Transform hierarchy split

crates/bevy_gltf/Cargo.toml

@@ -14,6 +14,7 @@ bevy_app = { path = "../bevy_app", version = "0.5.0" }
 bevy_asset = { path = "../bevy_asset", version = "0.5.0" }
 bevy_core = { path = "../bevy_core", version = "0.5.0" }
 bevy_ecs = { path = "../bevy_ecs", version = "0.5.0" }
+bevy_hierarchy = { path = "../bevy_hierarchy", version = "0.5.0" }
 bevy_pbr = { path = "../bevy_pbr", version = "0.5.0" }
 bevy_reflect = { path = "../bevy_reflect", version = "0.5.0", features = ["bevy"] }
 bevy_render = { path = "../bevy_render", version = "0.5.0" }

crates/bevy_gltf/src/loader.rs

@@ -4,6 +4,7 @@ use bevy_asset::{
 };
 use bevy_core::Name;
 use bevy_ecs::world::World;
+use bevy_hierarchy::prelude::{BuildWorldChildren, WorldChildBuilder};
 use bevy_log::warn;
 use bevy_math::Mat4;
 use bevy_pbr::prelude::{PbrBundle, StandardMaterial};
@@ -18,10 +19,7 @@ use bevy_render::{
     texture::{AddressMode, FilterMode, ImageType, SamplerDescriptor, TextureError, TextureFormat},
 };
 use bevy_scene::Scene;
-use bevy_transform::{
-    hierarchy::{BuildWorldChildren, WorldChildBuilder},
-    prelude::{GlobalTransform, Transform},
-};
+use bevy_transform::prelude::{GlobalTransform, Transform};
 use gltf::{
     mesh::Mode,
     texture::{MagFilter, MinFilter, WrappingMode},

crates/bevy_hierarchy/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "bevy_hierarchy"
+version = "0.5.0"
+edition = "2018"
+description = "Provides hierarchy and transform functionality for Bevy Engine"
+homepage = "https://bevyengine.org"
+repository = "https://github.com/bevyengine/bevy"
+license = "MIT OR Apache-2.0"
+keywords = ["bevy"]
+
+[dependencies]
+# bevy
+bevy_app = { path = "../bevy_app", version = "0.5.0" }
+bevy_ecs = { path = "../bevy_ecs", version = "0.5.0" }
+bevy_reflect = { path = "../bevy_reflect", version = "0.5.0", features = ["bevy"] }
+bevy_utils = { path = "../bevy_utils", version = "0.5.0" }
+
+# other
+smallvec = { version = "1.6", features = ["serde", "union", "const_generics"] }

crates/bevy_hierarchy/README.md

@@ -0,0 +1,3 @@
+# Bevy Hierarchy
+
+Provides the ability to work with a parent-child hierarchy of entities.

crates/bevy_hierarchy/src/components/mod.rs

@@ -0,0 +1,5 @@
+mod children;
+mod parent;
+
+pub use children::Children;
+pub use parent::{Parent, PreviousParent};

crates/bevy_transform/src/hierarchy/hierarchy_maintenance_system.rs → crates/bevy_hierarchy/src/hierarchy/hierarchy_maintenance_system.rs

