We're targeting .NET 5 for now to make development easier while
.NET 6 is not yet released.
TEMPORARY REGRESSIONS
---------------------
Assembly unloading is not implemented yet. As such, many Godot
resources are leaked at exit. This will be re-implemented later
together with assembly hot-reloading.
The main focus here was to remove the majority of code that relied on
Mono's embedding APIs, specially the reflection APIs. The embedding
APIs we still use are the bare minimum we need for things to work.
A lot of code was moved to C#. We no longer deal with any managed
objects (`MonoObject*`, and such) in native code, and all marshaling
is done in C#.
The reason for restructuring the code and move away from embedding APIs
is that once we move to .NET Core, we will be limited by the much more
minimal .NET hosting.
PERFORMANCE REGRESSIONS
-----------------------
Some parts of the code were written with little to no concern about
performance. This includes code that calls into script methods and
accesses script fields, properties and events.
The reason for this is that all of that will be moved to source
generators, so any work prior to that would be a waste of time.
DISABLED FEATURES
-----------------
Some code was removed as it no longer makes sense (or won't make sense
in the future).
Other parts were commented out with `#if 0`s and TODO warnings because
it doesn't make much sense to work on them yet as those parts will
change heavily when we switch to .NET Core but also when we start
introducing source generators.
As such, the following features were disabled temporarily:
- Assembly-reloading (will be done with ALCs in .NET Core).
- Properties/fields exports and script method listing (will be
handled by source generators in the future).
- Exception logging in the editor and stack info for errors.
- Exporting games.
- Building of C# projects. We no longer copy the Godot API assemblies
to the project directory, so MSBuild won't be able to find them. The
idea is to turn them into NuGet packages in the future, which could
also be obtained from local NuGet sources during development.
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.
All iOS devices since the iPhone 5S support ARMv8 (64-bit).
The last iOS version supported on ARMv7 devices is 10.x, which is
too old to run Godot 4.0 projects since the minimum supported
iOS version is 11.0.
This fixes a conflict with the `pressed` signal.
The new name is temporary and only intended to solve the conflict for upcoming
alpha builds. Discussions are still ongoing regarding the BaseButton API and
how to rename and refactor more of its properties, signals and methods to have
a clearer API in 4.0.
Apply suggestions from code review
Merging @akien-mga's suggestion with the matching change to the CS project
Co-authored-by: Rémi Verschelde <rverschelde@gmail.com>
Use `System.Array.Empty<T>` to get an empty array instead of allocating
a new one every time. Since arrays are immutable there is no need to
allocate them every time.
While there are still various bugs to solve and features to implement, the C#
support as of Godot 3.4 is fairly mature and already used by a number of users
in production. Now that we default to dotnet CLI as build tool, it also seems
to be more reliable than MSBuild.
The documentation can (and does for the most part) point out some caveats that
users should be aware of, but this info dialog has outlived its intended
purpose.
- Fix C++ compile errors about pending variable renames after the `Reference` to `RefCount` change.
- Fix C# compile errors due to the recent rename of `EnablePlugin()` and `Build()`, which are now underscore-prefixed in bindings.
- Additional rename: `godot_icall_Reference_Dtor` to `godot_icall_RefCounted_Dtor`.
This source generator adds a newly introduced attribute,
`ScriptPath` to all classes that:
- Are top-level classes (not inner/nested).
- Have the `partial` modifier.
- Inherit `Godot.Object`.
- The class name matches the file name.
A build error is thrown if the generator finds a class that meets these
conditions but is not declared `partial`, unless the class is annotated
with the `DisableGodotGenerators` attribute.
We also generate an `AssemblyHasScripts` assembly attribute which Godot
uses to get all the script classes in the assembly, eliminating the need
for Godot to search them. We can also avoid searching in assemblies that
don't have this attribute. This will be good for performance in the
future once we support multiple assemblies with Godot script classes.
This is an example of what the generated code looks like:
```
using Godot;
namespace Foo {
[ScriptPathAttribute("res://Player.cs")]
// Multiple partial declarations are allowed
[ScriptPathAttribute("res://Foo/Player.cs")]
partial class Player {}
}
[assembly:AssemblyHasScripts(new System.Type[] { typeof(Foo.Player) })]
```
The new attributes replace script metadata which we were generating by
determining the namespace of script classes with a very simple parser.
This fixes several issues with the old approach related to parser
errors and conditional compilation.
It also makes the task part of the MSBuild project build, rather than
a separate step executed by the Godot editor.
This is needed with newer Mono versions, at least with Mono 6.12+
Depends on the following commit from our build scripts:
godotengine/godot-mono-builds@9d75cff174
Main benefits:
- Projects can be built offline. Previously you needed internet
access the first time building to download the packages.
- Changes to packages like Godot.NET.Sdk can be easily tested
before publishing. This was already possible but required
too many manual steps.
- First time builds are a bit faster, as the Sdk package doesn't
need to be downloaded. In practice, the package is very small
so it makes little difference.
Bumped Godot.NET.Sdk to 4.0.0-dev3 in order to enable the
recent changes regarding '.mono/' -> '.godot/mono/'.
- Removed item list that displayed multiple build
configurations launched. Now we only display
the last build that was launched.
- Display build output next to the issues list.
Its visibility can be toggled off/on.
This build output is obtained from the MSBuild
process rather than the MSBuild logger. As such
it displays some MSBuild fatal errors that
previously couldn't be displayed.
- Added a context menu to the issues list with
the option to copy the issue text.
- Replaced the 'Build Project' button in the panel
with a popup menu with the options:
- Build Solution
- Rebuild Solution
- Clean Solution
- The bottom panel button was renamed from 'Mono'
to 'MSBuild' and now display an error/warning icon
if the last build had issues.
Because `Strings OS_OSX::get_name() const` now returns "macOS" (15a9f94346)
The C# GodotTools were still using "OSX" as identifier a few things were borken (e.g. dotnet/msbuild detection).
When NormalizePath was called with an absolute
path (with drive letter) on Windows, it would
prepend a file path separator to the path, e.g.:
'\C:\Program Files\'.
Apparently this was still accepted as a valid
path by DotNetGlob and it stopped working when
we switched to MSBuildGlob.
