2024-09-20 19:16:42 +00:00
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// FIXME(15321): solve CI failures, then replace with `#![expect()]`.
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#![allow(missing_docs, reason = "Not all docs are written yet, see #3492.")]
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2024-03-23 02:22:52 +00:00
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#![cfg_attr(docsrs, feature(doc_auto_cfg))]
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2024-02-03 21:40:55 +00:00
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Better Materials: AsBindGroup trait and derive, simpler Material trait (#5053)
# Objective
This PR reworks Bevy's Material system, making the user experience of defining Materials _much_ nicer. Bevy's previous material system leaves a lot to be desired:
* Materials require manually implementing the `RenderAsset` trait, which involves manually generating the bind group, handling gpu buffer data transfer, looking up image textures, etc. Even the simplest single-texture material involves writing ~80 unnecessary lines of code. This was never the long term plan.
* There are two material traits, which is confusing, hard to document, and often redundant: `Material` and `SpecializedMaterial`. `Material` implicitly implements `SpecializedMaterial`, and `SpecializedMaterial` is used in most high level apis to support both use cases. Most users shouldn't need to think about specialization at all (I consider it a "power-user tool"), so the fact that `SpecializedMaterial` is front-and-center in our apis is a miss.
* Implementing either material trait involves a lot of "type soup". The "prepared asset" parameter is particularly heinous: `&<Self as RenderAsset>::PreparedAsset`. Defining vertex and fragment shaders is also more verbose than it needs to be.
## Solution
Say hello to the new `Material` system:
```rust
#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
pub struct CoolMaterial {
#[uniform(0)]
color: Color,
#[texture(1)]
#[sampler(2)]
color_texture: Handle<Image>,
}
impl Material for CoolMaterial {
fn fragment_shader() -> ShaderRef {
"cool_material.wgsl".into()
}
}
```
Thats it! This same material would have required [~80 lines of complicated "type heavy" code](https://github.com/bevyengine/bevy/blob/v0.7.0/examples/shader/shader_material.rs) in the old Material system. Now it is just 14 lines of simple, readable code.
This is thanks to a new consolidated `Material` trait and the new `AsBindGroup` trait / derive.
### The new `Material` trait
The old "split" `Material` and `SpecializedMaterial` traits have been removed in favor of a new consolidated `Material` trait. All of the functions on the trait are optional.
The difficulty of implementing `Material` has been reduced by simplifying dataflow and removing type complexity:
```rust
// Old
impl Material for CustomMaterial {
fn fragment_shader(asset_server: &AssetServer) -> Option<Handle<Shader>> {
Some(asset_server.load("custom_material.wgsl"))
}
fn alpha_mode(render_asset: &<Self as RenderAsset>::PreparedAsset) -> AlphaMode {
render_asset.alpha_mode
}
}
// New
impl Material for CustomMaterial {
fn fragment_shader() -> ShaderRef {
"custom_material.wgsl".into()
}
fn alpha_mode(&self) -> AlphaMode {
self.alpha_mode
}
}
```
Specialization is still supported, but it is hidden by default under the `specialize()` function (more on this later).
### The `AsBindGroup` trait / derive
The `Material` trait now requires the `AsBindGroup` derive. This can be implemented manually relatively easily, but deriving it will almost always be preferable.
Field attributes like `uniform` and `texture` are used to define which fields should be bindings,
what their binding type is, and what index they should be bound at:
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
#[texture(1)]
#[sampler(2)]
color_texture: Handle<Image>,
}
```
In WGSL shaders, the binding looks like this:
```wgsl
struct CoolMaterial {
color: vec4<f32>;
};
[[group(1), binding(0)]]
var<uniform> material: CoolMaterial;
[[group(1), binding(1)]]
var color_texture: texture_2d<f32>;
[[group(1), binding(2)]]
var color_sampler: sampler;
```
Note that the "group" index is determined by the usage context. It is not defined in `AsBindGroup`. Bevy material bind groups are bound to group 1.
The following field-level attributes are supported:
* `uniform(BINDING_INDEX)`
* The field will be converted to a shader-compatible type using the `ShaderType` trait, written to a `Buffer`, and bound as a uniform. It can also be derived for custom structs.
* `texture(BINDING_INDEX)`
* This field's `Handle<Image>` will be used to look up the matching `Texture` gpu resource, which will be bound as a texture in shaders. The field will be assumed to implement `Into<Option<Handle<Image>>>`. In practice, most fields should be a `Handle<Image>` or `Option<Handle<Image>>`. If the value of an `Option<Handle<Image>>` is `None`, the new `FallbackImage` resource will be used instead. This attribute can be used in conjunction with a `sampler` binding attribute (with a different binding index).
* `sampler(BINDING_INDEX)`
* Behaves exactly like the `texture` attribute, but sets the Image's sampler binding instead of the texture.
Note that fields without field-level binding attributes will be ignored.
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
this_field_is_ignored: String,
}
```
As mentioned above, `Option<Handle<Image>>` is also supported:
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
#[texture(1)]
#[sampler(2)]
color_texture: Option<Handle<Image>>,
}
```
This is useful if you want a texture to be optional. When the value is `None`, the `FallbackImage` will be used for the binding instead, which defaults to "pure white".
Field uniforms with the same binding index will be combined into a single binding:
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
#[uniform(0)]
roughness: f32,
}
```
In WGSL shaders, the binding would look like this:
```wgsl
struct CoolMaterial {
color: vec4<f32>;
roughness: f32;
};
[[group(1), binding(0)]]
var<uniform> material: CoolMaterial;
```
Some less common scenarios will require "struct-level" attributes. These are the currently supported struct-level attributes:
* `uniform(BINDING_INDEX, ConvertedShaderType)`
* Similar to the field-level `uniform` attribute, but instead the entire `AsBindGroup` value is converted to `ConvertedShaderType`, which must implement `ShaderType`. This is useful if more complicated conversion logic is required.
* `bind_group_data(DataType)`
* The `AsBindGroup` type will be converted to some `DataType` using `Into<DataType>` and stored as `AsBindGroup::Data` as part of the `AsBindGroup::as_bind_group` call. This is useful if data needs to be stored alongside the generated bind group, such as a unique identifier for a material's bind group. The most common use case for this attribute is "shader pipeline specialization".
The previous `CoolMaterial` example illustrating "combining multiple field-level uniform attributes with the same binding index" can
also be equivalently represented with a single struct-level uniform attribute:
```rust
#[derive(AsBindGroup)]
#[uniform(0, CoolMaterialUniform)]
struct CoolMaterial {
color: Color,
roughness: f32,
}
#[derive(ShaderType)]
struct CoolMaterialUniform {
color: Color,
roughness: f32,
}
impl From<&CoolMaterial> for CoolMaterialUniform {
fn from(material: &CoolMaterial) -> CoolMaterialUniform {
CoolMaterialUniform {
color: material.color,
roughness: material.roughness,
}
}
}
```
### Material Specialization
Material shader specialization is now _much_ simpler:
```rust
#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
#[bind_group_data(CoolMaterialKey)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
is_red: bool,
}
#[derive(Copy, Clone, Hash, Eq, PartialEq)]
struct CoolMaterialKey {
is_red: bool,
}
impl From<&CoolMaterial> for CoolMaterialKey {
fn from(material: &CoolMaterial) -> CoolMaterialKey {
CoolMaterialKey {
is_red: material.is_red,
}
}
}
impl Material for CoolMaterial {
fn fragment_shader() -> ShaderRef {
"cool_material.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".to_string());
}
Ok(())
}
}
```
Setting `bind_group_data` is not required for specialization (it defaults to `()`). Scenarios like "custom vertex attributes" also benefit from this system:
```rust
impl Material for CustomMaterial {
fn vertex_shader() -> ShaderRef {
"custom_material.wgsl".into()
}
fn fragment_shader() -> ShaderRef {
"custom_material.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(())
}
}
```
### Ported `StandardMaterial` to the new `Material` system
Bevy's built-in PBR material uses the new Material system (including the AsBindGroup derive):
```rust
#[derive(AsBindGroup, Debug, Clone, TypeUuid)]
#[uuid = "7494888b-c082-457b-aacf-517228cc0c22"]
#[bind_group_data(StandardMaterialKey)]
#[uniform(0, StandardMaterialUniform)]
pub struct StandardMaterial {
pub base_color: Color,
#[texture(1)]
#[sampler(2)]
pub base_color_texture: Option<Handle<Image>>,
/* other fields omitted for brevity */
```
### Ported Bevy examples to the new `Material` system
The overall complexity of Bevy's "custom shader examples" has gone down significantly. Take a look at the diffs if you want a dopamine spike.
Please note that while this PR has a net increase in "lines of code", most of those extra lines come from added documentation. There is a significant reduction
in the overall complexity of the code (even accounting for the new derive logic).
---
## Changelog
### Added
* `AsBindGroup` trait and derive, which make it much easier to transfer data to the gpu and generate bind groups for a given type.
### Changed
* The old `Material` and `SpecializedMaterial` traits have been replaced by a consolidated (much simpler) `Material` trait. Materials no longer implement `RenderAsset`.
* `StandardMaterial` was ported to the new material system. There are no user-facing api changes to the `StandardMaterial` struct api, but it now implements `AsBindGroup` and `Material` instead of `RenderAsset` and `SpecializedMaterial`.
## Migration Guide
The Material system has been reworked to be much simpler. We've removed a lot of boilerplate with the new `AsBindGroup` derive and the `Material` trait is simpler as well!
