pub struct Added<T>(/* private fields */);
Expand description
A filter on a component that only retains results added after the system last ran.
A common use for this filter is one-time initialization.
To retain all results without filtering but still check whether they were added after the
system last ran, use Ref<T>
.
Examples
fn print_add_name_component(query: Query<&Name, Added<Name>>) {
for name in &query {
println!("Named entity created: {:?}", name)
}
}
Trait Implementations§
§impl<T> WorldQuery for Added<T>where
T: Component,
impl<T> WorldQuery for Added<T>where T: Component,
§type Fetch<'w> = AddedFetch<'w>
type Fetch<'w> = AddedFetch<'w>
Per archetype/table state used by this
WorldQuery
to fetch Self::Item
§type Item<'w> = bool
type Item<'w> = bool
The item returned by this
WorldQuery
§type ReadOnly = Added<T>
type ReadOnly = Added<T>
The read-only variant of this
WorldQuery
, which satisfies the ReadOnlyWorldQuery
trait.§type State = ComponentId
type State = ComponentId
State used to construct a
Self::Fetch
. This will be cached inside QueryState
,
so it is best to move as much data / computation here as possible to reduce the cost of
constructing Self::Fetch
.§fn shrink<'wlong, 'wshort>(
item: <Added<T> as WorldQuery>::Item<'wlong>
) -> <Added<T> as WorldQuery>::Item<'wshort>where
'wlong: 'wshort,
fn shrink<'wlong, 'wshort>( item: <Added<T> as WorldQuery>::Item<'wlong> ) -> <Added<T> as WorldQuery>::Item<'wshort>where 'wlong: 'wshort,
This function manually implements subtyping for the query items.
§unsafe fn init_fetch<'w>(
world: UnsafeWorldCell<'w>,
_: &ComponentId,
last_run: Tick,
this_run: Tick
) -> <Added<T> as WorldQuery>::Fetch<'w>
unsafe fn init_fetch<'w>( world: UnsafeWorldCell<'w>, _: &ComponentId, last_run: Tick, this_run: Tick ) -> <Added<T> as WorldQuery>::Fetch<'w>
Creates a new instance of this fetch. Read more
§const IS_DENSE: bool = _
const IS_DENSE: bool = _
Returns true if (and only if) every table of every archetype matched by this fetch contains
all of the matched components. This is used to select a more efficient “table iterator”
for “dense” queries. If this returns true,
WorldQuery::set_table
must be used before
WorldQuery::fetch
can be called for iterators. If this returns false,
WorldQuery::set_archetype
must be used before WorldQuery::fetch
can be called for
iterators.§const IS_ARCHETYPAL: bool = false
const IS_ARCHETYPAL: bool = false
Returns true if (and only if) this Fetch relies strictly on archetypes to limit which
components are accessed by the Query. Read more
§unsafe fn set_table<'w>(
fetch: &mut <Added<T> as WorldQuery>::Fetch<'w>,
_: &ComponentId,
table: &'w Table
)
unsafe fn set_table<'w>( fetch: &mut <Added<T> as WorldQuery>::Fetch<'w>, _: &ComponentId, table: &'w Table )
Adjusts internal state to account for the next
Table
. This will always be called on tables
that match this WorldQuery
. Read more§unsafe fn set_archetype<'w>(
fetch: &mut <Added<T> as WorldQuery>::Fetch<'w>,
component_id: &ComponentId,
_archetype: &'w Archetype,
table: &'w Table
)
unsafe fn set_archetype<'w>( fetch: &mut <Added<T> as WorldQuery>::Fetch<'w>, component_id: &ComponentId, _archetype: &'w Archetype, table: &'w Table )
Adjusts internal state to account for the next
Archetype
. This will always be called on
archetypes that match this WorldQuery
. Read more§unsafe fn fetch<'w>(
fetch: &mut <Added<T> as WorldQuery>::Fetch<'w>,
entity: Entity,
table_row: TableRow
) -> <Added<T> as WorldQuery>::Item<'w>
unsafe fn fetch<'w>( fetch: &mut <Added<T> as WorldQuery>::Fetch<'w>, entity: Entity, table_row: TableRow ) -> <Added<T> as WorldQuery>::Item<'w>
Fetch
Self::Item
for either the given entity
in the current Table
,
or for the given entity
in the current Archetype
. This must always be called after
WorldQuery::set_table
with a table_row
in the range of the current Table
or after
WorldQuery::set_archetype
with a entity
in the current archetype. Read more§unsafe fn filter_fetch(
fetch: &mut <Added<T> as WorldQuery>::Fetch<'_>,
entity: Entity,
table_row: TableRow
) -> bool
unsafe fn filter_fetch( fetch: &mut <Added<T> as WorldQuery>::Fetch<'_>, entity: Entity, table_row: TableRow ) -> bool
Safety Read more
§fn update_component_access(
_: &ComponentId,
access: &mut FilteredAccess<ComponentId>
)
fn update_component_access( _: &ComponentId, access: &mut FilteredAccess<ComponentId> )
Adds any component accesses used by this
WorldQuery
to access
.§fn update_archetype_component_access(
_: &ComponentId,
archetype: &Archetype,
access: &mut Access<ArchetypeComponentId>
)
fn update_archetype_component_access( _: &ComponentId, archetype: &Archetype, access: &mut Access<ArchetypeComponentId> )
§fn init_state(world: &mut World) -> ComponentId
fn init_state(world: &mut World) -> ComponentId
Creates and initializes a
State
for this WorldQuery
type.§fn matches_component_set(
_: &ComponentId,
set_contains_id: &impl Fn(ComponentId) -> bool
) -> bool
fn matches_component_set( _: &ComponentId, set_contains_id: &impl Fn(ComponentId) -> bool ) -> bool
Returns
true
if this query matches a set of components. Otherwise, returns false
.impl<T> ReadOnlyWorldQuery for Added<T>where T: Component,
SAFETY: read-only access
Auto Trait Implementations§
impl<T> RefUnwindSafe for Added<T>where T: RefUnwindSafe,
impl<T> Send for Added<T>where T: Send,
impl<T> Sync for Added<T>where T: Sync,
impl<T> Unpin for Added<T>where T: Unpin,
impl<T> UnwindSafe for Added<T>where T: UnwindSafe,
Blanket Implementations§
§impl<T, U> AsBindGroupShaderType<U> for Twhere
U: ShaderType,
&'a T: for<'a> Into<U>,
impl<T, U> AsBindGroupShaderType<U> for Twhere U: ShaderType, &'a T: for<'a> Into<U>,
§fn as_bind_group_shader_type(&self, _images: &RenderAssets<Image>) -> U
fn as_bind_group_shader_type(&self, _images: &RenderAssets<Image>) -> 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> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
§impl<T> Downcast for Twhere
T: Any,
impl<T> Downcast for Twhere T: Any,
§fn into_any(self: Box<T>) -> Box<dyn 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>
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)
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)
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.