Struct bevy::ecs::component::ComponentId

pub struct ComponentId(/* private fields */);
Expand description

A value which uniquely identifies the type of a Component or Resource within a World.

Each time a new Component type is registered within a World using e.g. World::init_component or World::init_component_with_descriptor or a Resource with e.g. World::init_resource, a corresponding ComponentId is created to track it.

While the distinction between ComponentId and TypeId may seem superficial, breaking them into two separate but related concepts allows components to exist outside of Rust’s type system. Each Rust type registered as a Component will have a corresponding ComponentId, but additional ComponentIds may exist in a World to track components which cannot be represented as Rust types for scripting or other advanced use-cases.

A ComponentId is tightly coupled to its parent World. Attempting to use a ComponentId from one World to access the metadata of a Component in a different World is undefined behavior and must not be attempted.

Given a type T which implements Component, the ComponentId for T can be retrieved from a World using World::component_id() or via Components::component_id(). Access to the ComponentId for a Resource is available via Components::resource_id().

Implementations§

§

impl ComponentId

pub const fn new(index: usize) -> ComponentId

Creates a new ComponentId.

The index is a unique value associated with each type of component in a given world. Usually, this value is taken from a counter incremented for each type of component registered with the world.

pub fn index(self) -> usize

Returns the index of the current component.

Examples found in repository?
examples/ecs/dynamic.rs (line 101)
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
fn main() {
    let mut world = World::new();
    let mut lines = std::io::stdin().lines();
    let mut component_names = HashMap::<String, ComponentId>::new();
    let mut component_info = HashMap::<ComponentId, ComponentInfo>::new();

    println!("{}", PROMPT);
    loop {
        print!("\n> ");
        let _ = std::io::stdout().flush();
        let Some(Ok(line)) = lines.next() else {
            return;
        };

        if line.is_empty() {
            return;
        };

        let Some((first, rest)) = line.trim().split_once(|c: char| c.is_whitespace()) else {
            match &line.chars().next() {
                Some('c') => println!("{}", COMPONENT_PROMPT),
                Some('s') => println!("{}", ENTITY_PROMPT),
                Some('q') => println!("{}", QUERY_PROMPT),
                _ => println!("{}", PROMPT),
            }
            continue;
        };

        match &first[0..1] {
            "c" => {
                rest.split(',').for_each(|component| {
                    let mut component = component.split_whitespace();
                    let Some(name) = component.next() else {
                        return;
                    };
                    let size = match component.next().map(|s| s.parse::<usize>()) {
                        Some(Ok(size)) => size,
                        _ => 0,
                    };
                    // Register our new component to the world with a layout specified by it's size
                    // SAFETY: [u64] is Send + Sync
                    let id = world.init_component_with_descriptor(unsafe {
                        ComponentDescriptor::new_with_layout(
                            name.to_string(),
                            StorageType::Table,
                            Layout::array::<u64>(size).unwrap(),
                            None,
                        )
                    });
                    let Some(info) = world.components().get_info(id) else {
                        return;
                    };
                    component_names.insert(name.to_string(), id);
                    component_info.insert(id, info.clone());
                    println!("Component {} created with id: {:?}", name, id.index());
                });
            }
            "s" => {
                let mut to_insert_ids = Vec::new();
                let mut to_insert_data = Vec::new();
                rest.split(',').for_each(|component| {
                    let mut component = component.split_whitespace();
                    let Some(name) = component.next() else {
                        return;
                    };

                    // Get the id for the component with the given name
                    let Some(&id) = component_names.get(name) else {
                        println!("Component {} does not exist", name);
                        return;
                    };

                    // Calculate the length for the array based on the layout created for this component id
                    let info = world.components().get_info(id).unwrap();
                    let len = info.layout().size() / std::mem::size_of::<u64>();
                    let mut values: Vec<u64> = component
                        .take(len)
                        .filter_map(|value| value.parse::<u64>().ok())
                        .collect();
                    values.resize(len, 0);