### Bevy 0.7 (old)
```rust
#[derive(Debug, Clone, TypeUuid)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
pub struct CustomMaterial {
color: Color,
color_texture: Handle<Image>,
}
#[derive(Clone)]
pub struct GpuCustomMaterial {
_buffer: Buffer,
bind_group: BindGroup,
}
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 byte_buffer = [0u8; Vec4::SIZE.get() as usize];
let mut buffer = encase::UniformBuffer::new(byte_buffer);
buffer.write(&color).unwrap();
let buffer = render_device.create_buffer_with_data(&BufferInitDescriptor {
contents: buffer.as_ref(),
label: None,
usage: BufferUsages::UNIFORM | BufferUsages::COPY_DST,
});
let (texture_view, texture_sampler) = if let Some(result) = material_pipeline
.mesh_pipeline
.get_image_texture(gpu_images, &Some(extracted_asset.color_texture.clone()))
{
result
} else {
return Err(PrepareAssetError::RetryNextUpdate(extracted_asset));
};
let bind_group = render_device.create_bind_group(&BindGroupDescriptor {
entries: &[
BindGroupEntry {
binding: 0,
resource: buffer.as_entire_binding(),
},
BindGroupEntry {
binding: 0,
resource: BindingResource::TextureView(texture_view),
},
BindGroupEntry {
binding: 1,
resource: BindingResource::Sampler(texture_sampler),
},
],
label: None,
layout: &material_pipeline.material_layout,
});
Ok(GpuCustomMaterial {
_buffer: buffer,
bind_group,
})
}
}
impl Material for CustomMaterial {
fn fragment_shader(asset_server: &AssetServer) -> Option<Handle<Shader>> {
Some(asset_server.load("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: Some(Vec4::min_size()),
},
count: None,
},
BindGroupLayoutEntry {
binding: 1,
visibility: ShaderStages::FRAGMENT,
ty: BindingType::Texture {
multisampled: false,
sample_type: TextureSampleType::Float { filterable: true },
view_dimension: TextureViewDimension::D2Array,
},
count: None,
},
BindGroupLayoutEntry {
binding: 2,
visibility: ShaderStages::FRAGMENT,
ty: BindingType::Sampler(SamplerBindingType::Filtering),
count: None,
},
],
label: None,
})
}
}
```
### Bevy 0.8 (new)
```rust
impl Material for CustomMaterial {
fn fragment_shader() -> ShaderRef {
"custom_material.wgsl".into()
}
}
#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
pub struct CustomMaterial {
#[uniform(0)]
color: Color,
#[texture(1)]
#[sampler(2)]
color_texture: Handle<Image>,
}
```
## Future Work
* Add support for more binding types (cubemaps, buffers, etc). This PR intentionally includes a bare minimum number of binding types to keep "reviewability" in check.
* Consider optionally eliding binding indices using binding names. `AsBindGroup` could pass in (optional?) reflection info as a "hint".
* This would make it possible for the derive to do this:
```rust
#[derive(AsBindGroup)]
pub struct CustomMaterial {
#[uniform]
color: Color,
#[texture]
#[sampler]
color_texture: Option<Handle<Image>>,
alpha_mode: AlphaMode,
}
```
* Or this
```rust
#[derive(AsBindGroup)]
pub struct CustomMaterial {
#[binding]
color: Color,
#[binding]
color_texture: Option<Handle<Image>>,
alpha_mode: AlphaMode,
}
```
* Or even this (if we flip to "include bindings by default")
```rust
#[derive(AsBindGroup)]
pub struct CustomMaterial {
color: Color,
color_texture: Option<Handle<Image>>,
#[binding(ignore)]
alpha_mode: AlphaMode,
}
```
* If we add the option to define custom draw functions for materials (which could be done in a type-erased way), I think that would be enough to support extra non-material bindings. Worth considering!
2022-06-30 23:48:46 +00:00
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mod as_bind_group;
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2023-01-30 18:12:16 +00:00
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mod extract_component;
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2022-05-30 18:36:03 +00:00
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mod extract_resource;
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RenderGraph Labelization (#10644)
# Objective
The whole `Cow<'static, str>` naming for nodes and subgraphs in
`RenderGraph` is a mess.
## Solution
Replaces hardcoded and potentially overlapping strings for nodes and
subgraphs inside `RenderGraph` with bevy's labelsystem.
---
## Changelog
* Two new labels: `RenderLabel` and `RenderSubGraph`.
* Replaced all uses for hardcoded strings with those labels
* Moved `Taa` label from its own mod to all the other `Labels3d`
* `add_render_graph_edges` now needs a tuple of labels
* Moved `ScreenSpaceAmbientOcclusion` label from its own mod with the
`ShadowPass` label to `LabelsPbr`
* Removed `NodeId`
* Renamed `Edges.id()` to `Edges.label()`
* Removed `NodeLabel`
* Changed examples according to the new label system
* Introduced new `RenderLabel`s: `Labels2d`, `Labels3d`, `LabelsPbr`,
`LabelsUi`
* Introduced new `RenderSubGraph`s: `SubGraph2d`, `SubGraph3d`,
`SubGraphUi`
* Removed `Reflect` and `Default` derive from `CameraRenderGraph`
component struct
* Improved some error messages
## Migration Guide
For Nodes and SubGraphs, instead of using hardcoded strings, you now
pass labels, which can be derived with structs and enums.
```rs
// old
#[derive(Default)]
struct MyRenderNode;
impl MyRenderNode {
pub const NAME: &'static str = "my_render_node"
}
render_app
.add_render_graph_node::<ViewNodeRunner<MyRenderNode>>(
core_3d::graph::NAME,
MyRenderNode::NAME,
)
.add_render_graph_edges(
core_3d::graph::NAME,
&[
core_3d::graph::node::TONEMAPPING,
MyRenderNode::NAME,
core_3d::graph::node::END_MAIN_PASS_POST_PROCESSING,
],
);
// new
use bevy::core_pipeline::core_3d::graph::{Labels3d, SubGraph3d};
#[derive(Debug, Hash, PartialEq, Eq, Clone, RenderLabel)]
pub struct MyRenderLabel;
#[derive(Default)]
struct MyRenderNode;
render_app
.add_render_graph_node::<ViewNodeRunner<MyRenderNode>>(
SubGraph3d,
MyRenderLabel,
)
.add_render_graph_edges(
SubGraph3d,
(
Labels3d::Tonemapping,
MyRenderLabel,
Labels3d::EndMainPassPostProcessing,
),
);
```
### SubGraphs
#### in `bevy_core_pipeline::core_2d::graph`
| old string-based path | new label |
|-----------------------|-----------|
| `NAME` | `SubGraph2d` |
#### in `bevy_core_pipeline::core_3d::graph`
| old string-based path | new label |
|-----------------------|-----------|
| `NAME` | `SubGraph3d` |
#### in `bevy_ui::render`
| old string-based path | new label |
|-----------------------|-----------|
| `draw_ui_graph::NAME` | `graph::SubGraphUi` |
### Nodes
#### in `bevy_core_pipeline::core_2d::graph`
| old string-based path | new label |
|-----------------------|-----------|
| `node::MSAA_WRITEBACK` | `Labels2d::MsaaWriteback` |
| `node::MAIN_PASS` | `Labels2d::MainPass` |
| `node::BLOOM` | `Labels2d::Bloom` |
| `node::TONEMAPPING` | `Labels2d::Tonemapping` |
| `node::FXAA` | `Labels2d::Fxaa` |
| `node::UPSCALING` | `Labels2d::Upscaling` |
| `node::CONTRAST_ADAPTIVE_SHARPENING` |
`Labels2d::ConstrastAdaptiveSharpening` |
| `node::END_MAIN_PASS_POST_PROCESSING` |
`Labels2d::EndMainPassPostProcessing` |
#### in `bevy_core_pipeline::core_3d::graph`
| old string-based path | new label |
|-----------------------|-----------|
| `node::MSAA_WRITEBACK` | `Labels3d::MsaaWriteback` |
| `node::PREPASS` | `Labels3d::Prepass` |
| `node::DEFERRED_PREPASS` | `Labels3d::DeferredPrepass` |
| `node::COPY_DEFERRED_LIGHTING_ID` | `Labels3d::CopyDeferredLightingId`
|
| `node::END_PREPASSES` | `Labels3d::EndPrepasses` |
| `node::START_MAIN_PASS` | `Labels3d::StartMainPass` |
| `node::MAIN_OPAQUE_PASS` | `Labels3d::MainOpaquePass` |
| `node::MAIN_TRANSMISSIVE_PASS` | `Labels3d::MainTransmissivePass` |
| `node::MAIN_TRANSPARENT_PASS` | `Labels3d::MainTransparentPass` |
| `node::END_MAIN_PASS` | `Labels3d::EndMainPass` |
| `node::BLOOM` | `Labels3d::Bloom` |
| `node::TONEMAPPING` | `Labels3d::Tonemapping` |
| `node::FXAA` | `Labels3d::Fxaa` |
| `node::UPSCALING` | `Labels3d::Upscaling` |
| `node::CONTRAST_ADAPTIVE_SHARPENING` |
`Labels3d::ContrastAdaptiveSharpening` |
| `node::END_MAIN_PASS_POST_PROCESSING` |
`Labels3d::EndMainPassPostProcessing` |
#### in `bevy_core_pipeline`
| old string-based path | new label |
|-----------------------|-----------|
| `taa::draw_3d_graph::node::TAA` | `Labels3d::Taa` |
#### in `bevy_pbr`
| old string-based path | new label |
|-----------------------|-----------|
| `draw_3d_graph::node::SHADOW_PASS` | `LabelsPbr::ShadowPass` |
| `ssao::draw_3d_graph::node::SCREEN_SPACE_AMBIENT_OCCLUSION` |
`LabelsPbr::ScreenSpaceAmbientOcclusion` |
| `deferred::DEFFERED_LIGHTING_PASS` | `LabelsPbr::DeferredLightingPass`
|
#### in `bevy_render`
| old string-based path | new label |
|-----------------------|-----------|
| `main_graph::node::CAMERA_DRIVER` | `graph::CameraDriverLabel` |
#### in `bevy_ui::render`
| old string-based path | new label |
|-----------------------|-----------|
| `draw_ui_graph::node::UI_PASS` | `graph::LabelsUi::UiPass` |
---
## Future work
* Make `NodeSlot`s also use types. Ideally, we have an enum with unit
variants where every variant resembles one slot. Then to make sure you
are using the right slot enum and make rust-analyzer play nicely with
it, we should make an associated type in the `Node` trait. With today's
system, we can introduce 3rd party slots to a node, and i wasnt sure if
this was used, so I didn't do this in this PR.
