From 2d0275ba958e9de5fbb8c68635177026a86487e8 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Fri, 9 Oct 2020 03:07:01 +0900
Subject: [PATCH] Fix first hitobject in osu! hidden mod not getting correct
 fade applied

---
 osu.Game.Rulesets.Osu/Mods/OsuModHidden.cs | 15 +++++++++++----
 osu.Game/Rulesets/Mods/ModHidden.cs        | 20 ++++++++++++++++++++
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/osu.Game.Rulesets.Osu/Mods/OsuModHidden.cs b/osu.Game.Rulesets.Osu/Mods/OsuModHidden.cs
index 80e40af717..d354a8a726 100644
--- a/osu.Game.Rulesets.Osu/Mods/OsuModHidden.cs
+++ b/osu.Game.Rulesets.Osu/Mods/OsuModHidden.cs
@@ -42,7 +42,11 @@ public override void ApplyToDrawableHitObjects(IEnumerable<DrawableHitObject> dr
         private double lastSliderHeadFadeOutStartTime;
         private double lastSliderHeadFadeOutDuration;
 
-        protected override void ApplyHiddenState(DrawableHitObject drawable, ArmedState state)
+        protected override void ApplyFirstObjectIncreaseVisibilityState(DrawableHitObject drawable, ArmedState state) => applyState(drawable, true);
+
+        protected override void ApplyHiddenState(DrawableHitObject drawable, ArmedState state) => applyState(drawable, false);
+
+        private void applyState(DrawableHitObject drawable, bool increaseVisibility)
         {
             if (!(drawable is DrawableOsuHitObject d))
                 return;
@@ -86,9 +90,12 @@ protected override void ApplyHiddenState(DrawableHitObject drawable, ArmedState
                         lastSliderHeadFadeOutStartTime = fadeOutStartTime;
                     }
 
-                    // we don't want to see the approach circle
-                    using (circle.BeginAbsoluteSequence(h.StartTime - h.TimePreempt, true))
-                        circle.ApproachCircle.Hide();
+                    if (!increaseVisibility)
+                    {
+                        // we don't want to see the approach circle
+                        using (circle.BeginAbsoluteSequence(h.StartTime - h.TimePreempt, true))
+                            circle.ApproachCircle.Hide();
+                    }
 
                     // fade out immediately after fade in.
                     using (drawable.BeginAbsoluteSequence(fadeOutStartTime, true))
diff --git a/osu.Game/Rulesets/Mods/ModHidden.cs b/osu.Game/Rulesets/Mods/ModHidden.cs
index a1915b974c..d81b439f6a 100644
--- a/osu.Game/Rulesets/Mods/ModHidden.cs
+++ b/osu.Game/Rulesets/Mods/ModHidden.cs
@@ -38,7 +38,13 @@ public void ReadFromConfig(OsuConfigManager config)
         public virtual void ApplyToDrawableHitObjects(IEnumerable<DrawableHitObject> drawables)
         {
             if (IncreaseFirstObjectVisibility.Value)
+            {
+                var firstObject = drawables.FirstOrDefault();
+                if (firstObject != null)
+                    firstObject.ApplyCustomUpdateState += ApplyFirstObjectIncreaseVisibilityState;
+
                 drawables = drawables.SkipWhile(h => !IsFirstHideableObject(h)).Skip(1);
+            }
 
             foreach (var dho in drawables)
                 dho.ApplyCustomUpdateState += ApplyHiddenState;
@@ -65,6 +71,20 @@ public ScoreRank AdjustRank(ScoreRank rank, double accuracy)
             }
         }
 
+        /// <summary>
+        /// Apply a special visibility state to the first object in a beatmap, if the user chooses to turn on the "increase first object visibility" setting.
+        /// </summary>
+        /// <param name="hitObject">The hit object to apply the state change to.</param>
+        /// <param name="state">The state of the hit object.</param>
+        protected virtual void ApplyFirstObjectIncreaseVisibilityState(DrawableHitObject hitObject, ArmedState state)
+        {
+        }
+
+        /// <summary>
+        /// Apply a hidden state to the provided object.
+        /// </summary>
+        /// <param name="hitObject">The hit object to apply the state change to.</param>
+        /// <param name="state">The state of the hit object.</param>
         protected virtual void ApplyHiddenState(DrawableHitObject hitObject, ArmedState state)
         {
         }