HandDriverUPM/HandDriver/SDK/Interaction SDK/Scripts/Runtime/InteractableSurface.cs

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

namespace UDE_HAND_INTERACTION
{
    public class InteractableSurface : MonoBehaviour, ISurface, IBounds, IClippedSurface<IBoundsClipper>
    {
        public enum NormalFacing
        {
            Backward,
            Forward,
        }

        public Transform Transform => transform;

        [SerializeField]
        private NormalFacing _facing = NormalFacing.Backward;

        [SerializeField]
        private bool _doubleSided = false;

        private InteractableSurface _interactableSurface;
        public ISurface BackingSurface => _interactableSurface;

        public enum SurfaceType
        {
            Square,
            Circle,
            Infinity
        }

        public SurfaceType surfaceType = SurfaceType.Square;
        [HideInInspector]
        public float _radius = 0.1f;

        [HideInInspector]
        public Vector3 _position = Vector3.zero;
        [HideInInspector]
        public float _width = 0.1f; 
        [HideInInspector]
        public float _height = 0.1f;

        public Vector3 Position
        {
            get => _position;
            set => _position = value;
        }

        public Vector3 Size
        {
            get => new(_width, _height, 0);
            set { _width = value[0];  _height = value[1]; }
        }


        [HideInInspector, SerializeField, Interface(typeof(IBoundsClipper))]
        private List<Object> _clippers;

        public bool GetLocalBounds(Transform localTo, out Bounds bounds)
        {
            Vector3 localPos = localTo.InverseTransformPoint(transform.TransformPoint(Position));
            Vector3 localSize = localTo.InverseTransformVector(transform.TransformVector(Size));
            bounds = new Bounds(localPos, localSize);
            return isActiveAndEnabled;
        }

        public IEnumerable<IBoundsClipper> GetClippers()
        {
            foreach (var clipper in _clippers)
            {
                yield return clipper as IBoundsClipper;
            }
        }

        public bool ClipBounds(in Bounds bounds, out Bounds clipped)
        {
            clipped = bounds;

            foreach (var clipperMono in _clippers)
            {
                IBoundsClipper clipper = clipperMono as IBoundsClipper;
                if (clipper == null || !clipper.GetLocalBounds(transform, out Bounds clipTo))
                {
                    continue;
                }

                if (!clipped.Clip(clipTo, out clipped))
                {
                    return false;
                }
            }

            return true;
        }

        protected virtual void Start()
        {
            _interactableSurface = GetComponent<InteractableSurface>();
            _clippers.Add(gameObject);
        }

        public Vector3 Normal
        {
            get
            {
                return _facing == NormalFacing.Forward ? transform.forward : -transform.forward;
            }
        }

        private bool IsPointAboveSurface(Vector3 point)
        {
            Plane plane = GetPlane();
            return plane.GetSide(point);
        }

        private Vector3 ClampPoint(in Vector3 point, in Bounds bounds)
        {
            Vector3 min = bounds.min;
            Vector3 max = bounds.max;
            Vector3 localPoint = Transform.InverseTransformPoint(point);

            Vector3 clamped = new(Mathf.Clamp(localPoint.x, min.x, max.x),Mathf.Clamp(localPoint.y, min.y, max.y),Mathf.Clamp(localPoint.z, min.z, max.z));

            return Transform.TransformPoint(clamped);
        }

        public bool ClosestSurfacePoint(in Vector3 point, out SurfaceHit hit, float maxDistance)
        {
            hit = new SurfaceHit();
            Plane plane = GetPlane();

            if(surfaceType == SurfaceType.Circle)
            {
                Vector3 vectorFromPlane = point - Transform.position;
                Vector3 planeNormal = Normal;
                Vector3 projectedPoint = Vector3.ProjectOnPlane(vectorFromPlane, planeNormal);

                float distanceFromCenterSqr = projectedPoint.sqrMagnitude;
                float worldRadius = Transform.lossyScale.x * _radius;
                if (distanceFromCenterSqr > worldRadius * worldRadius)
                {
                    projectedPoint = worldRadius * projectedPoint.normalized;
                }
                Vector3 closestPoint = projectedPoint + Transform.position;

