Replace UUID based IDs with a atomic-counted ones (#6988)

# Objective

- alternative to #2895 
- as mentioned in #2535 the uuid based ids in the render module should be replaced with atomic-counted ones

## Solution
- instead of generating a random UUID for each render resource, this implementation increases an atomic counter
- this might be replaced by the ids of wgpu if they expose them directly in the future

- I have not benchmarked this solution yet, but this should be slightly faster in theory.
- Bevymark does not seem to be affected much by this change, which is to be expected.

- Nothing of our API has changed, other than that the IDs have lost their IMO rather insignificant documentation.
- Maybe the documentation could be added back into the macro, but this would complicate the code.

Author: kurtkuehnert

crates/bevy_render/src/render_graph/node.rs

@@ -1,33 +1,17 @@
 use crate::{
+    define_atomic_id,
     render_graph::{
         Edge, InputSlotError, OutputSlotError, RenderGraphContext, RenderGraphError,
         RunSubGraphError, SlotInfo, SlotInfos, SlotType, SlotValue,
     },
     renderer::RenderContext,
 };
 use bevy_ecs::world::World;
-use bevy_utils::Uuid;
 use downcast_rs::{impl_downcast, Downcast};
 use std::{borrow::Cow, fmt::Debug};
 use thiserror::Error;
 
-/// A [`Node`] identifier.
-/// It automatically generates its own random uuid.
-///
-/// This id is used to reference the node internally (edges, etc).
-#[derive(Copy, Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
-pub struct NodeId(Uuid);
-
-impl NodeId {
-    #[allow(clippy::new_without_default)]
-    pub fn new() -> Self {
-        NodeId(Uuid::new_v4())
-    }
-
-    pub fn uuid(&self) -> &Uuid {
-        &self.0
-    }
-}
+define_atomic_id!(NodeId);
 
 /// A render node that can be added to a [`RenderGraph`](super::RenderGraph).
 ///

crates/bevy_render/src/render_resource/bind_group.rs

@@ -1,24 +1,19 @@
-pub use bevy_render_macros::AsBindGroup;
-use encase::ShaderType;
-
 use crate::{
+    define_atomic_id,
     prelude::Image,
     render_asset::RenderAssets,
-    render_resource::{BindGroupLayout, Buffer, Sampler, TextureView},
+    render_resource::{resource_macros::*, BindGroupLayout, Buffer, Sampler, TextureView},
     renderer::RenderDevice,
     texture::FallbackImage,
 };
-use bevy_reflect::Uuid;
+pub use bevy_render_macros::AsBindGroup;
+use encase::ShaderType;
 use std::ops::Deref;
 use wgpu::BindingResource;
 
-use crate::render_resource::resource_macros::*;
+define_atomic_id!(BindGroupId);
 render_resource_wrapper!(ErasedBindGroup, wgpu::BindGroup);
 
-/// A [`BindGroup`] identifier.
-#[derive(Copy, Clone, Hash, Eq, PartialEq, Debug)]
-pub struct BindGroupId(Uuid);
-
 /// Bind groups are responsible for binding render resources (e.g. buffers, textures, samplers)
 /// to a [`TrackedRenderPass`](crate::render_phase::TrackedRenderPass).
 /// This makes them accessible in the pipeline (shaders) as uniforms.
@@ -42,7 +37,7 @@ impl BindGroup {
 impl From<wgpu::BindGroup> for BindGroup {
     fn from(value: wgpu::BindGroup) -> Self {
         BindGroup {
-            id: BindGroupId(Uuid::new_v4()),
+            id: BindGroupId::new(),
             value: ErasedBindGroup::new(value),
         }
     }

crates/bevy_render/src/render_resource/bind_group_layout.rs

@@ -1,10 +1,7 @@
-use crate::render_resource::resource_macros::*;
-use bevy_reflect::Uuid;
+use crate::{define_atomic_id, render_resource::resource_macros::*};
 use std::ops::Deref;
 
-#[derive(Copy, Clone, Hash, Eq, PartialEq, Debug)]
-pub struct BindGroupLayoutId(Uuid);
-
+define_atomic_id!(BindGroupLayoutId);
 render_resource_wrapper!(ErasedBindGroupLayout, wgpu::BindGroupLayout);
 
 #[derive(Clone, Debug)]
@@ -34,7 +31,7 @@ impl BindGroupLayout {
 impl From<wgpu::BindGroupLayout> for BindGroupLayout {
     fn from(value: wgpu::BindGroupLayout) -> Self {
         BindGroupLayout {
-            id: BindGroupLayoutId(Uuid::new_v4()),
+            id: BindGroupLayoutId::new(),
             value: ErasedBindGroupLayout::new(value),
         }
     }

crates/bevy_render/src/render_resource/buffer.rs

@@ -1,11 +1,7 @@
-use bevy_utils::Uuid;
+use crate::{define_atomic_id, render_resource::resource_macros::render_resource_wrapper};
 use std::ops::{Bound, Deref, RangeBounds};
 
