This allows using generic Godot collections as type arguments for other
generic Godot collections. This also allows generic Godot collections
as parameter or return type in dynamic Callable invocations.
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.
Ensures that the versions always match the Godot version, albeit following
SemVer 2.0 so inserting a dot between "beta" and the build number.
For "stable" status, we omit the suffix as this would be interpreted as a
pre-release build too.
So we have:
| Godot version | Nupkg version |
| -------------- | -------------- |
| 4.0.0-beta | 4.0.0-beta |
| 4.0.0-beta2 | 4.0.0-beta.2 |
| 4.0.0-rc1 | 4.0.0-rc.1 |
| 4.0.0-stable | 4.0.0 |
Android was the last platform to still attempt to disable RTTI (for binary
size), but both the Android editor and now the ICU library used by templates
need RTTI.
There could still be the possibility to support this for non-ICU template
builds (i.e. without the TextServerAdvanced module), but since this isn't one
of the build configurations we test regularly it's pretty risky to keep this
option only for that specific use case. And our code is already littered with
`dynamic_cast`s which weren't guarded with `!defined(NO_SAFE_CAST)`.
If the delegate target is an Object, the connected signal will be registered in that object instead of the middleman. So when that object is destroyed, the signal will be properly disconnected.
Implements https://github.com/godotengine/godot-proposals/issues/3371.
New `target` presets
====================
The `tools` option is removed and `target` changes to use three new presets,
which match the builds users are familiar with. These targets control the
default optimization level and enable editor-specific and debugging code:
- `editor`: Replaces `tools=yes target=release_debug`.
* Defines: `TOOLS_ENABLED`, `DEBUG_ENABLED`, `-O2`/`/O2`
- `template_debug`: Replaces `tools=no target=release_debug`.
* Defines: `DEBUG_ENABLED`, `-O2`/`/O2`
- `template_release`: Replaces `tools=no target=release`.
* Defines: `-O3`/`/O2`
New `dev_build` option
======================
The previous `target=debug` is now replaced by a separate `dev_build=yes`
option, which can be used in combination with either of the three targets,
and changes the following:
- `dev_build`: Defines `DEV_ENABLED`, disables optimization (`-O0`/`/0d`),
enables generating debug symbols, does not define `NDEBUG` so `assert()`
works in thirdparty libraries, adds a `.dev` suffix to the binary name.
Note: Unlike previously, `dev_build` defaults to off so that users who
compile Godot from source get an optimized and small build by default.
Engine contributors should now set `dev_build=yes` in their build scripts or
IDE configuration manually.
Changed binary names
====================
The name of generated binaries and object files are changed too, to follow
this format:
`godot.<platform>.<target>[.dev][.double].<arch>[.<extra_suffix>][.<ext>]`
For example:
- `godot.linuxbsd.editor.dev.arm64`
- `godot.windows.template_release.double.x86_64.mono.exe`
Be sure to update your links/scripts/IDE config accordingly.
More flexible `optimize` and `debug_symbols` options
====================================================
The optimization level and whether to generate debug symbols can be further
specified with the `optimize` and `debug_symbols` options. So the default
values listed above for the various `target` and `dev_build` combinations
are indicative and can be replaced when compiling, e.g.:
`scons p=linuxbsd target=template_debug dev_build=yes optimize=debug`
will make a "debug" export template with dev-only code enabled, `-Og`
optimization level for GCC/Clang, and debug symbols. Perfect for debugging
complex crashes at runtime in an exported project.