                    // Collect the id and array to be inserted onto our entity
                    to_insert_ids.push(id);
                    to_insert_data.push(values);
                });

                let mut entity = world.spawn_empty();

                // Construct an `OwningPtr` for each component in `to_insert_data`
                let to_insert_ptr = to_owning_ptrs(&mut to_insert_data);

                // SAFETY:
                // - Component ids have been taken from the same world
                // - Each array is created to the layout specified in the world
                unsafe {
                    entity.insert_by_ids(&to_insert_ids, to_insert_ptr.into_iter());
                }

                println!("Entity spawned with id: {:?}", entity.id());
            }
            "q" => {
                let mut builder = QueryBuilder::<FilteredEntityMut>::new(&mut world);
                parse_query(rest, &mut builder, &component_names);
                let mut query = builder.build();

                query.iter_mut(&mut world).for_each(|filtered_entity| {
                    let terms = filtered_entity
                        .components()
                        .map(|id| {
                            let ptr = filtered_entity.get_by_id(id).unwrap();
                            let info = component_info.get(&id).unwrap();
                            let len = info.layout().size() / std::mem::size_of::<u64>();

                            // SAFETY:
                            // - All components are created with layout [u64]
                            // - len is calculated from the component descriptor
                            let data = unsafe {
                                std::slice::from_raw_parts_mut(
                                    ptr.assert_unique().as_ptr().cast::<u64>(),
                                    len,
                                )
                            };

                            // If we have write access, increment each value once
                            if filtered_entity.access().has_write(id) {
                                data.iter_mut().for_each(|data| {
                                    *data += 1;
                                });
                            }

                            format!("{}: {:?}", info.name(), data[0..len].to_vec())
                        })
                        .collect::<Vec<_>>()
                        .join(", ");

                    println!("{:?}: {}", filtered_entity.id(), terms);
                });
            }
            _ => continue,
        }
    }
}

Trait Implementations§

§

impl Clone for ComponentId

§

fn clone(&self) -> ComponentId

Returns a copy of the value. Read more
1.0.0 · source§

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
§

impl Debug for ComponentId

§

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter. Read more
§

impl<T> From<ComponentIdFor<'_, T>> for ComponentId
where T: Component,

§

fn from(to_component_id: ComponentIdFor<'_, T>) -> ComponentId

Converts to this type from the input type.
§

impl FromReflect for ComponentId
where ComponentId: Any + Send + Sync, usize: FromReflect + TypePath + RegisterForReflection,

§

fn from_reflect(reflect: &(dyn Reflect + 'static)) -> Option<ComponentId>

Constructs a concrete instance of Self from a reflected value.
§

fn take_from_reflect( reflect: Box<dyn Reflect>, ) -> Result<Self, Box<dyn Reflect>>

Attempts to downcast the given value to Self using, constructing the value using from_reflect if that fails. Read more
§

impl GetTypeRegistration for ComponentId
where ComponentId: Any + Send + Sync, usize: FromReflect + TypePath + RegisterForReflection,

§

fn get_type_registration() -> TypeRegistration

Returns the default TypeRegistration for this type.
§

fn register_type_dependencies(registry: &mut TypeRegistry)

Registers other types needed by this type. Read more
§

impl Hash for ComponentId

§

fn hash<__H>(&self, state: &mut __H)
where __H: Hasher,

Feeds this value into the given Hasher. Read more
1.3.0 · source§

fn hash_slice<H>(data: &[Self], state: &mut H)
where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher. Read more
§

impl Ord for ComponentId

§

fn cmp(&self, other: &ComponentId) -> Ordering

This method returns an Ordering between self and other. Read more
1.21.0 · source§

fn max(self, other: Self) -> Self
where Self: Sized,

Compares and returns the maximum of two values. Read more
1.21.0 · source§

fn min(self, other: Self) -> Self
where Self: Sized,

Compares and returns the minimum of two values. Read more
1.50.0 · source§

fn clamp(self, min: Self, max: Self) -> Self
where Self: Sized + PartialOrd,

Restrict a value to a certain interval. Read more
§

impl PartialEq for ComponentId

§

fn eq(&self, other: &ComponentId) -> bool

This method tests for self and other values to be equal, and is used by ==.
1.0.0 · source§