-use crate::render_resource::resource_macros::*;
-
-#[derive(Copy, Clone, Hash, Eq, PartialEq, Debug)]
-pub struct BufferId(Uuid);
-
+define_atomic_id!(BufferId);
 render_resource_wrapper!(ErasedBuffer, wgpu::Buffer);
 
 #[derive(Clone, Debug)]
@@ -42,7 +38,7 @@ impl Buffer {
 impl From<wgpu::Buffer> for Buffer {
     fn from(value: wgpu::Buffer) -> Self {
         Buffer {
-            id: BufferId(Uuid::new_v4()),
+            id: BufferId::new(),
             value: ErasedBuffer::new(value),
         }
     }

crates/bevy_render/src/render_resource/pipeline.rs

@@ -1,19 +1,16 @@
-use crate::render_resource::{BindGroupLayout, Shader};
+use super::ShaderDefVal;
+use crate::{
+    define_atomic_id,
+    render_resource::{resource_macros::render_resource_wrapper, BindGroupLayout, Shader},
+};
 use bevy_asset::Handle;
-use bevy_reflect::Uuid;
 use std::{borrow::Cow, ops::Deref};
 use wgpu::{
     BufferAddress, ColorTargetState, DepthStencilState, MultisampleState, PrimitiveState,
     VertexAttribute, VertexFormat, VertexStepMode,
 };
 
-use super::ShaderDefVal;
-use crate::render_resource::resource_macros::*;
-
-/// A [`RenderPipeline`] identifier.
-#[derive(Copy, Clone, Hash, Eq, PartialEq, Debug)]
-pub struct RenderPipelineId(Uuid);
-
+define_atomic_id!(RenderPipelineId);
 render_resource_wrapper!(ErasedRenderPipeline, wgpu::RenderPipeline);
 
 /// A [`RenderPipeline`] represents a graphics pipeline and its stages (shaders), bindings and vertex buffers.
@@ -36,7 +33,7 @@ impl RenderPipeline {
 impl From<wgpu::RenderPipeline> for RenderPipeline {
     fn from(value: wgpu::RenderPipeline) -> Self {
         RenderPipeline {
-            id: RenderPipelineId(Uuid::new_v4()),
+            id: RenderPipelineId::new(),
             value: ErasedRenderPipeline::new(value),
         }
     }
@@ -51,10 +48,7 @@ impl Deref for RenderPipeline {
     }
 }
 
-/// A [`ComputePipeline`] identifier.
-#[derive(Copy, Clone, Hash, Eq, PartialEq, Debug)]
-pub struct ComputePipelineId(Uuid);
-
+define_atomic_id!(ComputePipelineId);
 render_resource_wrapper!(ErasedComputePipeline, wgpu::ComputePipeline);
 
 /// A [`ComputePipeline`] represents a compute pipeline and its single shader stage.
@@ -78,7 +72,7 @@ impl ComputePipeline {
 impl From<wgpu::ComputePipeline> for ComputePipeline {
     fn from(value: wgpu::ComputePipeline) -> Self {
         ComputePipeline {
-            id: ComputePipelineId(Uuid::new_v4()),
+            id: ComputePipelineId::new(),
             value: ErasedComputePipeline::new(value),
         }
     }

crates/bevy_render/src/render_resource/resource_macros.rs

@@ -120,4 +120,32 @@ macro_rules! render_resource_wrapper {
     };
 }
 
+#[macro_export]
+macro_rules! define_atomic_id {
+    ($atomic_id_type:ident) => {
+        #[derive(Copy, Clone, Hash, Eq, PartialEq, Debug)]
+        pub struct $atomic_id_type(u32);
+
+        // We use new instead of default to indicate that each ID created will be unique.
+        #[allow(clippy::new_without_default)]
+        impl $atomic_id_type {
+            pub fn new() -> Self {
+                use std::sync::atomic::{AtomicU32, Ordering};
+
+                static COUNTER: AtomicU32 = AtomicU32::new(1);
+
+                match COUNTER.fetch_add(1, Ordering::Relaxed) {
+                    0 => {
+                        panic!(
+                            "The system ran out of unique `{}`s.",
+                            stringify!($atomic_id_type)
+                        );
+                    }
+                    id => Self(id),
+                }
+            }
+        }
+    };
+}
+
 pub use render_resource_wrapper;

