From 1cf8b599a1f6e52d6453a43e727f13c9d40e63ca Mon Sep 17 00:00:00 2001
From: LastExceed <chris20194@googlemail.com>
Date: Sun, 12 Jul 2020 13:57:44 +0200
Subject: [PATCH] implement fadein

---
 .../Mods/ManiaModFadeIn.cs                    | 93 ++++++++++++++++++-
 1 file changed, 92 insertions(+), 1 deletion(-)

diff --git a/osu.Game.Rulesets.Mania/Mods/ManiaModFadeIn.cs b/osu.Game.Rulesets.Mania/Mods/ManiaModFadeIn.cs
index 4c125ad6ef..d2b1307585 100644
--- a/osu.Game.Rulesets.Mania/Mods/ManiaModFadeIn.cs
+++ b/osu.Game.Rulesets.Mania/Mods/ManiaModFadeIn.cs
@@ -2,14 +2,24 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
+using System.Linq;
+using osu.Framework.Extensions.Color4Extensions;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Colour;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.Shapes;
 using osu.Framework.Graphics.Sprites;
+using osu.Framework.Testing;
 using osu.Game.Graphics;
 using osu.Game.Rulesets.Mania.Objects;
+using osu.Game.Rulesets.Mania.UI;
 using osu.Game.Rulesets.Mods;
+using osu.Game.Rulesets.UI;
+using osuTK.Graphics;
 
 namespace osu.Game.Rulesets.Mania.Mods
 {
-    public class ManiaModFadeIn : Mod
+    public class ManiaModFadeIn : Mod, IApplicableToDrawableRuleset<ManiaHitObject>
     {
         public override string Name => "Fade In";
         public override string Acronym => "FI";
@@ -19,5 +29,86 @@ namespace osu.Game.Rulesets.Mania.Mods
         public override double ScoreMultiplier => 1;
         public override bool Ranked => true;
         public override Type[] IncompatibleMods => new[] { typeof(ModFlashlight<ManiaHitObject>) };
+
+        private const float lanecover_size_filled = 0.5f;
+        private const float lanecover_size_gradient = 0.25f;
+
+        public void ApplyToDrawableRuleset(DrawableRuleset<ManiaHitObject> drawableRuleset)
+        {
+            ManiaPlayfield maniaPlayfield = (ManiaPlayfield)drawableRuleset.Playfield;
+
+            foreach (Column column in maniaPlayfield.Stages.SelectMany(stage => stage.Columns))
+            {
+                column.hitObjectArea.ChildrenOfType<BufferedContainer>().First().Add(new LaneCover(false)
+                {
+                    RelativeSizeAxes = Axes.Both,
+                    SizeFilled = lanecover_size_filled,
+                    SizeGradient = lanecover_size_gradient
+                });
+            }
+        }
+
+        private class LaneCover : CompositeDrawable
+        {
+            private readonly Box gradient;
+            private readonly Box filled;
+            private readonly bool reversed;
+
+            public LaneCover(bool reversed)
+            {
+                Blending = new BlendingParameters
+                {
+                    RGBEquation = BlendingEquation.Add,
+                    Source = BlendingType.Zero,
+                    Destination = BlendingType.One,
+                    AlphaEquation = BlendingEquation.Add,
+                    SourceAlpha = BlendingType.Zero,
+                    DestinationAlpha = BlendingType.OneMinusSrcAlpha
+                };
+
+                InternalChildren = new Drawable[]
+                {
+                    gradient = new Box
+                    {
+                        RelativeSizeAxes = Axes.Both,
+                        RelativePositionAxes = Axes.Both,
+                        Colour = ColourInfo.GradientVertical(Color4.White.Opacity(1f), Color4.White.Opacity(0f))
+                    },
+                    filled = new Box
+                    {
+                        RelativeSizeAxes = Axes.Both
+                    }
+                };
+
+                if (reversed)
+                {
+                    gradient.Colour = ColourInfo.GradientVertical(Color4.White.Opacity(0f), Color4.White.Opacity(1f));
+                    filled.Anchor = Anchor.BottomLeft;
+                    filled.Origin = Anchor.BottomLeft;
+                }
+
+                this.reversed = reversed;
+            }
+
+            public float SizeFilled
+            {
+                set
+                {
+                    filled.Height = value;
+                    if (!reversed)
+                        gradient.Y = value;
+                }
+            }
+
+            public float SizeGradient
+            {
+                set
+                {
+                    gradient.Height = value;
+                    if (reversed)
+                        gradient.Y = 1 - value - filled.Height;
+                }
+            }
+        }
     }
 }