ZhenShiXunYouJi2/Assets/Scripts/SUISSEngine/LinearParticles.cs

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

namespace SUISSEngine
{
	public class LinearParticles : MonoBehaviour
	{
		private void Start()
		{
			for (int i = 0; i < this.initialParticleCount; i++)
			{
				LinearParticles.Particle particle = this.CreateParticle();
				this.RandomizeParticle(particle);
			}
			this.SetNextSpawnTime();
		}

		private void Update()
		{
			if (this.spawnMethod == LinearParticles.SpawnMethod.Delayed)
			{
				while (Time.time >= this.nextSpawnTime)
				{
					LinearParticles.Particle particle = this.CreateParticle();
					this.RandomizeParticle(particle);
					this.MoveParticleToStart(particle);
					this.SetNextSpawnTime();
				}
			}
			Bounds bounds = default(Bounds);
			bounds.center = base.transform.TransformPoint(this.bounds.center);
			bounds.extents = base.transform.TransformDirection(this.bounds.extents);
			List<LinearParticles.Particle> list = null;
			foreach (LinearParticles.Particle particle2 in this.particles)
			{
				if (particle2 != null)
				{
					Vector3 localPosition = particle2.gameObject.transform.localPosition;
					localPosition.x += particle2.velocity.x * Time.deltaTime;
					localPosition.y += particle2.velocity.y * Time.deltaTime;
					particle2.gameObject.transform.localPosition = localPosition;
					Bounds bounds2 = default(Bounds);
					if (particle2.spriteRenderer == null)
					{
						bounds2.center = particle2.gameObject.transform.position;
						bounds2.extents = Vector3.zero;
					}
					else
					{
						bounds2 = particle2.spriteRenderer.bounds;
					}
					if (!bounds.Intersects(bounds2))
					{
						if (this.spawnMethod == LinearParticles.SpawnMethod.Delayed)
						{
							if (list == null)
							{
								list = new List<LinearParticles.Particle>();
							}
							list.Add(particle2);
						}
						else
						{
							if (this.spawnMethod != LinearParticles.SpawnMethod.Reuse)
							{
								throw new InvalidOperationException("Invalid spawn method");
							}
							this.RandomizeParticle(particle2);
							this.MoveParticleToStart(particle2);
						}
					}
				}
			}
			if (list != null)
			{
				foreach (LinearParticles.Particle particle3 in list)
				{
					this.particles.Remove(particle3);
					UnityEngine.Object.Destroy(particle3.gameObject);
				}
			}
		}

		private LinearParticles.Particle CreateParticle()
		{
			LinearParticles.Particle particle = null;
			if (this.prefabs != null && this.prefabs.Length > 0)
			{
				GameObject gameObject = null;
				if (this.prefabChoice == LinearParticles.PrefabChoice.Random)
				{
					gameObject = this.prefabs[UnityEngine.Random.Range(0, this.prefabs.Length)];
				}
				else if (this.prefabChoice == LinearParticles.PrefabChoice.Cycle)
				{
					gameObject = this.prefabs[this.nextPrefabIndex];
					this.nextPrefabIndex = (this.nextPrefabIndex + 1) % this.prefabs.Length;
				}
				if (gameObject != null)
				{
					GameObject gameObject2 = UnityEngine.Object.Instantiate<GameObject>(gameObject);
					gameObject2.transform.parent = base.transform;
					particle = new LinearParticles.Particle();
					particle.gameObject = gameObject2;
					particle.spriteRenderer = gameObject2.GetComponent<SpriteRenderer>();
					this.particles.Add(particle);
				}
			}
			return particle;
		}