@@ -71,101 +71,3 @@ pub fn parent_update_system(
         commands.entity(*e).insert(Children::with(v));
     });
 }
-#[cfg(test)]
-mod test {
-    use bevy_ecs::{
-        schedule::{Schedule, Stage, SystemStage},
-        system::CommandQueue,
-        world::World,
-    };
-
-    use super::*;
-    use crate::{hierarchy::BuildChildren, transform_propagate_system::transform_propagate_system};
-
-    #[test]
-    fn correct_children() {
-        let mut world = World::default();
-
-        let mut update_stage = SystemStage::parallel();
-        update_stage.add_system(parent_update_system);
-        update_stage.add_system(transform_propagate_system);
-
-        let mut schedule = Schedule::default();
-        schedule.add_stage("update", update_stage);
-
-        // Add parent entities
-        let mut command_queue = CommandQueue::default();
-        let mut commands = Commands::new(&mut command_queue, &world);
-        let mut children = Vec::new();
-        let parent = commands
-            .spawn()
-            .insert(Transform::from_xyz(1.0, 0.0, 0.0))
-            .id();
-        commands.entity(parent).with_children(|parent| {
-            children.push(
-                parent
-                    .spawn()
-                    .insert(Transform::from_xyz(0.0, 2.0, 0.0))
-                    .id(),
-            );
-            children.push(
-                parent
-                    .spawn()
-                    .insert(Transform::from_xyz(0.0, 3.0, 0.0))
-                    .id(),
-            );
-        });
-        command_queue.apply(&mut world);
-        schedule.run(&mut world);
-
-        assert_eq!(
-            world
-                .get::<Children>(parent)
-                .unwrap()
-                .0
-                .iter()
-                .cloned()
-                .collect::<Vec<_>>(),
-            children,
-        );
-
-        // Parent `e1` to `e2`.
-        (*world.get_mut::<Parent>(children[0]).unwrap()).0 = children[1];
-
-        schedule.run(&mut world);
-
-        assert_eq!(
-            world
-                .get::<Children>(parent)
-                .unwrap()
-                .iter()
-                .cloned()
-                .collect::<Vec<_>>(),
-            vec![children[1]]
-        );
-
-        assert_eq!(
-            world
-                .get::<Children>(children[1])
-                .unwrap()
-                .iter()
-                .cloned()
-                .collect::<Vec<_>>(),
-            vec![children[0]]
-        );
-
-        assert!(world.despawn(children[0]));
-
-        schedule.run(&mut world);
-
-        assert_eq!(
-            world
-                .get::<Children>(parent)
-                .unwrap()
-                .iter()
-                .cloned()
-                .collect::<Vec<_>>(),
-            vec![children[1]]
-        );
-    }
-}

crates/bevy_hierarchy/src/lib.rs

@@ -0,0 +1,34 @@
+pub mod components;
+pub mod hierarchy;
+
+pub mod prelude {
+    #[doc(hidden)]
+    pub use crate::{components::*, hierarchy::*};
+}
+
+use bevy_app::prelude::*;
+use bevy_ecs::schedule::{ParallelSystemDescriptorCoercion, SystemLabel};
+use prelude::{parent_update_system, Children, Parent, PreviousParent};
+
+#[derive(Default)]
+pub struct HierarchyPlugin;
+
+#[derive(Debug, Hash, PartialEq, Eq, Clone, SystemLabel)]
+pub struct ParentUpdate;
+
+impl Plugin for HierarchyPlugin {
+    fn build(&self, app: &mut App) {
+        app.register_type::<Children>()
+            .register_type::<Parent>()
+            .register_type::<PreviousParent>()
+            // add hierarchy system to startup so the first update is "correct"
+            .add_startup_system_to_stage(
+                StartupStage::PostStartup,
+                parent_update_system.label(ParentUpdate),
+            )
+            .add_system_to_stage(
+                CoreStage::PostUpdate,
+                parent_update_system.label(ParentUpdate),
+            );
+    }
+}

crates/bevy_internal/Cargo.toml

@@ -51,6 +51,7 @@ bevy_core = { path = "../bevy_core", version = "0.5.0" }
 bevy_derive = { path = "../bevy_derive", version = "0.5.0" }
 bevy_diagnostic = { path = "../bevy_diagnostic", version = "0.5.0" }
 bevy_ecs = { path = "../bevy_ecs", version = "0.5.0" }
+bevy_hierarchy = { path = "../bevy_hierarchy", version = "0.5.0" }
 bevy_input = { path = "../bevy_input", version = "0.5.0" }
 bevy_log = { path = "../bevy_log", version = "0.5.0" }
 bevy_math = { path = "../bevy_math", version = "0.5.0" }

