ZoneHighlighter/project/Terkoiz.MapZoneHighlighter/BoundedBoxes/ColliderBoundsController.cs

using UnityEngine;

namespace Terkoiz.MapZoneHighlighter.BoundedBoxes
{
    public class ColliderBoundsController : MonoBehaviour
    {
        public bool IsActive;

        public static readonly Color InactiveLineColor = new Color(1f, 0f, 0.8f, 0.8f);
        public static readonly Color ActiveLineColor = new Color(0f, 1f, 0f, 0.8f);

        private Bounds _bound;
        private Vector3[] _corners;
        private Vector3[,] _lines;
        private Quaternion _quat;

        private Camera _mainCamera;
        private ColliderBoundsRenderer _cameraLines;

        private Vector3 _topFrontLeft;
        private Vector3 _topFrontRight;
        private Vector3 _topBackLeft;
        private Vector3 _topBackRight;
        private Vector3 _bottomFrontLeft;
        private Vector3 _bottomFrontRight;
        private Vector3 _bottomBackLeft;
        private Vector3 _bottomBackRight;

        public Vector3 ScreenPosition;
        public bool IsOnScreen;
        public float DistanceToCamera;

        private void Start()
        {
            _mainCamera = Camera.main;
            _cameraLines = _mainCamera.GetComponent<ColliderBoundsRenderer>();
            Init();
        }

        public void Init()
        {
            CalculateBounds();
            SetPoints();
            SetLines();
            _cameraLines.SetOutlines(_lines, InactiveLineColor);
        }

        private void LateUpdate()
        {
            _cameraLines.SetOutlines(_lines, IsActive ? ActiveLineColor : InactiveLineColor);
        }

        private void OnGUI()
        {
            if (Camera.main == null)
            {
                return;
            }

            ScreenPosition = UIDrawingUtil.WorldPointToScreenPoint(transform.position);
            IsOnScreen = UIDrawingUtil.IsScreenPointVisible(ScreenPosition);
            DistanceToCamera = Vector3.Distance(Camera.main.transform.position, transform.position);
        }

        private void CalculateBounds()
        {
            BoxCollider coll = GetComponent<BoxCollider>();
            if (coll)
            {
                _bound = coll.bounds;
                _quat = Quaternion.Euler(0f, coll.transform.rotation.y, 0f);
            }
            else
            {
                Debug.LogError($"[{nameof(ColliderBoundsController)}] No collider attached to '{name}'");
            }
        }

        private void SetPoints()
        {
            Vector3 bc = transform.position + _quat * (_bound.center - transform.position);

            _topFrontRight = bc + _quat * Vector3.Scale(_bound.extents, new Vector3(1, 1, 1));
            _topFrontLeft = bc + _quat * Vector3.Scale(_bound.extents, new Vector3(-1, 1, 1));
            _topBackLeft = bc + _quat * Vector3.Scale(_bound.extents, new Vector3(-1, 1, -1));
            _topBackRight = bc + _quat * Vector3.Scale(_bound.extents, new Vector3(1, 1, -1));
            _bottomFrontRight = bc + _quat * Vector3.Scale(_bound.extents, new Vector3(1, -1, 1));
            _bottomFrontLeft = bc + _quat * Vector3.Scale(_bound.extents, new Vector3(-1, -1, 1));
            _bottomBackLeft = bc + _quat * Vector3.Scale(_bound.extents, new Vector3(-1, -1, -1));
            _bottomBackRight = bc + _quat * Vector3.Scale(_bound.extents, new Vector3(1, -1, -1));
            _corners = new Vector3[]
            {
                _topFrontRight, _topFrontLeft, _topBackLeft, _topBackRight, _bottomFrontRight, _bottomFrontLeft, _bottomBackLeft,
                _bottomBackRight
            };
        }

        private void SetLines()
        {
            const int linesCount = 12;

            _lines = new Vector3[linesCount, 2];
            for (int i = 0; i < 4; i++)
            {
                var i1 = (i + 1) % 4;
                _lines[i, 0] = _corners[i];
                _lines[i, 1] = _corners[i1];
                i1 = i + 4; //vertical lines
                _lines[i + 4, 0] = _corners[i];
                _lines[i + 4, 1] = _corners[i1];
                //bottom rectangle
                _lines[i + 8, 0] = _corners[i1];
                i1 = 4 + (i + 1) % 4;
                _lines[i + 8, 1] = _corners[i1];
            }
        }
    }
}