Merge branch 'main' into process-configs

Cargo.toml

@@ -2284,6 +2284,17 @@ description = "Illustrates how to (constantly) rotate an object around an axis"
 category = "Transforms"
 wasm = true
 
+[[example]]
+name = "align"
+path = "examples/transforms/align.rs"
+doc-scrape-examples = true
+
+[package.metadata.example.align]
+name = "Alignment"
+description = "A demonstration of Transform's axis-alignment feature"
+category = "Transforms"
+wasm = true
+
 [[example]]
 name = "scale"
 path = "examples/transforms/scale.rs"

crates/bevy_ecs/src/entity/mod.rs

@@ -139,7 +139,7 @@ type IdCursor = isize;
 /// [`Query::get`]: crate::system::Query::get
 /// [`World`]: crate::world::World
 /// [SemVer]: https://semver.org/
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Debug)]
 #[cfg_attr(feature = "bevy_reflect", derive(Reflect))]
 #[cfg_attr(
  feature = "bevy_reflect",
@@ -384,9 +384,15 @@ impl<'de> Deserialize<'de> for Entity {
  }
 }
 
-impl fmt::Debug for Entity {
+impl fmt::Display for Entity {
  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
- write!(f, "{}v{}", self.index(), self.generation())
+ write!(
+ f,
+ "{}v{}|{}",
+ self.index(),
+ self.generation(),
+ self.to_bits()
+ )
  }
 }
 
@@ -1147,4 +1153,14 @@ mod tests {
  assert_ne!(hash, first_hash);
  }
  }
+
+ #[test]
+ fn entity_display() {
+ let entity = Entity::from_raw(42);
+ let string = format!("{}", entity);
+ let bits = entity.to_bits().to_string();
+ assert!(string.contains("42"));
+ assert!(string.contains("v1"));
+ assert!(string.contains(&bits));
+ }
 }

crates/bevy_ecs/src/query/state.rs

@@ -188,9 +188,17 @@ impl<D: QueryData, F: QueryFilter> QueryState<D, F> {
 
  /// Checks if the query is empty for the given [`World`], where the last change and current tick are given.
  ///
+ /// This is equivalent to `self.iter().next().is_none()`, and thus the worst case runtime will be `O(n)`
+ /// where `n` is the number of *potential* matches. This can be notably expensive for queries that rely
+ /// on non-archetypal filters such as [`Added`] or [`Changed`] which must individually check each query
+ /// result for a match.
+ ///
  /// # Panics
  ///
  /// If `world` does not match the one used to call `QueryState::new` for this instance.
+ ///
+ /// [`Added`]: crate::query::Added
+ /// [`Changed`]: crate::query::Changed
  #[inline]
  pub fn is_empty(&self, world: &World, last_run: Tick, this_run: Tick) -> bool {
  self.validate_world(world.id());

crates/bevy_ecs/src/system/query.rs

@@ -1208,6 +1208,11 @@ impl<'w, 's, D: QueryData, F: QueryFilter> Query<'w, 's, D, F> {
 
  /// Returns `true` if there are no query items.
  ///
+ /// This is equivalent to `self.iter().next().is_none()`, and thus the worst case runtime will be `O(n)`
+ /// where `n` is the number of *potential* matches. This can be notably expensive for queries that rely
+ /// on non-archetypal filters such as [`Added`] or [`Changed`] which must individually check each query
+ /// result for a match.
+ ///
  /// # Example
  ///
  /// Here, the score is increased only if an entity with a `Player` component is present in the world:
@@ -1226,6 +1231,9 @@ impl<'w, 's, D: QueryData, F: QueryFilter> Query<'w, 's, D, F> {
  /// }
  /// # bevy_ecs::system::assert_is_system(update_score_system);
  /// ```
+ ///
+ /// [`Added`]: crate::query::Added
+ /// [`Changed`]: crate::query::Changed
  #[inline]
  pub fn is_empty(&self) -> bool {
  // SAFETY:

crates/bevy_ecs/src/system/system_registry.rs

@@ -38,9 +38,11 @@ impl<I, O> RemovedSystem<I, O> {
 ///
 /// These are opaque identifiers, keyed to a specific [`World`],
 /// and are created via [`World::register_system`].
-#[derive(Eq)]
 pub struct SystemId<I = (), O = ()>(Entity, std::marker::PhantomData<fn(I) -> O>);
 
+// A manual impl is used because the trait bounds should ignore the `I` and `O` phantom parameters.
+impl<I, O> Eq for SystemId<I, O> {}
+
 // A manual impl is used because the trait bounds should ignore the `I` and `O` phantom parameters.
 impl<I, O> Copy for SystemId<I, O> {}