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

using System;
using System.Reflection;
using log4net;
using Managers;
using Unity.Mathematics;
using UnityEngine;
using static AffectingForcesManager;

public class NimbleZoneDetection : MonoBehaviour
{
	private static ILog Log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
	public AffectingForcesManager forcesManager;

	public GameObject renderedZoneObject;


	public enum Gravities
	{
		DownGravity, NoGravity, InwardsGravity, OutwardsGravity
	}

	[SerializeField]
	private static float gravityFactor = 30f;
	[SerializeField]
	private Gravities outsideGravityFunction = Gravities.NoGravity;
	[SerializeField]
	private Zone zone = Zone.NimbleZone;

	// Ripple properties
	// These influence the shader on the nimble zone
	[SerializeField]
	private float rippleFrequency = 3f;
	[SerializeField]
	private float rippleDensity = 30f;
	[SerializeField]
	private float rippleAmplitude = 0.1f;
	[SerializeField]
	private float rippleRadius = 1f;
	[SerializeField]
	private float rippleDuration = 1f;
	[SerializeField]
	private float impactVelocityModifier = 1f;
	[SerializeField, Tooltip("Minimum ripple effect intensity.")]
	[Range(0, 1)]
	private float minImpact = 0.2f;
	[SerializeField, Tooltip("Velocity which makes the highest/most intense ripples.")]
	private float maxVelocity = 45f;
	private int maxRippleAmount = 5;
	private MeshRenderer meshRenderer;
	private Material material;

	void Awake()
	{
		meshRenderer = renderedZoneObject.GetComponent<MeshRenderer>();
		material = meshRenderer.material;
		ResetRippleShaderProperties();
	}

	/// <summary>
	/// Array of the available gravities.
	/// </summary>
	private Func<Transform, Vector3>[] gravityFunctions =
		{ DownGravity, NoGravity, InwardsGravity, OutwardsGravity };

	/// <summary>
	/// Function which returns a gravity zero vector.
	/// </summary>
	private static Func<Transform, Vector3> NoGravity =
		new(transform => new Vector3());

	/// <summary>
	/// Function which returns a gravity vector downwards, depending
	/// on the parent transforms rotation. 
	/// The parenting transform for a ship is the arena it's in.
	/// </summary>
	private static Func<Transform, Vector3> DownGravity =
		new(transform => transform.parent.rotation * Vector3.down * gravityFactor);

	/// <summary>
	/// Function which returns a gravity vector towards the center of the parenting transform.
	/// The parenting transform for a ship is the arena it's in.
	/// </summary>
	private static Func<Transform, Vector3> InwardsGravity =
		new(transform => (transform.position - transform.parent.position).normalized * -gravityFactor);

	/// <summary>
	/// Function which returns a gravity vector outwards from the center of the parenting transform.
	/// The parenting transform for a ship is the arena it's in.
	/// </summary>
	private static Func<Transform, Vector3> OutwardsGravity =
	new Func<Transform, Vector3>(transform =>
		(transform.position - transform.parent.position).normalized * gravityFactor);

	public Func<Transform, Vector3> GetGravityFunction(Gravities gravity)
	{
		return gravityFunctions[(int)gravity];
	}

	private void OnTriggerEnter(Collider collider)
	{
		int instanceID = collider.gameObject.GetInstanceID();
		if (collider.tag == "Spike"
		&& collider.attachedRigidbody.velocity.magnitude > 1)
		{
			SpawnRipple(collider, false);
			return;
		}
		if (collider.tag == "Ship")
		{
			forcesManager.SetGravityForInstance(instanceID, NoGravity);
			forcesManager.SetZoneForInstance(instanceID, zone);
		}
	}

	private void OnTriggerExit(Collider collider)
	{
		int instanceID = collider.gameObject.GetInstanceID();
		if (collider.tag == "Spike")
		{
			SpawnRipple(collider, true);
			return;
		}
		if (collider.tag == "Ship")
		{
			forcesManager.SetGravityForInstance(instanceID,
				GetGravityFunction(outsideGravityFunction));
			forcesManager.SetZoneForInstance(instanceID, Zone.OutsideZone);
		}
	}

	private void Update()
	{
		material.SetFloat("_ShaderTime", Time.timeSinceLevelLoad);
	}

