Add Immutable Component Support

Cargo.toml

@@ -1943,6 +1943,17 @@ description = "Creates a hierarchy of parents and children entities"
 category = "ECS (Entity Component System)"
 wasm = false
 
+[[example]]
+name = "immutable_components"
+path = "examples/ecs/immutable_components.rs"
+doc-scrape-examples = true
+
+[package.metadata.example.immutable_components]
+name = "Immutable Components"
+description = "Demonstrates the creation and utility of immutable components"
+category = "ECS (Entity Component System)"
+wasm = false
+
 [[example]]
 name = "iter_combinations"
 path = "examples/ecs/iter_combinations.rs"

benches/benches/bevy_ecs/change_detection.rs

@@ -1,5 +1,5 @@
 use bevy_ecs::{
-    component::Component,
+    component::{Component, ComponentMut},
     entity::Entity,
     prelude::{Added, Changed, EntityWorldMut, QueryState},
     query::QueryFilter,
@@ -124,7 +124,7 @@ fn all_added_detection(criterion: &mut Criterion) {
     }
 }
 
-fn all_changed_detection_generic<T: Component + Default + BenchModify>(
+fn all_changed_detection_generic<T: ComponentMut + Default + BenchModify>(
     group: &mut BenchGroup,
     entity_count: u32,
 ) {
@@ -172,7 +172,7 @@ fn all_changed_detection(criterion: &mut Criterion) {
     }
 }
 
-fn few_changed_detection_generic<T: Component + Default + BenchModify>(
+fn few_changed_detection_generic<T: ComponentMut + Default + BenchModify>(
     group: &mut BenchGroup,
     entity_count: u32,
 ) {
@@ -222,7 +222,7 @@ fn few_changed_detection(criterion: &mut Criterion) {
     }
 }
 
-fn none_changed_detection_generic<T: Component + Default>(
+fn none_changed_detection_generic<T: ComponentMut + Default>(
     group: &mut BenchGroup,
     entity_count: u32,
 ) {
@@ -271,7 +271,7 @@ fn insert_if_bit_enabled<const B: u16>(entity: &mut EntityWorldMut, i: u16) {
     }
 }
 
-fn add_archetypes_entities<T: Component + Default>(
+fn add_archetypes_entities<T: ComponentMut + Default>(
     world: &mut World,
     archetype_count: u16,
     entity_count: u32,
@@ -298,7 +298,7 @@ fn add_archetypes_entities<T: Component + Default>(
         }
     }
 }
-fn multiple_archetype_none_changed_detection_generic<T: Component + Default + BenchModify>(
+fn multiple_archetype_none_changed_detection_generic<T: ComponentMut + Default + BenchModify>(
     group: &mut BenchGroup,
     archetype_count: u16,
     entity_count: u32,

crates/bevy_animation/src/animation_curves.rs

@@ -82,7 +82,7 @@ use core::{
     marker::PhantomData,
 };
 
-use bevy_ecs::{component::Component, world::Mut};
+use bevy_ecs::{component::ComponentMut, world::Mut};
 use bevy_math::{
     curve::{
         cores::{UnevenCore, UnevenCoreError},
@@ -162,7 +162,7 @@ use crate::{
 /// [`AnimationClip`]: crate::AnimationClip
 pub trait AnimatableProperty: Reflect + TypePath {
     /// The type of the component that the property lives on.
-    type Component: Component;
+    type Component: ComponentMut;
 
     /// The type of the property to be animated.
     type Property: Animatable + FromReflect + Reflectable + Clone + Sync + Debug;

crates/bevy_animation/src/graph.rs

@@ -11,7 +11,7 @@ use bevy_derive::{Deref, DerefMut};
 use bevy_ecs::{
     component::Component,
     event::EventReader,
-    reflect::ReflectComponent,
+    reflect::{ReflectComponent, ReflectComponentMut},
     system::{Res, ResMut, Resource},
 };
 use bevy_reflect::{prelude::ReflectDefault, Reflect, ReflectSerialize};
@@ -127,7 +127,7 @@ pub struct AnimationGraph {
 
