# Objective
- Introduce a stable alternative to
[`std::any::type_name`](https://doc.rust-lang.org/std/any/fn.type_name.html).
- Rewrite of #5805 with heavy inspiration in design.
- On the path to #5830.
- Part of solving #3327.
## Solution
- Add a `TypePath` trait for static stable type path/name information.
- Add a `TypePath` derive macro.
- Add a `impl_type_path` macro for implementing internal and foreign
types in `bevy_reflect`.
---
## Changelog
- Added `TypePath` trait.
- Added `DynamicTypePath` trait and `get_type_path` method to `Reflect`.
- Added a `TypePath` derive macro.
- Added a `bevy_reflect::impl_type_path` for implementing `TypePath` on
internal and foreign types in `bevy_reflect`.
- Changed `bevy_reflect::utility::(Non)GenericTypeInfoCell` to
`(Non)GenericTypedCell<T>` which allows us to be generic over both
`TypeInfo` and `TypePath`.
- `TypePath` is now a supertrait of `Asset`, `Material` and
`Material2d`.
- `impl_reflect_struct` needs a `#[type_path = "..."]` attribute to be
specified.
- `impl_reflect_value` needs to either specify path starting with a
double colon (`::core::option::Option`) or an `in my_crate::foo`
declaration.
- Added `bevy_reflect_derive::ReflectTypePath`.
- Most uses of `Ident` in `bevy_reflect_derive` changed to use
`ReflectTypePath`.
## Migration Guide
- Implementors of `Asset`, `Material` and `Material2d` now also need to
derive `TypePath`.
- Manual implementors of `Reflect` will need to implement the new
`get_type_path` method.
## Open Questions
- [x] ~This PR currently does not migrate any usages of
`std::any::type_name` to use `bevy_reflect::TypePath` to ease the review
process. Should it?~ Migration will be left to a follow-up PR.
- [ ] This PR adds a lot of `#[derive(TypePath)]` and `T: TypePath` to
satisfy new bounds, mostly when deriving `TypeUuid`. Should we make
`TypePath` a supertrait of `TypeUuid`? [Should we remove `TypeUuid` in
favour of
`TypePath`?](2afbd85532 (r961067892))
		
	
			
		
			
				
	
	
		
			82 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
			
		
		
	
	
			82 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
//! A shader that samples a texture with view-independent UV coordinates.
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use bevy::{
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    prelude::*,
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    reflect::{TypePath, TypeUuid},
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    render::render_resource::{AsBindGroup, ShaderRef},
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};
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fn main() {
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    App::new()
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        .add_plugins(DefaultPlugins)
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        .add_plugin(MaterialPlugin::<CustomMaterial>::default())
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        .add_systems(Startup, setup)
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        .add_systems(Update, rotate_camera)
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        .run();
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}
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#[derive(Component)]
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struct MainCamera;
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fn setup(
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    mut commands: Commands,
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    asset_server: Res<AssetServer>,
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    mut meshes: ResMut<Assets<Mesh>>,
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    mut custom_materials: ResMut<Assets<CustomMaterial>>,
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    mut standard_materials: ResMut<Assets<StandardMaterial>>,
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) {
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    commands.spawn(PbrBundle {
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        mesh: meshes.add(shape::Plane::from_size(5.0).into()),
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        material: standard_materials.add(Color::rgb(0.3, 0.5, 0.3).into()),
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        ..default()
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    });
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    commands.spawn(PointLightBundle {
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        transform: Transform::from_xyz(4.0, 8.0, 4.0),
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        ..default()
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    });
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    commands.spawn(MaterialMeshBundle {
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        mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
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        transform: Transform::from_xyz(0.0, 0.5, 0.0),
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        material: custom_materials.add(CustomMaterial {
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            texture: asset_server.load(
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                "models/FlightHelmet/FlightHelmet_Materials_LensesMat_OcclusionRoughMetal.png",
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            ),
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        }),
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        ..default()
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    });
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    // camera
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    commands.spawn((
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        Camera3dBundle {
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            transform: Transform::from_xyz(4.0, 2.5, 4.0).looking_at(Vec3::ZERO, Vec3::Y),
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            ..default()
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        },
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        MainCamera,
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    ));
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}
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fn rotate_camera(mut camera: Query<&mut Transform, With<MainCamera>>, time: Res<Time>) {
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    let cam_transform = camera.single_mut().into_inner();
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    cam_transform.rotate_around(
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        Vec3::ZERO,
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        Quat::from_axis_angle(Vec3::Y, 45f32.to_radians() * time.delta_seconds()),
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    );
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    cam_transform.look_at(Vec3::ZERO, Vec3::Y);
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}
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#[derive(AsBindGroup, Debug, Clone, TypeUuid, TypePath)]
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#[uuid = "b62bb455-a72c-4b56-87bb-81e0554e234f"]
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pub struct CustomMaterial {
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    #[texture(0)]
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    #[sampler(1)]
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    texture: Handle<Image>,
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}
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impl Material for CustomMaterial {
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    fn fragment_shader() -> ShaderRef {
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        "shaders/custom_material_screenspace_texture.wgsl".into()
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    }
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}
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