How to forbid an NPC to move diagonally using Character Controller?

Questions & Answers
1

My game doesn't allow human players to move diagonally when played by 2 players. I started implementing the AI for when its only one player playing and so I need the computer to control the other player. Everything works perfectly fine except that it moves diagonally, which I dont want it to, and even though I have tried many things, they haven't worked. Any ideas?

This is how human player characters are forbidden to move diagonally:

    // Simple character controller movement with the keyboard.
function keyboardMove() {
    var toTarget : Vector3 = new Vector3();
    if (p1) {
        if (Input.GetAxisRaw("P1Vertical")) {
            toTarget.z = Input.GetAxis("P1Vertical");
            controller.Move(toTarget * Time.deltaTime * speed);
        }
        else if (Input.GetAxisRaw("P1Horizontal")) {
            toTarget.x = Input.GetAxis("P1Horizontal");
            controller.Move(toTarget * Time.deltaTime * speed);
        }
    }
    else if (p2) {
        if (Input.GetAxisRaw("P2Vertical")) {
            toTarget.z = Input.GetAxis("P2Vertical");
            controller.Move(toTarget * Time.deltaTime * speed);
        }
        else if (Input.GetAxisRaw("P2Horizontal")) {
            toTarget.x = Input.GetAxis("P2Horizontal");
            controller.Move(toTarget * Time.deltaTime * speed);
        }
    }

    if (toTarget.magnitude != 0) {
        transform.rotation = Quaternion.LookRotation(toTarget);
    }
}

And this is how the NPC keeps moving the way it wants...

function move(aTarget : Transform) {
    var toTarget : Vector3 = new Vector3();
    toTarget.x = aTarget.transform.position.x - transform.position.x;
    toTarget.y = 0;
    toTarget.z = aTarget.transform.position.z - transform.position.z;
    if(toTarget.magnitude <= 0.2) {
        reactToState(state);
        return;
    }
    toTarget.Normalize();
    controller.Move(toTarget * Time.deltaTime * speed);
    if (toTarget.magnitude != 0) {
        transform.rotation = Quaternion.LookRotation(toTarget);
    }
}

Even if I don't find the answers I'm pretty sure these are 2 useful (part of) scripts anyone can use! :)

2

Well.. I managed to find a solution..

var approximateDistance : float = 0.1;

function move(aTarget : Transform) : void {
    var speed : float;
    var toTarget : Vector3 = new Vector3();
    toTarget.x = aTarget.transform.position.x - transform.position.x;
    toTarget.y = 0;
    toTarget.z = aTarget.transform.position.z - transform.position.z;
    if(toTarget.magnitude <= approximateDistance*2) {
        reactToState(state);
        return;
    }

    if (toTarget.x > approximateDistance)
        var theTarget = new Vector3(1,0,0);
    else if (toTarget.z > 0.2) 
        theTarget = new Vector3(0,0,1);
    else {
        if (toTarget.x <= -approximateDistance)
            theTarget = new Vector3(-1, 0, 0);
        else if (toTarget.z <= -approximateDistance)
            theTarget = new Vector3(0, 0, -1);
    }
    controller.Move(theTarget * Time.deltaTime * speed);

    if (toTarget.magnitude != 0)
        transform.rotation = Quaternion.LookRotation(toTarget);
}