Revive headless mode

Celeste.Mod.mm/Celeste.Mod.mm.csproj

@@ -83,13 +83,14 @@
     <ProjectReference Include="..\DiscordGameSDK\DiscordGameSDK.csproj" />
     <ProjectReference Include="..\NETCoreifier\NETCoreifier.csproj" />
     <ProjectReference Include="..\EverestSplash\EverestSplash.csproj" /> <!-- Forces correct build dependency order -->
+    <!-- Ideally EverestSplash would not be copied to the build directory, but that cannot be easily disabled -->
   </ItemGroup>
 
   <Target Name="CopyEverestSplashFiles" AfterTargets="Publish">
     <ItemGroup> <!-- For some reason to use wildcards you have to use a property -->
-      <SplashBinaries Include="$(OutputPath)\publish\EverestSplash*;$(OutputPath)\publish\piton-runtime.yaml" />
+      <SplashBinaries Include="$(PublishDir)\EverestSplash*;$(PublishDir)\piton-runtime.yaml" />
     </ItemGroup>
-    <Move SourceFiles="@(SplashBinaries)" DestinationFolder="$(OutputPath)\publish\EverestSplash\" />
+    <Move SourceFiles="@(SplashBinaries)" DestinationFolder="$(PublishDir)\EverestSplash\" />
   </Target>
 
 </Project>

Celeste.Mod.mm/Mod/Core/CoreModule.cs

@@ -53,7 +53,7 @@ public override void LoadSettings() {
             base.LoadSettings();
 
             // The field can be set to true by default without the setter being called by YamlDotNet.
-            if (Settings.DiscordRichPresence) {
+            if (Settings.DiscordRichPresence && !Everest.Flags.IsHeadless) {
                 Everest.DiscordSDK.CreateInstance();
             }
 

Celeste.Mod.mm/Mod/Core/CoreModuleSettings.cs

@@ -586,7 +586,7 @@ public void CreateDiscordRichPresenceEntry(TextMenu menu, bool inGame) {
             TextMenu.Item masterSwitch = new TextMenu.OnOff(Dialog.Clean("modoptions_coremodule_discordrichpresence"), DiscordRichPresence)
                 .Change(value => {
                     DiscordRichPresence = value;
-                    if (DiscordRichPresence) {
+                    if (DiscordRichPresence && !Everest.Flags.IsHeadless) {
                         Everest.DiscordSDK.CreateInstance()?.UpdatePresence(session);
                     } else {
                         Everest.DiscordSDK.Instance?.Dispose();

Celeste.Mod.mm/Mod/Everest/Everest.Flags.cs

@@ -30,9 +30,9 @@ public static class Flags {
             public static bool VanillaIsFNA { get; private set;}
 
             /// <summary>
-            /// Is Everest running headlessly?
+            /// Is Everest running without a window?
             /// </summary>
-            public static bool IsHeadless { get; private set; }
+            public static bool IsHeadless { get; internal set; }
 
             /// <summary>
             /// Is the game running using Mono - always false on .NET Core Everest.
@@ -75,7 +75,6 @@ internal static void Initialize() {
                     VanillaIsXNA = !VanillaIsFNA;
                 }
 
-                IsHeadless = Environment.GetEnvironmentVariable("EVEREST_HEADLESS") == "1";
                 AvoidRenderTargets = Environment.GetEnvironmentVariable("EVEREST_NO_RT") == "1";
                 PreferLazyLoading = false;
 

Celeste.Mod.mm/Mod/Everest/Everest.cs

@@ -425,10 +425,8 @@ static void UnregisterModDetour(object detour) {
             // Before even initializing anything else, make sure to prepare any static flags.
             Flags.Initialize();
 
-            if (!Flags.IsHeadless) {
-                // Initialize the content helper.
-                Content.Initialize();
-            }
+            // Initialize the content helper.
+            Content.Initialize();
 
             MainThreadHelper.Instance = new MainThreadHelper(Celeste.Instance);
             STAThreadHelper.Instance = new STAThreadHelper(Celeste.Instance);
@@ -457,10 +455,8 @@ static void UnregisterModDetour(object detour) {
 
             Loader.LoadAuto();
 
-            if (!Flags.IsHeadless) {
-                // Load stray .bins afterwards.
-                Content.Crawl(new MapBinsInModsModContent(Path.Combine(PathEverest, "Mods")));
-            }
+            // Load stray .bins afterwards.
+            Content.Crawl(new MapBinsInModsModContent(Path.Combine(PathEverest, "Mods")));
 