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
§

impl PartialOrd for ComponentId

§

fn partial_cmp(&self, other: &ComponentId) -> Option<Ordering>

This method returns an ordering between self and other values if one exists. Read more
1.0.0 · source§

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator. Read more
1.0.0 · source§

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more
1.0.0 · source§

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator. Read more
1.0.0 · source§

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more
§

impl Reflect for ComponentId
where ComponentId: Any + Send + Sync, usize: FromReflect + TypePath + RegisterForReflection,

§

fn get_represented_type_info(&self) -> Option<&'static TypeInfo>

Returns the TypeInfo of the type represented by this value. Read more
§

fn into_any(self: Box<ComponentId>) -> Box<dyn Any>

Returns the value as a Box<dyn Any>.
§

fn as_any(&self) -> &(dyn Any + 'static)

Returns the value as a &dyn Any.
§

fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)

Returns the value as a &mut dyn Any.
§

fn into_reflect(self: Box<ComponentId>) -> Box<dyn Reflect>

Casts this type to a boxed reflected value.
§

fn as_reflect(&self) -> &(dyn Reflect + 'static)

Casts this type to a reflected value.
§

fn as_reflect_mut(&mut self) -> &mut (dyn Reflect + 'static)

Casts this type to a mutable reflected value.
§

fn clone_value(&self) -> Box<dyn Reflect>

Clones the value as a Reflect trait object. Read more
§

fn set(&mut self, value: Box<dyn Reflect>) -> Result<(), Box<dyn Reflect>>

Performs a type-checked assignment of a reflected value to this value. Read more
§

fn try_apply( &mut self, value: &(dyn Reflect + 'static), ) -> Result<(), ApplyError>

Tries to apply a reflected value to this value. Read more
§

fn reflect_kind(&self) -> ReflectKind

Returns a zero-sized enumeration of “kinds” of type. Read more
§

fn reflect_ref(&self) -> ReflectRef<'_>

Returns an immutable enumeration of “kinds” of type. Read more
§

fn reflect_mut(&mut self) -> ReflectMut<'_>

Returns a mutable enumeration of “kinds” of type. Read more
§

fn reflect_owned(self: Box<ComponentId>) -> ReflectOwned

Returns an owned enumeration of “kinds” of type. Read more
§

fn reflect_hash(&self) -> Option<u64>

Returns a hash of the value (which includes the type). Read more
§

fn reflect_partial_eq(&self, value: &(dyn Reflect + 'static)) -> Option<bool>

Returns a “partial equality” comparison result. Read more
§

fn debug(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Debug formatter for the value. Read more
§

fn apply(&mut self, value: &(dyn Reflect + 'static))

Applies a reflected value to this value. Read more
§

fn serializable(&self) -> Option<Serializable<'_>>

Returns a serializable version of the value. Read more
§

fn is_dynamic(&self) -> bool

Indicates whether or not this type is a dynamic type. Read more
§

impl SparseSetIndex for ComponentId

§

fn sparse_set_index(&self) -> usize

Gets the sparse set index corresponding to this instance.
§

fn get_sparse_set_index(value: usize) -> ComponentId

Creates a new instance of this type with the specified index.
§

impl TriggerTargets for ComponentId

§

fn components(&self) -> impl ExactSizeIterator

The components the trigger should target.
§

fn entities(&self) -> impl ExactSizeIterator

The entities the trigger should target.
§

impl TupleStruct for ComponentId
where ComponentId: Any + Send + Sync, usize: FromReflect + TypePath + RegisterForReflection,