## Unresolved Questions
When looking at the `post_processing` example, we have a struct for the
label and a struct for the node, this seems like boilerplate and on
discord, @IceSentry (sowy for the ping)
[asked](https://discord.com/channels/691052431525675048/743663924229963868/1175197016947699742)
if a node could automatically introduce a label (or i completely
misunderstood that). The problem with that is, that nodes like
`EmptyNode` exist multiple times *inside the same* (sub)graph, so there
we need extern labels to distinguish between those. Hopefully we can
find a way to reduce boilerplate and still have everything unique. For
EmptyNode, we could maybe make a macro which implements an "empty node"
for a type, but for nodes which contain code and need to be present
multiple times, this could get nasty...
2024-01-31 14:51:19 +00:00
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|
|
use bevy_macro_utils::{derive_label, BevyManifest};
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2022-05-30 18:36:03 +00:00
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use proc_macro::TokenStream;
|
RenderGraph Labelization (#10644)
# Objective
The whole `Cow<'static, str>` naming for nodes and subgraphs in
`RenderGraph` is a mess.
## Solution
Replaces hardcoded and potentially overlapping strings for nodes and
subgraphs inside `RenderGraph` with bevy's labelsystem.
---
## Changelog
* Two new labels: `RenderLabel` and `RenderSubGraph`.
* Replaced all uses for hardcoded strings with those labels
* Moved `Taa` label from its own mod to all the other `Labels3d`
* `add_render_graph_edges` now needs a tuple of labels
* Moved `ScreenSpaceAmbientOcclusion` label from its own mod with the
`ShadowPass` label to `LabelsPbr`
* Removed `NodeId`
* Renamed `Edges.id()` to `Edges.label()`
* Removed `NodeLabel`
* Changed examples according to the new label system
* Introduced new `RenderLabel`s: `Labels2d`, `Labels3d`, `LabelsPbr`,
`LabelsUi`
* Introduced new `RenderSubGraph`s: `SubGraph2d`, `SubGraph3d`,
`SubGraphUi`
* Removed `Reflect` and `Default` derive from `CameraRenderGraph`
component struct
* Improved some error messages
## Migration Guide
For Nodes and SubGraphs, instead of using hardcoded strings, you now
pass labels, which can be derived with structs and enums.
```rs
// old
#[derive(Default)]
struct MyRenderNode;
impl MyRenderNode {
pub const NAME: &'static str = "my_render_node"
}
render_app
.add_render_graph_node::<ViewNodeRunner<MyRenderNode>>(
core_3d::graph::NAME,
MyRenderNode::NAME,
)
.add_render_graph_edges(
core_3d::graph::NAME,
&[
core_3d::graph::node::TONEMAPPING,
MyRenderNode::NAME,
core_3d::graph::node::END_MAIN_PASS_POST_PROCESSING,
],
);
// new
use bevy::core_pipeline::core_3d::graph::{Labels3d, SubGraph3d};
#[derive(Debug, Hash, PartialEq, Eq, Clone, RenderLabel)]
pub struct MyRenderLabel;
#[derive(Default)]
struct MyRenderNode;
render_app
.add_render_graph_node::<ViewNodeRunner<MyRenderNode>>(
SubGraph3d,
MyRenderLabel,
)
.add_render_graph_edges(
SubGraph3d,
(
Labels3d::Tonemapping,
MyRenderLabel,
Labels3d::EndMainPassPostProcessing,
),
);
```
### SubGraphs
#### in `bevy_core_pipeline::core_2d::graph`
| old string-based path | new label |
|-----------------------|-----------|
| `NAME` | `SubGraph2d` |
#### in `bevy_core_pipeline::core_3d::graph`
| old string-based path | new label |
|-----------------------|-----------|
| `NAME` | `SubGraph3d` |
#### in `bevy_ui::render`
| old string-based path | new label |
|-----------------------|-----------|
| `draw_ui_graph::NAME` | `graph::SubGraphUi` |
### Nodes
#### in `bevy_core_pipeline::core_2d::graph`
| old string-based path | new label |
|-----------------------|-----------|
| `node::MSAA_WRITEBACK` | `Labels2d::MsaaWriteback` |
| `node::MAIN_PASS` | `Labels2d::MainPass` |
| `node::BLOOM` | `Labels2d::Bloom` |
| `node::TONEMAPPING` | `Labels2d::Tonemapping` |
| `node::FXAA` | `Labels2d::Fxaa` |
| `node::UPSCALING` | `Labels2d::Upscaling` |
| `node::CONTRAST_ADAPTIVE_SHARPENING` |
`Labels2d::ConstrastAdaptiveSharpening` |
| `node::END_MAIN_PASS_POST_PROCESSING` |
`Labels2d::EndMainPassPostProcessing` |
#### in `bevy_core_pipeline::core_3d::graph`
| old string-based path | new label |
|-----------------------|-----------|
| `node::MSAA_WRITEBACK` | `Labels3d::MsaaWriteback` |
| `node::PREPASS` | `Labels3d::Prepass` |
| `node::DEFERRED_PREPASS` | `Labels3d::DeferredPrepass` |
| `node::COPY_DEFERRED_LIGHTING_ID` | `Labels3d::CopyDeferredLightingId`
|
| `node::END_PREPASSES` | `Labels3d::EndPrepasses` |
| `node::START_MAIN_PASS` | `Labels3d::StartMainPass` |
| `node::MAIN_OPAQUE_PASS` | `Labels3d::MainOpaquePass` |
| `node::MAIN_TRANSMISSIVE_PASS` | `Labels3d::MainTransmissivePass` |
| `node::MAIN_TRANSPARENT_PASS` | `Labels3d::MainTransparentPass` |
| `node::END_MAIN_PASS` | `Labels3d::EndMainPass` |
| `node::BLOOM` | `Labels3d::Bloom` |
| `node::TONEMAPPING` | `Labels3d::Tonemapping` |
| `node::FXAA` | `Labels3d::Fxaa` |
| `node::UPSCALING` | `Labels3d::Upscaling` |
| `node::CONTRAST_ADAPTIVE_SHARPENING` |
`Labels3d::ContrastAdaptiveSharpening` |
| `node::END_MAIN_PASS_POST_PROCESSING` |
`Labels3d::EndMainPassPostProcessing` |
#### in `bevy_core_pipeline`
| old string-based path | new label |
|-----------------------|-----------|
| `taa::draw_3d_graph::node::TAA` | `Labels3d::Taa` |
#### in `bevy_pbr`
| old string-based path | new label |
|-----------------------|-----------|
| `draw_3d_graph::node::SHADOW_PASS` | `LabelsPbr::ShadowPass` |
| `ssao::draw_3d_graph::node::SCREEN_SPACE_AMBIENT_OCCLUSION` |
`LabelsPbr::ScreenSpaceAmbientOcclusion` |
| `deferred::DEFFERED_LIGHTING_PASS` | `LabelsPbr::DeferredLightingPass`
|
#### in `bevy_render`
| old string-based path | new label |
|-----------------------|-----------|
| `main_graph::node::CAMERA_DRIVER` | `graph::CameraDriverLabel` |
#### in `bevy_ui::render`
| old string-based path | new label |
|-----------------------|-----------|
| `draw_ui_graph::node::UI_PASS` | `graph::LabelsUi::UiPass` |
---
## Future work
* Make `NodeSlot`s also use types. Ideally, we have an enum with unit
variants where every variant resembles one slot. Then to make sure you
are using the right slot enum and make rust-analyzer play nicely with
it, we should make an associated type in the `Node` trait. With today's
system, we can introduce 3rd party slots to a node, and i wasnt sure if
this was used, so I didn't do this in this PR.
## Unresolved Questions
When looking at the `post_processing` example, we have a struct for the
label and a struct for the node, this seems like boilerplate and on
discord, @IceSentry (sowy for the ping)
[asked](https://discord.com/channels/691052431525675048/743663924229963868/1175197016947699742)
if a node could automatically introduce a label (or i completely
misunderstood that). The problem with that is, that nodes like
`EmptyNode` exist multiple times *inside the same* (sub)graph, so there
we need extern labels to distinguish between those. Hopefully we can
find a way to reduce boilerplate and still have everything unique. For
EmptyNode, we could maybe make a macro which implements an "empty node"
for a type, but for nodes which contain code and need to be present
multiple times, this could get nasty...
2024-01-31 14:51:19 +00:00
|
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use quote::format_ident;
|
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.
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
|
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|
use syn::{parse_macro_input, DeriveInput};
|
2022-05-30 18:36:03 +00:00
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|
pub(crate) fn bevy_render_path() -> syn::Path {
|
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BevyManifest::default()
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.maybe_get_path("bevy_render")
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// NOTE: If the derivation is within bevy_render, then we need to return 'crate'
|
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.unwrap_or_else(|| BevyManifest::parse_str("crate"))
|
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}
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#[proc_macro_derive(ExtractResource)]
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pub fn derive_extract_resource(input: TokenStream) -> TokenStream {
|
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extract_resource::derive_extract_resource(input)
|
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}
|
Better Materials: AsBindGroup trait and derive, simpler Material trait (#5053)
# Objective
This PR reworks Bevy's Material system, making the user experience of defining Materials _much_ nicer. Bevy's previous material system leaves a lot to be desired:
* Materials require manually implementing the `RenderAsset` trait, which involves manually generating the bind group, handling gpu buffer data transfer, looking up image textures, etc. Even the simplest single-texture material involves writing ~80 unnecessary lines of code. This was never the long term plan.
* There are two material traits, which is confusing, hard to document, and often redundant: `Material` and `SpecializedMaterial`. `Material` implicitly implements `SpecializedMaterial`, and `SpecializedMaterial` is used in most high level apis to support both use cases. Most users shouldn't need to think about specialization at all (I consider it a "power-user tool"), so the fact that `SpecializedMaterial` is front-and-center in our apis is a miss.
