vector.js

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

    this.min = function(vec)
    {
        x = Math.min(x, vec.x);
        y = Math.min(y, vec.y);
    }

    this.max = function(vec)
    {
        x = Math.max(x, vec.x);
        y = Math.max(y, vec.y);
    }

    this.midpoint = function(vec)
    {
        return new Vector((x+vec.x)*0.5, (y+vec.y)*0.5);
    }

    this.clone = function()
    {
        return new Vector(this.x, this.y);
    }

    this.normalize = function()
    {
        var len = this.length();
        this.x /= len;
        this.y /= len;
    }

    this.normalized = function()
    {
        var vec = new Vector(this.x, this.y);
        vec.normalize();
        return vec;
    }

    this.negate = function()
    {
        this.x = -this.x;
        this.y = -this.y;
    }

    this.sqrLength = function()
    {
        return this.x * this.x + this.y * this.y;
    }

    this.length = function()
    {
        return Math.sqrt(this.x * this.x + this.y * this.y);
    }

    this.scale = function(len)
    {
        this.x *= len;
        this.y *= len;
    }

    this.add = function(vec)
    {
        this.x += vec.x;
        this.y += vec.y;
    }

    this.sub = function(vec)
    {
        this.x -= vec.x;
        this.y -= vec.y;
    }

    this.diff = function(vec)
    {
        return new Vector(this.x-vec.x, this.y-vec.y);
    }

    this.distance = function(vec)
    {
        var x = this.x-vec.x;
        var y = this.y-vec.y;
        return Math.sqrt(x*x+y*y);
    }

    this.dot = function(vec)
    {
        return this.x*vec.x+this.y*vec.y;
    }

    this.equals = function(vec)
    {
        return this.x == vec.x && this.y == vec.y;
    }

    this.orthogonal = function()
    {
        return new Vector(this.y, -this.x);
    }

    this.distanceToLine = function(v0, v1)
    {
        var sqrLen = v1.diff(v0).sqrLength();
        var u = ((this.x-v0.x)*(v1.x-v0.x)+(this.y-v0.y)*(v1.y-v0.y))/sqrLen;
        var v1c = v1.diff(v0);
        v1c.scale(u);
        var pl = v0.clone();
        pl.add(v1c);
        return this.distance(pl);
    }
};


module.exports = Vector