Unity crosshair

MouseCrosshair.cs

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class MouseCrosshair : MonoBehaviour {
  
  protected int cursorState = 0; // index of states[] to draw on screen
  
  protected int cursorSizeX = 16;
  protected int cursorSizeY = 16;
  
  Rect cursorInfo;
  
  public Texture2D[] states;
  bool draw = true;
  
  void Awake(){
    
    //default loading
    if(states.Length <= 0){
      List<Texture2D> ts = new List<Texture2D>();
      Texture2D t;
      t = (Texture2D)Resources.Load("Textures/GUI/cursor_normal");
      if(t != null) ts.Add(t);
      t = (Texture2D)Resources.Load("Textures/GUI/cursor_action");
      if(t != null) ts.Add(t);
      states = ts.ToArray();
    }

    if(states.Length > 0){
      cursorSizeX = states[0].width;
      cursorSizeY = states[0].height;
    }

    cursorInfo = new Rect(0f,0f,cursorSizeX,cursorSizeY);
  }
  
  void Start(){
    cursorState = 0;
    event_resizeScreen();
  }
  
  public void toggle(bool flag){
    draw = flag;
  }
  
  /* to call when screen switch size */
  public void event_resizeScreen(){
    int w = (Mathf.CeilToInt (Camera.main.pixelWidth * 0.5f) - Mathf.CeilToInt(cursorSizeX * 0.5f));
    int h = (Mathf.CeilToInt (Camera.main.pixelHeight * 0.5f) - Mathf.CeilToInt(cursorSizeY * 0.5f));
    cursorInfo.x = w;
    cursorInfo.y = h;
    //Debug.Log (cursorInfo);
  }
  
  /* draw crosshair on screen */
  void OnGUI(){
    if(!draw) return;
    if(states.Length <= 0) return;
    GUI.DrawTexture(cursorInfo,states[cursorState]);
  }
  
}