Space-Smash-Out/Assets/Scripts/Ship.cs

using System;
using UnityEngine;
using static AffectingForcesManager;
using ShipHandling;
using Managers;
using GameLogic;

public class Ship : MonoBehaviour
{
	public int InstanceID { get; private set; }
	public ShipProperties props;
	public ShipState state;
	public BoostCapacityUI boostUI;
	// Private variables
	public CameraOperator cameraOperator;

	private AffectingForcesManager forceManager;
	private Rigidbody body;
	// Saves the current input value for thrust
	private bool canBoost = true;
	private TackleDetection[] tackleDetectors;
	private bool isCriticalTackle = false;
	private bool isTackled = false;
	private float tackledTime = 0f;
	// Current Zone the player occupies
	private Zone zone = Zone.NimbleZone;

	void Awake()
	{
		if (forceManager == null)
		{
			forceManager = GameObject.FindGameObjectWithTag("ForceManager").
				GetComponent<AffectingForcesManager>();
		}
		body = GetComponent<Rigidbody>();
	}

	// Start is called before the first frame update
	void Start()
	{
		InstanceID = gameObject.GetInstanceID();
		state.boostCapacity = props.maxBoostCapacity;
		boostUI.SetMinBoostRatio(props.minBoostCapacity / props.maxBoostCapacity);
		// GameManager.GM.RegisterPlayer(this);
		cameraOperator.AddPlayer(gameObject);

		tackleDetectors = GetComponentsInChildren<TackleDetection>();
		foreach (TackleDetection td in tackleDetectors)
		{
			td.TackleResponse.AddListener(StartTackleResponse);
		}
	}

	void OnDestroy()
	{
		foreach (TackleDetection td in tackleDetectors)
		{
			td.TackleResponse.RemoveAllListeners();
		}
	}

	// Update is called once per frame
	void FixedUpdate()
	{
		if (state.reset)
		{
			state.reset = false;
			body.velocity = Vector3.zero;
			body.transform.rotation = body.transform.parent.rotation;
			MatchManager.G.StartMatch();
		}

		// TODO: This could be more elegant maybe?
		if (MatchManager.G.matchState != MatchState.Match)
		{
			body.constraints = RigidbodyConstraints.FreezeAll;
			return;
		}
		body.constraints = RigidbodyConstraints.None;
		// TODO: This belongs in the state object
		zone = forceManager.GetZoneOfInstance(InstanceID);
		//BoostStateUpdate(Time.deltaTime);
		// Rotate the vehicle with the current steer velocity
		// Calculate the magnitude of the acceleration with the current thrust
		UpdateMovement();
		BoostStateUpdate(Time.deltaTime);
		UpdateTackleResponse(isCriticalTackle);
	}

	/// <summary>
	/// Movement logic and simulation of the ship.
	/// </summary>
	void UpdateMovement()
	{

		//Debug.Log("inupdatemove " + currentThrustInput);
		// Player rotation is always possible and same speed
		transform.Rotate(0, 0, -props.steerVelocity * state.steerInput * Time.deltaTime);

		// Get and apply the current Gravity
		state.currentGravity = forceManager.GetGravityForInstance(InstanceID)(transform);
		body.AddForce(state.currentGravity, ForceMode.Acceleration);

		float stunFactor = isCriticalTackle ? props.stunLooseControlFactor : 1f;

		float thrust = IsBoosting() ? 1f : state.thrustInput;
		Vector3 acceleration = props.thrustAcceleration * thrust * Time.deltaTime
			* transform.up * stunFactor;

		Vector3 currentVelocity = body.velocity;

		Vector3 boostedAcceleration = BoostAcceleration(acceleration, state.currentGravity);

		if (!isCriticalTackle)
		{
			// Add drag
			if (zone == Zone.NimbleZone)
			{
				Vector3 dragDecceleration = DragDecceleration(currentVelocity, zone);
				body.AddForce(dragDecceleration, ForceMode.Acceleration);

				if (!isTackled)
				{
					// Add anti drift acceleration
					Vector3 driftDampeningAcceleration =
						DriftDampeningAcceleration(currentVelocity, zone);
					body.AddForce(driftDampeningAcceleration, ForceMode.Acceleration);
				}
			}

			if (currentVelocity.magnitude <= props.normalMaxVelocity || IsBoosting()
				|| zone != Zone.NimbleZone)
			{
				body.AddForce(boostedAcceleration, ForceMode.Acceleration);
			}
			if (currentVelocity.magnitude >= props.absolutMaxVelocity && zone == Zone.NimbleZone)
			{
				body.velocity = body.velocity.normalized * props.absolutMaxVelocity;
			}
		}

		// Default torque drag
		body.AddRelativeTorque(body.angularVelocity * -props.torqueDrag, ForceMode.Acceleration);


		Debug.DrawRay(transform.position, transform.up * (currentVelocity.magnitude + 3) * 0.5f,
			Color.black);
	}

	/// <summary>
	/// Calculates a vector to mitigate the ship drifting when it's changing direction.
	/// </summary>
	/// <param name="currentVelocity">Current velocity of the ship</param>
	/// <param name="zone">Zone which the ship is in</param>
	/// <returns></returns>
	Vector3 DriftDampeningAcceleration(Vector3 currentVelocity, Zone zone)
	{
		Vector3 antiDriftVelocity;
		float antiDriftFactor;
		// Cancel out inertia/drifting
		Vector3 up = transform.up;
		Vector3 driftVelocity = currentVelocity - Vector3.Project(currentVelocity, up);
		if (driftVelocity.magnitude < 0.1)
		{
			return Vector3.zero;
		}

		antiDriftVelocity = Vector3.Reflect(-driftVelocity, up) - driftVelocity;
		antiDriftFactor = Mathf.InverseLerp(props.absolutMaxVelocity, props.normalMaxVelocity,
			currentVelocity.magnitude);

		antiDriftFactor = Mathf.Max(antiDriftFactor, props.minAntiDriftFactor);

