Infratest/Assets/Code/Example/Liminal/Character/LiminalCharacterController.cs

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

namespace Code.Example.Liminal.Character
{
    public enum CharacterState
    {
        Default,
    }

    public enum OrientationMethod
    {
        TowardsCamera,
        TowardsMovement,
    }

    public class PlayerCharacterInputs
    {
        public float MoveAxisForward;
        public float MoveAxisRight;
        public Quaternion CameraRotation;
        public bool CrouchDown;
        public bool CrouchUp;
    }

    public struct AICharacterInputs
    {
        public Vector3 MoveVector;
        public Vector3 LookVector;
    }

    public enum BonusOrientationMethod
    {
        None,
        TowardsGravity,
        TowardsGroundSlopeAndGravity,
    }

    public class LiminalCharacterController : MonoBehaviour, ICharacterController
    {
        public KinematicCharacterMotor Motor;

        [Header("Stable Movement")] public float MaxStableMoveSpeed = 10f;
        public float StableMovementSharpness = 15f;
        public float OrientationSharpness = 10f;
        public bool InfinitelySharpRotation;
        public OrientationMethod OrientationMethod = OrientationMethod.TowardsCamera;

        [Header("Air Movement")] public float MaxAirMoveSpeed = 15f;
        public float AirAccelerationSpeed = 15f;
        public float Drag = 0.1f;

        [Header("Misc")] public List<Collider> IgnoredColliders = new List<Collider>();
        public BonusOrientationMethod BonusOrientationMethod = BonusOrientationMethod.None;
        public float BonusOrientationSharpness = 10f;

        public Vector3 Gravity = new Vector3(0, -30f, 0);

        // public Transform MeshRoot; 
        public float CrouchedCapsuleHeight = 1f;

        public CharacterState CurrentCharacterState { get; private set; }

        private Collider[] _probedColliders = new Collider[8];
        private RaycastHit[] _probedHits = new RaycastHit[8];
        private Vector3 _moveInputVector;
        private Vector3 _lookInputVector;
        private Vector3 _internalVelocityAdd = Vector3.zero;
        private bool _shouldBeCrouching = false;
        private bool _isCrouching = false;


        public void Teleport(Vector3 position, Quaternion rotation)
        {
            Motor.SetPosition(position);
            Motor.SetRotation(rotation);
        }

        private void Awake()
        {
            // Handle initial state
            TransitionToState(CharacterState.Default);

            // Assign the characterController to the motor
            Motor.CharacterController = this;
        }

        /// <summary>
        /// Handles movement state transitions and enter/exit callbacks
        /// </summary>
        public void TransitionToState(CharacterState newState)
        {
            CharacterState tmpInitialState = CurrentCharacterState;
            OnStateExit(tmpInitialState, newState);
            CurrentCharacterState = newState;
            OnStateEnter(newState, tmpInitialState);
        }

        /// <summary>
        /// Event when entering a state
        /// </summary>
        private void OnStateEnter(CharacterState state, CharacterState fromState)
        {
            switch (state)
            {
                case CharacterState.Default:
                {
                    break;
                }
            }
        }

        /// <summary>
        /// Event when exiting a state
        /// </summary>
        private void OnStateExit(CharacterState state, CharacterState toState)
        {
            switch (state)
            {
                case CharacterState.Default:
                {
                    break;
                }
            }
        }

        /// <summary>
        /// This is called every frame by ExamplePlayer in order to tell the character what its inputs are
        /// </summary>
        public void SetInputs(PlayerCharacterInputs inputs)
        {
            // Clamp input
            Vector3 moveInputVector =
                Vector3.ClampMagnitude(new Vector3(inputs.MoveAxisRight, 0f, inputs.MoveAxisForward), 1f);

            // Calculate camera direction and rotation on the character plane
            Vector3 cameraPlanarDirection =
                Vector3.ProjectOnPlane(inputs.CameraRotation * Vector3.forward, Motor.CharacterUp).normalized;
            if (cameraPlanarDirection.sqrMagnitude == 0f)
            {
                cameraPlanarDirection = Vector3.ProjectOnPlane(inputs.CameraRotation * Vector3.up, Motor.CharacterUp)
                    .normalized;
            }

