Detecting when to deactivate a piece

At least when there are no other blocks on the board...

tetris/src/blocks.rs

@@ -1,17 +1,14 @@
+#![allow(clippy::single_match)]
 #![allow(clippy::type_complexity)]
 
 use super::*;
 
 // TODO:
 // - When shape asset is updated, shape layout update in real time
-// - Debug: gizmo outline entities
-//   - conditional enable/disable
-//   - entities without mesh should draw empty cross
 // - Debug: gizmo draw relationship lines
 //   - conditional enable/disable
 // - Debug: show FPS
 //   - conditional enable/disable
-// - Line entities
 // - Debug: Nametags
 //   - If it has a Name component, display that at the same Translation
 // - Disable shape when placed
@@ -31,6 +28,7 @@ impl Plugin for BlocksPlugin {
         app.init_asset::<ShapeAsset>()
             .init_asset_loader::<ShapeAssetLoader>()
             .add_message::<Movement>()
+            .add_message::<ShapeEvent>()
             .add_systems(OnEnter(Loading(true)), load_assets.run_if(run_once))
             .add_systems(
                 OnEnter(GameState::Setup),
@@ -49,6 +47,7 @@ impl Plugin for BlocksPlugin {
                     propogate_relative_position.run_if(any_component_changed::<RelativePosition>),
                     handle_kb_input.run_if(on_message::<KeyboardInput>),
                     handle_movement.run_if(on_message::<Movement>),
+                    handle_shape_event.run_if(on_message::<ShapeEvent>),
                 ),
             )
             .add_observer(add_shape)
@@ -108,11 +107,11 @@ struct GridPosition {
 #[derive(Debug, Error)]
 enum GridPositionError {
     #[error("X > X_MAX")]
-    XOver,
+    HitRight,
     #[error("X < 0")]
-    XUnder,
+    HitLeft,
     #[error("Y < 0")]
-    YUnder,
+    HitFloor,
     #[error("Y < 0 && X < 0")]
     BothUnder,
 }
@@ -130,17 +129,17 @@ impl GridPosition {
             // Both underflow
             (None, None) => Err(GridPositionError::BothUnder),
             // Just y underflows
-            (None, Some(_)) => Err(GridPositionError::XUnder),
+            (None, Some(_)) => Err(GridPositionError::HitLeft),
             // y underflow or x overflow
             (Some(x), None) => match x {
-                0..X_MAX => Err(GridPositionError::YUnder),
-                _ => Err(GridPositionError::XOver),
-            }
+                0..X_MAX => Err(GridPositionError::HitFloor),
+                _ => Err(GridPositionError::HitRight),
+            },
             // both good, may x overflow
             (Some(x), Some(y)) => match x {
-                0..X_MAX => Ok(GridPosition  { x, y }),
-                _ => Err(GridPositionError::XOver),
-            }
+                0..X_MAX => Ok(GridPosition { x, y }),
+                _ => Err(GridPositionError::HitRight),
+            },
         }
     }
 }
@@ -539,6 +538,12 @@ enum Movement {
     Right,
 }
 
+/// Things that can happen to a shape
+#[derive(Debug, Message, PartialEq)]
+enum ShapeEvent {
+    Deactivate,
+}
+
 /// Handle KeyBoard input
 /// Nothing is handled directly in this method,
 /// All key presses result in either a message, event, or state change
@@ -592,40 +597,54 @@ impl Orientation {
 fn handle_movement(
     mut moves: MessageReader<Movement>,
     mut shapes: Query<(&ShapeLayout, &mut GridPosition, &mut Orientation)>,
+    mut writer: MessageWriter<ShapeEvent>,
 ) {
-    moves.read().for_each(|m|  {
-        shapes.iter_mut().for_each(|(shape_layout, mut gp, mut o)| {
+    'outer: for m in moves.read() {
+        for (shape_layout, mut gp, mut o) in shapes.iter_mut() {
             // First determine if proposed positions are valid
             // Determine next orientation
-            let proposed_orientation = if *m == Movement::Rotate {
-                o.rotated()
-            } else {
-                *o
+            let proposed_orientation = match *m == Movement::Rotate {
+                true => o.rotated(),
+                false => *o,
             };
 
             // And next position
-            let proposed_position = match m {
-                Movement::Left => gp.add((-1, 0).into()),
-                Movement::Right => gp.add((1, 0).into()),
-                Movement::Down => gp.add((0, -1).into()),
-                Movement::Rotate => Ok(gp.clone()),
+            let offset: RelativePosition = match m {
+                Movement::Left => (-1, 0).into(),
+                Movement::Right => (1, 0).into(),
+                Movement::Down => (0, -1).into(),
+                Movement::Rotate => (0, 0).into(),
             };
 
-            if let Ok(pp) = proposed_position {
-                // Check that new positions are all valid
-                if shape_layout
-                    .positions(proposed_orientation)
-                    .iter()
-                    .all(|rp| pp.add(*rp).is_ok()) {
-                        // then commit the movement
-                        *gp = pp;
-                        *o = proposed_orientation;
-                } else {
-                    // invalid position!
+            // TODO: See if the proposed position would collide with another block
+            // If would collide downward, deactivate shape
+
+            // Check that new positions are all valid for all blocks
+            for pos in shape_layout.positions(proposed_orientation).iter() {
+                match gp.add(*pos).unwrap().add(offset) {
+                    Err(e) => {
+                        match e {
+                            GridPositionError::HitFloor => {
+                                writer.write(ShapeEvent::Deactivate);
+                            }
+                            _ => (), // Other errors are just ignored
+                        }
+                        // Either way skip the rest of this iteration of the loop
+                        continue 'outer;
+                    }
+                    Ok(_) => (), // Ignore OKs as no [bad] news is good news
                 }
-            } else {
-                // Invalid move!
             }
-        });
+
+            // If those checks went well, commit the proposed changes
+            *gp = gp.add(offset).unwrap();
+            *o = proposed_orientation;
+        }
+    }
+}
+
+fn handle_shape_event(mut reader: MessageReader<ShapeEvent>) {
+    reader.read().for_each(|msg| match msg {
+        ShapeEvent::Deactivate => warn!("TODO: Deactivate shape"),
     });
 }