Refactor opacity computation algorithm

Lawtrohux · May 12, 2022 · 4463a26 · 4463a26
1 parent ce095d6
commit 4463a26
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Showing 3 changed files with 28 additions and 13 deletions.
diff --git a/osu.Game.Rulesets.Osu/Difficulty/Preprocessing/OsuDifficultyHitObject.cs b/osu.Game.Rulesets.Osu/Difficulty/Preprocessing/OsuDifficultyHitObject.cs
@@ -4,6 +4,7 @@
 using System;
 using osu.Game.Rulesets.Difficulty.Preprocessing;
 using osu.Game.Rulesets.Objects;
+using osu.Game.Rulesets.Osu.Mods;
 using osu.Game.Rulesets.Osu.Objects;
 using osuTK;
 
@@ -85,19 +86,33 @@ public OsuDifficultyHitObject(HitObject hitObject, HitObject lastLastObject, Hit
             setDistances(clockRate);
         }
 
-        public double Opacity(double mapTime, bool hidden)
+        public double OpacityAt(double time, bool hidden)
         {
-            double ms = BaseObject.StartTime - mapTime;
-            if (ms < 0)
+            if (time > BaseObject.StartTime)
+            {
+                // Consider a hitobject as being invisible when its start time is passed.
+                // In reality the hitobject will be visible beyond its start time up until its hittable window has passed,
+                // but this is an approximation and such a case is unlikely to be hit where this function is used.
                 return 0.0;
+            }
 
-            double preemptTime = BaseObject.TimePreempt;
-            double fadeInTime = BaseObject.TimeFadeIn;
+            double fadeInStartTime = BaseObject.StartTime - BaseObject.TimePreempt;
+            double fadeInDuration = BaseObject.TimeFadeIn;
 
             if (hidden)
-                return Math.Clamp(Math.Min((1.0 - ms / preemptTime) * 2.5, (ms / preemptTime - 0.3) * (1.0 / 0.3)), 0.0, 1.0);
-            else
-                return Math.Clamp((preemptTime - ms) / fadeInTime, 0.0, 1.0);
+            {
+                // Taken from OsuModHidden.
+                double fadeOutStartTime = BaseObject.StartTime - BaseObject.TimePreempt + BaseObject.TimeFadeIn;
+                double fadeOutDuration = BaseObject.TimePreempt * OsuModHidden.FADE_OUT_DURATION_MULTIPLIER;
+
+                return Math.Min
+                (
+                    Math.Clamp((time - fadeInStartTime) / fadeInDuration, 0.0, 1.0),
+                    1.0 - Math.Clamp((time - fadeOutStartTime) / fadeOutDuration, 0.0, 1.0)
+                );
+            }
+
+            return Math.Clamp((time - fadeInStartTime) / fadeInDuration, 0.0, 1.0);
         }
 
         private void setDistances(double clockRate)

diff --git a/osu.Game.Rulesets.Osu/Difficulty/Skills/Flashlight.cs b/osu.Game.Rulesets.Osu/Difficulty/Skills/Flashlight.cs
@@ -70,7 +70,7 @@ private double strainValueOf(DifficultyHitObject current)
                     double stackNerf = Math.Min(1.0, (currentObj.LazyJumpDistance / scalingFactor) / 25.0);
 
                     // Bonus based on how visible the object is.
-                    double opacityBonus = 1.0 + max_opacity_bonus * (1.0 - osuCurrent.Opacity(currentHitObject.StartTime, hidden));
+                    double opacityBonus = 1.0 + max_opacity_bonus * (1.0 - osuCurrent.OpacityAt(currentHitObject.StartTime, hidden));
 
                     result += stackNerf * opacityBonus * scalingFactor * jumpDistance / cumulativeStrainTime;
                 }

diff --git a/osu.Game.Rulesets.Osu/Mods/OsuModHidden.cs b/osu.Game.Rulesets.Osu/Mods/OsuModHidden.cs
@@ -27,8 +27,8 @@ public class OsuModHidden : ModHidden, IHidesApproachCircles
 
         public override Type[] IncompatibleMods => new[] { typeof(IRequiresApproachCircles), typeof(OsuModSpinIn) };
 
-        private const double fade_in_duration_multiplier = 0.4;
-        private const double fade_out_duration_multiplier = 0.3;
+        public const double FADE_IN_DURATION_MULTIPLIER = 0.4;
+        public const double FADE_OUT_DURATION_MULTIPLIER = 0.3;
 
         protected override bool IsFirstAdjustableObject(HitObject hitObject) => !(hitObject is Spinner || hitObject is SpinnerTick);
 
@@ -41,7 +41,7 @@ public override void ApplyToBeatmap(IBeatmap beatmap)
 
             static void applyFadeInAdjustment(OsuHitObject osuObject)
             {
-                osuObject.TimeFadeIn = osuObject.TimePreempt * fade_in_duration_multiplier;
+                osuObject.TimeFadeIn = osuObject.TimePreempt * FADE_IN_DURATION_MULTIPLIER;
                 foreach (var nested in osuObject.NestedHitObjects.OfType<OsuHitObject>())
                     applyFadeInAdjustment(nested);
             }
@@ -156,7 +156,7 @@ private void applyHiddenState(DrawableHitObject drawableObject, bool increaseVis
             static (double fadeStartTime, double fadeDuration) getParameters(OsuHitObject hitObject)
             {
                 double fadeOutStartTime = hitObject.StartTime - hitObject.TimePreempt + hitObject.TimeFadeIn;
-                double fadeOutDuration = hitObject.TimePreempt * fade_out_duration_multiplier;
+                double fadeOutDuration = hitObject.TimePreempt * FADE_OUT_DURATION_MULTIPLIER;
 
                 // new duration from completed fade in to end (before fading out)
                 double longFadeDuration = hitObject.GetEndTime() - fadeOutStartTime;