bevy/examples/shader/array_texture.rs
Matthew Taylor 50a44417ba Derive AsBindGroup Improvements: Better errors, more options, update examples (#5364)
# Objective

- Provide better compile-time errors and diagnostics.
- Add more options to allow more textures types and sampler types.
- Update array_texture example to use upgraded AsBindGroup derive macro.

## Solution

Split out the parsing of the inner struct/field attributes (the inside part of a `#[foo(...)]` attribute) for better clarity

Parse the binding index for all inner attributes, as it is part of all attributes (`#[foo(0, ...)`), then allow each attribute implementer to parse the rest of the attribute metadata as needed. This should make it very trivial to extend/change if needed in the future.

Replaced invocations of `panic!` with the `syn::Error` type, providing fine-grained errors that retains span information. This provides much nicer compile-time errors, and even better IDE errors.

![image](https://user-images.githubusercontent.com/7478134/179452241-6d85d440-4b67-44da-80a7-9d47e8c88b8a.png)

Updated the array_texture example to demonstrate the new changes.

## New AsBindGroup attribute options


### `#[texture(u32, ...)]`
Where `...` is an optional list of arguments.
| Arguments    	| Values                                                         	| Default |
|--------------	|----------------------------------------------------------------	| ----------- |
| dimension = "..."    	| `"1d"`, `"2d"`, `"2d_array"`, `"3d"`, `"cube"`, `"cube_array"` 	|    `"2d"`    |
| sample_type = "..."  	| `"float"`, `"depth"`, `"s_int"` or `"u_int"`                   	|    `"float"`    |
| filterable = ...   	| `true`, `false`                                                	|    `true`     |
| multisampled = ... 	| `true`, `false`                                                	|    `false` |
| visibility(...) 	| `all`, `none`, or a list-combination of `vertex`, `fragment`, `compute` |   `vertex`, `fragment`   |

Example: `#[texture(0, dimension = "2d_array", visibility(vertex, fragment))]`


### `#[sampler(u32, ...)]`
Where `...` is an optional list of arguments.
| Arguments 	| Values                                            	| Default |
|-----------	|---------------------------------------------------	| ----------- |
| sampler_type = "..."   	| `"filtering"`, `"non_filtering"`, `"comparison"`. 	|  `"filtering"`  |
| visibility(...) 	| `all`, `none`, or a list-combination of `vertex`, `fragment`, `compute` |   `vertex`, `fragment`   |

Example: `#[sampler(0, sampler_type = "filtering", visibility(vertex, fragment)]`

## Changelog

- Added more options to `#[texture(...)]` and `#[sampler(...)]` attributes, supporting more kinds of materials. See above for details.
- Upgraded IDE and compile-time error messages.
- Updated array_texture example using the new options.
2022-07-19 22:05:43 +00:00

104 lines
3.0 KiB
Rust

use bevy::{
asset::LoadState,
prelude::*,
reflect::TypeUuid,
render::render_resource::{AsBindGroup, ShaderRef},
};
/// This example illustrates how to create a texture for use with a `texture_2d_array<f32>` shader
/// uniform variable.
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_plugin(MaterialPlugin::<ArrayTextureMaterial>::default())
.add_startup_system(setup)
.add_system(create_array_texture)
.run();
}
struct LoadingTexture {
is_loaded: bool,
handle: Handle<Image>,
}
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
// Start loading the texture.
commands.insert_resource(LoadingTexture {
is_loaded: false,
handle: asset_server.load("textures/array_texture.png"),
});
// light
commands.spawn_bundle(PointLightBundle {
point_light: PointLight {
intensity: 3000.0,
..Default::default()
},
transform: Transform::from_xyz(-3.0, 2.0, -1.0),
..Default::default()
});
commands.spawn_bundle(PointLightBundle {
point_light: PointLight {
intensity: 3000.0,
..Default::default()
},
transform: Transform::from_xyz(3.0, 2.0, 1.0),
..Default::default()
});
// camera
commands.spawn_bundle(Camera3dBundle {
transform: Transform::from_xyz(5.0, 5.0, 5.0).looking_at(Vec3::new(1.5, 0.0, 0.0), Vec3::Y),
..Default::default()
});
}
fn create_array_texture(
mut commands: Commands,
asset_server: Res<AssetServer>,
mut loading_texture: ResMut<LoadingTexture>,
mut images: ResMut<Assets<Image>>,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<ArrayTextureMaterial>>,
) {
if loading_texture.is_loaded
|| asset_server.get_load_state(loading_texture.handle.clone()) != LoadState::Loaded
{
return;
}
loading_texture.is_loaded = true;
let image = images.get_mut(&loading_texture.handle).unwrap();
// Create a new array texture asset from the loaded texture.
let array_layers = 4;
image.reinterpret_stacked_2d_as_array(array_layers);
// Spawn some cubes using the array texture
let mesh_handle = meshes.add(Mesh::from(shape::Cube { size: 1.0 }));
let material_handle = materials.add(ArrayTextureMaterial {
array_texture: loading_texture.handle.clone(),
});
for x in -5..=5 {
commands.spawn_bundle(MaterialMeshBundle {
mesh: mesh_handle.clone(),
material: material_handle.clone(),
transform: Transform::from_xyz(x as f32 + 0.5, 0.0, 0.0),
..Default::default()
});
}
}
#[derive(AsBindGroup, Debug, Clone, TypeUuid)]
#[uuid = "9c5a0ddf-1eaf-41b4-9832-ed736fd26af3"]
struct ArrayTextureMaterial {
#[texture(0, dimension = "2d_array")]
#[sampler(1)]
array_texture: Handle<Image>,
}
impl Material for ArrayTextureMaterial {
fn fragment_shader() -> ShaderRef {
"shaders/array_texture.wgsl".into()
}
}