Split TimePlugin out of CorePlugin

Author: CAD97

crates/bevy_core/Cargo.toml

@@ -16,7 +16,6 @@ bevy_ecs = { path = "../bevy_ecs", version = "0.8.0-dev", features = ["bevy_refl
 bevy_math = { path = "../bevy_math", version = "0.8.0-dev" }
 bevy_reflect = { path = "../bevy_reflect", version = "0.8.0-dev", features = ["bevy"] }
 bevy_tasks = { path = "../bevy_tasks", version = "0.8.0-dev" }
-bevy_time = { path = "../bevy_time", version = "0.8.0-dev" }
 bevy_utils = { path = "../bevy_utils", version = "0.8.0-dev" }
 
 # other

crates/bevy_core/src/lib.rs

@@ -17,27 +17,14 @@ pub mod prelude {
 }
 
 use bevy_app::prelude::*;
-use bevy_ecs::{
-    entity::Entity,
-    schedule::{ExclusiveSystemDescriptorCoercion, SystemLabel},
-    system::{IntoExclusiveSystem, ResMut},
-};
-use bevy_time::{FixedTimesteps, Time, Timer};
+use bevy_ecs::entity::Entity;
 use bevy_utils::HashSet;
 use std::ops::Range;
 
 /// Adds core functionality to Apps.
 #[derive(Default)]
 pub struct CorePlugin;
 
-/// A `SystemLabel` enum for ordering systems relative to core Bevy systems.
-#[derive(Debug, PartialEq, Eq, Clone, Hash, SystemLabel)]
-pub enum CoreSystem {
-    /// Updates the elapsed time. Any system that interacts with [Time] component should run after
-    /// this.
-    Time,
-}
-
 impl Plugin for CorePlugin {
     fn build(&self, app: &mut App) {
         // Setup the default bevy task pools
@@ -47,30 +34,17 @@ impl Plugin for CorePlugin {
             .unwrap_or_default()
             .create_default_pools(&mut app.world);
 
-        app.init_resource::<Time>()
-            .init_resource::<FixedTimesteps>()
-            .register_type::<HashSet<String>>()
+        app.register_type::<HashSet<String>>()
             .register_type::<Option<String>>()
             .register_type::<Entity>()
             .register_type::<Name>()
-            .register_type::<Range<f32>>()
-            .register_type::<Timer>()
-            // time system is added as an "exclusive system" to ensure it runs before other systems
-            // in CoreStage::First
-            .add_system_to_stage(
-                CoreStage::First,
-                time_system.exclusive_system().label(CoreSystem::Time),
-            );
+            .register_type::<Range<f32>>();
 
         register_rust_types(app);
         register_math_types(app);
     }
 }
 
-fn time_system(mut time: ResMut<Time>) {
-    time.update();
-}
-
 fn register_rust_types(app: &mut App) {
     app.register_type::<bool>()
         .register_type::<u8>()

crates/bevy_internal/src/default_plugins.rs

@@ -3,6 +3,7 @@ use bevy_app::{PluginGroup, PluginGroupBuilder};
 /// This plugin group will add all the default plugins:
 /// * [`LogPlugin`](bevy_log::LogPlugin)
 /// * [`CorePlugin`](bevy_core::CorePlugin)
+/// * [`TimePlugin`](bevy_time::TimePlugin)
 /// * [`TransformPlugin`](bevy_transform::TransformPlugin)
 /// * [`HierarchyPlugin`](bevy_hierarchy::HierarchyPlugin)
 /// * [`DiagnosticsPlugin`](bevy_diagnostic::DiagnosticsPlugin)
@@ -27,6 +28,7 @@ impl PluginGroup for DefaultPlugins {
     fn build(&mut self, group: &mut PluginGroupBuilder) {
         group.add(bevy_log::LogPlugin::default());
         group.add(bevy_core::CorePlugin::default());
+        group.add(bevy_time::TimePlugin::default());
         group.add(bevy_transform::TransformPlugin::default());
         group.add(bevy_hierarchy::HierarchyPlugin::default());
         group.add(bevy_diagnostic::DiagnosticsPlugin::default());
@@ -76,6 +78,7 @@ impl PluginGroup for DefaultPlugins {
 
