From 72c6c7de12e9833f52bf2d0718d70f044f8ab57e Mon Sep 17 00:00:00 2001 From: Elizabeth Hunt Date: Thu, 20 Jul 2023 20:47:32 -0700 Subject: a bit of refactoring; importing engine into bun for server --- engine/utils/rotateVector.ts | 15 +++++++++++++++ 1 file changed, 15 insertions(+) create mode 100644 engine/utils/rotateVector.ts (limited to 'engine/utils/rotateVector.ts') diff --git a/engine/utils/rotateVector.ts b/engine/utils/rotateVector.ts new file mode 100644 index 0000000..82bb54d --- /dev/null +++ b/engine/utils/rotateVector.ts @@ -0,0 +1,15 @@ +import type { Coord2D } from "../interfaces"; + +/** + * ([[cos(θ), -sin(θ),]) ([x,) + * ([sin(θ), cos(θ)] ]) ( y]) + */ +export const rotateVector = (vector: Coord2D, theta: number): Coord2D => { + const rads = (theta * Math.PI) / 180; + const [cos, sin] = [Math.cos(rads), Math.sin(rads)]; + + return { + x: vector.x * cos - vector.y * sin, + y: vector.x * sin + vector.y * cos, + }; +}; -- cgit v1.2.3-70-g09d2