                hit.Point = closestPoint;
                hit.Normal = plane.normal;
                hit.Distance = Vector3.Distance(point, closestPoint);
                if (Vector3.Distance(point, transform.position) > _radius) return false;
                return maxDistance <= 0 || hit.Distance <= maxDistance;
            }
            else if(surfaceType == SurfaceType.Square)
            {
                bool result = true;
                float hitDistance = plane.GetDistanceToPoint(point);
                if (maxDistance > 0 && Mathf.Abs(hitDistance) > maxDistance)
                {
                    result = false;
                }
                hit.Point = plane.ClosestPointOnPlane(point);
                hit.Distance = IsPointAboveSurface(point) ? hitDistance : -hitDistance;
                hit.Normal = plane.normal;

                if (result && GetLocalBounds(transform, out Bounds clippedPlane))
                {
                    hit.Point = ClampPoint(hit.Point, clippedPlane);
                    hit.Distance = Vector3.Distance(point, hit.Point);
                    float VaildMaxDist = Mathf.Sqrt(Mathf.Pow(_width, 2) + Mathf.Pow(_height, 2)) * 0.5f;
                    if (Vector3.Distance(point, transform.position) > VaildMaxDist) return false;
                    return maxDistance <= 0 || hit.Distance <= maxDistance;
                }
                return false;
            }
            else
            {
                float hitDistance = plane.GetDistanceToPoint(point);
                if (maxDistance > 0 && Mathf.Abs(hitDistance) > maxDistance)
                {
                    return false;
                }

                hit.Point = plane.ClosestPointOnPlane(point);
                hit.Distance = IsPointAboveSurface(point) ? hitDistance : -hitDistance;
                hit.Normal = plane.normal;

                return true;
            }
        }

        public Bounds Bounds
        {
            get
            {
                Vector3 size = new Vector3(Mathf.Abs(Normal.x) == 1f ? float.Epsilon : float.PositiveInfinity, Mathf.Abs(Normal.y) == 1f ? float.Epsilon : float.PositiveInfinity, Mathf.Abs(Normal.z) == 1f ? float.Epsilon : float.PositiveInfinity);
                return new Bounds(transform.position, size);
            }
        }

        public bool Raycast(in Ray ray, out SurfaceHit hit, float maxDistance)
        {
            hit = new SurfaceHit();
            Plane plane = GetPlane();

            if (!_doubleSided && !IsPointAboveSurface(ray.origin))
            {
                return false;
            }

            if (plane.Raycast(ray, out float hitDistance))
            {
                if (maxDistance > 0 && hitDistance > maxDistance)
                {
                    return false;
                }

                if (surfaceType == SurfaceType.Circle)
                {
                    Vector3 hitPointWorld = ray.GetPoint(hitDistance);
                    Vector3 hitPointLocal = Transform.InverseTransformPoint(hitPointWorld);

                    if (Mathf.Abs(hitPointLocal.x) > _radius || Mathf.Abs(hitPointLocal.y) > _radius)
                    {
                        return false;
                    }

                    hit.Point = hitPointWorld;
                    hit.Normal = plane.normal;
                    hit.Distance = hitDistance;
                }
                else if(surfaceType == SurfaceType.Square)
                {

                    hit.Point = ray.GetPoint(hitDistance);
                    hit.Normal = plane.normal;
                    hit.Distance = hitDistance;

                    Bounds InfiniteBounds = new Bounds(Vector3.zero, Vector3.one * float.PositiveInfinity);
                    return ClipBounds(InfiniteBounds, out Bounds clipBounds) && 
                        clipBounds.size != Vector3.zero &&
                        clipBounds.Contains(Transform.InverseTransformPoint(hit.Point));
                }
                else
                {
                    hit.Point = ray.GetPoint(hitDistance);
                    hit.Normal = plane.normal;
                    hit.Distance = hitDistance;
                }
                return true;
            }
            return false;
        }

        public Plane GetPlane()
        {
            return new Plane(Normal, transform.position);
        }

    }
}