From 81a9908c60012bde9ee9135c254ab2b891be5ecc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Dach?= <dach.bartlomiej@gmail.com>
Date: Thu, 22 Feb 2024 10:27:37 +0100
Subject: [PATCH] Extract common helper for BPM rounding

---
 osu.Game/Overlays/Mods/BeatmapAttributesDisplay.cs |  4 ++--
 osu.Game/Screens/Select/BeatmapInfoWedge.cs        |  7 ++++---
 osu.Game/Utils/FormatUtils.cs                      | 10 ++++++++++
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/osu.Game/Overlays/Mods/BeatmapAttributesDisplay.cs b/osu.Game/Overlays/Mods/BeatmapAttributesDisplay.cs
index 1db02b7cf2..2f0b39bfbd 100644
--- a/osu.Game/Overlays/Mods/BeatmapAttributesDisplay.cs
+++ b/osu.Game/Overlays/Mods/BeatmapAttributesDisplay.cs
@@ -1,7 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
@@ -20,6 +19,7 @@ using osu.Game.Graphics.Sprites;
 using osu.Game.Graphics.UserInterface;
 using osu.Game.Rulesets;
 using osu.Game.Rulesets.Mods;
+using osu.Game.Utils;
 using osuTK;
 
 namespace osu.Game.Overlays.Mods
@@ -169,7 +169,7 @@ namespace osu.Game.Overlays.Mods
             foreach (var mod in mods.Value.OfType<IApplicableToRate>())
                 rate = mod.ApplyToRate(0, rate);
 
-            bpmDisplay.Current.Value = (int)Math.Round(Math.Round(BeatmapInfo.Value.BPM) * rate);
+            bpmDisplay.Current.Value = FormatUtils.RoundBPM(BeatmapInfo.Value.BPM, rate);
 
             BeatmapDifficulty originalDifficulty = new BeatmapDifficulty(BeatmapInfo.Value.Difficulty);
 
diff --git a/osu.Game/Screens/Select/BeatmapInfoWedge.cs b/osu.Game/Screens/Select/BeatmapInfoWedge.cs
index c69cd6ead6..3cab4b67b6 100644
--- a/osu.Game/Screens/Select/BeatmapInfoWedge.cs
+++ b/osu.Game/Screens/Select/BeatmapInfoWedge.cs
@@ -31,6 +31,7 @@ using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.UI;
 using osu.Game.Graphics.Containers;
 using osu.Game.Resources.Localisation.Web;
+using osu.Game.Utils;
 
 namespace osu.Game.Screens.Select
 {
@@ -405,9 +406,9 @@ namespace osu.Game.Screens.Select
                 foreach (var mod in mods.Value.OfType<IApplicableToRate>())
                     rate = mod.ApplyToRate(0, rate);
 
-                int bpmMax = (int)Math.Round(Math.Round(beatmap.ControlPointInfo.BPMMaximum) * rate);
-                int bpmMin = (int)Math.Round(Math.Round(beatmap.ControlPointInfo.BPMMinimum) * rate);
-                int mostCommonBPM = (int)Math.Round(Math.Round(60000 / beatmap.GetMostCommonBeatLength()) * rate);
+                int bpmMax = FormatUtils.RoundBPM(beatmap.ControlPointInfo.BPMMaximum, rate);
+                int bpmMin = FormatUtils.RoundBPM(beatmap.ControlPointInfo.BPMMinimum, rate);
+                int mostCommonBPM = FormatUtils.RoundBPM(60000 / beatmap.GetMostCommonBeatLength(), rate);
 
                 string labelText = bpmMin == bpmMax
                     ? $"{bpmMin}"
diff --git a/osu.Game/Utils/FormatUtils.cs b/osu.Game/Utils/FormatUtils.cs
index 799dc75ca9..cccad3711c 100644
--- a/osu.Game/Utils/FormatUtils.cs
+++ b/osu.Game/Utils/FormatUtils.cs
@@ -49,5 +49,15 @@ namespace osu.Game.Utils
 
             return precision;
         }
+
+        /// <summary>
+        /// Applies rounding to the given BPM value.
+        /// </summary>
+        /// <remarks>
+        /// Double-rounding is applied intentionally (see https://github.com/ppy/osu/pull/18345#issue-1243311382 for rationale).
+        /// </remarks>
+        /// <param name="baseBpm">The base BPM to round.</param>
+        /// <param name="rate">Rate adjustment, if applicable.</param>
+        public static int RoundBPM(double baseBpm, double rate = 1) => (int)Math.Round(Math.Round(baseBpm) * rate);
     }
 }