Add support for asset bundles without an architecture suffix

Unity requires specifying the architecture when building asset bundles as part of BuildTarget. While compatibility between targets isn't guaranteed, in practice there are no differences between architectures.

<!-- ps-id: 49397d5b-21fc-4201-a0d6-e0c2f9627bf3 -->

Reactor.Assets/Assets/Build.cs

@@ -69,14 +69,14 @@ public static void BuildAssetBundles()
         }
     }
 
-    private static string GetTargetName(BuildTarget target)
+    private static string GetTargetName(BuildTarget target, bool includeArchitecture = false)
     {
         return target switch
         {
-            BuildTarget.StandaloneWindows => "win-x86",
-            BuildTarget.StandaloneWindows64 => "win-x64",
+            BuildTarget.StandaloneWindows => includeArchitecture ? "win-x86" : "win",
+            BuildTarget.StandaloneWindows64 => includeArchitecture ? "win-x64" : "win",
             BuildTarget.Android => "android",
-            BuildTarget.StandaloneLinux64 => "linux-x64",
+            BuildTarget.StandaloneLinux64 => includeArchitecture ? "linux-x64" : "linux",
             _ => throw new ArgumentOutOfRangeException(nameof(target), target, null),
         };
     }

Reactor/Utilities/AssetBundleManager.cs

@@ -3,8 +3,8 @@
 using System.IO;
 using System.Linq;
 using System.Reflection;
+using System.Runtime.InteropServices;
 using Il2CppInterop.Runtime.InteropTypes.Arrays;
-using MonoMod.Utils;
 using Reactor.Utilities.Extensions;
 using UnityEngine;
 
@@ -23,46 +23,65 @@ public static class AssetBundleManager
     /// <summary>
     /// Gets the target name of the current system.
     /// </summary>
-    public static string TargetName { get; }
+    [Obsolete("Use AssetBundleManager#GetTargetName instead")]
+    public static string TargetName { get; } = GetTargetName(true);
 
-    static AssetBundleManager()
+    /// <summary>
+    /// Gets the target name of the current system.
+    /// </summary>
+    /// <param name="includeArchitecture">A value indicating whether to include the process architecture.</param>
+    /// <returns>Target name of the current system.</returns>
+    public static string GetTargetName(bool includeArchitecture)
     {
-        if (PlatformHelper.Is(Platform.Android))
+        string operatingSystem;
+
+        if (OperatingSystem.IsWindows())
         {
-            TargetName = "android";
+            operatingSystem = "win";
+        }
+        else if (OperatingSystem.IsLinux())
+        {
+            operatingSystem = "linux";
+        }
+        else if (OperatingSystem.IsAndroid())
+        {
+            operatingSystem = "android";
         }
         else
         {
-            if (PlatformHelper.Is(Platform.Windows))
-            {
-                TargetName = "win";
-            }
-            else if (PlatformHelper.Is(Platform.Linux))
-            {
-                TargetName = "linux";
-            }
-            else
-            {
-                throw new PlatformNotSupportedException();
-            }
+            throw new PlatformNotSupportedException();
+        }
 
-            if (PlatformHelper.Is(Platform.ARM))
-            {
-                TargetName += Environment.Is64BitProcess ? "-arm64" : "-arm";
-            }
-            else
-            {
-                TargetName += Environment.Is64BitProcess ? "-x64" : "-x86";
-            }
+        if (!includeArchitecture)
+        {
+            return operatingSystem;
         }
+
+        return $"{operatingSystem}-{RuntimeInformation.ProcessArchitecture switch
+        {
+            Architecture.X86 => "x86",
+            Architecture.X64 => "x64",
+            Architecture.Arm => "arm",
+            Architecture.Arm64 => "arm64",
+            _ => throw new PlatformNotSupportedException(),
+        }}";
     }
 