	/// <summary>
	/// Calculates the effect which a given velocity has on a ripple property.
	/// </summary>
	/// <param name="duration">Initial value of the ripple property</param>
	/// <param name="velocity">Velocity of the impact</param>
	/// <returns></returns>
	private float ImpactVelocityEffect(float initial, float velocity)
	{
		return math.max(math.smoothstep(0, maxVelocity, velocity), minImpact)
			* impactVelocityModifier * initial;
	}

	/// <summary>
	/// Spawns ripples on the shader of the nimble zone.
	/// Up to 5 parallel ripples.
	/// </summary>
	/// <param name="collider"></param>
	/// <param name="isOutwardsRipple"></param>
	private void SpawnRipple(Collider collider, bool isOutwardsRipple)
	{
		Rigidbody body = collider.attachedRigidbody;
		GameObject gameObject = collider.gameObject;

		float velocity = body.velocity.magnitude;
		Vector3 position = gameObject.transform.position - transform.position;
		position = transform.InverseTransformDirection(position).normalized;

		Vector4[] rippleOrigins = material.GetVectorArray("_RippleOrigins");

		float currentTime = Time.timeSinceLevelLoad;
		float[] startedTimes = material.GetFloatArray("_RippleStartTimes");
		float[] startedRippleDurations = material.GetFloatArray("_RippleDurations");

		float[] rippleAmplitudes = material.GetFloatArray("_RippleAmplitudes");
		float[] rippleFrequencies = material.GetFloatArray("_RippleFrequencies");
		float[] rippleDensities = material.GetFloatArray("_RippleDensities");
		float[] rippleRadii = material.GetFloatArray("_RippleRadii");

		if (startedTimes == null)
		{
			Log.Warn("Ripple shader properties are null. Reseting shader");
			ResetRippleShaderProperties();
			return;
		}

		for (int i = 0; i < startedTimes.Length; ++i)
		{
			if (startedTimes[i] + startedRippleDurations[i] < currentTime)
			{
				rippleOrigins[i] = new Vector4(position.x, position.y, position.z, 0);
				material.SetVectorArray("_RippleOrigins", rippleOrigins);
				startedTimes[i] = currentTime;
				material.SetFloatArray("_RippleStartTimes", startedTimes);

				float amplitude = isOutwardsRipple ? rippleAmplitude : -rippleAmplitude;

				rippleAmplitudes[i] = ImpactVelocityEffect(amplitude, velocity);
				rippleFrequencies[i] = ImpactVelocityEffect(rippleFrequency, velocity);
				rippleDensities[i] = ImpactVelocityEffect(rippleDensity, velocity);
				startedRippleDurations[i] = ImpactVelocityEffect(rippleDuration, velocity);
				rippleRadii[i] = ImpactVelocityEffect(rippleRadius, velocity);
				material.SetFloatArray("_RippleAmplitudes", rippleAmplitudes);
				material.SetFloatArray("_RippleFrequencies", rippleFrequencies);
				material.SetFloatArray("_RippleDensities", rippleDensities);
				material.SetFloatArray("_RippleAmplitudes", rippleAmplitudes);
				material.SetFloatArray("_RippleDurations", startedRippleDurations);
				material.SetFloatArray("_RippleRadii", rippleRadii);
				break;
			}

		}
	}

	/// <summary>
	/// Resets the ripple shaders exposed properties to 0
	/// </summary>
	private void ResetRippleShaderProperties()
	{
		Vector4[] rippleOrigins = new Vector4[maxRippleAmount];
		float[] startedTimes = new float[maxRippleAmount];
		float[] rippleAmplitudes = new float[maxRippleAmount];
		float[] rippleFrequencies = new float[maxRippleAmount];
		float[] rippleDensities = new float[maxRippleAmount];
		float[] rippleDurations = new float[maxRippleAmount];
		float[] rippleRadii = new float[maxRippleAmount];

		// Initialize Ripple Shader Properties
		material.SetVectorArray("_RippleOrigins", rippleOrigins);
		material.SetFloatArray("_RippleStartTimes", startedTimes);
		material.SetFloatArray("_RippleAmplitudes", rippleAmplitudes);
		material.SetFloatArray("_RippleFrequencies", rippleFrequencies);
		material.SetFloatArray("_RippleDensities", rippleDensities);
		material.SetFloatArray("_RippleDurations", rippleDurations);
		material.SetFloatArray("_RippleRadii", rippleRadii);
	}
}