using UnityEngine;

using System.Collections;

using UnityEngine.UI;

/// <summary>

/// 用Kinect实现UI的点击：追踪左手手掌，移动到UI矩形内握拳表示点击该按钮。

/// </summary>

public class UIClick : MonoBehaviour {

    public Canvas canvas;

    public Image leftHandImage;  // 表示左手

    public Image btnImage;       // 要被点击的UI控件

    KinectManager _manager;

    void Start()

    {

    }

    void Update()

    {

        if (_manager == null)

        {

            _manager = KinectManager.Instance;

        }

        // 是否初始化完成

        if (_manager && _manager.IsInitialized())

        {

            // 是否人物被检测到

            if (_manager.IsUserDetected())

            {

                // 获取用户ID

                long userId = _manager.GetPrimaryUserID();

                // 获取目标关节点的索引（以左手为例）

                int jointIndex = (int)KinectInterop.JointType.HandLeft;

                // 判断目标关节点是否被追踪

                if (_manager.IsJointTracked(userId, jointIndex))

                {

                    // 获取目标关节点在Kinect坐标系（世界坐标）的位置

                    Vector3 leftHandPos = _manager.GetJointKinectPosition(userId, jointIndex);

                    // 左手的世界坐标 --> 屏幕坐标

                    Vector3 leftHandScreenPos = Camera.main.WorldToScreenPoint(leftHandPos);

                    Vector2 leftHandScreenPosTemp = new Vector2(leftHandScreenPos.x, leftHandScreenPos.y); // 降维

                    // 判断左手的UGUI坐标是否在Canvas所表示的矩形内

                    Vector2 leftHandUguiPos;

                    if (RectTransformUtility.ScreenPointToLocalPointInRectangle((RectTransform)canvas.transform, leftHandScreenPosTemp, null, out leftHandUguiPos))

                    {

                        RectTransform leftHandRTF = rightHandImage.transform as RectTransform;

                        // 屏幕坐标 --> UGUI坐标

                        leftHandRTF.anchoredPosition = leftHandUguiPos;

                    }

                    // 判断左手的UGUI坐标是否在Button所表示的矩形内

                    if (RectTransformUtility.RectangleContainsScreenPoint(btnImage.rectTransform, leftHandScreenPosTemp, null))

                    {

                        Debug.Log("在按钮中");

                        // 获取左手的手势状态

                        KinectInterop.HandState leftHandState = _manager.GetLeftHandState(userId);

                        if (leftHandState == KinectInterop.HandState.Closed)

                        {

                            Debug.Log("左手握拳");

                            // todo：点击按钮触发的事件

                        }

                    }

                    else

                    {

                        Debug.Log("在按钮外");

                    }

                }

            }

        }

    }

}