Stop epsilon and deceleration

src/ships/player.rs

@@ -10,7 +10,9 @@ use bevy::prelude::*;
 #[derive(Component)]
 #[require(Velocity)]
 pub struct PlayerMovement {
-    pub(super) acceleration: f32,
+    acceleration: f32,
+    deceleration: f32,
+    stop_epsilon: f32,
 }
 
 #[derive(Component)]
@@ -21,7 +23,11 @@ pub struct PlayerGun {
 
 pub fn spawn_player(commands: &mut Commands, sprite: Handle<Image>, at: Vec2) {
     commands.spawn((
-        PlayerMovement { acceleration: 100. },
+        PlayerMovement {
+            acceleration: 100.,
+            deceleration: 300.,
+            stop_epsilon: 50.,
+        },
         PlayerGun {
             shoot_timer: Timer::from_seconds(0.2, TimerMode::Once),
             damage: 1,
@@ -39,7 +45,7 @@ pub(super) fn player_movement_system(
     keyboard_input: Res<ButtonInput<KeyCode>>,
     query: Single<(&mut Velocity, &PlayerMovement)>,
 ) {
-    let (mut movable, player) = query.into_inner();
+    let (mut velocity, player) = query.into_inner();
     let mut movement_factor = 0.0;
     let mut rotation_factor = 0.0;
 
@@ -58,10 +64,38 @@ pub(super) fn player_movement_system(
         movement_factor -= 1.0;
     }
 
-    movable.linear_speed = (movable.linear_speed
+    if movement_factor > 0. {
+        if velocity.linear_speed >= 0. {
+            velocity.linear_speed = (velocity.linear_speed
                 + movement_factor * player.acceleration * time.delta_secs())
-    .clamp(-movable.max_linear_speed, movable.max_linear_speed);
-    movable.rotation_speed = rotation_factor * movable.max_rotation_speed;
+            .clamp(-velocity.max_linear_speed, velocity.max_linear_speed);
+        } else {
+            velocity.linear_speed = (velocity.linear_speed
+                + movement_factor * player.deceleration * time.delta_secs())
+            .clamp(-velocity.max_linear_speed, velocity.max_linear_speed);
+
+            if velocity.linear_speed > -player.stop_epsilon {
+                velocity.linear_speed = 0;
+            }
+        }
+    }
+    if movement_factor < 0. {
+        if velocity.linear_speed <= 0. {
+            velocity.linear_speed = (velocity.linear_speed
+                - movement_factor * player.acceleration * time.delta_secs())
+            .clamp(-velocity.max_linear_speed, velocity.max_linear_speed);
+        } else {
+            velocity.linear_speed = (velocity.linear_speed
+                - movement_factor * player.deceleration * time.delta_secs())
+            .clamp(-velocity.max_linear_speed, velocity.max_linear_speed);
+
+            if velocity.linear_speed < player.stop_epsilon {
+                velocity.linear_speed = 0;
+            }
+        }
+    }
+
+    velocity.rotation_speed = rotation_factor * velocity.max_rotation_speed;
 }
 
 pub fn player_shooting_system(