crates/bevy_internal/src/default_plugins.rs

@@ -10,6 +10,7 @@ use bevy_diagnostic::DiagnosticsPlugin;
 use bevy_gilrs::GilrsPlugin;
 #[cfg(feature = "bevy_gltf")]
 use bevy_gltf::GltfPlugin;
+use bevy_hierarchy::HierarchyPlugin;
 use bevy_input::InputPlugin;
 use bevy_log::LogPlugin;
 #[cfg(feature = "bevy_pbr")]
@@ -33,6 +34,7 @@ use bevy_winit::WinitPlugin;
 /// This plugin group will add all the default plugins:
 /// * [`LogPlugin`]
 /// * [`CorePlugin`]
+/// * [`HierarchyPlugin`]
 /// * [`TransformPlugin`]
 /// * [`DiagnosticsPlugin`]
 /// * [`InputPlugin`]
@@ -57,6 +59,7 @@ impl PluginGroup for DefaultPlugins {
     fn build(&mut self, group: &mut PluginGroupBuilder) {
         group.add(LogPlugin::default());
         group.add(CorePlugin::default());
+        group.add(HierarchyPlugin::default());
         group.add(TransformPlugin::default());
         group.add(DiagnosticsPlugin::default());
         group.add(InputPlugin::default());

crates/bevy_internal/src/lib.rs

@@ -29,6 +29,11 @@ pub mod ecs {
     pub use bevy_ecs::*;
 }
 
+pub mod hierarchy {
+    //! Parent-child hierarchy.
+    pub use bevy_hierarchy::*;
+}
+
 pub mod input {
     //! Resources and events for inputs, e.g. mouse/keyboard, touch, gamepads, etc.
     pub use bevy_input::*;

crates/bevy_internal/src/prelude.rs

@@ -1,7 +1,7 @@
 #[doc(hidden)]
 pub use crate::{
-    app::prelude::*, asset::prelude::*, core::prelude::*, ecs::prelude::*, input::prelude::*,
-    log::prelude::*, math::prelude::*, reflect::prelude::*, scene::prelude::*,
+    app::prelude::*, asset::prelude::*, core::prelude::*, ecs::prelude::*, hierarchy::prelude::*,
+    input::prelude::*, log::prelude::*, math::prelude::*, reflect::prelude::*, scene::prelude::*,
     transform::prelude::*, window::prelude::*, DefaultPlugins, MinimalPlugins,
 };
 

crates/bevy_render/src/lib.rs

@@ -16,7 +16,7 @@ use bevy_ecs::{
     schedule::{ParallelSystemDescriptorCoercion, SystemStage},
     system::{IntoExclusiveSystem, Res},
 };
-use bevy_transform::TransformSystem;
+use bevy_transform::TransformPropagate;
 use bevy_utils::tracing::warn;
 use draw::{OutsideFrustum, Visible};
 
@@ -189,7 +189,7 @@ impl Plugin for RenderPlugin {
             CoreStage::PostUpdate,
             camera::visible_entities_system
                 .label(RenderSystem::VisibleEntities)
-                .after(TransformSystem::TransformPropagate),
+                .after(TransformPropagate),
         )
         .add_system_to_stage(RenderStage::RenderResource, shader::shader_update_system)
         .add_system_to_stage(

crates/bevy_scene/Cargo.toml

@@ -13,8 +13,8 @@ keywords = ["bevy"]
 bevy_app = { path = "../bevy_app", version = "0.5.0" }
 bevy_asset = { path = "../bevy_asset", version = "0.5.0" }
 bevy_ecs = { path = "../bevy_ecs", version = "0.5.0" }
+bevy_hierarchy = { path = "../bevy_hierarchy", version = "0.5.0" }
 bevy_reflect = { path = "../bevy_reflect", version = "0.5.0", features = ["bevy"] }
-bevy_transform = { path = "../bevy_transform", version = "0.5.0" }
 bevy_utils = { path = "../bevy_utils", version = "0.5.0" }
 
 # other

crates/bevy_scene/src/command.rs

@@ -4,7 +4,7 @@ use bevy_ecs::{
     system::{Command, Commands},
     world::World,
 };
-use bevy_transform::hierarchy::ChildBuilder;
+use bevy_hierarchy::prelude::ChildBuilder;
 
 use crate::{Scene, SceneSpawner};
 

crates/bevy_scene/src/scene_spawner.rs

@@ -6,8 +6,8 @@ use bevy_ecs::{
     reflect::{ReflectComponent, ReflectMapEntities},
     world::{Mut, World},
 };
+use bevy_hierarchy::prelude::Parent;
 use bevy_reflect::TypeRegistryArc;
-use bevy_transform::prelude::Parent;
 use bevy_utils::{tracing::error, HashMap};
 use thiserror::Error;
 use uuid::Uuid;