 /// Minimal plugin group that will add the following plugins:
 /// * [`CorePlugin`](bevy_core::CorePlugin)
+/// * [`TimePlugin`](bevy_time::TimePlugin)
 /// * [`ScheduleRunnerPlugin`](bevy_app::ScheduleRunnerPlugin)
 ///
 /// See also [`DefaultPlugins`] for a more complete set of plugins
@@ -84,6 +87,7 @@ pub struct MinimalPlugins;
 impl PluginGroup for MinimalPlugins {
     fn build(&mut self, group: &mut PluginGroupBuilder) {
         group.add(bevy_core::CorePlugin::default());
+        group.add(bevy_time::TimePlugin::default());
         group.add(bevy_app::ScheduleRunnerPlugin::default());
     }
 }

crates/bevy_time/Cargo.toml

@@ -11,6 +11,7 @@ keywords = ["bevy"]
 
 [dependencies]
 # bevy
+bevy_app = { path = "../bevy_app", version = "0.8.0-dev" }
 bevy_ecs = { path = "../bevy_ecs", version = "0.8.0-dev", features = ["bevy_reflect"] }
 bevy_reflect = { path = "../bevy_reflect", version = "0.8.0-dev", features = ["bevy"] }
 bevy_utils = { path = "../bevy_utils", version = "0.8.0-dev" }

crates/bevy_time/src/lib.rs

@@ -14,3 +14,33 @@ pub mod prelude {
     #[doc(hidden)]
     pub use crate::{Time, Timer};
 }
+
+use bevy_app::prelude::*;
+use bevy_ecs::prelude::*;
+
+/// Adds time functionality to Apps.
+#[derive(Default)]
+pub struct TimePlugin;
+
+#[derive(Debug, PartialEq, Eq, Clone, Hash, SystemLabel)]
+/// Updates the elapsed time. Any system that interacts with [Time] component should run after
+/// this.
+pub struct TimeSystem;
+
+impl Plugin for TimePlugin {
+    fn build(&self, app: &mut App) {
+        app.init_resource::<Time>()
+            .init_resource::<FixedTimesteps>()
+            .register_type::<Timer>()
+            // time system is added as an "exclusive system" to ensure it runs before other systems
+            // in CoreStage::First
+            .add_system_to_stage(
+                CoreStage::First,
+                time_system.exclusive_system().at_start().label(TimeSystem),
+            );
+    }
+}
+
+fn time_system(mut time: ResMut<Time>) {
+    time.update();
+}

examples/2d/rotation.rs

@@ -1,7 +1,7 @@
 use bevy::{
-    time::FixedTimestep,
     math::{const_vec2, Vec3Swizzles},
     prelude::*,
+    time::FixedTimestep,
 };
 
 const TIME_STEP: f32 = 1.0 / 60.0;

examples/ecs/fixed_timestep.rs

@@ -1,6 +1,6 @@
 use bevy::{
-    time::{FixedTimestep, FixedTimesteps},
     prelude::*,
+    time::{FixedTimestep, FixedTimesteps},
 };
 
 const LABEL: &str = "my_fixed_timestep";

examples/ecs/iter_combinations.rs

@@ -1,4 +1,4 @@
-use bevy::{time::FixedTimestep, pbr::AmbientLight, prelude::*, render::camera::Camera};
+use bevy::{pbr::AmbientLight, prelude::*, render::camera::Camera, time::FixedTimestep};
 use rand::{thread_rng, Rng};
 
 #[derive(Debug, Hash, PartialEq, Eq, Clone, StageLabel)]

examples/games/alien_cake_addict.rs

@@ -1,4 +1,4 @@
-use bevy::{time::FixedTimestep, ecs::schedule::SystemSet, prelude::*, render::camera::Camera3d};
+use bevy::{ecs::schedule::SystemSet, prelude::*, render::camera::Camera3d, time::FixedTimestep};
 use rand::Rng;
 
 #[derive(Clone, Eq, PartialEq, Debug, Hash)]

examples/games/breakout.rs

@@ -1,10 +1,10 @@
 //! A simplified implementation of the classic game "Breakout"
 
 use bevy::{
-    time::FixedTimestep,
     math::{const_vec2, const_vec3},
     prelude::*,
     sprite::collide_aabb::{collide, Collision},
+    time::FixedTimestep,
 };
 
 // Defines the amount of time that should elapse between each physics step.

examples/stress_tests/bevymark.rs

@@ -1,7 +1,7 @@
 use bevy::{
-    time::FixedTimestep,
     diagnostic::{Diagnostics, FrameTimeDiagnosticsPlugin, LogDiagnosticsPlugin},
     prelude::*,
+    time::FixedTimestep,
     window::PresentMode,
 };
 use rand::{thread_rng, Rng};