Convert queries to a more general form

crates/bevy_ecs/macros/src/fetch.rs

@@ -352,6 +352,12 @@ pub fn derive_world_query_impl(input: TokenStream) -> TokenStream {
                     }
                 }
 
+                fn new_state(components: &#path::component::Components) -> Option<#state_struct_name #user_ty_generics> {
+                    Some(#state_struct_name {
+                        #(#named_field_idents: <#field_types>::new_state(components)?,)*
+                    })
+                }
+
                 fn matches_component_set(state: &Self::State, _set_contains_id: &impl Fn(#path::component::ComponentId) -> bool) -> bool {
                     true #(&& <#field_types>::matches_component_set(&state.#named_field_idents, _set_contains_id))*
                 }

crates/bevy_ecs/src/query/access.rs

@@ -198,6 +198,32 @@ impl<T: SparseSetIndex> Access<T> {
             && other.writes.is_disjoint(&self.reads_and_writes)
     }
 
+    /// [`Access`] is subset of `other` access.
+    pub fn is_subset(&self, other: &Access<T>) -> bool {
+        if self.writes_all {
+            return other.writes_all;
+        }
+
+        if other.writes_all {
+            return true;
+        }
+
+        if self.reads_all {
+            return other.reads_all || other.writes_all;
+        }
+
+        if other.reads_all {
+            return self.has_any_write();
+        }
+
+        let reads = self
+            .reads_and_writes
+            .difference(&self.writes)
+            .collect::<FixedBitSet>();
+
+        reads.is_subset(&other.reads_and_writes) && self.writes.is_subset(&other.writes)
+    }
+
     /// Returns a vector of elements that the access and `other` cannot access at the same time.
     pub fn get_conflicts(&self, other: &Access<T>) -> Vec<T> {
         let mut conflicts = FixedBitSet::default();
@@ -374,6 +400,11 @@ impl<T: SparseSetIndex> FilteredAccess<T> {
         })
     }
 
+    ///  access is compatible with other access. This does not take into account the filtered access.
+    pub fn is_subset(&self, other: &FilteredAccess<T>) -> bool {
+        self.access.is_subset(&other.access)
+    }
+
     /// Returns a vector of elements that this and `other` cannot access at the same time.
     pub fn get_conflicts(&self, other: &FilteredAccess<T>) -> Vec<T> {
         if !self.is_compatible(other) {

crates/bevy_ecs/src/query/fetch.rs

@@ -1,7 +1,7 @@
 use crate::{
     archetype::{Archetype, ArchetypeComponentId},
     change_detection::{Ticks, TicksMut},
-    component::{Component, ComponentId, ComponentStorage, StorageType, Tick},
+    component::{Component, ComponentId, ComponentStorage, Components, StorageType, Tick},
     entity::Entity,
     query::{Access, DebugCheckedUnwrap, FilteredAccess},
     storage::{ComponentSparseSet, Table, TableRow},
@@ -440,6 +440,10 @@ pub unsafe trait WorldQuery {
     /// Creates and initializes a [`State`](WorldQuery::State) for this [`WorldQuery`] type.
     fn init_state(world: &mut World) -> Self::State;
 
+    /// Creates a [`State`](WorldQuery::State) for this [`WorldQuery`] type. This should return
+    /// the same value as [`init_state`](Self::init_state).
+    fn new_state(components: &Components) -> Option<Self::State>;
+
     /// Returns `true` if this query matches a set of components. Otherwise, returns `false`.
     fn matches_component_set(
         state: &Self::State,
@@ -515,6 +519,10 @@ unsafe impl WorldQuery for Entity {
 
     fn init_state(_world: &mut World) {}
 
+    fn new_state(_components: &Components) -> Option<()> {
+        Some(())
+    }
+
     fn matches_component_set(
         _state: &Self::State,
         _set_contains_id: &impl Fn(ComponentId) -> bool,
@@ -595,6 +603,10 @@ unsafe impl WorldQuery for EntityRef<'_> {
 
     fn init_state(_world: &mut World) {}
 
+    fn new_state(_components: &Components) -> Option<()> {
+        Some(())
+    }
+
     fn matches_component_set(
         _state: &Self::State,
         _set_contains_id: &impl Fn(ComponentId) -> bool,
@@ -675,6 +687,10 @@ unsafe impl<'a> WorldQuery for EntityMut<'a> {
 
     fn init_state(_world: &mut World) {}
 
+    fn new_state(_components: &Components) -> Option<()> {
+        Some(())
+    }
+
     fn matches_component_set(
         _state: &Self::State,
         _set_contains_id: &impl Fn(ComponentId) -> bool,
@@ -815,6 +831,10 @@ unsafe impl<T: Component> WorldQuery for &T {
         world.init_component::<T>()
     }
 
+    fn new_state(components: &Components) -> Option<ComponentId> {
+        components.component_id::<T>()
+    }
+
     fn matches_component_set(
         &state: &ComponentId,
         set_contains_id: &impl Fn(ComponentId) -> bool,
@@ -976,6 +996,10 @@ unsafe impl<'__w, T: Component> WorldQuery for Ref<'__w, T> {
         world.init_component::<T>()
     }
 
