//-----------------------------------------------------------------  
//1，把本类作为一个组件，包含在 GameObject 中。  
//2，左手坐标系。  
//-----------------------------------------------------------------  
using System.Collections;  
using System.Collections.Generic;  
using UnityEngine;  
//-----------------------------------------------------------------  
public class FiCameraControl : MonoBehaviour  
{  
    public float moveSpeed = 30.0f;  
    public float rotateSpeed = 0.2f;  
  
  
    public static Vector3 kUpDirection = new Vector3(0.0f, 1.0f, 0.0f);  
  
  
    //控制摄像机旋转的成员变量。  
    private float m_fLastMousePosX = 0.0f;  
    private float m_fLastMousePosY = 0.0f;  
    private bool m_bMouseRightKeyDown = false;  
  
  
    //-----------------------------------------------------------------  
    void Start()  
    {  
  
  
    }  
    //-----------------------------------------------------------------  
    void Update()  
    {  
        //判断旋转  
        if (Input.GetMouseButtonDown(1)) //鼠标右键刚刚按下了  
        {  
            if (m_bMouseRightKeyDown == false)  
            {  
                m_bMouseRightKeyDown = true;  
                Vector3 kMousePos = Input.mousePosition;  
                m_fLastMousePosX = kMousePos.x;  
                m_fLastMousePosY = kMousePos.y;  
            }  
        }  
        else if (Input.GetMouseButtonUp(1)) //鼠标右键刚刚抬起了  
        {  
            if (m_bMouseRightKeyDown == true)  
            {  
                m_bMouseRightKeyDown = false;  
                m_fLastMousePosX = 0;  
                m_fLastMousePosY = 0;  
            }  
        }  
        else if (Input.GetMouseButton(1)) //鼠标右键处于按下状态中  
        {  
            if (m_bMouseRightKeyDown)  
            {  
                Vector3 kMousePos = Input.mousePosition;  
                float fDeltaX = kMousePos.x - m_fLastMousePosX;  
                float fDeltaY = kMousePos.y - m_fLastMousePosY;  
                m_fLastMousePosX = kMousePos.x;  
                m_fLastMousePosY = kMousePos.y;  
  
  
                Vector3 kNewEuler = transform.eulerAngles;  
                kNewEuler.x += (fDeltaY * rotateSpeed);  
                kNewEuler.y += -(fDeltaX * rotateSpeed);  
                transform.eulerAngles = kNewEuler;  
            }  
        }  
  
  
        //判断位移  
        float fMoveDeltaX = 0.0f;  
        float fMoveDeltaZ = 0.0f;  
        float fDeltaTime = Time.deltaTime;  
        if (Input.GetKey(KeyCode.A))  
        {  
            fMoveDeltaX -= moveSpeed * fDeltaTime;  
        }  
        if (Input.GetKey(KeyCode.D))  
        {  
            fMoveDeltaX += moveSpeed * fDeltaTime;  
        }  
        if (Input.GetKey(KeyCode.W))  
        {  
            fMoveDeltaZ += moveSpeed * fDeltaTime;  
        }  
        if (Input.GetKey(KeyCode.S))  
        {  
            fMoveDeltaZ -= moveSpeed * fDeltaTime;  
        }  
        if (fMoveDeltaX != 0.0f || fMoveDeltaZ != 0.0f)  
        {  
            Vector3 kForward = transform.forward;  
            Vector3 kRight = Vector3.Cross(kUpDirection, kForward);  
            Vector3 kNewPos = transform.position;  
            kNewPos += kRight * fMoveDeltaX;  
            kNewPos += kForward * fMoveDeltaZ;  
            transform.position = kNewPos;  
        }  
    }  
}  
//-----------------------------------------------------------------