- Moves interop functions to UnmanagedCallbacks struct that
contains the function pointers and is passed to C#.
- Implements UnmanagedCallbacksGenerator, a C# source generator that
generates the UnmanagedCallbacks struct in C# and the body for the
NativeFuncs methods (their implementation just calls the function
pointer in the UnmanagedCallbacks). The generated methods are needed
because .NET pins byref parameters of native calls, even if they are
'ref struct's, which don't need pinning. The generated methods use
`Unsafe.AsPointer` so that we can benefit from byref parameters
without suffering overhead of pinning.
Co-authored-by: Raul Santos <raulsntos@gmail.com>
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.
Previously we had a placeholder solution called 'Managed' to benefit from
tooling while editing the a part of the C# API.
Later the bindings generator would create the final 'GodotSharp' solution
including these C# files as well as the auto-generated C# API.
Now we replaced the 'Managed' solution with the final 'GodotSharp' solution
which is no longer auto-generated, and the bindings generator only takes
care of the auto-generated C# API.
This has the following benefits:
- It's less confusing as there will no longer be two versions of the same file
(the original and a generated copy of it). Now there's only one.
- We no longer need placeholder for auto-generated API classes, like Node or
Resource. We used them for benefiting from tooling. Now we can just use the
auto-generated API itself.
- Simplifies the build system and bindings generator. Removed lot of code
that is not needed anymore.
Also added a post-build target to the GodotTools project to copy the output to
the data dir. This makes it easy to iterate when doing changes to GodotTools,
as SCons doesn't have to be executed anymore just to copy these new files.