§

fn field(&self, index: usize) -> Option<&(dyn Reflect + 'static)>

Returns a reference to the value of the field with index index as a &dyn Reflect.
§

fn field_mut(&mut self, index: usize) -> Option<&mut (dyn Reflect + 'static)>

Returns a mutable reference to the value of the field with index index as a &mut dyn Reflect.
§

fn field_len(&self) -> usize

Returns the number of fields in the tuple struct.
§

fn iter_fields(&self) -> TupleStructFieldIter<'_>

Returns an iterator over the values of the tuple struct’s fields.
§

fn clone_dynamic(&self) -> DynamicTupleStruct

Clones the struct into a DynamicTupleStruct.
§

impl TypePath for ComponentId
where ComponentId: Any + Send + Sync,

§

fn type_path() -> &'static str

Returns the fully qualified path of the underlying type. Read more
§

fn short_type_path() -> &'static str

Returns a short, pretty-print enabled path to the type. Read more
§

fn type_ident() -> Option<&'static str>

Returns the name of the type, or None if it is anonymous. Read more
§

fn crate_name() -> Option<&'static str>

Returns the name of the crate the type is in, or None if it is anonymous. Read more
§

fn module_path() -> Option<&'static str>

Returns the path to the module the type is in, or None if it is anonymous. Read more
§

impl Typed for ComponentId
where ComponentId: Any + Send + Sync, usize: FromReflect + TypePath + RegisterForReflection,

§

fn type_info() -> &'static TypeInfo

Returns the compile-time info for the underlying type.
§

impl Copy for ComponentId

§

impl Eq for ComponentId

§

impl StructuralPartialEq for ComponentId

Auto Trait Implementations§

Blanket Implementations§

source§

impl<T> Any for T
where T: 'static + ?Sized,

source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
§

impl<T, U> AsBindGroupShaderType<U> for T
where U: ShaderType, &'a T: for<'a> Into<U>,

§

fn as_bind_group_shader_type(&self, _images: &RenderAssets<GpuImage>) -> U

Return the T ShaderType for self. When used in AsBindGroup derives, it is safe to assume that all images in self exist.
source§

impl<T> Borrow<T> for T
where T: ?Sized,

source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

impl<T> BorrowMut<T> for T
where T: ?Sized,

source§

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
§

impl<Q, K> Comparable<K> for Q
where Q: Ord + ?Sized, K: Borrow<Q> + ?Sized,

§

fn compare(&self, key: &K) -> Ordering

Compare self to key and return their ordering.
§

impl<T> Downcast<T> for T

§

fn downcast(&self) -> &T

§

impl<T> Downcast for T
where T: Any,

§

fn into_any(self: Box<T>) -> Box<dyn Any>

Convert Box<dyn Trait> (where Trait: Downcast) to Box<dyn Any>. Box<dyn Any> can then be further downcast into Box<ConcreteType> where ConcreteType implements Trait.
§

fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>

Convert Rc<Trait> (where Trait: Downcast) to Rc<Any>. Rc<Any> can then be further downcast into Rc<ConcreteType> where ConcreteType implements Trait.
§

fn as_any(&self) -> &(dyn Any + 'static)

Convert &Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot generate &Any’s vtable from &Trait’s.
§

fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)

Convert &mut Trait (where Trait: Downcast) to &Any. This is needed since Rust cannot generate &mut Any’s vtable from &mut Trait’s.
§

impl<T> DowncastSync for T
where T: Any + Send + Sync,

§

fn into_any_arc(self: Arc<T>) -> Arc<dyn Any + Sync + Send>

Convert Arc<Trait> (where Trait: Downcast) to Arc<Any>. Arc<Any> can then be further downcast into Arc<ConcreteType> where ConcreteType implements Trait.
§

impl<T> DynEq for T
where T: Any + Eq,

§

fn as_any(&self) -> &(dyn Any + 'static)

Casts the type to dyn Any.
§

fn dyn_eq(&self, other: &(dyn DynEq + 'static)) -> bool

This method tests for self and other values to be equal. Read more
§

impl<T> DynHash for T
where T: DynEq + Hash,

§

fn as_dyn_eq(&self) -> &(dyn DynEq + 'static)

Casts the type to dyn Any.
§

fn dyn_hash(&self, state: &mut dyn Hasher)

Feeds this value into the given Hasher.
§

impl<T> DynamicTypePath for T
where T: TypePath,

§

impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

§

fn equivalent(&self, key: &K) -> bool

Checks if this value is equivalent to the given key. Read more
§

impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

§

fn equivalent(&self, key: &K) -> bool

Compare self to key and return true if they are equal.
source§

impl<T> From<T> for T

source§

fn from(t: T) -> T

Returns the argument unchanged.

