vector_maths.js

function vec2(x, y) {
  
  return { x ,y };
  
}

function vec3(x, y, z) {
  
  return { x ,y, z };
  
}

function addVecs(v1, v2) {
  
  let x = v1.x + v2.x;
  
  let y = v1.y + v2.y;
  
  return vec2(x, y);
}

function subVecs(v1, v2) {
  
  let x = v1.x + (-v2.x);
  
  let y = v1.y + (-v2.y);
  
  return vec2(x, y);
}

// Magnitude
function vecLength(v) {
  
  let x = Math.pow(v.x, 2);
  
  let y = Math.pow(v.y, 2);
  
  return Math.sqrt(x + y);  
}

function vecNormalize(v) {
  
  let vl = vecLength(v);

  let x = v.x / vl;
  
  let y = v.y / vl;
  
  return vec2(x, y);
}

function vecDotProduct(v1, v2) {
  
  let x = v1.x * v2.x;
  
  let y = v1.y * v2.y;
  
  return x + y;
}

function vecCrossProduct(v1, v2) {
	
	let x = (v1.y * v2.z) - (v1.z * v2.y)
	
	let y = (v1.z * v2.x) - (v1.x * v2.z)
	
	let z = (v1.x * v2.y) - (v1.y * v2.x)
	
	return vec3(x, y, z)
}


let v1 = vec2(2, 4);

let v2 = vec2(3, 6);

let vs = subVecs(v1, v2);

let va = addVecs(v1, v2);

let vl = vecLength(v1);

let vn1 = vecNormalize(v1);

let vn2 = vecNormalize(vec2(5, 20));

let vdp = vecDotProduct(vec2(0.6, -0.8), vec2(0, 1));

let vcp = vecCrossProduct(vec3(20, 30, 12), vec3(2, 4, 5));