We will be progressively moving most code to C#.
The plan is to only use Mono's embedding APIs to set things at launch.
This will make it much easier to later support CoreCLR too which
doesn't have rich embedding APIs.
Additionally the code in C# is more maintainable and makes it easier
to implement new features, e.g.: runtime codegen which we could use to
avoid using reflection for marshaling everytime a field, property or
method is accessed.
SOME NOTES ON INTEROP
We make the same assumptions as GDNative about the size of the Godot
structures we use. We take it a bit further by also assuming the layout
of fields in some cases, which is riskier but let's us squeeze out some
performance by avoiding unnecessary managed to native calls.
Code that deals with native structs is less safe than before as there's
no RAII and copy constructors in C#. It's like using the GDNative C API
directly. One has to take special care to free values they own.
Perhaps we could use roslyn analyzers to check this, but I don't know
any that uses attributes to determine what's owned or borrowed.
As to why we maily use pointers for native structs instead of ref/out:
- AFAIK (and confirmed with a benchmark) ref/out are pinned
during P/Invoke calls and that has a cost.
- Native struct fields can't be ref/out in the first place.
- A `using` local can't be passed as ref/out, only `in`. Calling a
method or property on an `in` value makes a silent copy, so we want
to avoid `in`.
REGARDING THE BUILD SYSTEM
There's no longer a `mono_glue=yes/no` SCons options. We no longer
need to build with `mono_glue=no`, generate the glue and then build
again with `mono_glue=yes`. We build only once and generate the glue
(which is in C# now).
However, SCons no longer builds the C# projects for us. Instead one
must run `build_assemblies.py`, e.g.:
```sh
%godot_src_root%/modules/mono/build_scripts/build_assemblies.py \
--godot-output-dir=%godot_src_root%/bin \
--godot-target=release_debug`
```
We could turn this into a custom build target, but I don't know how
to do that with SCons (it's possible with Meson).
OTHER NOTES
Most of the moved code doesn't follow the C# naming convention and
still has the word Mono in the names despite no longer dealing with
Mono's embedding APIs. This is just temporary while transitioning,
to make it easier to understand what was moved where.
- Implements new `KeyValuePairs` and `KeyValuePairAt` internal calls
to get the `key` and the `value` in one call.
- Caches the `DictionaryEntry` to reuse properties without repeating
internal calls.
Happy new year to the wonderful Godot community!
2020 has been a tough year for most of us personally, but a good year for
Godot development nonetheless with a huge amount of work done towards Godot
4.0 and great improvements backported to the long-lived 3.2 branch.
We've had close to 400 contributors to engine code this year, authoring near
7,000 commit! (And that's only for the `master` branch and for the engine code,
there's a lot more when counting docs, demos and other first-party repos.)
Here's to a great year 2021 for all Godot users 🎆
Happy new year to the wonderful Godot community!
We're starting a new decade with a well-established, non-profit, free
and open source game engine, and tons of further improvements in the
pipeline from hundreds of contributors.
Godot will keep getting better, and we're looking forward to all the
games that the community will keep developing and releasing with it.
Expands to Object.call, Object.set and Object.get for accessing members. This means it can also access members from scripts written in other languages, like GDScript.
- We no longer generate RID and NodePath C# classes. Both will be maintained manually.
- We no longer generate C# declarations and runtime registration of internal calls for the following classes: RID, NodePath, String, GD, SignalAwaiter and Godot.Object (partial base).
- We no longer auto-generate the base members of Godot.Object. They will be maintained manually as a partial class.
This makes it easier to maintain these C# classes and their internal calls, as well as the bindings generator which no longer generates C# classes that don't derive from Godot Object, and it no longer generates the Godot.Object base members (which where unreadable in the bindings generator code).
- Added missing 'RID(Object from)' constructor to the RID C# class.
- Replaced MONO_GLUE_DISABLED constant macro with MONO_GLUE_ENABLED.
- Add sources in module/mono/glue even if glue is disabled, but surround glue files with ifdef MONO_GLUE_ENABLED.
