From 9ffbe1f8ca14b5a73dbd127abdedb8ccb0a1b417 Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Fri, 31 Jan 2025 23:36:15 +0100
Subject: [PATCH] Add support in scripting for using interfaces on structures

#2679
---
 .../Bindings/BindingsGenerator.Cpp.cs         | 28 ++++++++++++-------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/Source/Tools/Flax.Build/Bindings/BindingsGenerator.Cpp.cs b/Source/Tools/Flax.Build/Bindings/BindingsGenerator.Cpp.cs
index a189c363a..a2c5f6934 100644
--- a/Source/Tools/Flax.Build/Bindings/BindingsGenerator.Cpp.cs
+++ b/Source/Tools/Flax.Build/Bindings/BindingsGenerator.Cpp.cs
@@ -1932,19 +1932,20 @@ namespace Flax.Build.Bindings
             contents.Append('}').AppendLine();
         }
 
-        private static string GenerateCppInterfaceInheritanceTable(BuildData buildData, StringBuilder contents, ModuleInfo moduleInfo, VirtualClassInfo typeInfo, string typeNameNative)
+        private static string GenerateCppInterfaceInheritanceTable(BuildData buildData, StringBuilder contents, ModuleInfo moduleInfo, ClassStructInfo typeInfo, string typeNameNative, string typeNameInternal)
         {
             var interfacesPtr = "nullptr";
             var interfaces = typeInfo.Interfaces;
             if (interfaces != null)
             {
-                interfacesPtr = typeNameNative + "_Interfaces";
+                var virtualTypeInfo = typeInfo as VirtualClassInfo;
+                interfacesPtr = typeNameInternal + "_Interfaces";
                 contents.Append("static const ScriptingType::InterfaceImplementation ").Append(interfacesPtr).AppendLine("[] = {");
                 for (int i = 0; i < interfaces.Count; i++)
                 {
                     var interfaceInfo = interfaces[i];
-                    var scriptVTableOffset = typeInfo.GetScriptVTableOffset(interfaceInfo);
-                    contents.AppendLine($"    {{ &{interfaceInfo.NativeName}::TypeInitializer, (int16)VTABLE_OFFSET({typeInfo.NativeName}, {interfaceInfo.NativeName}), {scriptVTableOffset}, true }},");
+                    var scriptVTableOffset = virtualTypeInfo?.GetScriptVTableOffset(interfaceInfo) ?? 0;
+                    contents.AppendLine($"    {{ &{interfaceInfo.NativeName}::TypeInitializer, (int16)VTABLE_OFFSET({typeNameNative}, {interfaceInfo.NativeName}), {scriptVTableOffset}, true }},");
                 }
                 contents.AppendLine("    { nullptr, 0 },");
                 contents.AppendLine("};");
@@ -2248,7 +2249,7 @@ namespace Flax.Build.Bindings
             contents.AppendLine();
 
             // Interfaces
-            var interfacesTable = GenerateCppInterfaceInheritanceTable(buildData, contents, moduleInfo, classInfo, classTypeNameNative);
+            var interfacesTable = GenerateCppInterfaceInheritanceTable(buildData, contents, moduleInfo, classInfo, classTypeNameNative, classTypeNameInternal);
 
             // Type initializer
             if (GenerateCppIsTemplateInstantiationType(classInfo))
@@ -2263,7 +2264,7 @@ namespace Flax.Build.Bindings
                     contents.Append("&ScriptingType::DefaultSpawn, ");
                 else
                     contents.Append($"(ScriptingType::SpawnHandler)&{classTypeNameNative}::Spawn, ");
-                if (classInfo.BaseType != null && useScripting)
+                if (classInfo.BaseType != null)
                     contents.Append($"&{classInfo.BaseType.FullNameNative}::TypeInitializer, ");
                 else
                     contents.Append("nullptr, ");
@@ -2280,9 +2281,7 @@ namespace Flax.Build.Bindings
                 else
                     contents.Append("nullptr");
             }
-            contents.Append(", ").Append(interfacesTable);
-            contents.Append(");");
-            contents.AppendLine();
+            contents.Append(", ").Append(interfacesTable).Append(");").AppendLine();
 
             // Nested types
             foreach (var apiTypeInfo in classInfo.Children)
@@ -2489,13 +2488,22 @@ namespace Flax.Build.Bindings
             contents.Append('}').Append(';').AppendLine();
             contents.AppendLine();
 
+            // Interfaces
+            var interfacesTable = GenerateCppInterfaceInheritanceTable(buildData, contents, moduleInfo, structureInfo, structureTypeNameNative, structureTypeNameInternal);
+
+            // Type initializer
             if (GenerateCppIsTemplateInstantiationType(structureInfo))
                 contents.Append("template<> ");
             contents.Append($"ScriptingTypeInitializer {structureTypeNameNative}::TypeInitializer((BinaryModule*)GetBinaryModule{moduleInfo.Name}(), ");
             contents.Append($"StringAnsiView(\"{structureTypeNameManaged}\", {structureTypeNameManaged.Length}), ");
             contents.Append($"sizeof({structureTypeNameNative}), ");
             contents.Append($"&{structureTypeNameInternal}Internal::InitRuntime, ");
-            contents.Append($"&{structureTypeNameInternal}Internal::Ctor, &{structureTypeNameInternal}Internal::Dtor, &{structureTypeNameInternal}Internal::Copy, &{structureTypeNameInternal}Internal::Box, &{structureTypeNameInternal}Internal::Unbox, &{structureTypeNameInternal}Internal::GetField, &{structureTypeNameInternal}Internal::SetField);").AppendLine();
+            contents.Append($"&{structureTypeNameInternal}Internal::Ctor, &{structureTypeNameInternal}Internal::Dtor, &{structureTypeNameInternal}Internal::Copy, &{structureTypeNameInternal}Internal::Box, &{structureTypeNameInternal}Internal::Unbox, &{structureTypeNameInternal}Internal::GetField, &{structureTypeNameInternal}Internal::SetField, ");
+            if (structureInfo.BaseType != null)
+                contents.Append($"&{structureInfo.BaseType.FullNameNative}::TypeInitializer");
+            else
+                contents.Append("nullptr");
+            contents.Append(", ").Append(interfacesTable).Append(");").AppendLine();
 
             // Nested types
             foreach (var apiTypeInfo in structureInfo.Children)