OnGui元素与其他OnGui元素交互

在我的2d游戏中，我希望有一些OnGui元素供用户选择，然而，我使用的光标是另一个OnGui元素(使用kinect导航(，这在任何情况下都是可能的，目前我使用的是平面，但我会放大和缩小相机，所以我基本上需要将它们固定在屏幕上。任何想法、建议或解决方法。这是我当前的光标。

using UnityEngine;
using System;
using System.Collections;
public class PillarAgent : MonoBehaviour {
public SkeletonWrapper sw;
public Vector3 distance;
public float progress =0f;
public Texture2D cursor;
public Texture2D load;
public Camera mainCam;
public float startTime;
private int roundedRestSecounds;
// Use this for initialization
    float differencex = 0;
    float differencey = 0;
void Start () {
    distance =new Vector3(0f,0f,0f);
}
float translate(float value, float leftMin, float leftMax, 
        float rightMin,float rightMax)
{
    float leftSpan = leftMax - leftMin;
    float rightSpan= rightMax - rightMin;
    float valueScaled = (value-leftMin)/(leftSpan);
    return rightMin+(valueScaled * rightSpan);
}
// Update is called once per frame
void Update () {
    if (sw.pollSkeleton())
    {
        distance.x=sw.bonePos[0,0].x - sw.bonePos[0,7].x;//5 is left shoulder
        distance.y=sw.bonePos[0,0].y -sw.bonePos[0,7].y;

        differencex=translate(distance.x,.6f,0,0,Screen.width);
        differencey=translate(distance.y,-.5f,0,0,Screen.height);
        //Debug.Log();
        float width = sw.bonePos[0,5].x+ sw.bonePos[0,9].x;
        float height =sw.bonePos[0,4].y- sw.bonePos[0,0].y;
        float heightdiv= (height/2)+sw.bonePos[0,0].y;        
    }    
}
void OnGUI() {
    //left top width height
    Rect r = new Rect(differencex,differencey,80,50);
    GUI.Label(r,cursor);
    GUI.BeginGroup(new Rect(differencex,differencey+50,50*Mathf.Clamp01(progress),15));
    //Debug.Log(progress);
    GUI.DrawTexture(new Rect(0,0,50,50),load);
    GUI.EndGroup();
    transform.position =mainCam.ScreenToWorldPoint(new Vector3(differencex,Screen.height-differencey,50));
    //mainCam.fieldOfView()    
}
void OnCollisionStay(Collision Other)
{
    startTime+=Time.deltaTime;
    if(Other.gameObject.GetComponent(typeof(TextControl)))
    {
        roundedRestSecounds=Mathf.CeilToInt(Time.time);
        progress = Time.time *0.2f;
        CurrentState=true;
    }
    else if(Other.gameObject.tag==("Scalpal")){

        progress = startTime *0.5f;
        //scallpall activated
        //    
    }        
}
void OnCollisionExit(Collision Other){
    startTime =0f;
    progress =0f;        
}
public Boolean CurrentState{get;set;}
}

下一个类本质上是我拿起工具的类，目前这个代码不起作用(不知道为什么(，但我想做的是选择一些出现在屏幕上的工具，这样我就可以使用它们，例如拿起画笔开始画砖或其他什么。当我把工具放在飞机上的那一刻，我希望在相机移动的任何时候都能把它们放在屏幕上。

using UnityEngine;
using System.Collections;
public class SelectTool : MonoBehaviour {
public Tools tools;
public float startTime;
public bool ScalpalSelected;
public GameObject selectedTool;
void Start()
{
    tools = this.GetComponent<Tools>(); //in order to use this tools muyst be attached to the game object
    //this is essentially saying  with regards to this game object get the component named tools
}
void update()
{
}
void OnCollisionStay(Collision Other)
{
    startTime +=Time.deltaTime;
    if(startTime >5f){
        if(Other.collider.tag==("Scalpal"))
        {
            selectedTool = Other.collider.gameObject;
            Debug.Log(selectedTool+" What in gods good name is:" +tools.utilities[0]);
        }
        else {
            selectedTool=null;
        }
        if(selectedTool){
            for(int i=0;i<tools.utilities.Length;i++)
            {
            }    
        }

            ScalpalSelected=true;
            renderer.material.color = Color.yellow;    
    }
}
void OncollisionStay(Collision other){
    startTime = 0f;
}
}