using System;
using UnityEngine;

namespace CharacterPreview
{
    public class ModelMove:MonoBehaviour
    {
        private Camera _camera;
        public Camera currentCamera
        {
            get
            {
                if (!_camera)
                {
                    _camera = Camera.main;
                    if (!_camera)
                    {
                        _camera = FindObjectOfType<Camera>();
                    }
                }
                return _camera;
            }
        }
        private void Start()
        {
            if (currentCamera)
            {
                var worldPos = CameraLocalToWorld(currentCamera, new Vector3(1, -1, 1));
                transform.position = worldPos;
            }
            else
            {
                transform.position = new Vector3(8, 8, -16);
            }
        }
        /// <summary>
        /// 将摄像机局部坐标系中的点转换为世界坐标系中的点。
        /// 假设摄像机局部坐标系：前向为 +Z，右为 +X，上为 +Y。
        /// </summary>
        /// <param name="camera">目标摄像机</param>
        /// <param name="localPoint">在摄像机局部坐标系中的点</param>
        /// <returns>对应的世界坐标</returns>
        public static Vector3 CameraLocalToWorld(Camera camera, Vector3 localPoint)
        {
            if (camera == null)
                throw new System.ArgumentNullException(nameof(camera));

            Transform camTransform = camera.transform;
            // 旋转局部点到世界方向，然后加上摄像机位置
            return camTransform.position + camTransform.rotation * localPoint;
        }
    }
}