Add snapping.

src/navigation.rs

@@ -1,4 +1,7 @@
-use std::{collections::HashMap, error::Error, fmt::Debug, hash::Hash, marker::PhantomData};
+use std::{
+    collections::HashMap, error::Error, f32::consts::PI, fmt::Debug, hash::Hash,
+    marker::PhantomData,
+};
 
 use bevy::prelude::*;
 use bevy_input_actionmap::InputMap;
@@ -41,11 +44,15 @@ pub struct Speed(pub f32);
 #[reflect(Component)]
 pub struct Sprinting;
 
+#[derive(Default, Deref, DerefMut)]
+struct Snapping(bool);
+
 fn movement_controls<S, A: 'static>(
     mut commands: Commands,
     config: Res<NavigationConfig<S, A>>,
     input: Res<InputMap<A>>,
     time: Res<Time>,
+    mut snapping: ResMut<Snapping>,
     mut query: Query<
         (
             Entity,
@@ -66,6 +73,41 @@ fn movement_controls<S, A: 'static>(
     for (entity, mut velocity, mut speed, max_speed, rotation_speed, mut position, destination) in
         query.iter_mut()
     {
+        if **snapping {
+            if let Some(action) = config.action_forward.clone() {
+                if input.active(action) {
+                    continue;
+                }
+            }
+            if let Some(action) = config.action_backward.clone() {
+                if input.active(action) {
+                    continue;
+                }
+            }
+            if let Some(action) = config.action_left.clone() {
+                if input.active(action) {
+                    continue;
+                }
+            }
+            if let Some(action) = config.action_right.clone() {
+                if input.active(action) {
+                    continue;
+                }
+            }
+            if let (Some(_), Some(rotate_left), Some(rotate_right)) = (
+                rotation_speed,
+                config.action_rotate_left.clone(),
+                config.action_rotate_right.clone(),
+            ) {
+                if input.active(rotate_left) {
+                    continue;
+                }
+                if input.active(rotate_right) {
+                    continue;
+                }
+            }
+            **snapping = false;
+        } else {
             let sprinting = if let Some(action) = config.action_sprint.clone() {
                 input.active(action)
             } else {
@@ -173,6 +215,66 @@ fn movement_controls<S, A: 'static>(
             }
         }
     }
+}
+
+fn snap<S, A: 'static>(
+    mut tts: ResMut<Tts>,
+    input: Res<InputMap<A>>,
+    config: Res<NavigationConfig<S, A>>,
+    mut snapping: ResMut<Snapping>,
+    mut position: Query<(&mut RigidBodyPositionComponent, &CardinalDirection), With<Player>>,
+) -> Result<(), Box<dyn Error>>
+where
+    S: bevy::ecs::component::Component + Clone + Debug + Eq + Hash,
+    A: Hash + Eq + Clone + Send + Sync,
+{
+    if let Some(action) = config.action_snap_left.clone() {
+        if input.just_active(action) {
+            for (mut position, direction) in position.iter_mut() {
+                **snapping = true;
+                position.position.rotation = UnitComplex::new(match direction {
+                    CardinalDirection::North => PI,
+                    CardinalDirection::East => PI / 2.,
+                    CardinalDirection::South => 0.,
+                    CardinalDirection::West => PI * 1.5,
+                });
+            }
+        }
+    }
+    if let Some(action) = config.action_snap_right.clone() {
+        if input.just_active(action) {
+            for (mut position, direction) in position.iter_mut() {
+                **snapping = true;
+                position.position.rotation = UnitComplex::new(match direction {
+                    CardinalDirection::North => 0.,
+                    CardinalDirection::East => PI * 1.5,
+                    CardinalDirection::South => PI,
+                    CardinalDirection::West => PI / 2.,
+                });
+            }
+        }
+    }
+    if let Some(action) = config.action_snap_cardinal.clone() {
+        if input.just_active(action) {
+            for (mut position, direction) in position.iter_mut() {
+                **snapping = true;
+                let yaw: Angle = direction.into();
+                let yaw = yaw.radians();
+                position.position.rotation = UnitComplex::new(yaw);
+                tts.speak(direction.to_string(), true)?;
+            }
+        }
+    }
+    if let Some(action) = config.action_snap_reverse.clone() {
+        if input.just_active(action) {
+            for (mut position, _) in position.iter_mut() {
+                **snapping = true;
+                position.position.rotation *= UnitComplex::new(PI);
+            }
+        }
+    }
+    Ok(())
+}
 
 fn update_direction(
     mut commands: Commands,
@@ -230,6 +332,10 @@ pub struct NavigationConfig<S, A> {
     pub action_right: Option<A>,
     pub action_rotate_left: Option<A>,
     pub action_rotate_right: Option<A>,
+    pub action_snap_left: Option<A>,
+    pub action_snap_right: Option<A>,
+    pub action_snap_reverse: Option<A>,
+    pub action_snap_cardinal: Option<A>,
     pub action_sprint: Option<A>,
     pub forward_movement_factor: f32,
     pub backward_movement_factor: f32,
@@ -247,6 +353,10 @@ impl<S, A> Default for NavigationConfig<S, A> {
             action_right: None,
             action_rotate_left: None,
             action_rotate_right: None,
+            action_snap_left: None,
+            action_snap_right: None,
+            action_snap_reverse: None,
+            action_snap_cardinal: None,
             action_sprint: None,
             forward_movement_factor: 1.,
             backward_movement_factor: 1.,
@@ -280,19 +390,23 @@ where
             .get_resource::<NavigationConfig<S, A>>()
             .unwrap()
             .clone();
-        app.register_type::<MaxSpeed>()
+        app.init_resource::<Snapping>()
+            .register_type::<MaxSpeed>()
             .register_type::<RotationSpeed>()
             .register_type::<Sprinting>()
             .add_system(update_direction)
             .add_system(speak_direction.chain(error_handler))
             .add_system_to_stage(CoreStage::PostUpdate, remove_speed);
         if config.movement_control_states.is_empty() {
-            app.add_system(movement_controls::<S, A>);
+            app.add_system(movement_controls::<S, A>)
+                .add_system(snap::<S, A>.chain(error_handler));
         } else {
             let states = config.movement_control_states;
             for state in states {
                 app.add_system_set(
-                    SystemSet::on_update(state).with_system(movement_controls::<S, A>),
+                    SystemSet::on_update(state)
+                        .with_system(movement_controls::<S, A>)
+                        .with_system(snap::<S, A>.chain(error_handler)),
                 );
             }
         }