mirror of
https://github.com/bevyengine/bevy
synced 2024-11-23 05:03:47 +00:00
1efc762924
# 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))
88 lines
2.7 KiB
Rust
88 lines
2.7 KiB
Rust
//! A shader that reads a mesh's custom vertex attribute.
|
|
|
|
use bevy::{
|
|
pbr::{MaterialPipeline, MaterialPipelineKey},
|
|
prelude::*,
|
|
reflect::{TypePath, TypeUuid},
|
|
render::{
|
|
mesh::{MeshVertexAttribute, MeshVertexBufferLayout},
|
|
render_resource::{
|
|
AsBindGroup, RenderPipelineDescriptor, ShaderRef, SpecializedMeshPipelineError,
|
|
VertexFormat,
|
|
},
|
|
},
|
|
};
|
|
|
|
fn main() {
|
|
App::new()
|
|
.add_plugins(DefaultPlugins)
|
|
.add_plugin(MaterialPlugin::<CustomMaterial>::default())
|
|
.add_systems(Startup, setup)
|
|
.run();
|
|
}
|
|
|
|
// A "high" random id should be used for custom attributes to ensure consistent sorting and avoid collisions with other attributes.
|
|
// See the MeshVertexAttribute docs for more info.
|
|
const ATTRIBUTE_BLEND_COLOR: MeshVertexAttribute =
|
|
MeshVertexAttribute::new("BlendColor", 988540917, VertexFormat::Float32x4);
|
|
|
|
/// set up a simple 3D scene
|
|
fn setup(
|
|
mut commands: Commands,
|
|
mut meshes: ResMut<Assets<Mesh>>,
|
|
mut materials: ResMut<Assets<CustomMaterial>>,
|
|
) {
|
|
let mut mesh = Mesh::from(shape::Cube { size: 1.0 });
|
|
mesh.insert_attribute(
|
|
ATTRIBUTE_BLEND_COLOR,
|
|
// The cube mesh has 24 vertices (6 faces, 4 vertices per face), so we insert one BlendColor for each
|
|
vec![[1.0, 0.0, 0.0, 1.0]; 24],
|
|
);
|
|
|
|
// cube
|
|
commands.spawn(MaterialMeshBundle {
|
|
mesh: meshes.add(mesh),
|
|
transform: Transform::from_xyz(0.0, 0.5, 0.0),
|
|
material: materials.add(CustomMaterial {
|
|
color: Color::WHITE,
|
|
}),
|
|
..default()
|
|
});
|
|
|
|
// camera
|
|
commands.spawn(Camera3dBundle {
|
|
transform: Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
|
|
..default()
|
|
});
|
|
}
|
|
|
|
// This is the struct that will be passed to your shader
|
|
#[derive(AsBindGroup, Debug, Clone, TypeUuid, TypePath)]
|
|
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
|
|
pub struct CustomMaterial {
|
|
#[uniform(0)]
|
|
color: Color,
|
|
}
|
|
|
|
impl Material for CustomMaterial {
|
|
fn vertex_shader() -> ShaderRef {
|
|
"shaders/custom_vertex_attribute.wgsl".into()
|
|
}
|
|
fn fragment_shader() -> ShaderRef {
|
|
"shaders/custom_vertex_attribute.wgsl".into()
|
|
}
|
|
|
|
fn specialize(
|
|
_pipeline: &MaterialPipeline<Self>,
|
|
descriptor: &mut RenderPipelineDescriptor,
|
|
layout: &MeshVertexBufferLayout,
|
|
_key: MaterialPipelineKey<Self>,
|
|
) -> Result<(), SpecializedMeshPipelineError> {
|
|
let vertex_layout = layout.get_layout(&[
|
|
Mesh::ATTRIBUTE_POSITION.at_shader_location(0),
|
|
ATTRIBUTE_BLEND_COLOR.at_shader_location(1),
|
|
])?;
|
|
descriptor.vertex.buffers = vec![vertex_layout];
|
|
Ok(())
|
|
}
|
|
}
|