particle system abstraction to support multiple particle systems

src/VFX.cs

@@ -67,5 +67,25 @@ public class Particle
         this.vel = Vec3.Zero;
         this.ori = Quat.Identity;
         this.scl = 0.0f;
+
+public class ParticleSystem
+{
+    public Particle[] particles;
+    public int count;
+    public int index;
+
+    public ParticleSystem(int count)
+    {
+        this.particles = new Particle[count];
+        this.count = count;
+        this.index = 0;
+    }
+
+    public void Init()
+    {
+        for (int i = 0; i < particles.Length; i++)
+        {
+            particles[i] = new();
+        }
     }
 }