§

impl<S> FromSample<S> for S

§

fn from_sample_(s: S) -> S

§

impl<T> GetPath for T
where T: Reflect + ?Sized,

§

fn reflect_path<'p>( &self, path: impl ReflectPath<'p>, ) -> Result<&(dyn Reflect + 'static), ReflectPathError<'p>>

Returns a reference to the value specified by path. Read more
§

fn reflect_path_mut<'p>( &mut self, path: impl ReflectPath<'p>, ) -> Result<&mut (dyn Reflect + 'static), ReflectPathError<'p>>

Returns a mutable reference to the value specified by path. Read more
§

fn path<'p, T>( &self, path: impl ReflectPath<'p>, ) -> Result<&T, ReflectPathError<'p>>
where T: Reflect,

Returns a statically typed reference to the value specified by path. Read more
§

fn path_mut<'p, T>( &mut self, path: impl ReflectPath<'p>, ) -> Result<&mut T, ReflectPathError<'p>>
where T: Reflect,

Returns a statically typed mutable reference to the value specified by path. Read more
§

impl<S> GetTupleStructField for S
where S: TupleStruct,

§

fn get_field<T>(&self, index: usize) -> Option<&T>
where T: Reflect,

Returns a reference to the value of the field with index index, downcast to T.
§

fn get_field_mut<T>(&mut self, index: usize) -> Option<&mut T>
where T: Reflect,

Returns a mutable reference to the value of the field with index index, downcast to T.
§

impl<T> Instrument for T

§

fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
§

fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
source§

impl<T, U> Into<U> for T
where U: From<T>,

source§

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

source§

impl<T> IntoEither for T

source§

fn into_either(self, into_left: bool) -> Either<Self, Self>

Converts self into a Left variant of Either<Self, Self> if into_left is true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
source§

fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

Converts self into a Left variant of Either<Self, Self> if into_left(&self) returns true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
§

impl<F, T> IntoSample<T> for F
where T: FromSample<F>,

§

fn into_sample(self) -> T

§

impl<T> Pointable for T

§

const ALIGN: usize = _

The alignment of pointer.
§

type Init = T

The type for initializers.
§

unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
§

unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
§

unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
§

unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
source§

impl<T> Same for T

§

type Output = T

Should always be Self
source§

impl<T> ToOwned for T
where T: Clone,

§

type Owned = T

The resulting type after obtaining ownership.
source§

fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
source§

fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
§

impl<T, U> ToSample<U> for T
where U: FromSample<T>,

§

fn to_sample_(self) -> U

source§

impl<T, U> TryFrom<U> for T
where U: Into<T>,

§

type Error = Infallible

The type returned in the event of a conversion error.
source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
source§

impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

§

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
§

impl<T> TypeData for T
where T: 'static + Send + Sync + Clone,

§

fn clone_type_data(&self) -> Box<dyn TypeData>

§

impl<T> Upcast<T> for T

§

fn upcast(&self) -> Option<&T>

§

impl<V, T> VZip<V> for T
where V: MultiLane<T>,

§

fn vzip(self) -> V

§

impl<T> WithSubscriber for T

§

fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
§

fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more
§

impl<T> ConditionalSend for T
where T: Send,

§

impl<S, T> Duplex<S> for T
where T: FromSample<S> + ToSample<S>,

source§

impl<N> NodeTrait for N
where N: Copy + Ord + Hash,

§

impl<T> Settings for T
where T: 'static + Send + Sync,

§

impl<T> WasmNotSend for T
where T: Send,

§

impl<T> WasmNotSendSync for T
where T: WasmNotSend + WasmNotSync,

§

impl<T> WasmNotSync for T
where T: Sync,