From e6093b3fcbf387b99a5634bd93632f51f3403fb4 Mon Sep 17 00:00:00 2001
From: Elijah Voigt <elijah.caine.mv@gmail.com>
Date: Tue, 28 Oct 2025 16:26:25 -0700
Subject: [PATCH] Very rough swap mechanic

---
 src/bin/tetris/main.rs | 64 ++++++++++++++++++++++++++++++++++++------
 1 file changed, 55 insertions(+), 9 deletions(-)

diff --git a/src/bin/tetris/main.rs b/src/bin/tetris/main.rs
index c0c23b0..045b95c 100644
--- a/src/bin/tetris/main.rs
+++ b/src/bin/tetris/main.rs
@@ -24,6 +24,7 @@ fn main() {
         })
         .init_state::<GameState>()
         .init_resource::<ShapesBuffer>()
+        .init_resource::<ShapeStore>()
         .init_resource::<Score>()
         .add_systems(Startup, (init_world, init_debug_ui, init_ui))
         // Input and basic systems
@@ -49,7 +50,6 @@ fn main() {
                 update_shape_blocks
                     .run_if(any_component_added::<Shape>.or(any_component_changed::<Shape>)).after(update_position),
                 deactivate_shape.run_if(any_component_removed::<Shape>).after(update_shape_blocks),
-                check_line_removal,
                 // Clearing lines systems
                 clear_line.run_if(any_component_changed::<LineBlocks>),
                 adjust_block_lines
@@ -62,6 +62,7 @@ fn main() {
             Update,
             (
                 sync_resource_to_ui::<ShapesBuffer>.run_if(resource_changed::<ShapesBuffer>),
+                sync_resource_to_ui::<ShapeStore>.run_if(resource_changed::<ShapeStore>),
                 sync_resource_to_ui::<Score>.run_if(resource_changed::<Score>),
                 sync_singleton_to_ui::<Shape>.run_if(any_component_changed::<Shape>),
             ),
@@ -238,6 +239,18 @@ impl Display for ShapesBuffer {
     }
 }
 
+#[derive(Resource, Debug, Default)]
+struct ShapeStore(Option<Shape>);
+
+impl Display for ShapeStore {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self.0 {
+            Some(inner) => write!(f, "{}", inner.as_ascii()),
+            None => write!(f, "---")
+        }
+    }
+}
+
 fn init_world(
     mut commands: Commands,
     mut meshes: ResMut<Assets<Mesh>>,
@@ -279,6 +292,16 @@ fn init_ui(mut commands: Commands) {
                     parent.spawn(Text::new("Next:"));
                     parent.spawn((Text::new("???"), SyncResource::<ShapesBuffer>::default()));
                 });
+            parent
+                .spawn((Node {
+                    flex_direction: FlexDirection::Column,
+                    align_items: AlignItems::Center,
+                    ..default()
+                },))
+                .with_children(|parent| {
+                    parent.spawn(Text::new("Swap:"));
+                    parent.spawn((Text::new("???"), SyncResource::<ShapeStore>::default()));
+                });
             parent
                 .spawn((Node {
                     flex_direction: FlexDirection::Column,
@@ -589,9 +612,12 @@ fn kb_input(
                         KeyCode::ArrowRight => {
                             commands.entity(e).trigger(Movement::Right);
                         }
-                        KeyCode::Space => {
+                        KeyCode::Enter => {
                             commands.entity(e).trigger(Movement::Skip);
                         }
+                        KeyCode::Space => {
+                            commands.entity(e).trigger(Swap);
+                        }
                         KeyCode::Escape => next.set(match curr.get() {
                             GameState::Falling => GameState::Pause,
                             GameState::Pause => GameState::Falling,
@@ -650,7 +676,8 @@ fn add_piece(mut commands: Commands, mut shapes: ResMut<ShapesBuffer>) {
             GridPosition { y: Y_MAX - this_shape.height(), ..default() },
             this_shape,
         ))
-        .observe(movement);
+        .observe(movement)
+        .observe(swap);
 }
 
 /// When a line reaches 10 blocks, clear it
@@ -727,6 +754,11 @@ fn adjust_block_lines(
     });
 }
 
+/// Swap the current piece out
+#[derive(Event, Copy, Clone, PartialEq)]
+struct Swap;
+
+/// Movement events triggered on the piece
 #[derive(Event, Copy, Clone, PartialEq)]
 enum Movement {
     Down,
@@ -816,15 +848,29 @@ fn movement(
     }
 }
 
-fn check_line_removal(
-    mut events: RemovedComponents<Line>,
+fn swap(
+    trigger: Trigger<Swap>,
+    mut shapes: Query<&mut Shape>,
+    mut store: ResMut<ShapeStore>,
+    mut commands: Commands,
 ) {
-    events.read().for_each(|e| {
-        info!("Line entity {:?} removed", e);
-    });
+    info!("Swap called");
+    match store.0.as_mut() {
+        None => {
+            // Copy current shape into store
+            // De-activate entity
+            store.0 = Some(*shapes.get(trigger.target()).unwrap());
+            commands.entity(trigger.target()).despawn_related::<ShapeBlocks>().despawn();
+        }
+        Some(inner) => {
+            // Copy current shape into store
+            // Copy old shape into entity
+            let mut curr = shapes.get_mut(trigger.target()).unwrap();
+            std::mem::swap(&mut (*inner), &mut (*curr));
+        }
+    }
 }
 
-// TODO: Just despawn?
 fn deactivate_shape(
     mut events: RemovedComponents<Shape>,
     grid_positions: Query<&GridPosition>,