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