Kontra​.vector(​properties)

Extending Functionality#

Vectors are very flexible and easy to extend. If you need to modify or add functionality to the vector, you can modify or add to kontra.vector.prototype.

// add magnitude to all vectors
kontra.vector.prototype.magnitude = function() {
  return Math.sqrt(this.x * this.x + this.y * this.y);
}

let vector = kontra.vector(100, 200);
console.log(vector.magnitude());  // => ~223.61

kontra.vector​.add(vector, dt)#

vector {kontra.vector}

Vector to add to the current vector.

dt {number}

Optional. Time since last update.

Add two vectors together. Pass dt to adjust how much of the vector gets added.

let vector = kontra.vector(100, 200);
let vector2 = kontra.vector(50, 10);

vector.add(vector2);
console.log(vector);  //=> {x: 150, 210}

vector.add(vector2, 0.1);
console.log(vector);  //=> {x: 155, 211}

kontra.vector​.clamp(xMin, yMin, xMax, yMax)#

xMin {number}

Optional. Minimum x value. Defaults to -Infinity.

yMin {number}

Optional. Minimum y value. Defaults to -Infinity.

xMax {number}

Optional. Maximum x value. Defaults to Infinity.

yMax {number}

Optional. Maximum y value. Defaults to Infinity.

Clamp the vector between two points, preventing x and y from going below or above the minimum and maximum values. Perfect for keeping a sprite from going outside the game boundaries.

let vector = kontra.vector(100, 200);

vector.clamp(0, 0, 200, 300);

vector.x += 200;
console.log(vector.x);  //=> 200

vector.y -= 300;
console.log(vector.y);  //=> 0

vector.add({x: -500, 500);
console.log(vector);    //=> {x: 0, y: 300}

kontra.vector​.x#

{number}

X value of the vector.

kontra.vector​.y#

{number}

Y value of the vector.