 /// A [`Handle`] to the [`AnimationGraph`] to be used by the [`AnimationPlayer`](crate::AnimationPlayer) on the same entity.
 #[derive(Component, Clone, Debug, Default, Deref, DerefMut, Reflect, PartialEq, Eq, From)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 pub struct AnimationGraphHandle(pub Handle<AnimationGraph>);
 
 impl From<AnimationGraphHandle> for AssetId<AnimationGraph> {

crates/bevy_animation/src/lib.rs

@@ -357,7 +357,7 @@ impl Hash for AnimationTargetId {
 /// time. However, you can change [`AnimationTarget`]'s `player` property at
 /// runtime to change which player is responsible for animating the entity.
 #[derive(Clone, Copy, Component, Reflect, VisitEntities, VisitEntitiesMut)]
-#[reflect(Component, MapEntities, VisitEntities, VisitEntitiesMut)]
+#[reflect(ComponentMut, Component, MapEntities, VisitEntities, VisitEntitiesMut)]
 pub struct AnimationTarget {
     /// The ID of this animation target.
     ///
@@ -768,7 +768,7 @@ impl ActiveAnimation {
 /// Automatically added to any root animations of a scene when it is
 /// spawned.
 #[derive(Component, Default, Reflect)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 pub struct AnimationPlayer {
     active_animations: HashMap<AnimationNodeIndex, ActiveAnimation>,
     blend_weights: HashMap<AnimationNodeIndex, f32>,

crates/bevy_animation/src/transition.rs

@@ -5,7 +5,7 @@
 
 use bevy_ecs::{
     component::Component,
-    reflect::ReflectComponent,
+    reflect::{ReflectComponent, ReflectComponentMut},
     system::{Query, Res},
 };
 use bevy_reflect::{std_traits::ReflectDefault, Reflect};
@@ -29,7 +29,7 @@ use crate::{graph::AnimationNodeIndex, ActiveAnimation, AnimationPlayer};
 /// component to get confused about which animation is the "main" animation, and
 /// transitions will usually be incorrect as a result.
 #[derive(Component, Default, Reflect)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 pub struct AnimationTransitions {
     main_animation: Option<AnimationNodeIndex>,
     transitions: Vec<AnimationTransition>,

crates/bevy_app/src/app.rs

@@ -562,7 +562,7 @@ impl App {
     /// adding reflect data as specified in the [`Reflect`](bevy_reflect::Reflect) derive:
     /// ```ignore (No serde "derive" feature)
     /// #[derive(Component, Serialize, Deserialize, Reflect)]
-    /// #[reflect(Component, Serialize, Deserialize)] // will register ReflectComponent, ReflectSerialize, ReflectDeserialize
+    /// #[reflect(ComponentMut, Component, Serialize, Deserialize)] // will register ReflectComponent, ReflectSerialize, ReflectDeserialize
     /// ```
     ///
     /// See [`bevy_reflect::TypeRegistry::register`] for more information.

crates/bevy_audio/src/audio.rs

@@ -51,7 +51,7 @@ pub enum PlaybackMode {
 /// [`AudioSink`][crate::AudioSink] or [`SpatialAudioSink`][crate::SpatialAudioSink]
 /// components. Changes to this component will *not* be applied to already-playing audio.
 #[derive(Component, Clone, Copy, Debug, Reflect)]
-#[reflect(Default, Component, Debug)]
+#[reflect(Default, ComponentMut, Component, Debug)]
 pub struct PlaybackSettings {
     /// The desired playback behavior.
     pub mode: PlaybackMode,
@@ -147,7 +147,7 @@ impl PlaybackSettings {
 /// This must be accompanied by `Transform` and `GlobalTransform`.
 /// Only one entity with a `SpatialListener` should be present at any given time.
 #[derive(Component, Clone, Debug, Reflect)]
-#[reflect(Default, Component, Debug)]
+#[reflect(Default, ComponentMut, Component, Debug)]
 pub struct SpatialListener {
     /// Left ear position relative to the `GlobalTransform`.
     pub left_ear_offset: Vec3,
@@ -249,7 +249,7 @@ pub type AudioBundle = AudioSourceBundle<AudioSource>;
 /// Playback can be configured using the [`PlaybackSettings`] component. Note that changes to the
 /// `PlaybackSettings` component will *not* affect already-playing audio.
 #[derive(Component, Reflect)]
-#[reflect(Component)]
+#[reflect(ComponentMut, Component)]
 #[require(PlaybackSettings)]
 pub struct AudioPlayer<Source = AudioSource>(pub Handle<Source>)
 where

crates/bevy_core/src/name.rs

@@ -1,5 +1,5 @@
 #[cfg(feature = "bevy_reflect")]
-use bevy_ecs::reflect::ReflectComponent;
+use bevy_ecs::reflect::{ReflectComponent, ReflectComponentMut};
 use bevy_ecs::{component::Component, entity::Entity, query::QueryData};
 
 use alloc::borrow::Cow;
@@ -27,7 +27,7 @@ use bevy_reflect::{ReflectDeserialize, ReflectSerialize};
 #[cfg_attr(
     feature = "bevy_reflect",
     derive(Reflect),
-    reflect(Component, Default, Debug)
+    reflect(ComponentMut, Component, Default, Debug)
 )]
 #[cfg_attr(
     all(feature = "serialize", feature = "bevy_reflect"),