* Implementing either material trait involves a lot of "type soup". The "prepared asset" parameter is particularly heinous: `&<Self as RenderAsset>::PreparedAsset`. Defining vertex and fragment shaders is also more verbose than it needs to be.
## Solution
Say hello to the new `Material` system:
```rust
#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
pub struct CoolMaterial {
#[uniform(0)]
color: Color,
#[texture(1)]
#[sampler(2)]
color_texture: Handle<Image>,
}
impl Material for CoolMaterial {
fn fragment_shader() -> ShaderRef {
"cool_material.wgsl".into()
}
}
```
Thats it! This same material would have required [~80 lines of complicated "type heavy" code](https://github.com/bevyengine/bevy/blob/v0.7.0/examples/shader/shader_material.rs) in the old Material system. Now it is just 14 lines of simple, readable code.
This is thanks to a new consolidated `Material` trait and the new `AsBindGroup` trait / derive.
### The new `Material` trait
The old "split" `Material` and `SpecializedMaterial` traits have been removed in favor of a new consolidated `Material` trait. All of the functions on the trait are optional.
The difficulty of implementing `Material` has been reduced by simplifying dataflow and removing type complexity:
```rust
// Old
impl Material for CustomMaterial {
fn fragment_shader(asset_server: &AssetServer) -> Option<Handle<Shader>> {
Some(asset_server.load("custom_material.wgsl"))
}
fn alpha_mode(render_asset: &<Self as RenderAsset>::PreparedAsset) -> AlphaMode {
render_asset.alpha_mode
}
}
// New
impl Material for CustomMaterial {
fn fragment_shader() -> ShaderRef {
"custom_material.wgsl".into()
}
fn alpha_mode(&self) -> AlphaMode {
self.alpha_mode
}
}
```
Specialization is still supported, but it is hidden by default under the `specialize()` function (more on this later).
### The `AsBindGroup` trait / derive
The `Material` trait now requires the `AsBindGroup` derive. This can be implemented manually relatively easily, but deriving it will almost always be preferable.
Field attributes like `uniform` and `texture` are used to define which fields should be bindings,
what their binding type is, and what index they should be bound at:
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
#[texture(1)]
#[sampler(2)]
color_texture: Handle<Image>,
}
```
In WGSL shaders, the binding looks like this:
```wgsl
struct CoolMaterial {
color: vec4<f32>;
};
[[group(1), binding(0)]]
var<uniform> material: CoolMaterial;
[[group(1), binding(1)]]
var color_texture: texture_2d<f32>;
[[group(1), binding(2)]]
var color_sampler: sampler;
```
Note that the "group" index is determined by the usage context. It is not defined in `AsBindGroup`. Bevy material bind groups are bound to group 1.
The following field-level attributes are supported:
* `uniform(BINDING_INDEX)`
* The field will be converted to a shader-compatible type using the `ShaderType` trait, written to a `Buffer`, and bound as a uniform. It can also be derived for custom structs.
* `texture(BINDING_INDEX)`
* This field's `Handle<Image>` will be used to look up the matching `Texture` gpu resource, which will be bound as a texture in shaders. The field will be assumed to implement `Into<Option<Handle<Image>>>`. In practice, most fields should be a `Handle<Image>` or `Option<Handle<Image>>`. If the value of an `Option<Handle<Image>>` is `None`, the new `FallbackImage` resource will be used instead. This attribute can be used in conjunction with a `sampler` binding attribute (with a different binding index).
* `sampler(BINDING_INDEX)`
* Behaves exactly like the `texture` attribute, but sets the Image's sampler binding instead of the texture.
Note that fields without field-level binding attributes will be ignored.
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
this_field_is_ignored: String,
}
```
As mentioned above, `Option<Handle<Image>>` is also supported:
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
#[texture(1)]
#[sampler(2)]
color_texture: Option<Handle<Image>>,
}
```
This is useful if you want a texture to be optional. When the value is `None`, the `FallbackImage` will be used for the binding instead, which defaults to "pure white".
Field uniforms with the same binding index will be combined into a single binding:
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
#[uniform(0)]
roughness: f32,
}
```
In WGSL shaders, the binding would look like this:
```wgsl
struct CoolMaterial {
color: vec4<f32>;
roughness: f32;
};
[[group(1), binding(0)]]
var<uniform> material: CoolMaterial;
```
Some less common scenarios will require "struct-level" attributes. These are the currently supported struct-level attributes:
* `uniform(BINDING_INDEX, ConvertedShaderType)`
* Similar to the field-level `uniform` attribute, but instead the entire `AsBindGroup` value is converted to `ConvertedShaderType`, which must implement `ShaderType`. This is useful if more complicated conversion logic is required.
* `bind_group_data(DataType)`
* The `AsBindGroup` type will be converted to some `DataType` using `Into<DataType>` and stored as `AsBindGroup::Data` as part of the `AsBindGroup::as_bind_group` call. This is useful if data needs to be stored alongside the generated bind group, such as a unique identifier for a material's bind group. The most common use case for this attribute is "shader pipeline specialization".
The previous `CoolMaterial` example illustrating "combining multiple field-level uniform attributes with the same binding index" can
also be equivalently represented with a single struct-level uniform attribute:
```rust
#[derive(AsBindGroup)]
#[uniform(0, CoolMaterialUniform)]
struct CoolMaterial {
color: Color,
roughness: f32,
}
#[derive(ShaderType)]
struct CoolMaterialUniform {
color: Color,
roughness: f32,
}
impl From<&CoolMaterial> for CoolMaterialUniform {
fn from(material: &CoolMaterial) -> CoolMaterialUniform {
CoolMaterialUniform {
color: material.color,
roughness: material.roughness,
}
}
}
```
### Material Specialization
Material shader specialization is now _much_ simpler:
```rust
#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
#[bind_group_data(CoolMaterialKey)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
is_red: bool,
}
#[derive(Copy, Clone, Hash, Eq, PartialEq)]
struct CoolMaterialKey {
is_red: bool,
}
impl From<&CoolMaterial> for CoolMaterialKey {
fn from(material: &CoolMaterial) -> CoolMaterialKey {
CoolMaterialKey {
is_red: material.is_red,
}
}
}
impl Material for CoolMaterial {
fn fragment_shader() -> ShaderRef {
"cool_material.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".to_string());
}
Ok(())
}
}
```
Setting `bind_group_data` is not required for specialization (it defaults to `()`). Scenarios like "custom vertex attributes" also benefit from this system:
```rust
impl Material for CustomMaterial {
fn vertex_shader() -> ShaderRef {
"custom_material.wgsl".into()
}
fn fragment_shader() -> ShaderRef {
"custom_material.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(())
}
}
```
### Ported `StandardMaterial` to the new `Material` system
Bevy's built-in PBR material uses the new Material system (including the AsBindGroup derive):
```rust
#[derive(AsBindGroup, Debug, Clone, TypeUuid)]
#[uuid = "7494888b-c082-457b-aacf-517228cc0c22"]
#[bind_group_data(StandardMaterialKey)]
#[uniform(0, StandardMaterialUniform)]
pub struct StandardMaterial {
pub base_color: Color,
#[texture(1)]
#[sampler(2)]
pub base_color_texture: Option<Handle<Image>>,
/* other fields omitted for brevity */
```
### Ported Bevy examples to the new `Material` system
The overall complexity of Bevy's "custom shader examples" has gone down significantly. Take a look at the diffs if you want a dopamine spike.
Please note that while this PR has a net increase in "lines of code", most of those extra lines come from added documentation. There is a significant reduction
in the overall complexity of the code (even accounting for the new derive logic).
---
## Changelog
### Added
* `AsBindGroup` trait and derive, which make it much easier to transfer data to the gpu and generate bind groups for a given type.
### Changed
* The old `Material` and `SpecializedMaterial` traits have been replaced by a consolidated (much simpler) `Material` trait. Materials no longer implement `RenderAsset`.
* `StandardMaterial` was ported to the new material system. There are no user-facing api changes to the `StandardMaterial` struct api, but it now implements `AsBindGroup` and `Material` instead of `RenderAsset` and `SpecializedMaterial`.
## Migration Guide
The Material system has been reworked to be much simpler. We've removed a lot of boilerplate with the new `AsBindGroup` derive and the `Material` trait is simpler as well!
### Bevy 0.7 (old)
```rust
#[derive(Debug, Clone, TypeUuid)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
pub struct CustomMaterial {
color: Color,
color_texture: Handle<Image>,
}
#[derive(Clone)]
pub struct GpuCustomMaterial {
_buffer: Buffer,
bind_group: BindGroup,
}
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 byte_buffer = [0u8; Vec4::SIZE.get() as usize];
let mut buffer = encase::UniformBuffer::new(byte_buffer);
buffer.write(&color).unwrap();
let buffer = render_device.create_buffer_with_data(&BufferInitDescriptor {
contents: buffer.as_ref(),
label: None,
usage: BufferUsages::UNIFORM | BufferUsages::COPY_DST,
});
let (texture_view, texture_sampler) = if let Some(result) = material_pipeline
.mesh_pipeline
.get_image_texture(gpu_images, &Some(extracted_asset.color_texture.clone()))
{
result
} else {
return Err(PrepareAssetError::RetryNextUpdate(extracted_asset));
};
let bind_group = render_device.create_bind_group(&BindGroupDescriptor {
entries: &[
BindGroupEntry {
binding: 0,
resource: buffer.as_entire_binding(),
},
BindGroupEntry {
binding: 0,
resource: BindingResource::TextureView(texture_view),
},
BindGroupEntry {
binding: 1,
resource: BindingResource::Sampler(texture_sampler),
},
],
label: None,
layout: &material_pipeline.material_layout,
});
Ok(GpuCustomMaterial {
_buffer: buffer,
bind_group,
})
}
}
impl Material for CustomMaterial {
fn fragment_shader(asset_server: &AssetServer) -> Option<Handle<Shader>> {
Some(asset_server.load("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: Some(Vec4::min_size()),
},
count: None,
},
BindGroupLayoutEntry {
binding: 1,
visibility: ShaderStages::FRAGMENT,
ty: BindingType::Texture {
multisampled: false,
sample_type: TextureSampleType::Float { filterable: true },
view_dimension: TextureViewDimension::D2Array,
},
count: None,
},
BindGroupLayoutEntry {
binding: 2,
visibility: ShaderStages::FRAGMENT,
ty: BindingType::Sampler(SamplerBindingType::Filtering),
count: None,
},
],
label: None,
})
}
}
```
### Bevy 0.8 (new)
```rust
impl Material for CustomMaterial {
fn fragment_shader() -> ShaderRef {
"custom_material.wgsl".into()
}
}
#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
pub struct CustomMaterial {
#[uniform(0)]
color: Color,
#[texture(1)]
#[sampler(2)]
color_texture: Handle<Image>,
}
```
## Future Work
* Add support for more binding types (cubemaps, buffers, etc). This PR intentionally includes a bare minimum number of binding types to keep "reviewability" in check.