crates/bevy_render/src/render_resource/shader.rs

@@ -1,27 +1,16 @@
+use super::ShaderDefVal;
+use crate::define_atomic_id;
 use bevy_asset::{AssetLoader, AssetPath, Handle, LoadContext, LoadedAsset};
-use bevy_reflect::{TypeUuid, Uuid};
+use bevy_reflect::TypeUuid;
 use bevy_utils::{tracing::error, BoxedFuture, HashMap};
-use naga::back::wgsl::WriterFlags;
-use naga::valid::Capabilities;
-use naga::{valid::ModuleInfo, Module};
+use naga::{back::wgsl::WriterFlags, valid::Capabilities, valid::ModuleInfo, Module};
 use once_cell::sync::Lazy;
 use regex::Regex;
 use std::{borrow::Cow, marker::Copy, ops::Deref, path::PathBuf, str::FromStr};
 use thiserror::Error;
-use wgpu::Features;
-use wgpu::{util::make_spirv, ShaderModuleDescriptor, ShaderSource};
-
-use super::ShaderDefVal;
+use wgpu::{util::make_spirv, Features, ShaderModuleDescriptor, ShaderSource};
 
-#[derive(Copy, Clone, Hash, Eq, PartialEq, Debug)]
-pub struct ShaderId(Uuid);
-
-impl ShaderId {
-    #[allow(clippy::new_without_default)]
-    pub fn new() -> Self {
-        ShaderId(Uuid::new_v4())
-    }
-}
+define_atomic_id!(ShaderId);
 
 #[derive(Error, Debug)]
 pub enum ShaderReflectError {

crates/bevy_render/src/render_resource/texture.rs

@@ -1,12 +1,9 @@
-use bevy_utils::Uuid;
+use crate::define_atomic_id;
 use std::ops::Deref;
 
 use crate::render_resource::resource_macros::*;
 
-/// A [`Texture`] identifier.
-#[derive(Copy, Clone, Hash, Eq, PartialEq, Debug)]
-pub struct TextureId(Uuid);
-
+define_atomic_id!(TextureId);
 render_resource_wrapper!(ErasedTexture, wgpu::Texture);
 
 /// A GPU-accessible texture.
@@ -35,7 +32,7 @@ impl Texture {
 impl From<wgpu::Texture> for Texture {
     fn from(value: wgpu::Texture) -> Self {
         Texture {
-            id: TextureId(Uuid::new_v4()),
+            id: TextureId::new(),
             value: ErasedTexture::new(value),
         }
     }
@@ -50,10 +47,7 @@ impl Deref for Texture {
     }
 }
 
-/// A [`TextureView`] identifier.
-#[derive(Copy, Clone, Hash, Eq, PartialEq, Debug)]
-pub struct TextureViewId(Uuid);
-
+define_atomic_id!(TextureViewId);
 render_resource_wrapper!(ErasedTextureView, wgpu::TextureView);
 render_resource_wrapper!(ErasedSurfaceTexture, wgpu::SurfaceTexture);
 
@@ -104,7 +98,7 @@ impl TextureView {
 impl From<wgpu::TextureView> for TextureView {
     fn from(value: wgpu::TextureView) -> Self {
         TextureView {
-            id: TextureViewId(Uuid::new_v4()),
+            id: TextureViewId::new(),
             value: TextureViewValue::TextureView(ErasedTextureView::new(value)),
         }
     }
@@ -116,7 +110,7 @@ impl From<wgpu::SurfaceTexture> for TextureView {
         let texture = ErasedSurfaceTexture::new(value);
 
         TextureView {
-            id: TextureViewId(Uuid::new_v4()),
+            id: TextureViewId::new(),
             value: TextureViewValue::SurfaceTexture { texture, view },
         }
     }
@@ -134,10 +128,7 @@ impl Deref for TextureView {
     }
 }
 
-/// A [`Sampler`] identifier.
-#[derive(Copy, Clone, Hash, Eq, PartialEq, Debug)]
-pub struct SamplerId(Uuid);
-
+define_atomic_id!(SamplerId);
 render_resource_wrapper!(ErasedSampler, wgpu::Sampler);
 
 /// A Sampler defines how a pipeline will sample from a [`TextureView`].
@@ -162,7 +153,7 @@ impl Sampler {
 impl From<wgpu::Sampler> for Sampler {
     fn from(value: wgpu::Sampler) -> Self {
         Sampler {
-            id: SamplerId(Uuid::new_v4()),
+            id: SamplerId::new(),
             value: ErasedSampler::new(value),
         }
     }