.y, + ); + + const bottomRightX = Math.max( + this.topLeft.x, + this.bottomRight.x, + other.topLeft.x, + other.bottomRight.x, + ); + + const bottomRightY = Math.max( + this.topLeft.y, + this.bottomRight.y, + other.topLeft.y, + other.bottomRight.y, + ); + + return new Rect( + topLeftX, + topLeftY, + bottomRightX - topLeftX, + bottomRightY - topLeftY, + ); + } +} diff --git a/apps/web/src/math/index.ts b/apps/web/src/math/index.ts new file mode 100644 index 0000000..70dbb67 --- /dev/null +++ b/apps/web/src/math/index.ts @@ -0,0 +1,3 @@ +export function gcd(a: number, b: number): number { + return b === 0 ? Math.abs(a) : gcd(b, a % b); +} -- cgit v1.2.3