* Consider optionally eliding binding indices using binding names. `AsBindGroup` could pass in (optional?) reflection info as a "hint".
* This would make it possible for the derive to do this:
```rust
#[derive(AsBindGroup)]
pub struct CustomMaterial {
#[uniform]
color: Color,
#[texture]
#[sampler]
color_texture: Option<Handle<Image>>,
alpha_mode: AlphaMode,
}
```
* Or this
```rust
#[derive(AsBindGroup)]
pub struct CustomMaterial {
#[binding]
color: Color,
#[binding]
color_texture: Option<Handle<Image>>,
alpha_mode: AlphaMode,
}
```
* Or even this (if we flip to "include bindings by default")
```rust
#[derive(AsBindGroup)]
pub struct CustomMaterial {
color: Color,
color_texture: Option<Handle<Image>>,
#[binding(ignore)]
alpha_mode: AlphaMode,
}
```
* If we add the option to define custom draw functions for materials (which could be done in a type-erased way), I think that would be enough to support extra non-material bindings. Worth considering!
2022-06-30 23:48:46 +00:00
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2023-01-30 18:12:16 +00:00
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/// Implements `ExtractComponent` trait for a component.
|
2024-09-24 11:42:59 +00:00
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///
|
2023-01-30 18:12:16 +00:00
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/// The component must implement [`Clone`].
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/// The component will be extracted into the render world via cloning.
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/// Note that this only enables extraction of the component, it does not execute the extraction.
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|
/// See `ExtractComponentPlugin` to actually perform the extraction.
|
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///
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/// If you only want to extract a component conditionally, you may use the `extract_component_filter` attribute.
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///
|
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/// # Example
|
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///
|
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|
/// ```no_compile
|
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|
/// use bevy_ecs::component::Component;
|
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/// use bevy_render_macros::ExtractComponent;
|
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|
///
|
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|
/// #[derive(Component, Clone, ExtractComponent)]
|
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|
/// #[extract_component_filter(With<Camera>)]
|
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/// pub struct Foo {
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/// pub should_foo: bool,
|
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/// }
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///
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/// // Without a filter (unconditional).
|
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|
/// #[derive(Component, Clone, ExtractComponent)]
|
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|
/// pub struct Bar {
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/// pub should_bar: bool,
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/// }
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/// ```
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#[proc_macro_derive(ExtractComponent, attributes(extract_component_filter))]
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pub fn derive_extract_component(input: TokenStream) -> TokenStream {
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extract_component::derive_extract_component(input)
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}
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2023-01-09 18:50:55 +00:00
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#[proc_macro_derive(
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AsBindGroup,
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2024-01-21 18:47:13 +00:00
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attributes(uniform, storage_texture, texture, sampler, bind_group_data, storage)
|
2023-01-09 18:50:55 +00:00
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)]
|
Better Materials: AsBindGroup trait and derive, simpler Material trait (#5053)
# Objective
This PR reworks Bevy's Material system, making the user experience of defining Materials _much_ nicer. Bevy's previous material system leaves a lot to be desired:
* Materials require manually implementing the `RenderAsset` trait, which involves manually generating the bind group, handling gpu buffer data transfer, looking up image textures, etc. Even the simplest single-texture material involves writing ~80 unnecessary lines of code. This was never the long term plan.
* There are two material traits, which is confusing, hard to document, and often redundant: `Material` and `SpecializedMaterial`. `Material` implicitly implements `SpecializedMaterial`, and `SpecializedMaterial` is used in most high level apis to support both use cases. Most users shouldn't need to think about specialization at all (I consider it a "power-user tool"), so the fact that `SpecializedMaterial` is front-and-center in our apis is a miss.
* Implementing either material trait involves a lot of "type soup". The "prepared asset" parameter is particularly heinous: `&<Self as RenderAsset>::PreparedAsset`. Defining vertex and fragment shaders is also more verbose than it needs to be.
## Solution
Say hello to the new `Material` system:
```rust
#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
pub struct CoolMaterial {
#[uniform(0)]
color: Color,
#[texture(1)]
#[sampler(2)]
color_texture: Handle<Image>,
}
impl Material for CoolMaterial {
fn fragment_shader() -> ShaderRef {
"cool_material.wgsl".into()
}
}
```
Thats it! This same material would have required [~80 lines of complicated "type heavy" code](https://github.com/bevyengine/bevy/blob/v0.7.0/examples/shader/shader_material.rs) in the old Material system. Now it is just 14 lines of simple, readable code.
This is thanks to a new consolidated `Material` trait and the new `AsBindGroup` trait / derive.
### The new `Material` trait
The old "split" `Material` and `SpecializedMaterial` traits have been removed in favor of a new consolidated `Material` trait. All of the functions on the trait are optional.
The difficulty of implementing `Material` has been reduced by simplifying dataflow and removing type complexity:
```rust
// Old
impl Material for CustomMaterial {
fn fragment_shader(asset_server: &AssetServer) -> Option<Handle<Shader>> {
Some(asset_server.load("custom_material.wgsl"))
}
fn alpha_mode(render_asset: &<Self as RenderAsset>::PreparedAsset) -> AlphaMode {
render_asset.alpha_mode
}
}
// New
impl Material for CustomMaterial {
fn fragment_shader() -> ShaderRef {
"custom_material.wgsl".into()
}
fn alpha_mode(&self) -> AlphaMode {
self.alpha_mode
}
}
```
Specialization is still supported, but it is hidden by default under the `specialize()` function (more on this later).
### The `AsBindGroup` trait / derive
The `Material` trait now requires the `AsBindGroup` derive. This can be implemented manually relatively easily, but deriving it will almost always be preferable.
Field attributes like `uniform` and `texture` are used to define which fields should be bindings,
what their binding type is, and what index they should be bound at:
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
#[texture(1)]
#[sampler(2)]
color_texture: Handle<Image>,
}
```
In WGSL shaders, the binding looks like this:
```wgsl
struct CoolMaterial {
color: vec4<f32>;
};
[[group(1), binding(0)]]
var<uniform> material: CoolMaterial;
[[group(1), binding(1)]]
var color_texture: texture_2d<f32>;
[[group(1), binding(2)]]
var color_sampler: sampler;
```
Note that the "group" index is determined by the usage context. It is not defined in `AsBindGroup`. Bevy material bind groups are bound to group 1.
The following field-level attributes are supported:
* `uniform(BINDING_INDEX)`
* The field will be converted to a shader-compatible type using the `ShaderType` trait, written to a `Buffer`, and bound as a uniform. It can also be derived for custom structs.
* `texture(BINDING_INDEX)`
* This field's `Handle<Image>` will be used to look up the matching `Texture` gpu resource, which will be bound as a texture in shaders. The field will be assumed to implement `Into<Option<Handle<Image>>>`. In practice, most fields should be a `Handle<Image>` or `Option<Handle<Image>>`. If the value of an `Option<Handle<Image>>` is `None`, the new `FallbackImage` resource will be used instead. This attribute can be used in conjunction with a `sampler` binding attribute (with a different binding index).
* `sampler(BINDING_INDEX)`
* Behaves exactly like the `texture` attribute, but sets the Image's sampler binding instead of the texture.
Note that fields without field-level binding attributes will be ignored.
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
this_field_is_ignored: String,
}
```
As mentioned above, `Option<Handle<Image>>` is also supported:
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
#[texture(1)]
#[sampler(2)]
color_texture: Option<Handle<Image>>,
}
```
This is useful if you want a texture to be optional. When the value is `None`, the `FallbackImage` will be used for the binding instead, which defaults to "pure white".
Field uniforms with the same binding index will be combined into a single binding:
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
#[uniform(0)]
roughness: f32,
}
```
In WGSL shaders, the binding would look like this:
```wgsl
struct CoolMaterial {
color: vec4<f32>;
roughness: f32;
};
[[group(1), binding(0)]]
var<uniform> material: CoolMaterial;
```
Some less common scenarios will require "struct-level" attributes. These are the currently supported struct-level attributes:
* `uniform(BINDING_INDEX, ConvertedShaderType)`
* Similar to the field-level `uniform` attribute, but instead the entire `AsBindGroup` value is converted to `ConvertedShaderType`, which must implement `ShaderType`. This is useful if more complicated conversion logic is required.
* `bind_group_data(DataType)`
* The `AsBindGroup` type will be converted to some `DataType` using `Into<DataType>` and stored as `AsBindGroup::Data` as part of the `AsBindGroup::as_bind_group` call. This is useful if data needs to be stored alongside the generated bind group, such as a unique identifier for a material's bind group. The most common use case for this attribute is "shader pipeline specialization".
