simplify keyboard_input example

examples/input/keyboard_input.rs

@@ -6,74 +6,21 @@ use bevy::{
 fn main() {
     App::build()
         .add_default_plugins()
-        .add_startup_system(setup.system())
-        .add_system(move_on_input.system())
+        .add_system(keyboard_input_system.system())
         .run();
 }
 
-/// This system moves our cube left when the "left" key is pressed and moves it right when the "right" key is pressed
-fn move_on_input(
-    world: &mut SubWorld,
-    time: Res<Time>,
-    keyboard_input: Res<Input<KeyCode>>,
-    query: &mut Query<(Write<Translation>, Read<Handle<Mesh>>)>,
-) {
-    let moving_left = keyboard_input.pressed(KeyCode::Left);
-    let moving_right = keyboard_input.pressed(KeyCode::Right);
-
-    if keyboard_input.just_pressed(KeyCode::Left) {
-        println!("left just pressed");
+/// This system prints 'A' key state
+fn keyboard_input_system(keyboard_input: Res<Input<KeyCode>>) {
+    if keyboard_input.pressed(KeyCode::A) {
+        println!("'A' currently pressed");
     }
 
-    if keyboard_input.just_released(KeyCode::Left) {
-        println!("left just released");
+    if keyboard_input.just_pressed(KeyCode::A) {
+        println!("'A' just pressed");
     }
 
-    let speed = 3.0;
-    for (mut translation, _) in query.iter_mut(world) {
-        if moving_left {
-            translation.0 += math::vec3(speed, 0.0, 0.0) * time.delta_seconds;
-        }
-
-        if moving_right {
-            translation.0 += math::vec3(-speed, 0.0, 0.0) * time.delta_seconds;
-        }
+    if keyboard_input.just_released(KeyCode::A) {
+        println!("'A' just released");
     }
 }
-
-/// Creates a simple scene containing the cube we will be controlling
-fn setup(
-    command_buffer: &mut CommandBuffer,
-    mut meshes: ResMut<Assets<Mesh>>,
-    mut materials: ResMut<Assets<StandardMaterial>>,
-) {
-    let cube_handle = meshes.add(Mesh::from(shape::Cube { size: 1.0 }));
-    let cube_material_handle = materials.add(StandardMaterial {
-        albedo: Color::rgb(0.5, 0.4, 0.3),
-        ..Default::default()
-    });
-
-    command_buffer
-        .build()
-        // cube
-        .add_entity(MeshEntity {
-            mesh: cube_handle,
-            material: cube_material_handle,
-            translation: Translation::new(0.0, 0.0, 1.0),
-            ..Default::default()
-        })
-        // light
-        .add_entity(LightEntity {
-            translation: Translation::new(4.0, -4.0, 5.0),
-            ..Default::default()
-        })
-        // camera
-        .add_entity(PerspectiveCameraEntity {
-            local_to_world: LocalToWorld::new_sync_disabled(Mat4::look_at_rh(
-                Vec3::new(0.0, 8.0, 5.0),
-                Vec3::new(0.0, 0.0, 0.0),
-                Vec3::new(0.0, 0.0, 1.0),
-            )),
-            ..Default::default()
-        });
-}