     /// <summary>
     /// Gets the file name for an asset bundle named <paramref name="assetBundleName"/>.
     /// </summary>
     /// <param name="assetBundleName">The name of the asset bundle.</param>
     /// <returns>File name of the asset bundle.</returns>
-    public static string GetFileName(string assetBundleName) => $"{assetBundleName}-{TargetName}{BundleExtension}";
+    [Obsolete("Use the overload with includeArchitecture instead")]
+    public static string GetFileName(string assetBundleName) => GetFileName(assetBundleName, true);
+
+    /// <summary>
+    /// Gets the file name for an asset bundle named <paramref name="assetBundleName"/>.
+    /// </summary>
+    /// <param name="assetBundleName">The name of the asset bundle.</param>
+    /// <param name="includeArchitecture">A value indicating whether to include the process architecture.</param>
+    /// <returns>File name of the asset bundle.</returns>
+    public static string GetFileName(string assetBundleName, bool includeArchitecture) => $"{assetBundleName}-{GetTargetName(includeArchitecture)}{BundleExtension}";
 
     private static bool TryFindFile(Assembly assembly, string fileName, [NotNullWhen(true)] out string? path)
     {
@@ -72,6 +91,7 @@ private static bool TryFindFile(Assembly assembly, string fileName, [NotNullWhen
             var filePath = Path.Combine(pluginDirectoryPath, fileName);
             if (File.Exists(filePath))
             {
+                Debug($"Loading an asset bundle from {filePath}");
                 path = filePath;
                 return true;
             }
@@ -86,6 +106,8 @@ private static bool TryLoadResource(Assembly assembly, string fileName, [NotNull
         var resourceName = assembly.GetManifestResourceNames().SingleOrDefault(n => n.EndsWith(fileName, StringComparison.Ordinal));
         if (resourceName != null)
         {
+            Debug($"Loading an asset bundle from {resourceName}");
+
             using var stream = assembly.GetManifestResourceStream(resourceName) ?? throw new InvalidOperationException("Resource stream was null");
 
             var length = (int) stream.Length;
@@ -119,8 +141,13 @@ public static AssetBundle Load(string name)
     /// <exception cref="AssetBundleNotFoundException">Couldn't find an assetbundle named <paramref name="name"/>.</exception>
     public static AssetBundle Load(Assembly assembly, string name)
     {
-        var fileName = GetFileName(name);
+        return TryLoad(assembly, GetFileName(name, includeArchitecture: true))
+               ?? TryLoad(assembly, GetFileName(name, includeArchitecture: false))
+               ?? throw new AssetBundleNotFoundException(name);
+    }
 
+    private static AssetBundle? TryLoad(Assembly assembly, string fileName)
+    {
         if (TryFindFile(assembly, fileName, out var filePath))
         {
             return AssetBundle.LoadFromFile(filePath);
@@ -131,7 +158,7 @@ public static AssetBundle Load(Assembly assembly, string name)
             return AssetBundle.LoadFromMemory(data);
         }
 
-        throw new AssetBundleNotFoundException(name);
+        return null;
     }
 
     /// <summary>
@@ -154,8 +181,13 @@ public static AssetBundleCreateRequest LoadAsync(string name)
     /// <exception cref="AssetBundleNotFoundException">Couldn't find an assetbundle named <paramref name="name"/>.</exception>
     public static AssetBundleCreateRequest LoadAsync(Assembly assembly, string name)
     {
-        var fileName = GetFileName(name);
+        return TryLoadAsync(assembly, GetFileName(name, includeArchitecture: true))
+               ?? TryLoadAsync(assembly, GetFileName(name, includeArchitecture: false))
+               ?? throw new AssetBundleNotFoundException(name);
+    }
 
+    private static AssetBundleCreateRequest? TryLoadAsync(Assembly assembly, string fileName)
+    {
         if (TryFindFile(assembly, fileName, out var filePath))
         {
             return AssetBundle.LoadFromFileAsync(filePath);
@@ -166,7 +198,7 @@ public static AssetBundleCreateRequest LoadAsync(Assembly assembly, string name)
             return AssetBundle.LoadFromMemoryAsync(data);
         }
 
-        throw new AssetBundleNotFoundException(name);
+        return null;
     }
 }