fly camera

src/plugins/game.rs

@@ -1,14 +1,32 @@
-use bevy::prelude::*;
+use std::f32::consts::FRAC_PI_2;
+
+use bevy::{
+	input::mouse::MouseMotion,
+	prelude::*,
+	window::{CursorGrabMode, PrimaryWindow},
+};
 // use bevy_rapier3d::prelude::*;
 
 #[derive(Default)]
-pub struct GamePlugin {}
+pub struct GamePlugin;
+
+#[derive(Component, Default)]
+pub struct MainCamera;
+
+#[derive(Component, Default)]
+pub struct CameraRoot;
+#[derive(Component, Default)]
+pub struct CameraPitch(pub f32);
+#[derive(Component)]
+pub struct Unfocused;
 
 impl Plugin for GamePlugin {
 	fn build(&self, app: &mut bevy::app::App) {
 		// app.add_plugins(RapierPhysicsPlugin::<NoUserData>::default());
 
 		app.add_systems(Startup, (setup_scene, spawn_ship));
+
+		app.add_systems(Update, ((camera_yaw, camera_pitch).chain(), camera_toggle, fly_camera));
 	}
 }
 
@@ -16,8 +34,23 @@ fn setup_scene(
 	mut commands: Commands,
 	mut meshes: ResMut<Assets<Mesh>>,
 	mut materials: ResMut<Assets<StandardMaterial>>,
+	mut window: Single<&mut Window, With<PrimaryWindow>>,
 ) {
-	commands.spawn((Camera3d::default(), Transform::from_xyz(0.0, 1.3, 0.0)));
+	window.cursor_options.visible = false;
+	window.cursor_options.grab_mode = CursorGrabMode::Locked;
+
+	commands.spawn((
+		Name::new("Camera Root"),
+		Transform::from_xyz(0.0, 1.3, 0.0),
+		CameraRoot::default(),
+		Visibility::default(),
+		children![(
+			Camera3d::default(),
+			CameraPitch::default(),
+			MainCamera::default(),
+			Transform::default()
+		)],
+	));
 
 	commands.spawn((
 		DirectionalLight {
@@ -83,3 +116,84 @@ fn spawn_ship(
 		],
 	));
 }
+
+pub fn camera_toggle(
+	key: Res<ButtonInput<KeyCode>>,
+	window_query: Single<&mut Window, With<PrimaryWindow>>,
+	camera: Single<Entity, With<CameraRoot>>,
+	mut commands: Commands,
+) {
+	let mut window = window_query.into_inner();
+	if key.just_pressed(KeyCode::Escape) {
+		if window.cursor_options.visible {
+			commands.entity(camera.into_inner()).remove::<Unfocused>();
+			window.cursor_options.grab_mode = CursorGrabMode::Locked;
+			window.cursor_options.visible = false;
+		} else {
+			commands.entity(camera.into_inner()).insert(Unfocused);
+			window.cursor_options.grab_mode = CursorGrabMode::None;
+			window.cursor_options.visible = true;
+		}
+	}
+}
+
+const FLY_SPEED: f32 = 10.0;
+pub fn fly_camera(
+	cam_query: Single<&mut Transform, (With<CameraRoot>, Without<Unfocused>)>,
+	cam_pitch: Single<&CameraPitch>,
+	key: Res<ButtonInput<KeyCode>>,
+	time: Res<Time>,
+) {
+	let mut move_dir = Vec3::ZERO;
+	let pitch = cam_pitch.0;
+	let mut cam_transform = cam_query.into_inner();
+
+	if key.pressed(KeyCode::KeyW) {
+		move_dir.z = -1.0;
+	} else if key.pressed(KeyCode::KeyS) {
+		move_dir.z = 1.0;
+	}
+
+	if key.pressed(KeyCode::KeyD) {
+		move_dir.x = 1.0;
+	} else if key.pressed(KeyCode::KeyA) {
+		move_dir.x = -1.0;
+	}
+
+	move_dir = cam_transform.rotation
+		* Quat::from_rotation_x(pitch)
+		* move_dir.normalize_or_zero()
+		* time.delta_secs()
+		* FLY_SPEED;
+
+	cam_transform.translation += move_dir;
+}
+
+pub fn camera_yaw(
+	cam_yaw_query: Single<&mut Transform, (With<CameraRoot>, Without<Unfocused>)>,
+	cam_query: Single<&mut CameraPitch>,
+	mouse_motion: EventReader<MouseMotion>,
+	time: Res<Time>,
+) {
+	let mut yaw_transform = cam_yaw_query.into_inner();
+	let mut pitch = cam_query.into_inner();
+
+	let delta = get_mouse_delta(mouse_motion) * -time.delta_secs();
+
+	yaw_transform.rotate_y(delta.x);
+
+	pitch.0 = (pitch.0 + delta.y).clamp(-FRAC_PI_2 + 0.001, FRAC_PI_2 - 0.001);
+}
+
+pub fn camera_pitch(cam_query: Single<(&mut Transform, &CameraPitch)>) {
+	let (mut cam_transform, pitch) = cam_query.into_inner();
+	cam_transform.rotation = Quat::from_rotation_x(pitch.0);
+}
+
+fn get_mouse_delta(mut mouse_motion: EventReader<MouseMotion>) -> Vec2 {
+	let mut delta = Vec2::ZERO;
+	for e in mouse_motion.read() {
+		delta += e.delta;
+	}
+	return delta;
+}