From 5b1b36436f0ec4ccf95f9dbdf45c28f5a87c3fbc Mon Sep 17 00:00:00 2001
From: Opelkuh <25430283+Opelkuh@users.noreply.github.com>
Date: Sun, 5 Sep 2021 01:01:49 +0200
Subject: [PATCH] Add cursor velocity to star particles

---
 .../Legacy/LegacyCursorStarParticles.cs       | 40 +++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/osu.Game.Rulesets.Osu/Skinning/Legacy/LegacyCursorStarParticles.cs b/osu.Game.Rulesets.Osu/Skinning/Legacy/LegacyCursorStarParticles.cs
index f10d9a0fa9..52d4eedf42 100644
--- a/osu.Game.Rulesets.Osu/Skinning/Legacy/LegacyCursorStarParticles.cs
+++ b/osu.Game.Rulesets.Osu/Skinning/Legacy/LegacyCursorStarParticles.cs
@@ -131,6 +131,44 @@ namespace osu.Game.Rulesets.Osu.Skinning.Legacy
             public StarParticleSpewer(Texture texture, int perSecond)
                 : base(texture, perSecond, particle_lifetime_max)
             {
+                Active.BindValueChanged(_ => resetVelocityCalculation());
+            }
+
+            private Vector2 screenPosition => ToScreenSpace(OriginPosition);
+
+            private Vector2 screenVelocity;
+
+            private const double velocity_calculation_delay = 15;
+            private double lastVelocityCalculation;
+            private Vector2 positionDifference;
+            private Vector2? lastPosition;
+
+            protected override void Update()
+            {
+                base.Update();
+
+                if (lastPosition != null)
+                {
+                    positionDifference += (screenPosition - lastPosition.Value);
+                    lastVelocityCalculation += Clock.ElapsedFrameTime;
+                }
+
+                lastPosition = screenPosition;
+
+                if (lastVelocityCalculation > velocity_calculation_delay)
+                {
+                    screenVelocity = positionDifference / (float)lastVelocityCalculation;
+
+                    positionDifference = Vector2.Zero;
+                    lastVelocityCalculation = 0;
+                }
+            }
+
+            private void resetVelocityCalculation()
+            {
+                positionDifference = Vector2.Zero;
+                lastVelocityCalculation = 0;
+                lastPosition = null;
             }
 
             protected override FallingParticle SpawnParticle()
@@ -170,6 +208,8 @@ namespace osu.Game.Rulesets.Osu.Skinning.Legacy
                         break;
                 }
 
+                p.Velocity += screenVelocity * 50;
+
                 return p;
             }
         }