// p = current touch point
var p_ : Vector2;
var t_ : float;

var velocities : float[] = new float[5];
var i : int;

function TouchStart ( p : Vector2 ) {
    velocities = new float[5];
    p_ = p;
    t_ = Time.time;
    i = 0;
}

function TouchEnd () {
    velocities = new float[5];
}

function Touching( p : Vector2 ) {
    var velocity : float = Vector2.Distance(p, p_) / (Time.time - t_);

    i = (i+1) % velocities.length;

    velocities[i] = Vector2.Distance(p, p_) / (Time.time - t_);

    p_ = p;
    t_ = Time.time;
}

function GetAvgVelocity () {
    var avgVelocity : float = 0.0;
    for ( var d : float in velocities )
        avgVelocity += d / velocities.length;

    return avgVelocity;
}

// sum len(point(t) - point(t-1)) over t  where t = start of touch ... now
// divided by time since start of touch