adapt examples to use system functions and state pattern

crates/bevy_input/src/lib.rs

@@ -4,7 +4,7 @@ pub mod system;
 
 use bevy_app::{AppBuilder, AppPlugin};
 use keyboard::KeyboardInput;
-use mouse::{MouseButtonInput, MouseMotion};
+use mouse::{MouseButtonInput, MouseMotionInput};
 
 #[derive(Default)]
 pub struct InputPlugin;
@@ -13,6 +13,6 @@ impl AppPlugin for InputPlugin {
     fn build(&self, app: &mut AppBuilder) {
         app.add_event::<KeyboardInput>()
             .add_event::<MouseButtonInput>()
-            .add_event::<MouseMotion>();
+            .add_event::<MouseMotionInput>();
     }
 }

crates/bevy_input/src/mouse.rs

@@ -15,6 +15,6 @@ pub enum MouseButton {
 }
 
 #[derive(Debug, Clone)]
-pub struct MouseMotion {
+pub struct MouseMotionInput {
     pub delta: (f64, f64),
 }

crates/bevy_winit/src/lib.rs

@@ -4,7 +4,7 @@ pub use winit_windows::*;
 
 use bevy_input::{
     keyboard::KeyboardInput,
-    mouse::{MouseButtonInput, MouseMotion},
+    mouse::{MouseButtonInput, MouseMotionInput},
 };
 
 use bevy_app::{App, AppBuilder, AppExit, AppPlugin, EventReader, Events, GetEventReader};
@@ -114,8 +114,8 @@ pub fn winit_runner(mut app: App) {
             event::Event::DeviceEvent { ref event, .. } => match event {
                 DeviceEvent::MouseMotion { delta } => {
                     let mut mouse_motion_events =
-                        app.resources.get_mut::<Events<MouseMotion>>().unwrap();
-                    mouse_motion_events.send(MouseMotion { delta: *delta });
+                        app.resources.get_mut::<Events<MouseMotionInput>>().unwrap();
+                    mouse_motion_events.send(MouseMotionInput { delta: *delta });
                 }
                 _ => {}
             },

examples/headless.rs

@@ -17,7 +17,7 @@ fn main() {
         .add_plugin(ScheduleRunnerPlugin {
             run_mode: RunMode::Once,
         })
-        .add_system(hello_world.system())
+        .add_system(hello_world_system.system())
         .run();
 
     // this app loops forever at 60 fps
@@ -27,10 +27,10 @@ fn main() {
                 wait: Some(Duration::from_secs_f64(1.0 / 60.0)),
             },
         })
-        .add_system(hello_world.system())
+        .add_system(hello_world_system.system())
         .run();
 }
 
-pub fn hello_world() {
+fn hello_world_system() {
     println!("hello world");
 }

examples/hello_world.rs

@@ -3,10 +3,10 @@ use bevy::prelude::*;
 fn main() {
     App::build()
         .add_default_plugins()
-        .add_system(hello_world.system())
+        .add_system(hello_world_system.system())
         .run();
 }
 
-pub fn hello_world() {
+fn hello_world_system() {
     println!("hello world");
 }

examples/input_keyboard.rs

@@ -6,53 +6,60 @@ use bevy::{
 fn main() {
     App::build()
         .add_default_plugins()
-        .add_system_init(move_on_input_system)
+        .add_resource_init::<State>()
+        .add_system(collect_input_system.system())
+        .add_system(move_system.system())
         .add_startup_system(setup)
         .run();
 }
 
+#[derive(Resource)]
+struct State {
+    event_reader: EventReader<KeyboardInput>,
+    moving_right: bool,
+    moving_left: bool,
+}
+
+/// adjusts move state based on keyboard input
+fn collect_input_system(
+    mut state: ResourceMut<State>,
+    keyboard_input_events: Resource<Events<KeyboardInput>>,
+) {
+    for event in state.event_reader.iter(&keyboard_input_events) {
+        match event {
+            KeyboardInput {
+                virtual_key_code: Some(VirtualKeyCode::Left),
+                state: element_state,
+                ..
+            } => {
+                state.moving_left = element_state.is_pressed();
+            }
+            KeyboardInput {
+                virtual_key_code: Some(VirtualKeyCode::Right),
+                state: element_state,
+                ..
+            } => {
+                state.moving_right = element_state.is_pressed();
+            }
+            _ => {}
+        }
+    }
+}
+
 /// moves our cube left when the "left" key is pressed. moves it right when the "right" key is pressed
-pub fn move_on_input_system(resources: &mut Resources) -> Box<dyn Schedulable> {
-    let mut keyboard_input_event_reader = resources.get_event_reader::<KeyboardInput>();
-    let mut moving_left = false;
-    let mut moving_right = false;
-    SystemBuilder::new("input_handler")
-        .read_resource::<Time>()
-        .read_resource::<Events<KeyboardInput>>()
-        .with_query(<(Write<Translation>, Read<Handle<Mesh>>)>::query())
-        .build(
-            move |_command_buffer, world, (time, keyboard_input_events), mesh_query| {
-                for event in keyboard_input_event_reader.iter(&keyboard_input_events) {
-                    match event {
-                        KeyboardInput {
-                            virtual_key_code: Some(VirtualKeyCode::Left),
-                            state,
-                            ..
-                        } => {
-                            moving_left = state.is_pressed();
-                        }
-                        KeyboardInput {
-                            virtual_key_code: Some(VirtualKeyCode::Right),
-                            state,
-                            ..
-                        } => {
-                            moving_right = state.is_pressed();
-                        }
-                        _ => {}
-                    }
-                }
+fn move_system(
+    state: Resource<State>,
+    time: Resource<Time>,
+    mut translation: RefMut<Translation>,
+    _: Ref<Handle<Mesh>>,
+) {
+    if state.moving_left {
+        translation.0 += math::vec3(1.0, 0.0, 0.0) * time.delta_seconds;
+    }
 