		private void RandomizeParticle(LinearParticles.Particle particle)
		{
			Vector3 center = this.bounds.center;
			center.x += (UnityEngine.Random.value - 0.5f) * this.bounds.size.x;
			center.y += (UnityEngine.Random.value - 0.5f) * this.bounds.size.y;
			center.z += (UnityEngine.Random.value - 0.5f) * this.bounds.size.z;
			particle.gameObject.transform.localPosition = center;
			float num = UnityEngine.Random.Range(this.minScale, this.maxScale);
			particle.gameObject.transform.localScale = new Vector3(num, num, 1f);
			particle.velocity = this.direction.normalized * UnityEngine.Random.Range(this.minSpeed, this.maxSpeed);
			if (this.angleVariation != 0f)
			{
				Vector3 point = new Vector3(particle.velocity.x, particle.velocity.y, 0f);
				float angle = this.angleVariation * (UnityEngine.Random.value - 0.5f);
				Quaternion rotation = Quaternion.AngleAxis(angle, new Vector3(0f, 0f, 1f));
				point = rotation * point;
				particle.velocity = new Vector2(point.x, point.y);
			}
		}

		private void MoveParticleToStart(LinearParticles.Particle particle)
		{
			Bounds bounds = default(Bounds);
			bounds.center = base.transform.TransformPoint(this.bounds.center);
			bounds.extents = base.transform.TransformDirection(this.bounds.extents);
			Bounds bounds2 = default(Bounds);
			if (particle.spriteRenderer == null)
			{
				bounds2.center = particle.gameObject.transform.position;
				bounds2.extents = Vector3.zero;
			}
			else
			{
				bounds2 = particle.spriteRenderer.bounds;
			}
			if (!bounds.Intersects(bounds2))
			{
				return;
			}
			Vector3 vector = -particle.velocity.normalized;
			Bounds bounds3 = bounds2;
			float num = 0f;
			float num2 = (bounds.extents.x + bounds.extents.y) * 0.5f;
			bounds3.center = new Vector3(bounds2.center.x + vector.x * num2, bounds2.center.y + vector.y * num2, bounds2.center.z);
			while (bounds.Intersects(bounds3))
			{
				num = num2;
				num2 *= 2f;
				bounds3.center = new Vector3(bounds2.center.x + vector.x * num2, bounds2.center.y + vector.y * num2, bounds2.center.z);
			}
			float num3 = 1f / this.island.pixelsPerUnit;
			while (num2 - num > num3)
			{
				float num4 = (num + num2) * 0.5f;
				bounds3.center = new Vector3(bounds2.center.x + vector.x * num4, bounds2.center.y + vector.y * num4, bounds2.center.z);
				if (bounds.Intersects(bounds3))
				{
					num = num4;
				}
				else
				{
					num2 = num4;
				}
			}
			Vector3 localPosition = particle.gameObject.transform.localPosition;
			localPosition.x += vector.x * num;
			localPosition.y += vector.y * num;
			particle.gameObject.transform.localPosition = localPosition;
		}

		private void SetNextSpawnTime()
		{
			this.nextSpawnTime = Time.time + UnityEngine.Random.Range(this.minDelay, this.maxDelay);
		}

		public int initialParticleCount;

		public GameObject[] prefabs;

		public LinearParticles.PrefabChoice prefabChoice;

		public LinearParticles.SpawnMethod spawnMethod;

		public float minDelay = 1f;

		public float maxDelay = 1f;

		public Bounds bounds = new Bounds(Vector3.zero, Vector3.zero);

		public float minScale = 1f;

		public float maxScale = 1f;

		public Vector2 direction = new Vector2(1f, 0f);

		public float angleVariation;

		public float minSpeed = 1f;

		public float maxSpeed = 1f;

		[ParentReference]
		public IsometricIsland island;

		private List<LinearParticles.Particle> particles = new List<LinearParticles.Particle>();

		private int nextPrefabIndex;

		private float nextSpawnTime;

		public enum PrefabChoice
		{
			Random,
			Cycle
		}

		public enum SpawnMethod
		{
			Delayed,
			Reuse
		}

		private class Particle
		{
			public GameObject gameObject;

			public SpriteRenderer spriteRenderer;

			public Vector2 velocity;
		}
	}
}