/* 3D Vector type

fields:
    number x
    number y
    number z

consructors:
    default(number x, number y, number z) aka new keyword
    zero()
    fill(number) fills each field with the same value
    copy(vector) creates new vector the same as the old

methods:
    add(vector) => vector, object keeps unchanged
    sub(vector) => vector, object keeps unchanged
    mul(vector) => vector, object keeps unchanged
    div(vector) => vector, object keeps unchanged
    negative() => vector, object keeps unchanged
    scale(number) => vector, object keeps unchanged
    cross(vector) => vector, object keeps unchanged
    dot(vector) => number
    length() => number
    normalize() => vector, object keeps unchanged

    prototype.toString() => string
*/

function Vector(x, y, z)
{
    this.x = x;
    this.y = y;
    this.z = z;

    this.add = (a) => new Vector(this.x + a.x, this.y + a.y, this.z + a.z);

    this.sub = (a) => new Vector(this.x - a.x, this.y - a.y, this.z - a.z);

    this.mul = (a) => new Vector(this.x * a.x, this.y * a.y, this.z * a.z);

    this.div = (a) => new Vector(this.x / a.x, this.y / a.y, this.z / a.z);

    this.negative = () => new Vector(-this.x, -this.y, -this.z);

    this.scale = (value) => new Vector(this.x * value, this.y * value, this.z * value);

    this.cross = (a) => new Vector(
        this.y * a.z - this.z * a.y,
        this.x * a.z - this.z * a.x,
        this.x * a.y - this.y * a.x
    );

    this.dot = (a) => this.x * a.x + this.y * a.y + this.z * a.z;

    this.length = () => Math.sqrt(this.dot(this));

    this.normalize = () => this.scale(1 / this.length());
}

Vector.zero = () => new Vector(0, 0, 0);

Vector.fill = (value) => new Vector(value, value, value);

Vector.copy = (a) => new Vector(a.x, a.y, a.z);

Vector.prototype.toString = function()
{
    return `x: ${this.x}\ty: ${this.y}\tz: ${this.z}`;
}