Fix game-over bug

src/snake.rs

@@ -13,6 +13,11 @@ use iyes_loopless::prelude::*;
 #[derive(Debug, Clone, PartialEq, Eq, Hash, StageLabel)]
 struct MovementStage;
 
+#[derive(Debug, Clone, PartialEq, Eq, Hash, SystemLabel)]
+enum SystemLabel {
+    Collision,
+}
+
 pub struct SnakePlugin;
 
 impl Plugin for SnakePlugin {
@@ -31,17 +36,20 @@ impl Plugin for SnakePlugin {
             .add_system(
                 apply_direction_system
                     .run_in_state(AppState::InGame)
-                    .run_if(tick_triggered),
+                    .run_if(tick_triggered)
+                    .before(SystemLabel::Collision),
             )
             .add_system(
                 game_over_system
                     .run_in_state(AppState::InGame)
-                    .run_if(tick_triggered),
+                    .run_if(tick_triggered)
+                    .after(SystemLabel::Collision),
             )
             .add_system(
                 collision_system
                     .run_in_state(AppState::InGame)
-                    .run_if(tick_triggered),
+                    .run_if(tick_triggered)
+                    .label(SystemLabel::Collision),
             )
             .add_system(add_direction_system.run_in_state(AppState::Begin))
             .add_system(change_direction_system.run_in_state(AppState::InGame))
@@ -217,14 +225,14 @@ fn segments_movement_system(
             continue;
         }
 
-        // ... then the other elements
+        // Move other elements
         for (&segment, &previous_segment) in segments.0.iter().rev().tuple_windows() {
             let previous_coordinate = *segment_query.get(previous_segment).unwrap();
             let mut coordinate = segment_query.get_mut(segment).unwrap();
             *coordinate = previous_coordinate;
         }
 
-        // First move head ...
+        // Move head
         let head = *segments.0.first().expect("Snake has always a head");
         let mut head_coordinate = segment_query.get_mut(head).unwrap();
         *head_coordinate = next_grid_coordinate(&head_coordinate, direction);