The previous `CoolMaterial` example illustrating "combining multiple field-level uniform attributes with the same binding index" can
also be equivalently represented with a single struct-level uniform attribute:
```rust
#[derive(AsBindGroup)]
#[uniform(0, CoolMaterialUniform)]
struct CoolMaterial {
color: Color,
roughness: f32,
}
#[derive(ShaderType)]
struct CoolMaterialUniform {
color: Color,
roughness: f32,
}
impl From<&CoolMaterial> for CoolMaterialUniform {
fn from(material: &CoolMaterial) -> CoolMaterialUniform {
CoolMaterialUniform {
color: material.color,
roughness: material.roughness,
}
}
}
```
### Material Specialization
Material shader specialization is now _much_ simpler:
```rust
#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
#[bind_group_data(CoolMaterialKey)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
is_red: bool,
}
#[derive(Copy, Clone, Hash, Eq, PartialEq)]
struct CoolMaterialKey {
is_red: bool,
}
impl From<&CoolMaterial> for CoolMaterialKey {
fn from(material: &CoolMaterial) -> CoolMaterialKey {
CoolMaterialKey {
is_red: material.is_red,
}
}
}
impl Material for CoolMaterial {
fn fragment_shader() -> ShaderRef {
"cool_material.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".to_string());
}
Ok(())
}
}
```
Setting `bind_group_data` is not required for specialization (it defaults to `()`). Scenarios like "custom vertex attributes" also benefit from this system:
```rust
impl Material for CustomMaterial {
fn vertex_shader() -> ShaderRef {
"custom_material.wgsl".into()
}
fn fragment_shader() -> ShaderRef {
"custom_material.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(())
}
}
```
### Ported `StandardMaterial` to the new `Material` system
Bevy's built-in PBR material uses the new Material system (including the AsBindGroup derive):
```rust
#[derive(AsBindGroup, Debug, Clone, TypeUuid)]
#[uuid = "7494888b-c082-457b-aacf-517228cc0c22"]
#[bind_group_data(StandardMaterialKey)]
#[uniform(0, StandardMaterialUniform)]
pub struct StandardMaterial {
pub base_color: Color,
#[texture(1)]
#[sampler(2)]
pub base_color_texture: Option<Handle<Image>>,
/* other fields omitted for brevity */
```
### Ported Bevy examples to the new `Material` system
The overall complexity of Bevy's "custom shader examples" has gone down significantly. Take a look at the diffs if you want a dopamine spike.
Please note that while this PR has a net increase in "lines of code", most of those extra lines come from added documentation. There is a significant reduction
in the overall complexity of the code (even accounting for the new derive logic).
---
## Changelog
### Added
* `AsBindGroup` trait and derive, which make it much easier to transfer data to the gpu and generate bind groups for a given type.
### Changed
* The old `Material` and `SpecializedMaterial` traits have been replaced by a consolidated (much simpler) `Material` trait. Materials no longer implement `RenderAsset`.
* `StandardMaterial` was ported to the new material system. There are no user-facing api changes to the `StandardMaterial` struct api, but it now implements `AsBindGroup` and `Material` instead of `RenderAsset` and `SpecializedMaterial`.
## Migration Guide
The Material system has been reworked to be much simpler. We've removed a lot of boilerplate with the new `AsBindGroup` derive and the `Material` trait is simpler as well!
### Bevy 0.7 (old)
```rust
#[derive(Debug, Clone, TypeUuid)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
pub struct CustomMaterial {
color: Color,
color_texture: Handle<Image>,
}
#[derive(Clone)]
pub struct GpuCustomMaterial {
_buffer: Buffer,
bind_group: BindGroup,
}
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 byte_buffer = [0u8; Vec4::SIZE.get() as usize];
let mut buffer = encase::UniformBuffer::new(byte_buffer);
buffer.write(&color).unwrap();
let buffer = render_device.create_buffer_with_data(&BufferInitDescriptor {
contents: buffer.as_ref(),
label: None,
usage: BufferUsages::UNIFORM | BufferUsages::COPY_DST,
});
let (texture_view, texture_sampler) = if let Some(result) = material_pipeline
.mesh_pipeline
.get_image_texture(gpu_images, &Some(extracted_asset.color_texture.clone()))
{
result
} else {
return Err(PrepareAssetError::RetryNextUpdate(extracted_asset));
};
let bind_group = render_device.create_bind_group(&BindGroupDescriptor {
entries: &[
BindGroupEntry {
binding: 0,
resource: buffer.as_entire_binding(),
},
BindGroupEntry {
binding: 0,
resource: BindingResource::TextureView(texture_view),
},
BindGroupEntry {
binding: 1,
resource: BindingResource::Sampler(texture_sampler),
},
],
label: None,
layout: &material_pipeline.material_layout,
});
Ok(GpuCustomMaterial {
_buffer: buffer,
bind_group,
})
}
}
impl Material for CustomMaterial {
fn fragment_shader(asset_server: &AssetServer) -> Option<Handle<Shader>> {
Some(asset_server.load("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: Some(Vec4::min_size()),
},
count: None,
},
BindGroupLayoutEntry {
binding: 1,
visibility: ShaderStages::FRAGMENT,
ty: BindingType::Texture {
multisampled: false,
sample_type: TextureSampleType::Float { filterable: true },
view_dimension: TextureViewDimension::D2Array,
},
count: None,
},
BindGroupLayoutEntry {
binding: 2,
visibility: ShaderStages::FRAGMENT,
ty: BindingType::Sampler(SamplerBindingType::Filtering),
count: None,
},
],
label: None,
})
}
}
```
### Bevy 0.8 (new)
```rust
impl Material for CustomMaterial {
fn fragment_shader() -> ShaderRef {
"custom_material.wgsl".into()
}
}
#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
pub struct CustomMaterial {
#[uniform(0)]
color: Color,
#[texture(1)]
#[sampler(2)]
color_texture: Handle<Image>,
}
```
## Future Work
* Add support for more binding types (cubemaps, buffers, etc). This PR intentionally includes a bare minimum number of binding types to keep "reviewability" in check.
* Consider optionally eliding binding indices using binding names. `AsBindGroup` could pass in (optional?) reflection info as a "hint".
* This would make it possible for the derive to do this:
```rust
#[derive(AsBindGroup)]
pub struct CustomMaterial {
#[uniform]
color: Color,
#[texture]
#[sampler]
color_texture: Option<Handle<Image>>,
alpha_mode: AlphaMode,
}
```
* Or this
```rust
#[derive(AsBindGroup)]
pub struct CustomMaterial {
#[binding]
color: Color,
#[binding]
color_texture: Option<Handle<Image>>,
alpha_mode: AlphaMode,
}
```
* Or even this (if we flip to "include bindings by default")
```rust
#[derive(AsBindGroup)]
pub struct CustomMaterial {
color: Color,
color_texture: Option<Handle<Image>>,
#[binding(ignore)]
alpha_mode: AlphaMode,
}
```
* If we add the option to define custom draw functions for materials (which could be done in a type-erased way), I think that would be enough to support extra non-material bindings. Worth considering!
2022-06-30 23:48:46 +00:00
|
|
|
pub fn derive_as_bind_group(input: TokenStream) -> TokenStream {
|
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.
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
|
|
|
let input = parse_macro_input!(input as DeriveInput);
|
|
|
|
|
|
|
|
|
|
as_bind_group::derive_as_bind_group(input).unwrap_or_else(|err| err.to_compile_error().into())
|
Better Materials: AsBindGroup trait and derive, simpler Material trait (#5053)
# Objective
This PR reworks Bevy's Material system, making the user experience of defining Materials _much_ nicer. Bevy's previous material system leaves a lot to be desired:
* Materials require manually implementing the `RenderAsset` trait, which involves manually generating the bind group, handling gpu buffer data transfer, looking up image textures, etc. Even the simplest single-texture material involves writing ~80 unnecessary lines of code. This was never the long term plan.
* There are two material traits, which is confusing, hard to document, and often redundant: `Material` and `SpecializedMaterial`. `Material` implicitly implements `SpecializedMaterial`, and `SpecializedMaterial` is used in most high level apis to support both use cases. Most users shouldn't need to think about specialization at all (I consider it a "power-user tool"), so the fact that `SpecializedMaterial` is front-and-center in our apis is a miss.
* Implementing either material trait involves a lot of "type soup". The "prepared asset" parameter is particularly heinous: `&<Self as RenderAsset>::PreparedAsset`. Defining vertex and fragment shaders is also more verbose than it needs to be.
## Solution
Say hello to the new `Material` system:
```rust
#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
pub struct CoolMaterial {
#[uniform(0)]
color: Color,
#[texture(1)]
#[sampler(2)]
color_texture: Handle<Image>,
}
impl Material for CoolMaterial {
fn fragment_shader() -> ShaderRef {
"cool_material.wgsl".into()
}
}
```
Thats it! This same material would have required [~80 lines of complicated "type heavy" code](https://github.com/bevyengine/bevy/blob/v0.7.0/examples/shader/shader_material.rs) in the old Material system. Now it is just 14 lines of simple, readable code.
This is thanks to a new consolidated `Material` trait and the new `AsBindGroup` trait / derive.
### The new `Material` trait
The old "split" `Material` and `SpecializedMaterial` traits have been removed in favor of a new consolidated `Material` trait. All of the functions on the trait are optional.
The difficulty of implementing `Material` has been reduced by simplifying dataflow and removing type complexity:
```rust
// Old
impl Material for CustomMaterial {
fn fragment_shader(asset_server: &AssetServer) -> Option<Handle<Shader>> {
Some(asset_server.load("custom_material.wgsl"))
}
fn alpha_mode(render_asset: &<Self as RenderAsset>::PreparedAsset) -> AlphaMode {
render_asset.alpha_mode
}
}
// New
impl Material for CustomMaterial {
fn fragment_shader() -> ShaderRef {
"custom_material.wgsl".into()
}
fn alpha_mode(&self) -> AlphaMode {
self.alpha_mode
}
}
```
Specialization is still supported, but it is hidden by default under the `specialize()` function (more on this later).
### The `AsBindGroup` trait / derive
The `Material` trait now requires the `AsBindGroup` derive. This can be implemented manually relatively easily, but deriving it will almost always be preferable.