            Quaternion cameraPlanarRotation = Quaternion.LookRotation(cameraPlanarDirection, Motor.CharacterUp);

            switch (CurrentCharacterState)
            {
                case CharacterState.Default:
                {
                    // Move and look inputs
                    _moveInputVector = cameraPlanarRotation * moveInputVector;

                    switch (OrientationMethod)
                    {
                        case OrientationMethod.TowardsCamera:
                            _lookInputVector = cameraPlanarDirection;
                            break;
                        case OrientationMethod.TowardsMovement:
                            _lookInputVector = _moveInputVector.normalized;
                            break;
                    }


                    // Crouching input
                    if (inputs.CrouchDown)
                    {
                        _shouldBeCrouching = true;

                        if (!_isCrouching)
                        {
                            _isCrouching = true;
                            Motor.SetCapsuleDimensions(0.5f, CrouchedCapsuleHeight, CrouchedCapsuleHeight * 0.5f);
                            // MeshRoot.localScale = new Vector3(1f, 0.5f, 1f);
                        }
                    }
                    else if (inputs.CrouchUp)
                    {
                        _shouldBeCrouching = false;
                    }

                    break;
                }
            }
        }

        /// <summary>
        /// This is called every frame by the AI script in order to tell the character what its inputs are
        /// </summary>
        public void SetInputs(ref AICharacterInputs inputs)
        {
            _moveInputVector = inputs.MoveVector;
            _lookInputVector = inputs.LookVector;
        }

        private Quaternion _tmpTransientRot;

        /// <summary>
        /// (Called by KinematicCharacterMotor during its update cycle)
        /// This is called before the character begins its movement update
        /// </summary>
        public void BeforeCharacterUpdate(float deltaTime)
        {
        }

        /// <summary>
        /// (Called by KinematicCharacterMotor during its update cycle)
        /// This is where you tell your character what its rotation should be right now. 
        /// This is the ONLY place where you should set the character's rotation
        /// </summary>
        public void UpdateRotation(ref Quaternion currentRotation, float deltaTime)
        {
            switch (CurrentCharacterState)
            {
                case CharacterState.Default:
                {
                    if (!InfinitelySharpRotation)
                    {
                        if (_lookInputVector.sqrMagnitude > 0f && OrientationSharpness > 0f)
                        {
                            // Smoothly interpolate from current to target look direction
                            Vector3 smoothedLookInputDirection = Vector3.Slerp(Motor.CharacterForward,
                                _lookInputVector, 1 - Mathf.Exp(-OrientationSharpness * deltaTime)).normalized;

                            // Set the current rotation (which will be used by the KinematicCharacterMotor)
                            currentRotation =
                                Quaternion.LookRotation(smoothedLookInputDirection, Motor.CharacterUp);
                        }
                    }
                    else
                    {
                        currentRotation = Quaternion.LookRotation(_lookInputVector, Motor.CharacterUp);
                    }

                    Vector3 currentUp = (currentRotation * Vector3.up);
                    if (BonusOrientationMethod == BonusOrientationMethod.TowardsGravity)
                    {
                        // Rotate from current up to invert gravity
                        Vector3 smoothedGravityDir = Vector3.Slerp(currentUp, -Gravity.normalized,
                            1 - Mathf.Exp(-BonusOrientationSharpness * deltaTime));
                        currentRotation = Quaternion.FromToRotation(currentUp, smoothedGravityDir) * currentRotation;
                    }
                    else if (BonusOrientationMethod == BonusOrientationMethod.TowardsGroundSlopeAndGravity)
                    {
                        if (Motor.GroundingStatus.IsStableOnGround)
                        {
                            Vector3 initialCharacterBottomHemiCenter =
                                Motor.TransientPosition + (currentUp * Motor.Capsule.radius);

