Method FromInterface

Source/Engine/Scripting/ScriptingObject.cpp:166–221

}

ScriptingObject* ScriptingObject::FromInterface(void* interfaceObj, const ScriptingTypeHandle& interfaceType)
{
    if (!interfaceObj || !interfaceType)
        return nullptr;
    PROFILE_CPU();

    // Find the type which implements this interface and has the same vtable as interface object
    // TODO: implement vtableInterface->type hashmap caching in Scripting service to optimize sequential interface casts
    auto& modules = BinaryModule::GetModules();
    for (auto module : modules)
    {
        for (auto& type : module->Types)
        {
            if (type.Type != ScriptingTypes::Script)
                continue;
            auto interfaceImpl = type.GetInterface(interfaceType);
            if (!interfaceImpl || !interfaceImpl->IsNative)
                continue;

            // Get vtable for this type
            void* vtable = type.Script.VTable;
            if (!vtable && type.GetDefaultInstance())
            {
                // Use vtable from default instance of this type
                vtable = *(void***)type.GetDefaultInstance();
            }

            // Check if object interface vtable matches the type interface vtable value
            ScriptingObject* predictedObj = (ScriptingObject*)((byte*)interfaceObj - interfaceImpl->VTableOffset);
            void* predictedVTable = *(void***)predictedObj;
            if (vtable == predictedVTable)
            {
                ASSERT(predictedObj->GetType().GetInterface(interfaceType));
                return predictedObj;
            }

            // Check for case of passing object directly
            predictedObj = (ScriptingObject*)interfaceObj;
            predictedVTable = *(void***)predictedObj;
            if (vtable == predictedVTable)
            {
                ASSERT(predictedObj->GetType().GetInterface(interfaceType));
                return predictedObj;
            }
        }
    }

    // Special case for interface wrapper object
    for (const auto& e : ScriptingObjectsInterfaceWrappers)
    {
        if (e.Value == interfaceObj)
            return e.Key.First;
    }

    return nullptr;
}

void* ScriptingObject::ToInterface(ScriptingObject* obj, const ScriptingTypeHandle& interfaceType)