             // Also let all mods parse the arguments.
             Queue<string> args = new Queue<string>(Args);

Celeste.Mod.mm/Mod/UI/OuiOOBE.cs

@@ -327,7 +327,7 @@ private IEnumerator FadeBgTo(float to) {
         }
 
         public override bool IsStart(Overworld overworld, Overworld.StartMode start) {
-            if (start != Overworld.StartMode.Titlescreen)
+            if (start != Overworld.StartMode.Titlescreen || Everest.Flags.IsHeadless)
                 return false;
             if (CoreModule.Settings.CurrentVersion != null) {
                 if (CoreModule.Settings.SaveDataFlush ?? false)

Celeste.Mod.mm/MonoModRules.Game.cs

@@ -2,6 +2,7 @@
 using Mono.Cecil;
 using Mono.Cecil.Cil;
 using Mono.Collections.Generic;
+using Monocle;
 using MonoMod.Cil;
 using MonoMod.InlineRT;
 using MonoMod.Utils;
@@ -154,20 +155,33 @@ public static void GamePreProcessor(MonoModder modder) {
             if (IsRelinkingXNAInstall)
                 modder.Log("[Celeste.Mod.mm] Converting XNA game install to FNA");
 
-            static void VisitType(TypeDefinition type) {
+            MethodReference stubAttrCtor = RulesModule.GetType($"MonoMod.{nameof(PatchStubExternAttribute)}").Methods.First(m => m.IsConstructor);
+            stubAttrCtor = modder.Module.ImportReference(stubAttrCtor);
+
+            static void VisitType(TypeDefinition type, MethodReference stubAttrCtor) {
                 // Remove readonly attribute from all static fields
                 // This "fixes" https://github.com/dotnet/runtime/issues/11571, which breaks some mods
                 foreach (FieldDefinition field in type.Fields)
                     if ((field.Attributes & FieldAttributes.Static) != 0)
                         field.Attributes &= ~FieldAttributes.InitOnly;
 
+                // Stub out extern FMOD methods in headless mode
+                if (MonoModRule.Flag.Get("Headless") && type.Namespace.StartsWith("FMOD")) {
+                    foreach (MethodDefinition method in type.Methods) {
+                        if ((method.Attributes & MethodAttributes.Static) != 0 && method.Name.StartsWith("FMOD_")) {
+                            // Console.WriteLine($"ADDING ATTR {method}");
+                            method.CustomAttributes.Add(new CustomAttribute(stubAttrCtor));
+                        }
+                    }
+                }
+
                 // Visit nested types
                 foreach (TypeDefinition nestedType in type.NestedTypes)
-                    VisitType(nestedType);
+                    VisitType(nestedType, stubAttrCtor);
             }
 
             foreach (TypeDefinition type in modder.Module.Types)
-                VisitType(type);
+                VisitType(type, stubAttrCtor);
         }
 
         public static void GamePostProcessor(MonoModder modder) {

Celeste.Mod.mm/MonoModRules.cs

@@ -36,6 +36,13 @@ public ForceNameAttribute(string name) {}
     /// </summary>
     [MonoModCustomMethodAttribute(nameof(MonoModRules.PatchInitblk))]
     class PatchInitblkAttribute : Attribute { }
+
+    /// <summary>
+    /// Patches an extern method to be stubbed. Uses default values for return type / out-parameters
+    /// </summary>
+    [MonoModIfFlag("Headless")]
+    [MonoModCustomMethodAttribute(nameof(MonoModRules.PatchStubExtern))]
+    class PatchStubExternAttribute : Attribute { }
 #endregion
 
     static partial class MonoModRules {
@@ -102,6 +109,9 @@ private static void InitCommonRules(MonoModder modder) {
             if (MonoModder.Version < monoModderAsmRef.Version)
                 throw new Exception($"Unexpected version of MonoMod patcher: {MonoModder.Version} (expected {monoModderAsmRef.Version}+)");
 
+            // Data is set by MiniInstaller
+            MonoModRule.Flag.Set("Headless", (bool?)AppDomain.CurrentDomain.GetData("Everest_IsHeadless") ?? false);
+
             // Add common post processor
             modder.PostProcessors += CommonPostProcessor;
         }
@@ -220,6 +230,82 @@ public static void PatchInitblk(ILContext il, CustomAttribute attrib) {
             }
         }
 
