yichael_smartbow/Assets/BowArrow/Scripts/Game/CrossHair.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.SceneManagement;
/* 准心对象 */
public class CrossHair : MonoBehaviour
{
    public static CrossHair ins;
    private Image image = null;
    private bool open = false; 
    private bool visiable = false;

    void Awake()
    {
        ins = this;
    }

    void Start()
    {
        this.image = this.GetComponent<Image>();
        this.open = UserSettings.ins.openCrossHair;
        this.visiable = this.image.enabled;
        this.SetVisiable(false);
        //如果是靶子场景，把准心改为黑色
        if (SceneManager.GetActiveScene().name.Equals("Game")) {
            this.image.color = Color.black;
        }
    }

    void Update()
    {
        if (open) SetVisiable(ArmBow.ins && ArmBow.ins.IsCanShoot());
    }

    void SetVisiable(bool value)
    {
        if (this.visiable == value) return;
        this.visiable = value;
        this.GetComponent<Image>().enabled = this.visiable;
    }

    public void SetOpen(bool open) {
        this.open = open;
        if (!this.open) {
            SetVisiable(false);
        }
    }

    public bool GetOpen() {
        return this.open;
    }

    public RaycastHit GetRaycastHit() {
        float maxDistance = 100;
        int layerMask = 1 << 8; //TargetLayerMask
        RaycastHit raycastHit;
        Ray ray;
        if (Camera.main.name.EndsWith("Fixed")) {
            ray = new Ray(BowCamera.ins.transform.position, BowCamera.ins.transform.forward);
        } else {
            ray = Camera.main.ScreenPointToRay(this.transform.position, Camera.MonoOrStereoscopicEye.Mono);
        }
        Physics.Raycast(ray.origin, ray.direction, out raycastHit, maxDistance, layerMask);
        return raycastHit;
    }    

    #region 固定相机更新
        RectTransform _parentRTF;
        RectTransform parentRTF {
            get {
                if (!_parentRTF) {
                    _parentRTF = transform.parent.GetComponent<RectTransform>();
                }
                return _parentRTF;
            }
        }
        Vector3 centerPoint = new Vector3(0.5f, 0.5f, 0);
        Vector3 targetPosition;
        public void UpdatePostionWhenFixedCamera() {
            if (!visiable) return;
            Transform transform = BowCamera.ins.transform;
            Ray ray = new Ray(transform.position, transform.forward);
            RaycastHit hitInfo;
            if (Physics.Raycast(ray, out hitInfo, 100)) {
                targetPosition = hitInfo.point;
            } else {
                targetPosition = transform.position + transform.forward * 100f;
            }
            Vector3 v3 = Camera.main.WorldToViewportPoint(targetPosition) - centerPoint;
            v3.x *= parentRTF.rect.width;
            v3.y *= parentRTF.rect.height;
            v3.z = 0;
            this.transform.localPosition = v3;
        }
    #endregion
}