Ignacio Roldán Etcheverry 282bd37e5c C#: Remove need for reflection to invoking callable delegates ... We aim to make the C# API reflection-free, mainly for concerns about performance, and to be able to target NativeAOT in refletion-free mode, which reduces the binary size. One of the main usages of reflection still left was the dynamic invokation of callable delegates, and for some time I wasn't sure I would find an alternative solution that I'd be happy with. The new solution uses trampoline functions to invoke the delegates: ``` static void Trampoline(object delegateObj, NativeVariantPtrArgs args, out godot_variant ret) { if (args.Count != 1) throw new ArgumentException($"Callable expected 1 arguments but received {args.Count}."); string res = ((Func<int, string>)delegateObj)( VariantConversionCallbacks.GetToManagedCallback<int>()(args[0]) ); ret = VariantConversionCallbacks.GetToVariantCallback<string>()(res); } Callable.CreateWithUnsafeTrampoline((int num) => "Foo" + num, &Trampoline); ``` Of course, this is too much boilerplate for user code. To improve this, the `Callable.From` methods were added. These are overloads that take `Action` and `Func` delegates, which covers the most common use cases: lambdas and method groups: ``` // Lambda Callable.From((int num) => "Foo" + num); // Method group string AppendNum(int num) => "Foo" + num; Callable.From(AppendNum); ``` Unfortunately, due to limitations in the C# language, implicit conversions from delegates to `Callable` are not supported. `Callable.From` does not support custom delegates. These should be uncommon, but the Godot C# API actually uses them for event signals. As such, the bindings generator was updated to generate trampoline functions for event signals. It was also optimized to use `Action` instead of a custom delegate for parameterless signals, which removes the need for the trampoline functions for those signals. The change to reflection-free invokation removes one of the last needs for `ConvertVariantToManagedObjectOfType`. The only remaining usage is from calling script constructors with parameters from the engine (`CreateManagedForGodotObjectScriptInstance`). Once that one is made reflection-free, `ConvertVariantToManagedObjectOfType` can be removed.		2022-10-30 01:24:15 +02:00
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GodotSharp	C#: Remove need for reflection to invoking callable delegates	2022-10-30 01:24:15 +02:00
runtime_interop.cpp	C#: Remove need for reflection to invoking callable delegates	2022-10-30 01:24:15 +02:00
runtime_interop.h	C#: Replace P/Invoke with delegate pointers	2022-08-22 03:36:52 +02:00