GridSystem.cs

using UnityEngine;
using System.Collections;

public class GridSystem : MonoBehaviour {

	public static GridSystem grid;
	
	public GameObject bottomLeftObject;
	public GameObject topRightObject;
	public float gridSize;
	public int renderThingsThisManyGridSectorsAway;

	GameObject player;

	[HideInInspector]
	public int gridDivisionsX = 0;
	[HideInInspector]
	public int gridDivisionsZ = 0;
	float gridStartX;
	float gridStartZ;
	float gridEndX;
	float gridEndZ;

	float[] gridX;
	float[] gridZ;

	public Vector2[] rangeX;
	public Vector2[] rangeZ;

	public int playerSectorX;
	public int playerSectorZ;

	// Use this for initialization
	void Awake () {
		grid = this;

		player = GameObject.FindGameObjectWithTag ("Player");
		gridStartX = bottomLeftObject.transform.position.x;
		gridStartZ = bottomLeftObject.transform.position.z;
		gridEndX = topRightObject.transform.position.x;
		gridEndZ = topRightObject.transform.position.z;

		for(float x = gridStartX; x< gridEndX; x+= gridSize){
			gridDivisionsX +=1;
		}
		for (float z = gridStartZ; z<gridEndZ; z+= gridSize) {
			gridDivisionsZ +=1;	
		}
		rangeX = new Vector2[gridDivisionsX];
		for (int x = 0; x<gridDivisionsX; x+=1) {
			rangeX[x] = new Vector2 ((gridStartX + gridSize * x), (gridStartX + gridSize * (x + 1)));
		}
		rangeZ = new Vector2[gridDivisionsZ];
		for(int z = 0; z<gridDivisionsZ; z+=1){
			rangeZ[z] = new Vector2 ((gridStartZ + gridSize * z), (gridStartZ + gridSize * (z + 1)));
		}
		playerSectorX = GridSectorX (player.transform.position.x);
		playerSectorZ = GridSectorZ (player.transform.position.z);


	}

	void Start(){




	}
	// Update is called once per frame
	void Update () {
		if (player == null) {
			player = GameObject.FindGameObjectWithTag("Player");
		}

		//remember to comment this out later
		//for (int x = 0; x<gridDivisionsX; x+=1) {
		//	Debug.DrawRay(new Vector3(rangeX[x].x,0,rangeX[0].y), new Vector3 (0,0,gridEndZ-gridStartZ),Color.green);
		//}
		//for (int z = 0; z<gridDivisionsZ; z+=1) {
		//	Debug.DrawRay (new Vector3(rangeZ[0].x, 0, rangeZ[z].y), new Vector3 (gridEndX-gridStartX,0,0), Color.cyan);	
		//}
		//remember to comment this out later

		playerSectorX = GridSectorX (player.transform.position.x);
		playerSectorZ = GridSectorZ (player.transform.position.z);


	}

	public int GridSectorX (float objectX){
		int gridRegionX = 1000;
		for (int x = 0; x<rangeX.Length; x+=1) {
			if(objectX >= rangeX[x].x && objectX < rangeX[x].y){
				gridRegionX = x;
			}
		}
		return gridRegionX;
	}

	public int GridSectorZ(float objectZ){
		int gridRegionZ = 1000;
		for (int z = 0; z<rangeZ.Length; z+=1) {
			if(objectZ >= rangeZ[z].x && objectZ < rangeZ[z].y){
				gridRegionZ = z;
			}		
		}
		return gridRegionZ;
	}


}