bevy/examples/shader/shader_material.rs
Jakob Hellermann d305e4f026 only use unique type UUIDs (#3579)
Out of curiosity I ran `rg -F -I '#[uuid = "' | sort` to see if there were any duplicate UUIDs, and they were. Now there aren't any.
2022-02-12 19:58:02 +00:00

131 lines
4.5 KiB
Rust

use bevy::{
ecs::system::{lifetimeless::SRes, SystemParamItem},
pbr::MaterialPipeline,
prelude::*,
reflect::TypeUuid,
render::{
render_asset::{PrepareAssetError, RenderAsset},
render_resource::{
std140::{AsStd140, Std140},
BindGroup, BindGroupDescriptor, BindGroupEntry, BindGroupLayout,
BindGroupLayoutDescriptor, BindGroupLayoutEntry, BindingType, Buffer,
BufferBindingType, BufferInitDescriptor, BufferSize, BufferUsages, ShaderStages,
},
renderer::RenderDevice,
},
};
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_plugin(MaterialPlugin::<CustomMaterial>::default())
.add_startup_system(setup)
.run();
}
/// set up a simple 3D scene
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<CustomMaterial>>,
) {
// cube
commands.spawn().insert_bundle(MaterialMeshBundle {
mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
transform: Transform::from_xyz(0.0, 0.5, 0.0),
material: materials.add(CustomMaterial {
color: Color::GREEN,
}),
..Default::default()
});
// camera
commands.spawn_bundle(PerspectiveCameraBundle {
transform: Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
..Default::default()
});
}
// This is the struct that will be passed to your shader
#[derive(Debug, Clone, TypeUuid)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
pub struct CustomMaterial {
color: Color,
}
#[derive(Clone)]
pub struct GpuCustomMaterial {
_buffer: Buffer,
bind_group: BindGroup,
}
// The implementation of [`Material`] needs this impl to work properly.
impl RenderAsset for CustomMaterial {
type ExtractedAsset = CustomMaterial;
type PreparedAsset = GpuCustomMaterial;
type Param = (SRes<RenderDevice>, SRes<MaterialPipeline<Self>>);
fn extract_asset(&self) -> Self::ExtractedAsset {
self.clone()
}
fn prepare_asset(
extracted_asset: Self::ExtractedAsset,
(render_device, material_pipeline): &mut SystemParamItem<Self::Param>,
) -> Result<Self::PreparedAsset, PrepareAssetError<Self::ExtractedAsset>> {
let color = Vec4::from_slice(&extracted_asset.color.as_linear_rgba_f32());
let buffer = render_device.create_buffer_with_data(&BufferInitDescriptor {
contents: color.as_std140().as_bytes(),
label: None,
usage: BufferUsages::UNIFORM | BufferUsages::COPY_DST,
});
let bind_group = render_device.create_bind_group(&BindGroupDescriptor {
entries: &[BindGroupEntry {
binding: 0,
resource: buffer.as_entire_binding(),
}],
label: None,
layout: &material_pipeline.material_layout,
});
Ok(GpuCustomMaterial {
_buffer: buffer,
bind_group,
})
}
}
impl Material for CustomMaterial {
// When creating a custom material, you need to define either a vertex shader, a fragment shader or both.
// If you don't define one of them it will use the default mesh shader which can be found at
// <https://github.com/bevyengine/bevy/blob/latest/crates/bevy_pbr/src/render/mesh.wgsl>
// For this example we don't need a vertex shader
// fn vertex_shader(asset_server: &AssetServer) -> Option<Handle<Shader>> {
// // Use the same path as the fragment shader since wgsl let's you define both shader in the same file
// Some(asset_server.load("shaders/custom_material.wgsl"))
// }
fn fragment_shader(asset_server: &AssetServer) -> Option<Handle<Shader>> {
Some(asset_server.load("shaders/custom_material.wgsl"))
}
fn bind_group(render_asset: &<Self as RenderAsset>::PreparedAsset) -> &BindGroup {
&render_asset.bind_group
}
fn bind_group_layout(render_device: &RenderDevice) -> BindGroupLayout {
render_device.create_bind_group_layout(&BindGroupLayoutDescriptor {
entries: &[BindGroupLayoutEntry {
binding: 0,
visibility: ShaderStages::FRAGMENT,
ty: BindingType::Buffer {
ty: BufferBindingType::Uniform,
has_dynamic_offset: false,
min_binding_size: BufferSize::new(Vec4::std140_size_static() as u64),
},
count: None,
}],
label: None,
})
}
}