Field attributes like `uniform` and `texture` are used to define which fields should be bindings,
what their binding type is, and what index they should be bound at:
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
#[texture(1)]
#[sampler(2)]
color_texture: Handle<Image>,
}
```
In WGSL shaders, the binding looks like this:
```wgsl
struct CoolMaterial {
color: vec4<f32>;
};
[[group(1), binding(0)]]
var<uniform> material: CoolMaterial;
[[group(1), binding(1)]]
var color_texture: texture_2d<f32>;
[[group(1), binding(2)]]
var color_sampler: sampler;
```
Note that the "group" index is determined by the usage context. It is not defined in `AsBindGroup`. Bevy material bind groups are bound to group 1.
The following field-level attributes are supported:
* `uniform(BINDING_INDEX)`
* The field will be converted to a shader-compatible type using the `ShaderType` trait, written to a `Buffer`, and bound as a uniform. It can also be derived for custom structs.
* `texture(BINDING_INDEX)`
* This field's `Handle<Image>` will be used to look up the matching `Texture` gpu resource, which will be bound as a texture in shaders. The field will be assumed to implement `Into<Option<Handle<Image>>>`. In practice, most fields should be a `Handle<Image>` or `Option<Handle<Image>>`. If the value of an `Option<Handle<Image>>` is `None`, the new `FallbackImage` resource will be used instead. This attribute can be used in conjunction with a `sampler` binding attribute (with a different binding index).
* `sampler(BINDING_INDEX)`
* Behaves exactly like the `texture` attribute, but sets the Image's sampler binding instead of the texture.
Note that fields without field-level binding attributes will be ignored.
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
this_field_is_ignored: String,
}
```
As mentioned above, `Option<Handle<Image>>` is also supported:
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
#[texture(1)]
#[sampler(2)]
color_texture: Option<Handle<Image>>,
}
```
This is useful if you want a texture to be optional. When the value is `None`, the `FallbackImage` will be used for the binding instead, which defaults to "pure white".
Field uniforms with the same binding index will be combined into a single binding:
```rust
#[derive(AsBindGroup)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
#[uniform(0)]
roughness: f32,
}
```
In WGSL shaders, the binding would look like this:
```wgsl
struct CoolMaterial {
color: vec4<f32>;
roughness: f32;
};
[[group(1), binding(0)]]
var<uniform> material: CoolMaterial;
```
Some less common scenarios will require "struct-level" attributes. These are the currently supported struct-level attributes:
* `uniform(BINDING_INDEX, ConvertedShaderType)`
* Similar to the field-level `uniform` attribute, but instead the entire `AsBindGroup` value is converted to `ConvertedShaderType`, which must implement `ShaderType`. This is useful if more complicated conversion logic is required.
* `bind_group_data(DataType)`
* The `AsBindGroup` type will be converted to some `DataType` using `Into<DataType>` and stored as `AsBindGroup::Data` as part of the `AsBindGroup::as_bind_group` call. This is useful if data needs to be stored alongside the generated bind group, such as a unique identifier for a material's bind group. The most common use case for this attribute is "shader pipeline specialization".
The previous `CoolMaterial` example illustrating "combining multiple field-level uniform attributes with the same binding index" can
also be equivalently represented with a single struct-level uniform attribute:
```rust
#[derive(AsBindGroup)]
#[uniform(0, CoolMaterialUniform)]
struct CoolMaterial {
color: Color,
roughness: f32,
}
#[derive(ShaderType)]
struct CoolMaterialUniform {
color: Color,
roughness: f32,
}
impl From<&CoolMaterial> for CoolMaterialUniform {
fn from(material: &CoolMaterial) -> CoolMaterialUniform {
CoolMaterialUniform {
color: material.color,
roughness: material.roughness,
}
}
}
```
### Material Specialization
Material shader specialization is now _much_ simpler:
```rust
#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
#[bind_group_data(CoolMaterialKey)]
struct CoolMaterial {
#[uniform(0)]
color: Color,
is_red: bool,
}
#[derive(Copy, Clone, Hash, Eq, PartialEq)]
struct CoolMaterialKey {
is_red: bool,
}
impl From<&CoolMaterial> for CoolMaterialKey {
fn from(material: &CoolMaterial) -> CoolMaterialKey {
CoolMaterialKey {
is_red: material.is_red,
}
}
}
impl Material for CoolMaterial {
fn fragment_shader() -> ShaderRef {
"cool_material.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".to_string());
}
Ok(())
}
}
```
Setting `bind_group_data` is not required for specialization (it defaults to `()`). Scenarios like "custom vertex attributes" also benefit from this system:
```rust
impl Material for CustomMaterial {
fn vertex_shader() -> ShaderRef {
"custom_material.wgsl".into()
}
fn fragment_shader() -> ShaderRef {
"custom_material.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(())
}
}
```
### Ported `StandardMaterial` to the new `Material` system
Bevy's built-in PBR material uses the new Material system (including the AsBindGroup derive):
```rust
#[derive(AsBindGroup, Debug, Clone, TypeUuid)]
#[uuid = "7494888b-c082-457b-aacf-517228cc0c22"]
#[bind_group_data(StandardMaterialKey)]
#[uniform(0, StandardMaterialUniform)]
pub struct StandardMaterial {
pub base_color: Color,
#[texture(1)]
#[sampler(2)]
pub base_color_texture: Option<Handle<Image>>,
/* other fields omitted for brevity */
```
### Ported Bevy examples to the new `Material` system
The overall complexity of Bevy's "custom shader examples" has gone down significantly. Take a look at the diffs if you want a dopamine spike.
Please note that while this PR has a net increase in "lines of code", most of those extra lines come from added documentation. There is a significant reduction
in the overall complexity of the code (even accounting for the new derive logic).
---
## Changelog
### Added
* `AsBindGroup` trait and derive, which make it much easier to transfer data to the gpu and generate bind groups for a given type.
### Changed
* The old `Material` and `SpecializedMaterial` traits have been replaced by a consolidated (much simpler) `Material` trait. Materials no longer implement `RenderAsset`.
* `StandardMaterial` was ported to the new material system. There are no user-facing api changes to the `StandardMaterial` struct api, but it now implements `AsBindGroup` and `Material` instead of `RenderAsset` and `SpecializedMaterial`.
## Migration Guide
The Material system has been reworked to be much simpler. We've removed a lot of boilerplate with the new `AsBindGroup` derive and the `Material` trait is simpler as well!
### Bevy 0.7 (old)
```rust
#[derive(Debug, Clone, TypeUuid)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
pub struct CustomMaterial {
color: Color,
color_texture: Handle<Image>,
}
#[derive(Clone)]
pub struct GpuCustomMaterial {
_buffer: Buffer,
bind_group: BindGroup,
}
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 byte_buffer = [0u8; Vec4::SIZE.get() as usize];
let mut buffer = encase::UniformBuffer::new(byte_buffer);
buffer.write(&color).unwrap();
let buffer = render_device.create_buffer_with_data(&BufferInitDescriptor {
contents: buffer.as_ref(),
label: None,
usage: BufferUsages::UNIFORM | BufferUsages::COPY_DST,
});
let (texture_view, texture_sampler) = if let Some(result) = material_pipeline
.mesh_pipeline
.get_image_texture(gpu_images, &Some(extracted_asset.color_texture.clone()))
{
result
} else {
return Err(PrepareAssetError::RetryNextUpdate(extracted_asset));
};
let bind_group = render_device.create_bind_group(&BindGroupDescriptor {
entries: &[
BindGroupEntry {
binding: 0,
resource: buffer.as_entire_binding(),
},
BindGroupEntry {
binding: 0,
resource: BindingResource::TextureView(texture_view),
},
BindGroupEntry {
binding: 1,
resource: BindingResource::Sampler(texture_sampler),
},
],
label: None,
layout: &material_pipeline.material_layout,
});
Ok(GpuCustomMaterial {
_buffer: buffer,
bind_group,
})
}
}
impl Material for CustomMaterial {
fn fragment_shader(asset_server: &AssetServer) -> Option<Handle<Shader>> {
Some(asset_server.load("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: Some(Vec4::min_size()),
},
count: None,
},
BindGroupLayoutEntry {
binding: 1,
visibility: ShaderStages::FRAGMENT,
ty: BindingType::Texture {
multisampled: false,
sample_type: TextureSampleType::Float { filterable: true },
view_dimension: TextureViewDimension::D2Array,
},
count: None,
},
BindGroupLayoutEntry {
binding: 2,
visibility: ShaderStages::FRAGMENT,
ty: BindingType::Sampler(SamplerBindingType::Filtering),
count: None,
},
],
label: None,
})
}
}
```
### Bevy 0.8 (new)
```rust
impl Material for CustomMaterial {
fn fragment_shader() -> ShaderRef {
"custom_material.wgsl".into()
}
}
#[derive(AsBindGroup, TypeUuid, Debug, Clone)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
pub struct CustomMaterial {
#[uniform(0)]
color: Color,
#[texture(1)]
#[sampler(2)]
color_texture: Handle<Image>,
}
```
## Future Work
* Add support for more binding types (cubemaps, buffers, etc). This PR intentionally includes a bare minimum number of binding types to keep "reviewability" in check.
* Consider optionally eliding binding indices using binding names. `AsBindGroup` could pass in (optional?) reflection info as a "hint".
* This would make it possible for the derive to do this:
```rust
#[derive(AsBindGroup)]
pub struct CustomMaterial {
#[uniform]
color: Color,
#[texture]
#[sampler]
color_texture: Option<Handle<Image>>,
alpha_mode: AlphaMode,
}
```
* Or this
```rust
#[derive(AsBindGroup)]
pub struct CustomMaterial {
#[binding]
color: Color,
#[binding]
color_texture: Option<Handle<Image>>,
alpha_mode: AlphaMode,
}
```
* Or even this (if we flip to "include bindings by default")
```rust
#[derive(AsBindGroup)]
pub struct CustomMaterial {
color: Color,
color_texture: Option<Handle<Image>>,
#[binding(ignore)]
alpha_mode: AlphaMode,
}
```
* If we add the option to define custom draw functions for materials (which could be done in a type-erased way), I think that would be enough to support extra non-material bindings. Worth considering!
