bevy/examples/shader/shader_defs.rs
Joona Aalto 0166db33f7
Deprecate shapes in bevy_render::mesh::shape (#11773)
# Objective

#11431 and #11688 implemented meshing support for Bevy's new geometric
primitives. The next step is to deprecate the shapes in
`bevy_render::mesh::shape` and to later remove them completely for 0.14.

## Solution

Deprecate the shapes and reduce code duplication by utilizing the
primitive meshing API for the old shapes where possible.

Note that some shapes have behavior that can't be exactly reproduced
with the new primitives yet:

- `Box` is more of an AABB with min/max extents
- `Plane` supports a subdivision count
- `Quad` has a `flipped` property

These types have not been changed to utilize the new primitives yet.

---

## Changelog

- Deprecated all shapes in `bevy_render::mesh::shape`
- Changed all examples to use new primitives for meshing

## Migration Guide

Bevy has previously used rendering-specific types like `UVSphere` and
`Quad` for primitive mesh shapes. These have now been deprecated to use
the geometric primitives newly introduced in version 0.13.

Some examples:

```rust
let before = meshes.add(shape::Box::new(5.0, 0.15, 5.0));
let after = meshes.add(Cuboid::new(5.0, 0.15, 5.0));

let before = meshes.add(shape::Quad::default());
let after = meshes.add(Rectangle::default());

let before = meshes.add(shape::Plane::from_size(5.0));
// The surface normal can now also be specified when using `new`
let after = meshes.add(Plane3d::default().mesh().size(5.0, 5.0));

let before = meshes.add(
    Mesh::try_from(shape::Icosphere {
        radius: 0.5,
        subdivisions: 5,
    })
    .unwrap(),
);
let after = meshes.add(Sphere::new(0.5).mesh().ico(5).unwrap());
```
2024-02-08 18:01:34 +00:00

100 lines
2.9 KiB
Rust

//! A shader that uses "shaders defs", which selectively toggle parts of a shader.
use bevy::{
pbr::{MaterialPipeline, MaterialPipelineKey},
prelude::*,
reflect::TypePath,
render::{
mesh::MeshVertexBufferLayout,
render_resource::{
AsBindGroup, RenderPipelineDescriptor, ShaderRef, SpecializedMeshPipelineError,
},
},
};
fn main() {
App::new()
.add_plugins((DefaultPlugins, MaterialPlugin::<CustomMaterial>::default()))
.add_systems(Startup, setup)
.run();
}
/// set up a simple 3D scene
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<CustomMaterial>>,
) {
// blue cube
commands.spawn(MaterialMeshBundle {
mesh: meshes.add(Cuboid::default()),
transform: Transform::from_xyz(-1.0, 0.5, 0.0),
material: materials.add(CustomMaterial {
color: Color::BLUE,
is_red: false,
}),
..default()
});
// red cube (with green color overridden by the IS_RED "shader def")
commands.spawn(MaterialMeshBundle {
mesh: meshes.add(Cuboid::default()),
transform: Transform::from_xyz(1.0, 0.5, 0.0),
material: materials.add(CustomMaterial {
color: Color::GREEN,
is_red: true,
}),
..default()
});
// camera
commands.spawn(Camera3dBundle {
transform: Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
..default()
});
}
impl Material for CustomMaterial {
fn fragment_shader() -> ShaderRef {
"shaders/shader_defs.wgsl".into()
}
fn specialize(
_pipeline: &MaterialPipeline<Self>,
descriptor: &mut RenderPipelineDescriptor,
_layout: &MeshVertexBufferLayout,
key: MaterialPipelineKey<Self>,
) -> Result<(), SpecializedMeshPipelineError> {
if key.bind_group_data.is_red {
let fragment = descriptor.fragment.as_mut().unwrap();
fragment.shader_defs.push("IS_RED".into());
}
Ok(())
}
}
// This is the struct that will be passed to your shader
#[derive(Asset, TypePath, AsBindGroup, Debug, Clone)]
#[bind_group_data(CustomMaterialKey)]
struct CustomMaterial {
#[uniform(0)]
color: Color,
is_red: bool,
}
// This key is used to identify a specific permutation of this material pipeline.
// In this case, we specialize on whether or not to configure the "IS_RED" shader def.
// Specialization keys should be kept as small / cheap to hash as possible,
// as they will be used to look up the pipeline for each drawn entity with this material type.
#[derive(Eq, PartialEq, Hash, Clone)]
struct CustomMaterialKey {
is_red: bool,
}
impl From<&CustomMaterial> for CustomMaterialKey {
fn from(material: &CustomMaterial) -> Self {
Self {
is_red: material.is_red,
}
}
}