From ee0e2ca9005bd1a0cc0695e41f22d328835c3ee9 Mon Sep 17 00:00:00 2001
From: rushiiMachine <33725716+rushiiMachine@users.noreply.github.com>
Date: Wed, 27 Mar 2024 01:30:16 -0700
Subject: [PATCH] feat: PatchShowModsInGameplay

---
 .../Patches/PatchShowModsInGameplay.cs        | 98 +++++++++++++++++++
 Osu.Stubs/Player.cs                           | 20 ++++
 2 files changed, 118 insertions(+)
 create mode 100644 Osu.Patcher.Hook/Patches/PatchShowModsInGameplay.cs

diff --git a/Osu.Patcher.Hook/Patches/PatchShowModsInGameplay.cs b/Osu.Patcher.Hook/Patches/PatchShowModsInGameplay.cs
new file mode 100644
index 0000000..3512477
--- /dev/null
+++ b/Osu.Patcher.Hook/Patches/PatchShowModsInGameplay.cs
@@ -0,0 +1,98 @@
+using System;
+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>
+///     Makes the mods list overlay that is shown when entering play mode always show, like in a replay
+///     but faded to a user customizable amount.
+/// </summary>
+[HarmonyPatch]
+[UsedImplicitly]
+public class PatchShowModsInGameplay
+{
+    // TODO: make this user configurable
+    private const float ModsNewAlpha = .2f;
+
+    [UsedImplicitly]
+    [HarmonyTargetMethod]
+    private static MethodBase Target() => Player.OnLoadComplete.Reference;
+
+    [UsedImplicitly]
+    [HarmonyTranspiler]
+    private static IEnumerable<CodeInstruction> Transpiler(IEnumerable<CodeInstruction> instructions)
+    {
+        // Replace a "0f" representing a fade target value after an arbitrary "94f" constant
+        // Also set the pSprite parameter "alwaysDraw" to true
+
+        var replaceState = ReplaceState.Find;
+
+        return instructions.Manipulator(
+            inst =>
+            {
+                switch (replaceState)
+                {
+                    case ReplaceState.Find when inst.Is(Ldc_R4, 94f):
+                        replaceState = ReplaceState.ReplaceAlwaysDraw;
+                        return false;
+
+                    // This is calling "InputManager.get_ReplayMode()"
+                    case ReplaceState.ReplaceAlwaysDraw when inst.opcode == Call:
+                        return true;
+
+                    // This is loading the transformation fade end value
+                    case ReplaceState.ReplaceFadeEndValue when inst.Is(Ldc_R4, 0f):
+                        return true;
+
+                    case ReplaceState.Finished:
+                    default:
+                        return false;
+                }
+            },
+            inst =>
+            {
+                switch (replaceState)
+                {
+                    case ReplaceState.ReplaceAlwaysDraw:
+                        inst.opcode = Ldc_I4_1; // Load "true" for the parameter "alwaysDraw"
+                        inst.operand = null;
+                        replaceState = ReplaceState.ReplaceFadeEndValue;
+                        break;
+                    case ReplaceState.ReplaceFadeEndValue:
+                        inst.operand = ModsNewAlpha;
+                        replaceState = ReplaceState.Finished;
+                        break;
+                    case ReplaceState.Find:
+                    case ReplaceState.Finished:
+                    default:
+                        throw new Exception();
+                }
+            }
+        );
+    }
+
+    [UsedImplicitly]
+    [HarmonyFinalizer]
+    [SuppressMessage("ReSharper", "InconsistentNaming")]
+    private static void Finalizer(Exception? __exception)
+    {
+        if (__exception != null)
+        {
+            Console.WriteLine($"Exception due to {nameof(PatchShowModsInGameplay)}: {__exception}");
+        }
+    }
+
+    private enum ReplaceState
+    {
+        Find,
+        ReplaceAlwaysDraw,
+        ReplaceFadeEndValue,
+        Finished,
+    }
+}
\ No newline at end of file
diff --git a/Osu.Stubs/Player.cs b/Osu.Stubs/Player.cs
index 8cb0041..85691d6 100644
--- a/Osu.Stubs/Player.cs
+++ b/Osu.Stubs/Player.cs
@@ -33,4 +33,24 @@ public static class Player
             Br_S,
         }
     );
+
+    /// <summary>
+    ///     Original: <c>OnLoadComplete(bool success)</c>
+    ///     b20240124: <c>#=zXb_K4cZvV$uy</c>
+    /// </summary>
+    [UsedImplicitly]
+    public static readonly LazyMethod<bool> OnLoadComplete = new(
+        "Player#OnLoadComplete(...)",
+        new[]
+        {
+            Br,
+            Ldloc_S,
+            Callvirt,
+            Unbox_Any,
+            Stloc_2,
+            Ldsfld,
+            Ldfld,
+            Call,
+        }
+    );
 }
\ No newline at end of file