From f89d52bfbf2e6427689703acabbd6aa6a07bbc43 Mon Sep 17 00:00:00 2001
From: Elijah Voigt <elijah.caine.mv@gmail.com>
Date: Tue, 7 Oct 2025 15:49:24 -0700
Subject: [PATCH] Add bounds checking for pieces

---
 src/bin/tetris/main.rs | 91 +++++++++++++++++++++++++++++-------------
 1 file changed, 63 insertions(+), 28 deletions(-)

diff --git a/src/bin/tetris/main.rs b/src/bin/tetris/main.rs
index 7ebd37d..1c85953 100644
--- a/src/bin/tetris/main.rs
+++ b/src/bin/tetris/main.rs
@@ -26,18 +26,49 @@ const SCALE: f32 = 30.0;
 #[derive(Component, Default, Debug, Clone, Copy)]
 #[require(Transform, Visibility)]
 struct GridPosition {
-    x: isize,
-    y: isize,
+    x: usize,
+    y: usize,
+}
+
+// TODO: Restirct movement to within the grid
+impl GridPosition {
+    fn move_up(&mut self) {
+        if self.y + 1 < 20 {
+            self.y = self.y.saturating_add(1);
+        }
+    }
+
+    fn move_down(&mut self) {
+        self.y = self.y.saturating_sub(1);
+    }
+
+    fn move_left(&mut self) {
+        self.x = self.x.saturating_sub(1);
+    }
+
+    fn move_right(&mut self) {
+        if self.x + 1 < 10 {
+            self.x = self.x.saturating_add(1);
+        }
+    }
 }
 
 impl From<&GridPosition> for Vec3 {
     fn from(GridPosition { x, y }: &GridPosition) -> Vec3 {
-        Vec3::new((*x as f32) * SCALE, (*y as f32) * SCALE, 0.0)
+        // Grid Positions start in the bottom left of the area
+        // So (0, 0) is the bottom left, (0, 9) is the bottom right, etc
+
+        let x_0 = -SCALE * 5.0 + (0.5 * SCALE);
+        let x = x_0 + ((*x as f32) * SCALE);
+
+        let y_0 = -SCALE * 10.0 + (0.5 * SCALE);
+        let y = y_0 + ((*y as f32) * SCALE);
+        Vec3::new(x, y, 0.0)
     }
 }
 
-impl From<(isize, isize)> for GridPosition {
-    fn from((x, y): (isize, isize)) -> GridPosition {
+impl From<(usize, usize)> for GridPosition {
+    fn from((x, y): (usize, usize)) -> GridPosition {
         GridPosition { x, y }
     }
 }
@@ -53,6 +84,12 @@ impl std::ops::Add for GridPosition {
     }
 }
 
+impl std::ops::AddAssign<&GridPosition> for GridPosition {
+    fn add_assign(&mut self, rhs: &GridPosition) {
+        *self = *self + *rhs;
+    }
+}
+
 #[derive(Component, Default, Debug)]
 enum Orientation {
     #[default]
@@ -106,30 +143,34 @@ fn init_pieces(
                 color: WHITE.into(),
                 ..default()
             });
+            let mesh = meshes.add(Rectangle::new(SCALE, SCALE));
             parent.spawn((
-                Mesh2d(meshes.add(Rectangle::new(SCALE, SCALE))),
+                Mesh2d(mesh.clone()),
                 MeshMaterial2d(mat.clone()),
                 Transform::from_xyz(0.0, 0.0, 0.0),
             ));
             parent.spawn((
-                Mesh2d(meshes.add(Rectangle::new(SCALE, SCALE))),
+                Mesh2d(mesh.clone()),
                 MeshMaterial2d(mat.clone()),
                 Transform::from_xyz(SCALE, 0.0, 0.0),
             ));
             parent.spawn((
-                Mesh2d(meshes.add(Rectangle::new(SCALE, SCALE))),
+                Mesh2d(mesh.clone()),
                 MeshMaterial2d(mat.clone()),
                 Transform::from_xyz(0.0, SCALE, 0.0),
             ));
+            parent.spawn((
+                Mesh2d(mesh.clone()),
+                MeshMaterial2d(mat.clone()),
+                Transform::from_xyz(-SCALE, 0.0, 0.0),
+            ));
         });
 }
 
 fn update_position(mut query: Query<(&GridPosition, &mut Transform), Changed<GridPosition>>) {
     query.iter_mut().for_each(|(gp, mut t)| {
-        let tmp: Vec3 = gp.into();
-        debug!("Updating position {:?}", tmp);
-
         t.translation = gp.into();
+        debug!("Updating position {:?}", t.translation);
     });
 }
 
@@ -146,24 +187,18 @@ fn kb_movement(mut events: EventReader<KeyboardInput>, mut query: Query<(&mut Gr
              key_code, state, ..
          }| {
             if let ButtonState::Pressed = state {
-                let diff: GridPosition = match key_code {
-                    KeyCode::ArrowUp => (0, 1),
-                    KeyCode::ArrowDown => (0, -1),
-                    KeyCode::ArrowLeft => (-1, 0),
-                    KeyCode::ArrowRight => (1, 0),
-                    _ => (0, 0),
-                }
-                .into();
-                query.iter_mut().for_each(|(mut gp, _)| {
-                    debug!("Moving by {:?}", diff);
-                    *gp = *gp + diff;
+                // TODO: Restict movement based on size/orientation of piece
+                // Check if children would be outside play area...
+                query.iter_mut().for_each(|(mut gp, mut o)| {
+                    match key_code {
+                        KeyCode::ArrowUp => gp.move_up(),
+                        KeyCode::ArrowDown => gp.move_down(),
+                        KeyCode::ArrowLeft => gp.move_left(),
+                        KeyCode::ArrowRight => gp.move_right(),
+                        KeyCode::Enter => *o = o.next(),
+                        _ => ()
+                    }
                 });
-
-                if let KeyCode::Enter = key_code {
-                    query.iter_mut().for_each(|(_, mut o)| {
-                        *o = o.next();
-                    });
-                }
             }
         },
     );