2022-06-30 23:48:46 +00:00
|
|
|
}
|
RenderGraph Labelization (#10644)
# Objective
The whole `Cow<'static, str>` naming for nodes and subgraphs in
`RenderGraph` is a mess.
## Solution
Replaces hardcoded and potentially overlapping strings for nodes and
subgraphs inside `RenderGraph` with bevy's labelsystem.
---
## Changelog
* Two new labels: `RenderLabel` and `RenderSubGraph`.
* Replaced all uses for hardcoded strings with those labels
* Moved `Taa` label from its own mod to all the other `Labels3d`
* `add_render_graph_edges` now needs a tuple of labels
* Moved `ScreenSpaceAmbientOcclusion` label from its own mod with the
`ShadowPass` label to `LabelsPbr`
* Removed `NodeId`
* Renamed `Edges.id()` to `Edges.label()`
* Removed `NodeLabel`
* Changed examples according to the new label system
* Introduced new `RenderLabel`s: `Labels2d`, `Labels3d`, `LabelsPbr`,
`LabelsUi`
* Introduced new `RenderSubGraph`s: `SubGraph2d`, `SubGraph3d`,
`SubGraphUi`
* Removed `Reflect` and `Default` derive from `CameraRenderGraph`
component struct
* Improved some error messages
## Migration Guide
For Nodes and SubGraphs, instead of using hardcoded strings, you now
pass labels, which can be derived with structs and enums.
```rs
// old
#[derive(Default)]
struct MyRenderNode;
impl MyRenderNode {
pub const NAME: &'static str = "my_render_node"
}
render_app
.add_render_graph_node::<ViewNodeRunner<MyRenderNode>>(
core_3d::graph::NAME,
MyRenderNode::NAME,
)
.add_render_graph_edges(
core_3d::graph::NAME,
&[
core_3d::graph::node::TONEMAPPING,
MyRenderNode::NAME,
core_3d::graph::node::END_MAIN_PASS_POST_PROCESSING,
],
);
// new
use bevy::core_pipeline::core_3d::graph::{Labels3d, SubGraph3d};
#[derive(Debug, Hash, PartialEq, Eq, Clone, RenderLabel)]
pub struct MyRenderLabel;
#[derive(Default)]
struct MyRenderNode;
render_app
.add_render_graph_node::<ViewNodeRunner<MyRenderNode>>(
SubGraph3d,
MyRenderLabel,
)
.add_render_graph_edges(
SubGraph3d,
(
Labels3d::Tonemapping,
MyRenderLabel,
Labels3d::EndMainPassPostProcessing,
),
);
```
### SubGraphs
#### in `bevy_core_pipeline::core_2d::graph`
| old string-based path | new label |
|-----------------------|-----------|
| `NAME` | `SubGraph2d` |
#### in `bevy_core_pipeline::core_3d::graph`
| old string-based path | new label |
|-----------------------|-----------|
| `NAME` | `SubGraph3d` |
#### in `bevy_ui::render`
| old string-based path | new label |
|-----------------------|-----------|
| `draw_ui_graph::NAME` | `graph::SubGraphUi` |
### Nodes
#### in `bevy_core_pipeline::core_2d::graph`
| old string-based path | new label |
|-----------------------|-----------|
| `node::MSAA_WRITEBACK` | `Labels2d::MsaaWriteback` |
| `node::MAIN_PASS` | `Labels2d::MainPass` |
| `node::BLOOM` | `Labels2d::Bloom` |
| `node::TONEMAPPING` | `Labels2d::Tonemapping` |
| `node::FXAA` | `Labels2d::Fxaa` |
| `node::UPSCALING` | `Labels2d::Upscaling` |
| `node::CONTRAST_ADAPTIVE_SHARPENING` |
`Labels2d::ConstrastAdaptiveSharpening` |
| `node::END_MAIN_PASS_POST_PROCESSING` |
`Labels2d::EndMainPassPostProcessing` |
#### in `bevy_core_pipeline::core_3d::graph`
| old string-based path | new label |
|-----------------------|-----------|
| `node::MSAA_WRITEBACK` | `Labels3d::MsaaWriteback` |
| `node::PREPASS` | `Labels3d::Prepass` |
| `node::DEFERRED_PREPASS` | `Labels3d::DeferredPrepass` |
| `node::COPY_DEFERRED_LIGHTING_ID` | `Labels3d::CopyDeferredLightingId`
|
| `node::END_PREPASSES` | `Labels3d::EndPrepasses` |
| `node::START_MAIN_PASS` | `Labels3d::StartMainPass` |
| `node::MAIN_OPAQUE_PASS` | `Labels3d::MainOpaquePass` |
| `node::MAIN_TRANSMISSIVE_PASS` | `Labels3d::MainTransmissivePass` |
| `node::MAIN_TRANSPARENT_PASS` | `Labels3d::MainTransparentPass` |
| `node::END_MAIN_PASS` | `Labels3d::EndMainPass` |
| `node::BLOOM` | `Labels3d::Bloom` |
| `node::TONEMAPPING` | `Labels3d::Tonemapping` |
| `node::FXAA` | `Labels3d::Fxaa` |
| `node::UPSCALING` | `Labels3d::Upscaling` |
| `node::CONTRAST_ADAPTIVE_SHARPENING` |
`Labels3d::ContrastAdaptiveSharpening` |
| `node::END_MAIN_PASS_POST_PROCESSING` |
`Labels3d::EndMainPassPostProcessing` |
#### in `bevy_core_pipeline`
| old string-based path | new label |
|-----------------------|-----------|
| `taa::draw_3d_graph::node::TAA` | `Labels3d::Taa` |
#### in `bevy_pbr`
| old string-based path | new label |
|-----------------------|-----------|
| `draw_3d_graph::node::SHADOW_PASS` | `LabelsPbr::ShadowPass` |
| `ssao::draw_3d_graph::node::SCREEN_SPACE_AMBIENT_OCCLUSION` |
`LabelsPbr::ScreenSpaceAmbientOcclusion` |
| `deferred::DEFFERED_LIGHTING_PASS` | `LabelsPbr::DeferredLightingPass`
|
#### in `bevy_render`
| old string-based path | new label |
|-----------------------|-----------|
| `main_graph::node::CAMERA_DRIVER` | `graph::CameraDriverLabel` |
#### in `bevy_ui::render`
| old string-based path | new label |
|-----------------------|-----------|
| `draw_ui_graph::node::UI_PASS` | `graph::LabelsUi::UiPass` |
---
## Future work
* Make `NodeSlot`s also use types. Ideally, we have an enum with unit
variants where every variant resembles one slot. Then to make sure you
are using the right slot enum and make rust-analyzer play nicely with
it, we should make an associated type in the `Node` trait. With today's
system, we can introduce 3rd party slots to a node, and i wasnt sure if
this was used, so I didn't do this in this PR.
## Unresolved Questions
When looking at the `post_processing` example, we have a struct for the
label and a struct for the node, this seems like boilerplate and on
discord, @IceSentry (sowy for the ping)
[asked](https://discord.com/channels/691052431525675048/743663924229963868/1175197016947699742)
if a node could automatically introduce a label (or i completely
misunderstood that). The problem with that is, that nodes like
`EmptyNode` exist multiple times *inside the same* (sub)graph, so there
we need extern labels to distinguish between those. Hopefully we can
find a way to reduce boilerplate and still have everything unique. For
EmptyNode, we could maybe make a macro which implements an "empty node"
for a type, but for nodes which contain code and need to be present
multiple times, this could get nasty...
2024-01-31 14:51:19 +00:00
|
|
|
|
|
|
|
|
/// Derive macro generating an impl of the trait `RenderLabel`.
|
|
|
|
|
///
|
|
|
|
|
/// This does not work for unions.
|
|
|
|
|
#[proc_macro_derive(RenderLabel)]
|
|
|
|
|
pub fn derive_render_label(input: TokenStream) -> TokenStream {
|
|
|
|
|
let input = parse_macro_input!(input as DeriveInput);
|
|
|
|
|
let mut trait_path = bevy_render_path();
|
|
|
|
|
trait_path
|
|
|
|
|
.segments
|
|
|
|
|
.push(format_ident!("render_graph").into());
|
|
|
|
|
let mut dyn_eq_path = trait_path.clone();
|
|
|
|
|
trait_path
|
|
|
|
|
.segments
|
|
|
|
|
.push(format_ident!("RenderLabel").into());
|
|
|
|
|
dyn_eq_path.segments.push(format_ident!("DynEq").into());
|
|
|
|
|
derive_label(input, "RenderLabel", &trait_path, &dyn_eq_path)
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/// Derive macro generating an impl of the trait `RenderSubGraph`.
|
|
|
|
|
///
|
|
|
|
|
/// This does not work for unions.
|
|
|
|
|
#[proc_macro_derive(RenderSubGraph)]
|
|
|
|
|
pub fn derive_render_sub_graph(input: TokenStream) -> TokenStream {
|
|
|
|
|
let input = parse_macro_input!(input as DeriveInput);
|
|
|
|
|
let mut trait_path = bevy_render_path();
|
|
|
|
|
trait_path
|
|
|
|
|
.segments
|
|
|
|
|
.push(format_ident!("render_graph").into());
|
|
|
|
|
let mut dyn_eq_path = trait_path.clone();
|
|
|
|
|
trait_path
|
|
|
|
|
.segments
|
|
|
|
|
.push(format_ident!("RenderSubGraph").into());
|
|
|
|
|
dyn_eq_path.segments.push(format_ident!("DynEq").into());
|
|
|
|
|
derive_label(input, "RenderSubGraph", &trait_path, &dyn_eq_path)
|
|
|
|
|
}
|