crates/bevy_core_pipeline/src/auto_exposure/settings.rs

@@ -2,7 +2,10 @@ use core::ops::RangeInclusive;
 
 use super::compensation_curve::AutoExposureCompensationCurve;
 use bevy_asset::Handle;
-use bevy_ecs::{prelude::Component, reflect::ReflectComponent};
+use bevy_ecs::{
+    prelude::Component,
+    reflect::{ReflectComponent, ReflectComponentMut},
+};
 use bevy_image::Image;
 use bevy_reflect::{std_traits::ReflectDefault, Reflect};
 use bevy_render::extract_component::ExtractComponent;
@@ -24,7 +27,7 @@ use bevy_utils::default;
 ///
 /// **Auto Exposure requires compute shaders and is not compatible with WebGL2.**
 #[derive(Component, Clone, Reflect, ExtractComponent)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 pub struct AutoExposure {
     /// The range of exposure values for the histogram.
     ///

crates/bevy_core_pipeline/src/bloom/settings.rs

@@ -1,5 +1,9 @@
 use super::downsampling_pipeline::BloomUniforms;
-use bevy_ecs::{prelude::Component, query::QueryItem, reflect::ReflectComponent};
+use bevy_ecs::{
+    prelude::Component,
+    query::QueryItem,
+    reflect::{ReflectComponent, ReflectComponentMut},
+};
 use bevy_math::{AspectRatio, URect, UVec4, Vec4};
 use bevy_reflect::{std_traits::ReflectDefault, Reflect};
 use bevy_render::{extract_component::ExtractComponent, prelude::Camera};
@@ -25,7 +29,7 @@ use bevy_render::{extract_component::ExtractComponent, prelude::Camera};
 /// See <https://starlederer.github.io/bloom/> for a visualization of the parametric curve
 /// used in Bevy as well as a visualization of the curve's respective scattering profile.
 #[derive(Component, Reflect, Clone)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 pub struct Bloom {
     /// Controls the baseline of how much the image is scattered (default: 0.15).
     ///

crates/bevy_core_pipeline/src/contrast_adaptive_sharpening/mod.rs

@@ -36,7 +36,7 @@ pub use node::CasNode;
 ///
 /// To use this, add the [`ContrastAdaptiveSharpening`] component to a 2D or 3D camera.
 #[derive(Component, Reflect, Clone)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 pub struct ContrastAdaptiveSharpening {
     /// Enable or disable sharpening.
     pub enabled: bool,
@@ -68,7 +68,7 @@ impl Default for ContrastAdaptiveSharpening {
 }
 
 #[derive(Component, Default, Reflect, Clone)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 pub struct DenoiseCas(bool);
 
 /// The uniform struct extracted from [`ContrastAdaptiveSharpening`] attached to a [`Camera`].

crates/bevy_core_pipeline/src/core_2d/camera_2d.rs

@@ -22,7 +22,7 @@ use bevy_transform::prelude::{GlobalTransform, Transform};
 /// A 2D camera component. Enables the 2D render graph for a [`Camera`].
 #[derive(Component, Default, Reflect, Clone, ExtractComponent)]
 #[extract_component_filter(With<Camera>)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 #[require(
     Camera,
     DebandDither,

crates/bevy_core_pipeline/src/core_3d/camera_3d.rs

@@ -23,7 +23,7 @@ use serde::{Deserialize, Serialize};
 /// This means "forward" is -Z.
 #[derive(Component, Reflect, Clone, ExtractComponent)]
 #[extract_component_filter(With<Camera>)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 #[require(
     Camera,
     DebandDither(|| DebandDither::Enabled),

crates/bevy_core_pipeline/src/dof/mod.rs

@@ -21,7 +21,7 @@ use bevy_ecs::{
     component::Component,
     entity::Entity,
     query::{QueryItem, With},
-    reflect::ReflectComponent,
+    reflect::{ReflectComponent, ReflectComponentMut},
     schedule::IntoSystemConfigs as _,
     system::{lifetimeless::Read, Commands, Query, Res, ResMut, Resource},
     world::{FromWorld, World},
@@ -77,7 +77,7 @@ pub struct DepthOfFieldPlugin;
 ///
 /// [depth of field]: https://en.wikipedia.org/wiki/Depth_of_field
 #[derive(Component, Clone, Copy, Reflect)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 pub struct DepthOfField {
     /// The appearance of the effect.
     pub mode: DepthOfFieldMode,

crates/bevy_core_pipeline/src/fxaa/mod.rs

@@ -51,7 +51,7 @@ impl Sensitivity {
 /// A component for enabling Fast Approximate Anti-Aliasing (FXAA)
 /// for a [`bevy_render::camera::Camera`].
 #[derive(Reflect, Component, Clone, ExtractComponent)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 #[extract_component_filter(With<Camera>)]
 #[doc(alias = "FastApproximateAntiAliasing")]
 pub struct Fxaa {

