using System.Collections;
using System.Collections.Generic;
using UnityEngine;

namespace MyFrameworkPure
{
    /// <summary>
    /// 通过缩放物体模拟摄像机正交渲染
    /// </summary>
    public class OrthographicRender : MonoBehaviour
    {
        public Camera renderCamera;

        [SerializeField] private float scale = 0.3f;

        [SerializeField] private bool lateUpdate;

        // Start is called before the first frame update
        void Start()
        {
            if (!renderCamera)
                renderCamera = Camera.main;
        }
        // Update is called once per frame
        void Update()
        {
            if (lateUpdate)
                return;
            transform.localScale = Vector3.one * GetHandleSize(renderCamera, transform.position) * scale;
        }

        void LateUpdate()
        {
            if (!lateUpdate)
                return;
            transform.localScale = Vector3.one * GetHandleSize(renderCamera, transform.position) * scale;
        }

        public static float GetHandleSize(Camera camera, Vector3 position)
        {
            float result;
            if (camera)
            {
                Transform transform = camera.transform;
                Vector3 position2 = transform.position;
                float z = Vector3.Dot(position - position2, transform.TransformDirection(new Vector3(0f, 0f, 1f)));
                Vector3 a = camera.WorldToScreenPoint(position2 + transform.TransformDirection(new Vector3(0f, 0f, z)));
                Vector3 b = camera.WorldToScreenPoint(position2 + transform.TransformDirection(new Vector3(1f, 0f, z)));
                float magnitude = (a - b).magnitude;
                result = 80f / Mathf.Max(magnitude, 0.0001f);
            }
            else
            {
                result = 20f;
            }
            return result;
        }

    }
}