                            Vector3 smoothedGroundNormal = Vector3.Slerp(Motor.CharacterUp,
                                Motor.GroundingStatus.GroundNormal,
                                1 - Mathf.Exp(-BonusOrientationSharpness * deltaTime));
                            currentRotation = Quaternion.FromToRotation(currentUp, smoothedGroundNormal) *
                                              currentRotation;

                            // Move the position to create a rotation around the bottom hemi center instead of around the pivot
                            Motor.SetTransientPosition(initialCharacterBottomHemiCenter +
                                                       (currentRotation * Vector3.down * Motor.Capsule.radius));
                        }
                        else
                        {
                            Vector3 smoothedGravityDir = Vector3.Slerp(currentUp, -Gravity.normalized,
                                1 - Mathf.Exp(-BonusOrientationSharpness * deltaTime));
                            currentRotation = Quaternion.FromToRotation(currentUp, smoothedGravityDir) *
                                              currentRotation;
                        }
                    }
                    else
                    {
                        Vector3 smoothedGravityDir = Vector3.Slerp(currentUp, Vector3.up,
                            1 - Mathf.Exp(-BonusOrientationSharpness * deltaTime));
                        currentRotation = Quaternion.FromToRotation(currentUp, smoothedGravityDir) * currentRotation;
                    }

                    break;
                }
            }
        }

        /// <summary>
        /// (Called by KinematicCharacterMotor during its update cycle)
        /// This is where you tell your character what its velocity should be right now. 
        /// This is the ONLY place where you can set the character's velocity
        /// </summary>
        public void UpdateVelocity(ref Vector3 currentVelocity, float deltaTime)
        {
            switch (CurrentCharacterState)
            {
                case CharacterState.Default:
                {
                    // Ground movement
                    if (Motor.GroundingStatus.IsStableOnGround)
                    {
                        float currentVelocityMagnitude = currentVelocity.magnitude;

                        Vector3 effectiveGroundNormal = Motor.GroundingStatus.GroundNormal;

                        // Reorient velocity on slope
                        currentVelocity = Motor.GetDirectionTangentToSurface(currentVelocity, effectiveGroundNormal) *
                                          currentVelocityMagnitude;

                        // Calculate target velocity
                        Vector3 inputRight = Vector3.Cross(_moveInputVector, Motor.CharacterUp);
                        Vector3 reorientedInput = Vector3.Cross(effectiveGroundNormal, inputRight).normalized *
                                                  _moveInputVector.magnitude;
                        Vector3 targetMovementVelocity = reorientedInput * MaxStableMoveSpeed;

                        // Smooth movement Velocity
                        currentVelocity = Vector3.Lerp(currentVelocity, targetMovementVelocity,
                            1f - Mathf.Exp(-StableMovementSharpness * deltaTime));
                    }
                    // Air movement
                    else
                    {
                        // Add move input
                        if (_moveInputVector.sqrMagnitude > 0f)
                        {
                            Vector3 addedVelocity = _moveInputVector * AirAccelerationSpeed * deltaTime;

                            Vector3 currentVelocityOnInputsPlane =
                                Vector3.ProjectOnPlane(currentVelocity, Motor.CharacterUp);

                            // Limit air velocity from inputs
                            if (currentVelocityOnInputsPlane.magnitude < MaxAirMoveSpeed)
                            {
                                // clamp addedVel to make total vel not exceed max vel on inputs plane
                                Vector3 newTotal = Vector3.ClampMagnitude(currentVelocityOnInputsPlane + addedVelocity,
                                    MaxAirMoveSpeed);
                                addedVelocity = newTotal - currentVelocityOnInputsPlane;
                            }
                            else
                            {
                                // Make sure added vel doesn't go in the direction of the already-exceeding velocity
                                if (Vector3.Dot(currentVelocityOnInputsPlane, addedVelocity) > 0f)
                                {
                                    addedVelocity = Vector3.ProjectOnPlane(addedVelocity,
                                        currentVelocityOnInputsPlane.normalized);
                                }
                            }

