This base implementation is still very barebones but it defines the path
for how exporting will work (at least when embedding the .NET runtime).
Many manual steps are still needed, which should be automatized in the
future. For example, in addition to the API assemblies, now you also
need to copy the GodotPlugins assembly to each game project.
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.
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.
MSBuild Item returns empty strings if an attribute isn't set (which
caused an IndexOutOfRangeException in NormalizePath).
We were treating Excludes incorrectly, Remove directives provide the
intended behaviour in the auto-including csproj format.
Godot.NET.Sdk
-------------
Godot uses its own custom MSBuild Sdk for game
projects. This new Sdk adds its own functionality
on top of 'Microsoft.NET.Sdk'.
The new Sdk is resolved from the NuGet package.
All the default boilerplate was moved from game
projects to the Sdk. The default csproj for
game project can now be as simple as:
```
<Project Sdk="Godot.NET.Sdk/4.0.0-dev2">
<PropertyGroup>
<TargetFramework>netstandard2.1</TargetFramework>
</PropertyGroup>
</Project>
```
Source files are included by automatically so
Godot no longer needs to keep the csproj in sync
when creating new source files.
Define constants
----------------
Godot defines a list of constants for conditional
compilation. When exporting games, this list also
included engine 'features' and platform 'bits'.
There were a few problems with that:
- The 'features' constants were only defined when
exporting games. Not when building the game for
running in the editor player.
- If the project was built externally by an IDE,
the constants wouldn't be defined at all.
The new Sdk assigns default values to these
constants when not built from the Godot editor,
i.e.: when built from an IDE or from the command
line. The default define constants are determined
from the system MSBuild is running on.
However, it's not possible for MSBuild to
determine the set of supported engine features.
It's also not possible to determine if a project
is being built to run on a 32-bit or 64-bit
Godot executable.
As such the 'features' and 'bits' constants had
to be removed.
The benefit of checking those at compile time
was questionable, and they can still be checked
at runtime.
The new list of define constants includes:
- GODOT
- GODOT_<PLATFORM>
Defaults to the platform MSBuild is running on.
- GODOT_<PC/MOBILE/WEB>
- TOOLS
When building with the 'Debug' configuration
(editor and editor player).
- GODOT_REAL_T_IS_DOUBLE
Not defined by default unless $(GodotRealTIsDouble)
is overriden to be 'true'.
.NET Standard
-------------
The target framework of game projects was changed
to 'netstandard2.1'.
By adding a reference to the 'Microsoft.NETFramework.ReferenceAssemblies' nuget
package, we can build projects targeting .NET Framework with the dotnet CLI.
By referencing this package we also don't need to install Mono on Linux/macOS
or .NET Framework on Windows, as the assemblies are taken from the package.
This was a regression from 93d7ec8836 (#38110).
Mono's old implementation of Microsoft.Build hardcodes HasUnsavedChanges to
always return true.
This workaround can be reverted once we switch to official Microsoft.Build.
Make the build system automatically build the C# Api assemblies to be shipped with the editor.
Make the editor, editor player and debug export templates use Api assemblies built with debug symbols.
Always run MSBuild to build the editor tools and Api assemblies when building Godot.
Several bugs fixed related to assembly hot reloading and restoring state.
Fix StringExtensions internal calls not being registered correctly, resulting in MissingMethodException.