+    fn new_state(components: &Components) -> Option<ComponentId> {
+        components.component_id::<T>()
+    }
+
     fn matches_component_set(
         &state: &ComponentId,
         set_contains_id: &impl Fn(ComponentId) -> bool,
@@ -1137,6 +1161,10 @@ unsafe impl<'__w, T: Component> WorldQuery for &'__w mut T {
         world.init_component::<T>()
     }
 
+    fn new_state(components: &Components) -> Option<ComponentId> {
+        components.component_id::<T>()
+    }
+
     fn matches_component_set(
         &state: &ComponentId,
         set_contains_id: &impl Fn(ComponentId) -> bool,
@@ -1249,6 +1277,10 @@ unsafe impl<T: WorldQuery> WorldQuery for Option<T> {
         T::init_state(world)
     }
 
+    fn new_state(components: &Components) -> Option<T::State> {
+        T::new_state(components)
+    }
+
     fn matches_component_set(
         _state: &T::State,
         _set_contains_id: &impl Fn(ComponentId) -> bool,
@@ -1384,6 +1416,10 @@ unsafe impl<T: Component> WorldQuery for Has<T> {
         world.init_component::<T>()
     }
 
+    fn new_state(components: &Components) -> Option<ComponentId> {
+        components.component_id::<T>()
+    }
+
     fn matches_component_set(
         _state: &Self::State,
         _set_contains_id: &impl Fn(ComponentId) -> bool,
@@ -1480,6 +1516,10 @@ macro_rules! impl_tuple_fetch {
                 ($($name::init_state(_world),)*)
             }
 
+            fn new_state(_components: &Components) -> Option<Self::State> {
+                Some(($($name::new_state(_components)?,)*))
+            }
+
             fn matches_component_set(state: &Self::State, _set_contains_id: &impl Fn(ComponentId) -> bool) -> bool {
                 let ($($name,)*) = state;
                 true $(&& $name::matches_component_set($name, _set_contains_id))*
@@ -1603,6 +1643,10 @@ macro_rules! impl_anytuple_fetch {
                 ($($name::init_state(_world),)*)
             }
 
+            fn new_state(_components: &Components) -> Option<Self::State> {
+                Some(($($name::new_state(_components)?,)*))
+            }
+
             fn matches_component_set(_state: &Self::State, _set_contains_id: &impl Fn(ComponentId) -> bool) -> bool {
                 let ($($name,)*) = _state;
                 false $(|| $name::matches_component_set($name, _set_contains_id))*
@@ -1677,6 +1721,10 @@ unsafe impl<Q: WorldQuery> WorldQuery for NopWorldQuery<Q> {
         Q::init_state(world)
     }
 
+    fn new_state(components: &Components) -> Option<Self::State> {
+        Q::new_state(components)
+    }
+
     fn matches_component_set(
         state: &Self::State,
         set_contains_id: &impl Fn(ComponentId) -> bool,
@@ -1740,6 +1788,10 @@ unsafe impl<T: ?Sized> WorldQuery for PhantomData<T> {
 
     fn init_state(_world: &mut World) -> Self::State {}
 
+    fn new_state(_components: &Components) -> Option<Self::State> {
+        Some(())
+    }
+
     fn matches_component_set(
         _state: &Self::State,
         _set_contains_id: &impl Fn(ComponentId) -> bool,

crates/bevy_ecs/src/query/filter.rs

@@ -1,6 +1,6 @@
 use crate::{
     archetype::{Archetype, ArchetypeComponentId},
-    component::{Component, ComponentId, ComponentStorage, StorageType, Tick},
+    component::{Component, ComponentId, ComponentStorage, Components, StorageType, Tick},
     entity::Entity,
     query::{Access, DebugCheckedUnwrap, FilteredAccess, WorldQuery},
     storage::{Column, ComponentSparseSet, Table, TableRow},
@@ -105,6 +105,10 @@ unsafe impl<T: Component> WorldQuery for With<T> {
         world.init_component::<T>()
     }
 
+    fn new_state(components: &Components) -> Option<Self::State> {
+        components.component_id::<T>()
+    }
+
     fn matches_component_set(
         &id: &ComponentId,
         set_contains_id: &impl Fn(ComponentId) -> bool,
@@ -206,6 +210,10 @@ unsafe impl<T: Component> WorldQuery for Without<T> {
         world.init_component::<T>()
     }
 
+    fn new_state(components: &Components) -> Option<Self::State> {
+        components.component_id::<T>()
+    }
+
     fn matches_component_set(
         &id: &ComponentId,
         set_contains_id: &impl Fn(ComponentId) -> bool,
@@ -370,6 +378,10 @@ macro_rules! impl_query_filter_tuple {
                 ($($filter::init_state(world),)*)
             }
 
+            fn new_state(components: &Components) -> Option<Self::State> {
+                Some(($($filter::new_state(components)?,)*))
+            }
+
             fn matches_component_set(_state: &Self::State, _set_contains_id: &impl Fn(ComponentId) -> bool) -> bool {
                 let ($($filter,)*) = _state;
                 false $(|| $filter::matches_component_set($filter, _set_contains_id))*
@@ -533,6 +545,10 @@ macro_rules! impl_tick_filter {
                 world.init_component::<T>()
             }
 
+            fn new_state(components: &Components) -> Option<ComponentId> {
+                components.component_id::<T>()
+            }
+
             fn matches_component_set(&id: &ComponentId, set_contains_id: &impl Fn(ComponentId) -> bool) -> bool {
                 set_contains_id(id)
             }