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");
                    }
                }
            }
        }
    }
}