-                for (mut translation, _mesh) in mesh_query.iter_mut(world) {
-                    if moving_left {
-                        translation.0 += math::vec3(1.0, 0.0, 0.0) * time.delta_seconds;
-                    }
-
-                    if moving_right {
-                        translation.0 += math::vec3(-1.0, 0.0, 0.0) * time.delta_seconds;
-                    }
-                }
-            },
-        )
+    if state.moving_right {
+        translation.0 += math::vec3(-1.0, 0.0, 0.0) * time.delta_seconds;
+    }
 }
 
 /// creates a simple scene

examples/input_mouse.rs

@@ -1,34 +1,36 @@
 use bevy::{
-    input::mouse::{MouseButtonInput, MouseMotion},
+    input::mouse::{MouseButtonInput, MouseMotionInput},
     prelude::*,
 };
 
 fn main() {
     App::build()
         .add_default_plugins()
-        .add_system_init(mouse_input_system)
+        .add_resource_init::<State>()
+        .add_system(mouse_input_system.system())
         .run();
 }
 
-/// prints out mouse events as they come in
-pub fn mouse_input_system(resources: &mut Resources) -> Box<dyn Schedulable> {
-    let mut mouse_button_input_event_reader = resources.get_event_reader::<MouseButtonInput>();
-    let mut mouse_motion_event_reader = resources.get_event_reader::<MouseMotion>();
-    SystemBuilder::new("mouse_input")
-        .read_resource::<Events<MouseButtonInput>>()
-        .read_resource::<Events<MouseMotion>>()
-        .build(
-            move |_command_buffer,
-                  _world,
-                  (mouse_button_input_events, mouse_motion_events),
-                  _queries| {
-                for event in mouse_button_input_event_reader.iter(&mouse_button_input_events) {
-                    println!("{:?}", event);
-                }
-
-                for event in mouse_motion_event_reader.iter(&mouse_motion_events) {
-                    println!("{:?}", event);
-                }
-            },
-        )
+#[derive(Resource)]
+struct State {
+    mouse_button_event_reader: EventReader<MouseButtonInput>,
+    mouse_motion_event_reader: EventReader<MouseMotionInput>,
+}
+
+/// prints out mouse events as they come in
+fn mouse_input_system(
+    mut state: ResourceMut<State>,
+    mouse_button_input_events: Ref<Events<MouseButtonInput>>,
+    mouse_motion_events: Ref<Events<MouseMotionInput>>,
+) {
+    for event in state
+        .mouse_button_event_reader
+        .iter(&mouse_button_input_events)
+    {
+        println!("{:?}", event);
+    }
+
+    for event in state.mouse_motion_event_reader.iter(&mouse_motion_events) {
+        println!("{:?}", event);
+    }
 }

examples/parenting.rs

@@ -6,12 +6,12 @@ fn main() {
     App::build()
         .add_default_plugins()
         .add_startup_system(setup)
-        .add_system(rotator.system())
+        .add_system(rotator_system.system())
         .run();
 }
 
 /// rotates the parent, which will result in the child also rotating
-fn rotator(time: Resource<Time>, _rotator: RefMut<Rotator>, mut rotation: RefMut<Rotation>) {
+fn rotator_system(time: Resource<Time>, _rotator: RefMut<Rotator>, mut rotation: RefMut<Rotation>) {
     rotation.0 = rotation.0 * Quat::from_rotation_x(3.0 * time.delta_seconds);
 }
 

examples/serializing.rs

@@ -35,7 +35,7 @@ fn main() {
 
 #[derive(Serialize, Deserialize, TypeUuid)]
 #[uuid = "14dec17f-ae14-40a3-8e44-e487fc423287"]
-pub struct Test {
+struct Test {
     pub x: f32,
     pub y: f32,
 }

examples/startup_system.rs

@@ -3,14 +3,14 @@ use bevy::prelude::*;
 fn main() {
     App::build()
         .add_default_plugins()
-        .add_startup_system(startup.system())
+        .add_startup_system(startup_system.system())
         .run();
 }
 
 /// Set up a simple scene using a "startup system".
 /// Startup systems are run exactly once when the app starts up.
 /// They run right before "normal" systems run.
-fn startup(
+fn startup_system(
     command_buffer: &mut CommandBuffer,
     mut meshes: ResourceMut<AssetStorage<Mesh>>,
     mut materials: ResourceMut<AssetStorage<StandardMaterial>>,

examples/ui_bench.rs

@@ -4,7 +4,7 @@ fn main() {
     App::build()
         .add_default_plugins()
         .add_startup_system(setup)
-        .add_system(build_move_system())
+        .add_system(move_system.system())
         .add_plugin(DiagnosticsPlugin {
             print_diagnostics: true,
             ..Default::default()
@@ -12,18 +12,10 @@ fn main() {
         .run();
 }
 
-fn build_move_system() -> Box<dyn Schedulable> {
-    SystemBuilder::new("move")
-        .read_resource::<Time>()
-        .with_query(<Write<Node>>::query())
-        .build(move |_, world, time, query| {
-            for (_i, mut node) in query.iter_mut(world).enumerate() {
-                if node.color.r > 0.2 {
-                    node.position += Vec2::new(0.1 * time.delta_seconds, 0.0);
-                    // println!("{}", node.position.x());
-                }
-            }
-        })
+fn move_system(time: Resource<Time>, mut node: RefMut<Node>) {
+    if node.color.r > 0.2 {
+        node.position += Vec2::new(0.1 * time.delta_seconds, 0.0);
+    }
 }
 
 fn setup(world: &mut World, _resources: &mut Resources) {