JavaScript - rotate localized vector 2D to right direction (clockwise direction)

In this short article, we would like to show how to rotate any localized vector 2D to the right side (90 degrees) using Javascript.

Quick solution:

function rotateRight(vector) {
  	var a = vector.a;
  	var b = vector.b;
  	return {
      	a: { x: a.y, y: -a.x },  // check: https://dirask.com/posts/jMqM0j
      	b: { x: b.y, y: -b.x }
    };
}

var vector1 = {a: {x: -1, y: 2}, b: {x: -2, y: 4}};  // vector [A1, B1] = (-1, 2) -> (-2, 4)
var vector2 = rotateRight(vector1);                  // vector [A2, B2] = ( 2, 1) -> ( 4, 2)

Rotation preview:

Practical example

// ONLINE-RUNNER:browser;

function rotateRight(vector) {
  	var a = vector.a;
  	var b = vector.b;
  	return {
      	a: { x: a.y, y: -a.x },  // check: https://dirask.com/posts/jMqM0j
      	b: { x: b.y, y: -b.x }
    };
}


// Helper methods:

function printPoint(point) {
	return '(' + point.x + ', ' + point.y + ')';
}

function printVector(name, vector) {
  	console.log(name + ': ' + printPoint(vector.a) + ' -> ' + printPoint(vector.b));
}


// Usage example:
                                  // direction:
var vector1 = {                   //   ↑
	a: {x: 0, y: 1},              // a = beginning point
  	b: {x: 0, y: 2}               // b = ending point (arrow/head)
};          

var vector2 = rotateRight(vector1);   //   →
var vector3 = rotateRight(vector2);   //   ↓
var vector4 = rotateRight(vector3);   //   ←

printVector('vector1', vector1);  // ( 0,  1) -> ( 0,  2)  ↑
printVector('vector2', vector2);  // ( 1,  0) -> ( 2,  0)  →
printVector('vector3', vector3);  // ( 0, -1) -> ( 0, -2)  ↓
printVector('vector4', vector4);  // (-1,  0) -> (-2,  0)  ←

See also

1. JavaScript - rotate localized vector 2D to left direction (counterclockwise direction)

2. JavaScript - rotate vector 2D to right direction (clockwise direction)

3. JavaScript - rotate vector 2D to left direction (counterclockwise direction)