From 822a62e4fdc792772d848e70b872e03f3289302d Mon Sep 17 00:00:00 2001
From: rushiiMachine <33725716+rushiiMachine@users.noreply.github.com>
Date: Sat, 23 Mar 2024 23:36:58 -0700
Subject: [PATCH] feat: PatchBeatmapThumbnailAlpha

---
 .../Patches/PatchBeatmapThumbnailAlpha.cs     | 72 +++++++++++++++++++
 Osu.Stubs/BeatmapTreeItem.cs                  | 62 ++++++++++++++++
 Osu.Stubs/BeatmapTreeManager.cs               |  2 +-
 3 files changed, 135 insertions(+), 1 deletion(-)
 create mode 100644 Osu.Patcher.Hook/Patches/PatchBeatmapThumbnailAlpha.cs
 create mode 100644 Osu.Stubs/BeatmapTreeItem.cs

diff --git a/Osu.Patcher.Hook/Patches/PatchBeatmapThumbnailAlpha.cs b/Osu.Patcher.Hook/Patches/PatchBeatmapThumbnailAlpha.cs
new file mode 100644
index 0000000..0cea4a0
--- /dev/null
+++ b/Osu.Patcher.Hook/Patches/PatchBeatmapThumbnailAlpha.cs
@@ -0,0 +1,72 @@
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.Reflection;
+using HarmonyLib;
+using JetBrains.Annotations;
+using Osu.Stubs;
+using static System.Reflection.Emit.OpCodes;
+
+namespace Osu.Patcher.Hook.Patches;
+
+/// <summary>
+///     Changes the default alpha on beatmap thumbnails in song select.
+/// </summary>
+[HarmonyPatch]
+[UsedImplicitly]
+public class PatchBeatmapThumbnailAlpha : BasePatch
+{
+    // TODO: make this user configurable through settings
+    private const int NewDeselectedAlpha = 185; // 0-255
+
+    [UsedImplicitly]
+    [HarmonyTargetMethods]
+    private static IEnumerable<MethodBase> Target() =>
+    [
+        BeatmapTreeItem.PopulateSprites.Reference,
+        BeatmapTreeItem.UpdateSprites.Reference,
+    ];
+
+    /// <summary>
+    ///     Changes the target color used as an alpha overlay over the thumbnail.
+    ///     Replaces all <c>50</c>s as in <c>new Color(50, 50, 50, ...)</c> with a higher value.
+    ///     Applied to both <c>UpdateSprites</c> and <c>PopulateSprites</c>.
+    /// </summary>
+    [UsedImplicitly]
+    [HarmonyTranspiler]
+    private static IEnumerable<CodeInstruction> ChangeDeselectFade(IEnumerable<CodeInstruction> instructions) =>
+        instructions.Manipulator(
+            inst => inst.Is(Ldc_I4_S, 50),
+            inst => inst.operand = NewDeselectedAlpha
+        );
+
+
+    /// <summary>
+    ///     Avoid re-fading in from zero when alpha already high from previous patches.
+    ///     Replaces the following code with Nop: <code>thumbnail.FadeInFromZero(instant ? 0 : 1000);</code>
+    ///     This is only applicable to <c>UpdateSprites()</c>.
+    /// </summary>
+    [UsedImplicitly]
+    [HarmonyTranspiler]
+    [SuppressMessage("ReSharper", "InconsistentNaming")]
+    private static IEnumerable<CodeInstruction> DisableFadeInFromZero(
+        IEnumerable<CodeInstruction> instructions,
+        MethodBase __originalMethod)
+    {
+        if (__originalMethod != BeatmapTreeItem.UpdateSprites.Reference)
+            return instructions;
+
+        return NoopSignature(instructions, new[]
+        {
+            Ldarg_0,
+            Ldfld,
+            Ldloc_0,
+            Ldfld,
+            Brtrue_S,
+            Ldc_I4,
+            Br_S,
+            Ldc_I4_0,
+            Callvirt,
+            Pop,
+        });
+    }
+}
\ No newline at end of file
diff --git a/Osu.Stubs/BeatmapTreeItem.cs b/Osu.Stubs/BeatmapTreeItem.cs
new file mode 100644
index 0000000..692e724
--- /dev/null
+++ b/Osu.Stubs/BeatmapTreeItem.cs
@@ -0,0 +1,62 @@
+using JetBrains.Annotations;
+using Osu.Stubs.Opcode;
+using static System.Reflection.Emit.OpCodes;
+
+namespace Osu.Stubs;
+
+/// <summary>
+///     Original: <c>osu.GameplayElements.Beatmaps.BeatmapTreeItem</c>
+///     b20240102.2: <c>#=z5dQ2d9vSoRzE9rWp7h5_dJ$Z1Sw13QcKf_J$7ZjIN21zOue2gQ==</c>
+/// </summary>
+[UsedImplicitly]
+public static class BeatmapTreeItem
+{
+    /// <summary>
+    ///     Original: <c>PopulateSprites(TreeItemState lastState, bool instant)</c>
+    ///     b20240102.2: <c>#=ztf5JjnV1ubq2KLwXBg==</c>
+    /// </summary>
+    [UsedImplicitly]
+    public static readonly LazyMethod UpdateSprites = new(
+        "BeatmapTreeItem#UpdateSprites(...)",
+        new[]
+        {
+            Pop,
+            Ldsfld,
+            Ldftn,
+            Newobj,
+            Dup,
+            Stsfld,
+            Callvirt,
+            Ret,
+            Ldarg_0,
+            Ldfld,
+            Ldloc_0,
+            Ldftn,
+            Newobj,
+        }
+    );
+
+    /// <summary>
+    ///     Original: <c>PopulateSprites()</c>
+    ///     b20240102.2: <c>#=zGdedQLY8W$wSqdNzBA==</c>
+    /// </summary>
+    [UsedImplicitly]
+    public static readonly LazyMethod PopulateSprites = new(
+        "BeatmapTreeItem#PopulateSprites()",
+        new[]
+        {
+            Brfalse,
+            Ldsfld,
+            Ldfld,
+            Ldc_I4,
+            Clt,
+            Ldc_I4_0,
+            Ceq,
+            Stloc_S,
+            Ldarg_0,
+            Ldc_I4_5,
+            Newarr,
+            Dup,
+        }
+    );
+}
\ No newline at end of file
diff --git a/Osu.Stubs/BeatmapTreeManager.cs b/Osu.Stubs/BeatmapTreeManager.cs
index a7bcd2d..32423a3 100644
--- a/Osu.Stubs/BeatmapTreeManager.cs
+++ b/Osu.Stubs/BeatmapTreeManager.cs
@@ -4,7 +4,7 @@
 namespace Osu.Stubs;
 
 /// <summary>
-///     Original: <c>osu.GameplayElements.Beatmaps:BeatmapTreeManager</c>
+///     Original: <c>osu.GameplayElements.Beatmaps.BeatmapTreeManager</c>
 ///     b20240102.2: <c>#=zV51QPv13Z_vZJRxEY28cvGye77gU6YZQsv_F5muuWuN62V5sIQ==</c>
 /// </summary>
 [UsedImplicitly]