HeavenStudio/Assets/Plugins/BezierSolution/Utilities/ParticlesFollowBezier.cs

106 lines
3 KiB
C#

using System.Collections.Generic;
using UnityEngine;
namespace BezierSolution
{
[AddComponentMenu( "Bezier Solution/Particles Follow Bezier" )]
[HelpURL( "https://github.com/yasirkula/UnityBezierSolution" )]
[RequireComponent( typeof( ParticleSystem ) )]
[ExecuteInEditMode]
public class ParticlesFollowBezier : MonoBehaviour
{
private const int MAX_PARTICLE_COUNT = 25000;
public enum FollowMode { Relaxed, Strict };
public BezierSpline spline;
public FollowMode followMode = FollowMode.Relaxed;
private Transform cachedTransform;
private ParticleSystem cachedPS;
private ParticleSystem.MainModule cachedMainModule;
private ParticleSystem.Particle[] particles;
private List<Vector4> particleData;
private void Awake()
{
cachedTransform = transform;
cachedPS = GetComponent<ParticleSystem>();
cachedMainModule = cachedPS.main;
particles = new ParticleSystem.Particle[cachedMainModule.maxParticles];
if( followMode == FollowMode.Relaxed )
particleData = new List<Vector4>( particles.Length );
}
#if UNITY_EDITOR
private void OnEnable()
{
Awake();
}
#endif
#if UNITY_EDITOR
private void LateUpdate()
{
if( !UnityEditor.EditorApplication.isPlaying )
FixedUpdate();
}
#endif
private void FixedUpdate()
{
if( spline == null || cachedPS == null )
return;
if( particles.Length < cachedMainModule.maxParticles && particles.Length < MAX_PARTICLE_COUNT )
System.Array.Resize( ref particles, Mathf.Min( cachedMainModule.maxParticles, MAX_PARTICLE_COUNT ) );
bool isLocalSpace = cachedMainModule.simulationSpace != ParticleSystemSimulationSpace.World;
int aliveParticles = cachedPS.GetParticles( particles );
Vector3 initialPoint = spline.GetPoint( 0f );
if( followMode == FollowMode.Relaxed )
{
if( particleData == null )
particleData = new List<Vector4>( particles.Length );
cachedPS.GetCustomParticleData( particleData, ParticleSystemCustomData.Custom1 );
// Credit: https://forum.unity3d.com/threads/access-to-the-particle-system-lifecycle-events.328918/#post-2295977
for( int i = 0; i < aliveParticles; i++ )
{
Vector4 particleDat = particleData[i];
Vector3 point = spline.GetPoint( 1f - ( particles[i].remainingLifetime / particles[i].startLifetime ) );
if( !isLocalSpace )
point = cachedTransform.TransformPoint( point - initialPoint );
// Move particles alongside the spline
if( particleDat.w != 0f )
particles[i].position += point - (Vector3) particleDat;
particleDat = point;
particleDat.w = 1f;
particleData[i] = particleDat;
}
cachedPS.SetCustomParticleData( particleData, ParticleSystemCustomData.Custom1 );
}
else
{
for( int i = 0; i < aliveParticles; i++ )
{
Vector3 point = spline.GetPoint( 1f - ( particles[i].remainingLifetime / particles[i].startLifetime ) ) - initialPoint;
if( !isLocalSpace )
point = cachedTransform.TransformPoint( point );
particles[i].position = point;
}
}
cachedPS.SetParticles( particles, aliveParticles );
}
}
}