crates/bevy_core_pipeline/src/motion_blur/mod.rs

@@ -11,7 +11,10 @@ use crate::{
 use bevy_app::{App, Plugin};
 use bevy_asset::{load_internal_asset, Handle};
 use bevy_ecs::{
-    bundle::Bundle, component::Component, query::With, reflect::ReflectComponent,
+    bundle::Bundle,
+    component::Component,
+    query::With,
+    reflect::{ReflectComponent, ReflectComponentMut},
     schedule::IntoSystemConfigs,
 };
 use bevy_reflect::{std_traits::ReflectDefault, Reflect};
@@ -69,7 +72,7 @@ pub struct MotionBlurBundle {
 /// # }
 /// ````
 #[derive(Reflect, Component, Clone, ExtractComponent, ShaderType)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 #[extract_component_filter(With<Camera>)]
 #[require(DepthPrepass, MotionVectorPrepass)]
 pub struct MotionBlur {

crates/bevy_core_pipeline/src/oit/mod.rs

@@ -80,6 +80,8 @@ impl Component for OrderIndependentTransparencySettings {
     }
 }
 
+impl ComponentMut for OrderIndependentTransparencySettings {}
+
 /// A plugin that adds support for Order Independent Transparency (OIT).
 /// This can correctly render some scenes that would otherwise have artifacts due to alpha blending, but uses more memory.
 ///

crates/bevy_core_pipeline/src/post_process/mod.rs

@@ -9,7 +9,7 @@ use bevy_ecs::{
     component::Component,
     entity::Entity,
     query::{QueryItem, With},
-    reflect::ReflectComponent,
+    reflect::{ReflectComponent, ReflectComponentMut},
     schedule::IntoSystemConfigs as _,
     system::{lifetimeless::Read, Commands, Query, Res, ResMut, Resource},
     world::{FromWorld, World},
@@ -96,7 +96,7 @@ pub struct PostProcessingPlugin;
 ///
 /// [Gjøl & Svendsen 2016]: https://github.com/playdeadgames/publications/blob/master/INSIDE/rendering_inside_gdc2016.pdf
 #[derive(Reflect, Component, Clone)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 pub struct ChromaticAberration {
     /// The lookup texture that determines the color gradient.
     ///

crates/bevy_core_pipeline/src/prepass/mod.rs

@@ -52,24 +52,24 @@ pub const MOTION_VECTOR_PREPASS_FORMAT: TextureFormat = TextureFormat::Rg16Float
 
 /// If added to a [`crate::prelude::Camera3d`] then depth values will be copied to a separate texture available to the main pass.
 #[derive(Component, Default, Reflect, Clone)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 pub struct DepthPrepass;
 
 /// If added to a [`crate::prelude::Camera3d`] then vertex world normals will be copied to a separate texture available to the main pass.
 /// Normals will have normal map textures already applied.
 #[derive(Component, Default, Reflect, Clone)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 pub struct NormalPrepass;
 
 /// If added to a [`crate::prelude::Camera3d`] then screen space motion vectors will be copied to a separate texture available to the main pass.
 #[derive(Component, Default, Reflect, Clone)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 pub struct MotionVectorPrepass;
 
 /// If added to a [`crate::prelude::Camera3d`] then deferred materials will be rendered to the deferred gbuffer texture and will be available to subsequent passes.
 /// Note the default deferred lighting plugin also requires `DepthPrepass` to work correctly.
 #[derive(Component, Default, Reflect)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 pub struct DeferredPrepass;
 
 #[derive(Component, ShaderType, Clone)]

crates/bevy_core_pipeline/src/smaa/mod.rs

@@ -44,7 +44,7 @@ use bevy_ecs::{
     component::Component,
     entity::Entity,
     query::{QueryItem, With},
-    reflect::ReflectComponent,
+    reflect::{ReflectComponent, ReflectComponentMut},
     schedule::IntoSystemConfigs as _,
     system::{lifetimeless::Read, Commands, Query, Res, ResMut, Resource},
     world::{FromWorld, World},
@@ -92,7 +92,7 @@ pub struct SmaaPlugin;
 /// A component for enabling Subpixel Morphological Anti-Aliasing (SMAA)
 /// for a [`bevy_render::camera::Camera`].
 #[derive(Clone, Copy, Default, Component, Reflect, ExtractComponent)]
-#[reflect(Component, Default)]
+#[reflect(ComponentMut, Component, Default)]
 #[doc(alias = "SubpixelMorphologicalAntiAliasing")]
 pub struct Smaa {
     /// A predefined set of SMAA parameters: i.e. a quality level.