From 8e20f90ed5b836c79e4fd591f6d6a3c5d741d7cc Mon Sep 17 00:00:00 2001
From: ekrctb <ekrctb@gmail.com>
Date: Fri, 4 Jun 2021 19:54:46 +0900
Subject: [PATCH] Use seeded RNG for catch explosion animation

The animation is always the same when a replay is rewound or a beatmap is played multiple times.
---
 osu.Game.Rulesets.Catch/UI/Catcher.cs           | 2 +-
 osu.Game.Rulesets.Catch/UI/HitExplosion.cs      | 9 +++++----
 osu.Game.Rulesets.Catch/UI/HitExplosionEntry.cs | 4 +++-
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/osu.Game.Rulesets.Catch/UI/Catcher.cs b/osu.Game.Rulesets.Catch/UI/Catcher.cs
index 75ed4c3c0f..1c29e8b20c 100644
--- a/osu.Game.Rulesets.Catch/UI/Catcher.cs
+++ b/osu.Game.Rulesets.Catch/UI/Catcher.cs
@@ -506,7 +506,7 @@ namespace osu.Game.Rulesets.Catch.UI
         }
 
         private void addLighting(CatchHitObject hitObject, float x, Color4 colour) =>
-            hitExplosionContainer.Add(new HitExplosionEntry(Time.Current, x, hitObject.Scale, colour));
+            hitExplosionContainer.Add(new HitExplosionEntry(Time.Current, x, hitObject.Scale, colour, hitObject.RandomSeed));
 
         private CaughtObject getCaughtObject(PalpableCatchHitObject source)
         {
diff --git a/osu.Game.Rulesets.Catch/UI/HitExplosion.cs b/osu.Game.Rulesets.Catch/UI/HitExplosion.cs
index c1effa939e..d9ab428231 100644
--- a/osu.Game.Rulesets.Catch/UI/HitExplosion.cs
+++ b/osu.Game.Rulesets.Catch/UI/HitExplosion.cs
@@ -7,6 +7,7 @@ using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Effects;
 using osu.Framework.Utils;
 using osu.Game.Rulesets.Objects.Pooling;
+using osu.Game.Utils;
 using osuTK;
 using osuTK.Graphics;
 
@@ -74,10 +75,10 @@ namespace osu.Game.Rulesets.Catch.UI
             setColour(entry.ObjectColour);
 
             using (BeginAbsoluteSequence(entry.LifetimeStart))
-                applyTransforms();
+                applyTransforms(entry.RNGSeed);
         }
 
-        private void applyTransforms()
+        private void applyTransforms(int randomSeed)
         {
             ClearTransforms(true);
 
@@ -90,8 +91,8 @@ namespace osu.Game.Rulesets.Catch.UI
                 .FadeOut(duration * 2);
 
             const float angle_variangle = 15; // should be less than 45
-            directionalGlow1.Rotation = RNG.NextSingle(-angle_variangle, angle_variangle);
-            directionalGlow2.Rotation = RNG.NextSingle(-angle_variangle, angle_variangle);
+            directionalGlow1.Rotation = StatelessRNG.NextSingle(-angle_variangle, angle_variangle, randomSeed, 4);
+            directionalGlow2.Rotation = StatelessRNG.NextSingle(-angle_variangle, angle_variangle, randomSeed, 5);
 
             this.FadeInFromZero(50).Then().FadeOut(duration, Easing.Out).Expire();
         }
diff --git a/osu.Game.Rulesets.Catch/UI/HitExplosionEntry.cs b/osu.Game.Rulesets.Catch/UI/HitExplosionEntry.cs
index d0dfdfcafd..b142962a8a 100644
--- a/osu.Game.Rulesets.Catch/UI/HitExplosionEntry.cs
+++ b/osu.Game.Rulesets.Catch/UI/HitExplosionEntry.cs
@@ -11,13 +11,15 @@ namespace osu.Game.Rulesets.Catch.UI
         public readonly float Position;
         public readonly float Scale;
         public readonly Color4 ObjectColour;
+        public readonly int RNGSeed;
 
-        public HitExplosionEntry(double startTime, float position, float scale, Color4 objectColour)
+        public HitExplosionEntry(double startTime, float position, float scale, Color4 objectColour, int rngSeed)
         {
             LifetimeStart = startTime;
             Position = position;
             Scale = scale;
             ObjectColour = objectColour;
+            RNGSeed = rngSeed;
         }
     }
 }