boids/vector.mjs

class Vector
{
    constructor(x = 0, y = 0)
    {
        this.x = x;
        this.y = y;
    }

    add(vector)
    {
        return new Vector(this.x + vector.x, this.y + vector.y);
    }

    addMut(vector)
    {
        this.x += vector.x;
        this.y += vector.y;
        return this;
    }

    sub(vector)
    {
        return new Vector(this.x - vector.x, this.y - vector.y);
    }

    subMut(vector)
    {
        this.x -= vector.x;
        this.y -= vector.y;
        return this;
    }

    mul(scalar)
    {
        return new Vector(this.x * scalar, this.y * scalar);
    }

    mulMut(scalar)
    {
        this.x *= scalar;
        this.y *= scalar;
        return this;
    }

    div(scalar)
    {
        return this.mul(1 / scalar);
    }

    divMut(scalar)
    {
        return this.mulMut(1 / scalar);
    }

    rotate(angle)
    {
        const cos = Math.cos(angle);
        const sin = Math.sin(angle);

        return new Vector(
            cos * this.x - sin * this.y,
            cos * this.y + sin * this.x,
        );
    }

    angle()
    {
        return Math.PI / 2 - Math.atan2(this.x, this.y);
    }

    normSquared()
    {
        return this.x * this.x + this.y * this.y;
    }
}

export default Vector;