crates/bevy_transform/Cargo.toml

@@ -12,9 +12,6 @@ keywords = ["bevy"]
 # bevy
 bevy_app = { path = "../bevy_app", version = "0.5.0" }
 bevy_ecs = { path = "../bevy_ecs", version = "0.5.0" }
+bevy_hierarchy = { path = "../bevy_hierarchy", version = "0.5.0" }
 bevy_math = { path = "../bevy_math", version = "0.5.0" }
 bevy_reflect = { path = "../bevy_reflect", version = "0.5.0", features = ["bevy"] }
-bevy_utils = { path = "../bevy_utils", version = "0.5.0" }
-
-# other
-smallvec = { version = "1.6", features = ["serde", "union", "const_generics"] }

crates/bevy_transform/README.md

@@ -1,3 +1,5 @@
 # Bevy Transform
 
-This crate is largely a 1:1 port from [legion_transform](https://github.com/AThilenius/legion_transform) (ecs: legion, math: nalgebra) to bevy (ecs: bevy_ecs, math: glam)
+This crate was largely a 1:1 port from [legion_transform](https://github.com/AThilenius/legion_transform) (ecs: legion, math: nalgebra) to bevy (ecs: bevy_ecs, math: glam)
+
+It has since been split into two crates; this one, and `bevy_hierarchy`.

crates/bevy_transform/src/components/mod.rs

@@ -1,9 +1,5 @@
-mod children;
 mod global_transform;
-mod parent;
 mod transform;
 
-pub use children::Children;
 pub use global_transform::*;
-pub use parent::{Parent, PreviousParent};
 pub use transform::*;

crates/bevy_transform/src/lib.rs

@@ -1,52 +1,38 @@
 pub mod components;
-pub mod hierarchy;
 pub mod transform_propagate_system;
 
 pub mod prelude {
     #[doc(hidden)]
-    pub use crate::{components::*, hierarchy::*, TransformPlugin};
+    pub use crate::{components::*, TransformPlugin};
 }
 
 use bevy_app::prelude::*;
 use bevy_ecs::schedule::{ParallelSystemDescriptorCoercion, SystemLabel};
-use prelude::{parent_update_system, Children, GlobalTransform, Parent, PreviousParent, Transform};
+use bevy_hierarchy::ParentUpdate;
+use prelude::{GlobalTransform, Transform};
 
 #[derive(Default)]
 pub struct TransformPlugin;
 
 #[derive(Debug, Hash, PartialEq, Eq, Clone, SystemLabel)]
-pub enum TransformSystem {
-    TransformPropagate,
-    ParentUpdate,
-}
+pub struct TransformPropagate;
 
 impl Plugin for TransformPlugin {
     fn build(&self, app: &mut App) {
-        app.register_type::<Children>()
-            .register_type::<Parent>()
-            .register_type::<PreviousParent>()
-            .register_type::<Transform>()
+        app.register_type::<Transform>()
             .register_type::<GlobalTransform>()
             // add transform systems to startup so the first update is "correct"
-            .add_startup_system_to_stage(
-                StartupStage::PostStartup,
-                parent_update_system.label(TransformSystem::ParentUpdate),
-            )
             .add_startup_system_to_stage(
                 StartupStage::PostStartup,
                 transform_propagate_system::transform_propagate_system
-                    .label(TransformSystem::TransformPropagate)
-                    .after(TransformSystem::ParentUpdate),
-            )
-            .add_system_to_stage(
-                CoreStage::PostUpdate,
-                parent_update_system.label(TransformSystem::ParentUpdate),
+                    .label(TransformPropagate)
+                    .after(ParentUpdate),
             )
             .add_system_to_stage(
                 CoreStage::PostUpdate,
                 transform_propagate_system::transform_propagate_system
-                    .label(TransformSystem::TransformPropagate)
-                    .after(TransformSystem::ParentUpdate),
+                    .label(TransformPropagate)
+                    .after(ParentUpdate),
             );
     }
 }