+        public static void PatchStubExtern(MethodDefinition method, CustomAttribute attrib) {
+            // Console.WriteLine($"RUNNING STUB {method} {method.Attributes}");
+            method.Attributes &= ~(MethodAttributes.PInvokeImpl | MethodAttributes.CompilerControlled | MethodAttributes.HideBySig);
+
+            ILContext il = new ILContext(method);
+            ILCursor cursor = new ILCursor(il);
+
+            TypeDefinition returnType = method.ReturnType.Resolve();
+
+            // Insert 'outParam = default;'
+            foreach (ParameterDefinition param in method.Parameters) {
+                if (!param.IsOut) continue;
+
+                TypeDefinition paramType = param.ParameterType.Resolve();
+                TypeReference enumType = paramType.IsEnum ? GetEnumUnderlyingType(paramType) : null;
+
+                if (paramType.FullName is "System.Byte" or "System.SByte" || enumType?.FullName is "System.Byte" or "System.SByte") {
+                    cursor.EmitLdarg(param.Index);
+                    cursor.EmitLdcI4(0);
+                    cursor.EmitStindI1();
+                } else if (paramType.FullName is "System.Int16" or "System.UInt16" || enumType?.FullName is "System.Int16" or "System.UInt16") {
+                    cursor.EmitLdarg(param.Index);
+                    cursor.EmitLdcI4(0);
+                    cursor.EmitStindI2();
+                } else if (paramType.FullName is "System.Int32" or "System.UInt32" || enumType?.FullName is "System.Int32" or "System.UInt32") {
+                    cursor.EmitLdarg(param.Index);
+                    cursor.EmitLdcI4(0);
+                    cursor.EmitStindI4();
+                } else if (paramType.FullName is "System.Int64" or "System.UInt64" || enumType?.FullName is "System.Int64" or "System.UInt64") {
+                    cursor.EmitLdarg(param.Index);
+                    cursor.EmitLdcI8(0);
+                    cursor.EmitStindI8();
+                } else if (paramType.FullName is "System.IntPtr" or "System.UIntPtr" || enumType?.FullName is "System.IntPtr" or "System.UIntPtr") {
+                    cursor.EmitLdarg(param.Index);
+                    cursor.EmitLdcI4(0);
+                    cursor.EmitConvI();
+                    cursor.EmitStindI();
+                } else if (paramType.FullName is "System.Single" || enumType?.FullName is "System.Single") {
+                    cursor.EmitLdarg(param.Index);
+                    cursor.EmitLdcR4(0.0f);
+                    cursor.EmitStindR4();
+                } else if (paramType.FullName is "System.Double" || enumType?.FullName is "System.Double") {
+                    cursor.EmitLdarg(param.Index);
+                    cursor.EmitLdcR8(0.0);
+                    cursor.EmitStindR8();
+                } else if (paramType.IsValueType) {
+                    cursor.EmitLdarg(param.Index);
+                    cursor.EmitInitobj(MonoModRule.Modder.Module.ImportReference(paramType));
+                } else {
+                    cursor.EmitLdarg(param.Index);
+                    cursor.EmitLdnull();
+                    cursor.EmitStindRef();
+                }
+            }
+
+            // Insert 'return default;'
+            if (returnType.FullName == "System.Void") {
+                cursor.EmitRet();
+            } else if (returnType.IsPrimitive || returnType.IsEnum) {
+                cursor.EmitLdcI4(0);
+                cursor.EmitRet();
+            } else if (!returnType.IsValueType) {
+                cursor.EmitLdnull();
+                cursor.EmitRet();
+            } else {
+                throw new Exception($"Unsupported return type '{returnType.FullName}' of method '{method.FullName}' to be stubbed");
+            }
+
+            return;
+
+            // Adapted from Mono.Cecil.Rocks.TypeDefinitionsRock.GetEnumUnderlyingType
+            static TypeReference GetEnumUnderlyingType(TypeDefinition enumType) {
+                return enumType.Fields.First(f => !f.IsStatic).FieldType;
+            }
+        }
+
         /// <summary>
         /// Fix ILSpy unable to decompile enumerator after MonoMod patching<br />
         /// (<code>yield-return decompiler failed: Unexpected instruction in Iterator.Dispose()</code>)

