gistfile1.cs

using UnityEngine;
using System.Collections;

public class FormationController : MonoBehaviour {
	public GameObject enemyPrefab;
	public float width = 10;
	public float height = 5;
	public float speed;
	public float padding;
	
	private float xmin;
	private float xmax;
	private bool moveRight;
	private bool moveLeft;
	
	// Use this for initialization
	void Start () {
		foreach(Transform child in transform){
			GameObject enemy = Instantiate(enemyPrefab, child.transform.position, Quaternion.identity) as GameObject;
			enemy.transform.parent = child;
			
			float distance = transform.position.z - Camera.main.transform.position.z;
			Vector3 leftMost = Camera.main.ViewportToWorldPoint(new Vector3( 0,0,distance));
			Vector3 rightMost = Camera.main.ViewportToWorldPoint(new Vector3( 1,0,distance));
			
			xmin = leftMost.x + padding;
			xmax = rightMost.x - padding;

		}
		moveLeft = true;
	}
	 
	void OnDrawGizmos(){
		
		
		
		float gizmoWidth, gizmoHeight;
		
		gizmoWidth = transform.position.x + 0.5f * width;
		gizmoHeight = transform.position.y + 0.5f * height;
		Gizmos.DrawWireCube(new Vector3(0,5,0), new Vector3(gizmoWidth, gizmoHeight,0 ));
		
		 
	}
	
	// Update is called once per frame
	void Update () {
			
		checkMin();
		checkMax();
		if (moveLeft == true) { 
			
			transform.position += Vector3.left * speed * Time.deltaTime;
			
			}
		
			
		else if (moveRight == true) { 
			
			transform.position += Vector3.right * speed * Time.deltaTime;
			
		}
		float newX = Mathf.Clamp (transform.position.x, xmin, xmax);
		transform.position = new Vector3(newX, transform.position.y, transform.position.z);
		
	}
	
	void checkMin() {
		if (transform.position.x == xmin){
			moveLeft = false;
			moveRight = true;
		}	
	}
	
	void checkMax() {
		if (transform.position.x == xmax){
			moveRight = false;
			moveLeft = true;
		}
	}
}