                            // Prevent air-climbing sloped walls
                            if (Motor.GroundingStatus.FoundAnyGround)
                            {
                                if (Vector3.Dot(currentVelocity + addedVelocity, addedVelocity) > 0f)
                                {
                                    Vector3 perpenticularObstructionNormal = Vector3
                                        .Cross(Vector3.Cross(Motor.CharacterUp, Motor.GroundingStatus.GroundNormal),
                                            Motor.CharacterUp).normalized;
                                    addedVelocity =
                                        Vector3.ProjectOnPlane(addedVelocity, perpenticularObstructionNormal);
                                }
                            }

                            // Apply added velocity
                            currentVelocity += addedVelocity;
                        }

                        // Gravity
                        currentVelocity += Gravity * deltaTime;

                        // Drag
                        currentVelocity *= (1f / (1f + (Drag * deltaTime)));
                    }

                    // Take into account additive velocity
                    if (_internalVelocityAdd.sqrMagnitude > 0f)
                    {
                        currentVelocity += _internalVelocityAdd;
                        _internalVelocityAdd = Vector3.zero;
                    }

                    break;
                }
            }
        }

        /// <summary>
        /// (Called by KinematicCharacterMotor during its update cycle)
        /// This is called after the character has finished its movement update
        /// </summary>
        public void AfterCharacterUpdate(float deltaTime)
        {
            switch (CurrentCharacterState)
            {
                case CharacterState.Default:
                {
                    // Handle uncrouching
                    if (_isCrouching && !_shouldBeCrouching)
                    {
                        // Do an overlap test with the character's standing height to see if there are any obstructions
                        Motor.SetCapsuleDimensions(0.5f, 2f, 1f);
                        if (Motor.CharacterOverlap(
                                Motor.TransientPosition,
                                Motor.TransientRotation,
                                _probedColliders,
                                Motor.CollidableLayers,
                                QueryTriggerInteraction.Ignore) > 0)
                        {
                            // If obstructions, just stick to crouching dimensions
                            Motor.SetCapsuleDimensions(0.5f, CrouchedCapsuleHeight, CrouchedCapsuleHeight * 0.5f);
                        }
                        else
                        {
                            // If no obstructions, uncrouch
                            // MeshRoot.localScale = new Vector3(1f, 1f, 1f);
                            _isCrouching = false;
                        }
                    }

                    break;
                }
            }
        }

        public void PostGroundingUpdate(float deltaTime)
        {
            // Handle landing and leaving ground
            if (Motor.GroundingStatus.IsStableOnGround && !Motor.LastGroundingStatus.IsStableOnGround)
            {
                OnLanded();
            }
            else if (!Motor.GroundingStatus.IsStableOnGround && Motor.LastGroundingStatus.IsStableOnGround)
            {
                OnLeaveStableGround();
            }
        }

        public bool IsColliderValidForCollisions(Collider coll)
        {
            if (IgnoredColliders.Count == 0)
            {
                return true;
            }

            if (IgnoredColliders.Contains(coll))
            {
                return false;
            }

            return true;
        }

        public void OnGroundHit(Collider hitCollider, Vector3 hitNormal, Vector3 hitPoint,
            ref HitStabilityReport hitStabilityReport)
        {
        }

        public void OnMovementHit(Collider hitCollider, Vector3 hitNormal, Vector3 hitPoint,
            ref HitStabilityReport hitStabilityReport)
        {
        }

        public void AddVelocity(Vector3 velocity)
        {
            switch (CurrentCharacterState)
            {
                case CharacterState.Default:
                {
                    _internalVelocityAdd += velocity;
                    break;
                }
            }
        }

        public void ProcessHitStabilityReport(Collider hitCollider, Vector3 hitNormal, Vector3 hitPoint,
            Vector3 atCharacterPosition, Quaternion atCharacterRotation, ref HitStabilityReport hitStabilityReport)
        {
        }

        protected void OnLanded()
        {
        }

        protected void OnLeaveStableGround()
        {
        }

        public void OnDiscreteCollisionDetected(Collider hitCollider)
        {
        }
    }
}