Celeste.Mod.mm/Patches/Audio.cs

@@ -48,9 +48,15 @@ internal static void CheckFmod(RESULT result) {
 
         [MonoModReplace]
         public static void Init() {
+            if (Everest.Flags.IsHeadless) {
+                // Stub out audio system
+                system = new FMOD.Studio.System(IntPtr.Zero);
+                return;
+            }
+
             bool fmodLiveUpdate = Settings.Instance.LaunchWithFMODLiveUpdate;
             Settings.Instance.LaunchWithFMODLiveUpdate |= CoreModule.Settings.LaunchWithFMODLiveUpdateInEverest;
-        
+
             // Original initialization code
             {
                 FMOD.Studio.INITFLAGS flags = FMOD.Studio.INITFLAGS.NORMAL;
@@ -111,6 +117,10 @@ public static void Init() {
         }
 
         public static void IngestNewBanks() {
+            if (Everest.Flags.IsHeadless) {
+                return;
+            }
+
             lock (Everest.Content.Map) {
                 foreach (ModAsset asset in Everest.Content.Map.Values.Where(asset => asset.Type == typeof(AssetTypeBank))) {
                     if (!ingestedModBankPaths.Contains(asset.PathVirtual)) {
@@ -122,6 +132,10 @@ public static void IngestNewBanks() {
 
         [MonoModReplace]
         public static void Unload() {
+            if (Everest.Flags.IsHeadless) {
+                return;
+            }
+
             if (system == null)
                 return;
 
@@ -137,6 +151,10 @@ public static void Unload() {
         /// Loads an FMOD Bank from the given asset.
         /// </summary>
         public static Bank IngestBank(ModAsset asset) {
+            if (Everest.Flags.IsHeadless) {
+                return new Bank(IntPtr.Zero);
+            }
+
             Logger.Verbose("Audio.IngestBank", asset.PathVirtual);
             ingestedModBankPaths.Add(asset.PathVirtual);
 
@@ -188,6 +206,10 @@ public static Bank IngestBank(ModAsset asset) {
         /// Loads an FMOD GUID table from the given asset.
         /// </summary>
         public static void IngestGUIDs(ModAsset asset) {
+            if (Everest.Flags.IsHeadless) {
+                return;
+            }
+
             Logger.Verbose("Audio.IngestGUIDs", asset.PathVirtual);
             using (Stream stream = asset.Stream)
             using (StreamReader reader = new StreamReader(asset.Stream)) {
@@ -222,15 +244,15 @@ public static void IngestGUIDs(ModAsset asset) {
 
         public static extern void orig_ReleaseUnusedDescriptions();
         public static void ReleaseUnusedDescriptions() {
-            if (!CoreModule.Settings.UnloadUnusedAudio)
+            if (Everest.Flags.IsHeadless || !CoreModule.Settings.UnloadUnusedAudio)
                 return;
             orig_ReleaseUnusedDescriptions();
         }
 
 
         [MonoModReplace]
         public static string GetEventName(EventInstance instance) {
-            if (instance == null)
+            if (Everest.Flags.IsHeadless || instance == null)
                 return "";
 
             instance.getDescription(out EventDescription desc);
@@ -241,7 +263,7 @@ public static string GetEventName(EventInstance instance) {
         }
 
         public static string GetEventName(EventDescription desc) {
-            if (desc == null)
+            if (Everest.Flags.IsHeadless || desc == null)
                 return "";
 
             desc.getID(out Guid id);
@@ -256,7 +278,7 @@ public static string GetEventName(EventDescription desc) {
         }
 
         public static string GetBankName(Bank bank) {
-            if (bank == null)
+            if (Everest.Flags.IsHeadless || bank == null)
                 return "";
 
             bank.getID(out Guid id);
@@ -270,6 +292,10 @@ public static string GetBankName(Bank bank) {
 
         [MonoModReplace]
         public static EventDescription GetEventDescription(string path) {
+            if (Everest.Flags.IsHeadless) {
+                return new EventDescription(IntPtr.Zero);
+            }
+
             EventDescription desc = null;
             if (path == null || Audio.cachedEventDescriptions.TryGetValue(path, out desc))
                 return desc;
@@ -311,6 +337,10 @@ public static class patch_Banks {
 
             [MonoModReplace]
             public static Bank Load(string name, bool loadStrings) {
+                if (Everest.Flags.IsHeadless) {
+                    return new Bank(IntPtr.Zero);
+                }
+
                 if (Banks == null)
                     Banks = new Dictionary<string, Bank>();