		Debug.DrawRay(transform.position, currentVelocity.normalized * currentVelocity.magnitude * 2, Color.cyan);
		Debug.DrawRay(transform.position, driftVelocity.normalized * 5, Color.red);
		Debug.DrawRay(transform.position, antiDriftVelocity.normalized * 5, Color.green);

		return antiDriftVelocity * props.antiDriftAmount * antiDriftFactor;
	}

	/// <summary>
	/// Calculates drag on the ship depending on it's velocity and inhabited zone.
	/// </summary>
	/// <param name="currentVelocity">Velocity of the ship</param>
	/// <param name="zone">Zone which the ship is in</param>
	/// <returns></returns>
	Vector3 DragDecceleration(Vector3 currentVelocity, Zone zone)
	{
		Vector3 drag = new Vector3();
		float minDragFactor = Mathf.InverseLerp(props.absolutMaxVelocity, props.normalMaxVelocity,
			currentVelocity.magnitude);

		float normalDragFactor = Mathf.InverseLerp(props.normalMaxVelocity, 0,
			currentVelocity.magnitude);

		if (!IsBoosting() && zone == Zone.NimbleZone)
		{
			drag -= currentVelocity.normalized * props.normalDrag;
		}
		if (currentVelocity.magnitude >= props.normalMaxVelocity && zone == Zone.NimbleZone)
		{
			drag -= currentVelocity.normalized * props.maximumDrag;
		}
		return drag;
	}

	/// <summary>
	/// Is the boost input pressed and boosting possible?
	/// </summary>
	/// <returns>Boosting state</returns>
	bool IsBoosting()
	{
		return state.boostInput > 0 && canBoost;
	}

	/// <summary>
	/// Applies boost to an acceleration vector.
	/// This includes increasing acceleration and mitigating
	/// the gravity.
	/// </summary>
	/// <param name="acceleration">Current acceleration vector</param>
	/// <param name="currentGravity">Gravity vector which is in force</param>
	/// <returns></returns>
	Vector3 BoostAcceleration(Vector3 acceleration, Vector3 currentGravity)
	{
		if (IsBoosting())
		{
			acceleration *= props.boostMagnitude;
			acceleration -= currentGravity * props.boostAntiGravityFactor;
		}
		return acceleration;
	}

	/// <summary>
	/// Logic which depletes boost capacity when boost conditions are met.
	/// </summary>
	/// <param name="deltaTime">Time delta of the current frame</param>
	void BoostStateUpdate(float deltaTime)
	{
		boostUI.UpdateFill(Math.Min(state.boostCapacity / props.maxBoostCapacity, 1));
		if (IsBoosting() && state.thrustInput != 0)
		{
			state.boostCapacity -= deltaTime;
		}
		if (canBoost && zone == Zone.OutsideZone)
		{
			state.boostCapacity -= deltaTime * props.outsideBoostRate;
		}
		if (state.boostCapacity <= 0)
		{
			canBoost = false;
		}

		if ((state.boostInput <= 0 || state.thrustInput == 0 || !canBoost)
			&& zone == Zone.NimbleZone
			&& state.boostCapacity <= props.maxBoostCapacity)
		{
			state.boostCapacity += deltaTime;
		}
		// When your boost capacity is still critical, you can't start boosting immediately again.
		// TODO: This is not tested well enough with players.
		if (canBoost == false && state.boostCapacity >= props.minBoostCapacity)
		{
			canBoost = true;
		}
	}

	/// <summary>
	/// Logic which sets the isTackled state.
	/// </summary>
	/// <param name="gotTackled">Use true to process a tackle hit</param>
	void UpdateTackleResponse(bool gotTackled = false)
	{
		if (gotTackled && !isTackled)
		{
			isTackled = true;
			tackledTime = isCriticalTackle ? props.tackleCriticalStunTime :
				props.tackleBodyStunTime;
			return;
		}
		tackledTime -= Time.deltaTime;
		if (tackledTime <= 0)
		{
			isTackled = false;
			isCriticalTackle = false;
			tackledTime = 0;
		}
	}

	/// <summary>
	///	Called by the collision regions which detect tackling.
	///	Adds resulting forces to the ship and intiates the tackle
	///	response.
	/// </summary>
	/// <param name="tackleKind">Kind of the tackle. Depends on collision region.</param>
	/// <param name="collider">Object which has collided with the collision region.</param>
	void StartTackleResponse(TackleKind tackleKind, Collider collider)
	{
		float tacklePowerFactor = props.criticalTacklePowerFactor;
		if (tackleKind == TackleKind.Critical)
		{
			isCriticalTackle = true;
		}
		else
		{
			isCriticalTackle = false;
			tacklePowerFactor = props.normalTacklePowerFactor;
		}
		Vector3 colliderVelocity = collider.attachedRigidbody.velocity;
		Vector3 tackleDirection = transform.position - collider.transform.position;
		tackleDirection = Vector3.ProjectOnPlane(tackleDirection, Vector3.Cross(transform.up, transform.right));
		body.AddForce(colliderVelocity.magnitude * tackleDirection * tacklePowerFactor,
			ForceMode.Acceleration);
		UpdateTackleResponse(true);
	}

}