From ab1d5235284bb0b3f98c602736262403da9eb6e0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Dach?= <dach.bartlomiej@gmail.com>
Date: Tue, 15 Aug 2023 07:44:05 +0200
Subject: [PATCH] Fix kiai stars flickering on and off during gameplay

Closes #24503.

The problematic reset of `lastParticleAdded` has been moved to a place
that should hopefully (a) not cause such problems and (b) be much more
explicit about what's happening.
---
 osu.Game/Graphics/ParticleSpewer.cs | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/osu.Game/Graphics/ParticleSpewer.cs b/osu.Game/Graphics/ParticleSpewer.cs
index 37a4fe77bd5a..64c70095bf95 100644
--- a/osu.Game/Graphics/ParticleSpewer.cs
+++ b/osu.Game/Graphics/ParticleSpewer.cs
@@ -49,6 +49,18 @@ protected ParticleSpewer(Texture texture, int perSecond, double maxDuration)
             this.maxDuration = maxDuration;
         }
 
+        protected override void LoadComplete()
+        {
+            base.LoadComplete();
+
+            Active.BindValueChanged(active =>
+            {
+                // ensure that particles can be spawned immediately after the spewer becomes active.
+                if (active.NewValue)
+                    lastParticleAdded = null;
+            });
+        }
+
         protected override void Update()
         {
             base.Update();
@@ -56,12 +68,8 @@ protected override void Update()
             Invalidate(Invalidation.DrawNode);
 
             if (!Active.Value || !CanSpawnParticles)
-            {
-                lastParticleAdded = null;
                 return;
-            }
 
-            // Always want to spawn the first particle in an activation immediately.
             if (lastParticleAdded == null)
             {
                 lastParticleAdded = Time.Current;