From 16f1a7694d9397a9acac2acfd0c39f38ef438547 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Fri, 30 Jun 2023 18:43:37 +0900
Subject: [PATCH] Add time-based flourish support

---
 .../Skinning/Argon/ArgonDrumSamplePlayer.cs   | 53 ++++++++++++++-----
 1 file changed, 41 insertions(+), 12 deletions(-)

diff --git a/osu.Game.Rulesets.Taiko/Skinning/Argon/ArgonDrumSamplePlayer.cs b/osu.Game.Rulesets.Taiko/Skinning/Argon/ArgonDrumSamplePlayer.cs
index 67d417c599..72e5ac5b3d 100644
--- a/osu.Game.Rulesets.Taiko/Skinning/Argon/ArgonDrumSamplePlayer.cs
+++ b/osu.Game.Rulesets.Taiko/Skinning/Argon/ArgonDrumSamplePlayer.cs
@@ -2,6 +2,7 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Collections.Generic;
+using System.Linq;
 using osu.Framework.Allocation;
 using osu.Game.Audio;
 using osu.Game.Rulesets.Taiko.Objects;
@@ -18,12 +19,20 @@ namespace osu.Game.Rulesets.Taiko.Skinning.Argon
 
         public partial class ArgonDrumSampleTriggerSource : DrumSampleTriggerSource
         {
+            private readonly HitObjectContainer hitObjectContainer;
+
             [Resolved]
             private ISkinSource skinSource { get; set; } = null!;
 
+            /// <summary>
+            /// The minimum time to leave between flourishes that are added to strong rim hits.
+            /// </summary>
+            private const double time_between_flourishes = 2000;
+
             public ArgonDrumSampleTriggerSource(HitObjectContainer hitObjectContainer, SampleBalance balance)
                 : base(hitObjectContainer, balance)
             {
+                this.hitObjectContainer = hitObjectContainer;
                 // TODO: pool flourish sample
             }
 
@@ -44,21 +53,41 @@ namespace osu.Game.Rulesets.Taiko.Skinning.Argon
                 }
 
                 // let the magic begin...
+                var samplesToPlay = new List<ISampleInfo> { new VolumeAwareHitSampleInfo(originalSample, strong) };
 
-                if (strong)
+                if (strong && hitType == HitType.Rim && canPlayFlourish(hitObject))
+                    samplesToPlay.Add(new VolumeAwareHitSampleInfo(hitObject.CreateHitSampleInfo(HitSampleInfo.HIT_FLOURISH), true));
+
+                PlaySamples(samplesToPlay.ToArray());
+            }
+
+            private bool canPlayFlourish(TaikoHitObject hitObject)
+            {
+                double? lastFlourish = null;
+
+                // TODO: check on nested strong hits. we're not accounting for them here yet.
+
+                var hitObjects = hitObjectContainer.AliveObjects
+                                                   .Reverse()
+                                                   .Select(d => d.HitObject)
+                                                   .OfType<Hit>()
+                                                   .Where(h => h.IsStrong && h.Type == HitType.Rim);
+
+                // Add an additional 'flourish' sample to strong rim hits (that are at least `time_between_flourishes` apart).
+                // This is applied to hitobjects in reverse order, as to sound more musically coherent by biasing towards to
+                // end of groups/combos of strong rim hits instead of the start.
+                foreach (var h in hitObjects)
                 {
-                    PlaySamples(new ISampleInfo[]
-                    {
-                        new VolumeAwareHitSampleInfo(originalSample, true),
-                        // TODO: flourish should only play every time_between_flourishes.
-                        new VolumeAwareHitSampleInfo(hitObject.CreateHitSampleInfo(hitType == HitType.Rim ? HitSampleInfo.HIT_FLOURISH : string.Empty), true),
-                        new VolumeAwareHitSampleInfo(originalSample)
-                    });
-                }
-                else
-                {
-                    PlaySamples(new ISampleInfo[] { new VolumeAwareHitSampleInfo(new VolumeAwareHitSampleInfo(originalSample)) });
+                    bool canFlourish = lastFlourish == null || lastFlourish - h.StartTime >= time_between_flourishes;
+
+                    if (canFlourish)
+                        lastFlourish = h.StartTime;
+
+                    if (h == hitObject)
+                        return canFlourish;
                 }
+
+                return false;
             }
 
             private class VolumeAwareHitSampleInfo : HitSampleInfo