From c4af2bbf69f81f7349d683011dc286a2333a0b07 Mon Sep 17 00:00:00 2001
From: Givikap120 <givikap120@gmail.com>
Date: Tue, 26 Mar 2024 02:55:06 +0200
Subject: [PATCH] optimisation

---
 .../Difficulty/Evaluators/ReadingEvaluator.cs    |  8 +++-----
 .../Preprocessing/OsuDifficultyHitObject.cs      | 16 ++++++++++++++--
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/osu.Game.Rulesets.Osu/Difficulty/Evaluators/ReadingEvaluator.cs b/osu.Game.Rulesets.Osu/Difficulty/Evaluators/ReadingEvaluator.cs
index fde3ebe7e9..0987d3630a 100644
--- a/osu.Game.Rulesets.Osu/Difficulty/Evaluators/ReadingEvaluator.cs
+++ b/osu.Game.Rulesets.Osu/Difficulty/Evaluators/ReadingEvaluator.cs
@@ -192,7 +192,7 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Evaluators
             if (current.BaseObject is Spinner || current.Index == 0)
                 return 0;
 
-            double difficulty = Math.Pow(4 * Math.Log(Math.Max(1, EvaluateDensityOf(current))), 2.5);
+            double difficulty = Math.Pow(4 * Math.Log(Math.Max(1, ((OsuDifficultyHitObject)current).Density)), 2.5);
 
             double overlapBonus = EvaluateOverlapDifficultyOf(current) * difficulty;
             difficulty += overlapBonus;
@@ -202,7 +202,7 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Evaluators
 
         public static double EvaluateAimingDensityFactorOf(DifficultyHitObject current)
         {
-            double difficulty = EvaluateDensityOf(current);
+            double difficulty = ((OsuDifficultyHitObject)current).Density;
 
             double overlapBonus = EvaluateOverlapDifficultyOf(current) * difficulty;
             difficulty += overlapBonus * 0.1; // Overlaps should affect aiming part much less
@@ -330,10 +330,8 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Evaluators
         {
             var currObj = (OsuDifficultyHitObject)current;
 
-            double density = ReadingEvaluator.EvaluateDensityOf(current, false);
-
             // Consider that density matters only starting from 3rd note on the screen
-            double densityFactor = Math.Max(0, density - 1) / 4;
+            double densityFactor = Math.Max(0, currObj.Density - 1) / 4;
 
             // This is kinda wrong cuz it returns value bigger than preempt
             // double timeSpentInvisible = getDurationSpentInvisible(currObj) / 1000 / currObj.ClockRate;
diff --git a/osu.Game.Rulesets.Osu/Difficulty/Preprocessing/OsuDifficultyHitObject.cs b/osu.Game.Rulesets.Osu/Difficulty/Preprocessing/OsuDifficultyHitObject.cs
index 47efc28cbb..640c2c1ab4 100644
--- a/osu.Game.Rulesets.Osu/Difficulty/Preprocessing/OsuDifficultyHitObject.cs
+++ b/osu.Game.Rulesets.Osu/Difficulty/Preprocessing/OsuDifficultyHitObject.cs
@@ -90,6 +90,11 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Preprocessing
         /// </summary>
         public double RhythmDifficulty { get; private set; }
 
+        /// <summary>
+        /// Density of the object for given preempt. Saved for optimization, density calculation is expensive.
+        /// </summary>
+        public double Density { get; private set; }
+
         /// <summary>
         /// Objects that was visible after the note was hit together with cumulative overlapping difficulty. Saved for optimization to avoid O(x^4) time complexity.
         /// </summary>
@@ -140,8 +145,13 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Preprocessing
             setDistances(clockRate);
 
             RhythmDifficulty = RhythmEvaluator.EvaluateDifficultyOf(this);
+            Density = ReadingEvaluator.EvaluateDensityOf(this);
+            OverlapObjects = getOverlapObjects();
+        }
 
-            OverlapObjects = new List<OverlapObject>();
+        private List<OverlapObject> getOverlapObjects()
+        {
+            List<OverlapObject> overlapObjects = new List<OverlapObject>();
 
             double totalOverlapnessDifficulty = 0;
             double currentTime = DeltaTime;
@@ -204,9 +214,11 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Preprocessing
                 }
 
                 totalOverlapnessDifficulty += currentOverlapness;
-                OverlapObjects.Add(new OverlapObject(loopObj, totalOverlapnessDifficulty));
+                overlapObjects.Add(new OverlapObject(loopObj, totalOverlapnessDifficulty));
                 prevObject = loopObj;
             }
+
+            return overlapObjects;
         }
 
         private static double getSimilarity(double timeA, double timeB)