feat: core gameplay

src/common.rs

@@ -16,7 +16,13 @@ pub fn button_system (
     }
 }
 
-pub fn despawn_screen <T: Component> (to_despawn: Query<Entity, With<T>>, mut commands: Commands) {
+pub fn despawn_screen <T: Component> (to_despawn: Query<Entity, With<T>>, commands: &mut Commands) {
+    for entity in &to_despawn {
+        commands.entity(entity).despawn_recursive();
+    }
+}
+
+pub fn despawn_screen_move <T: Component> (to_despawn: Query<Entity, With<T>>, mut commands: Commands) {
     for entity in &to_despawn {
         commands.entity(entity).despawn_recursive();
     }

src/game.rs

@@ -1,11 +1,13 @@
-use crate::prelude::*;
+use itertools::Itertools;
+use rand::{distributions::{Distribution, WeightedIndex}, seq::IteratorRandom};
+
+use crate::{common::despawn_screen, prelude::*};
 
 #[derive(Component)]
 pub struct FieldView;
 
 
 
-
 pub fn enter (
     mut commands: Commands,
     asset_server: Res<AssetServer>,
@@ -80,10 +82,10 @@ pub fn enter (
 
     let mut start = vec![0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1];
     start.shuffle(thread);
-    *field = Field(start);
+    *field = Field(start, 4);
 
 
-    render_field(commands, asset_server, field.into());
+    // render_field(commands, asset_server, field.into(), q);
 }
 
 pub fn update_scoreboard (score: Res<Score>, mut query: Query<&mut Text, With<ScoreboardUi>>) {
@@ -95,30 +97,39 @@ pub fn render_field (
     mut commands: Commands,
     asset_server: Res<AssetServer>,
     field: Res<Field>,
+    mut prev_field: ResMut<PrevField>,
+    q: Query<Entity, With<FieldView>>,
 ) {
+    if prev_field.0 != field.0 {
+        despawn_screen::<FieldView>(q, &mut commands);
+
         for (idx, &val) in field.iter().enumerate() {
             if val > 0 {
                 spawn_square_at(&mut commands, val, idx, asset_server.clone());
             }
         }
+
+        prev_field.0 = field.0.clone();
+    }
+
 }
 
 
-fn spawn_square_at (commands: &mut Commands, level: u32, position: usize, asset_server: AssetServer) {
+fn spawn_square_at (commands: &mut Commands, level: u8, position: usize, asset_server: AssetServer) {
     let font = asset_server.load("proxima_thin.ttf");
     let Some(&(x, y)) = sq_origins.get(position) else {
         return;
     };
 
-    let text = 2i32.pow(level);
+    let text = 2i32.pow(level as u32).to_string();
     let label = Text2dBundle {
-        text: Text::from_section(text.to_string(), TextStyle {
+        text: Text::from_section(text, TextStyle {
             font,
             font_size: 44.,
             color: Color::WHITE,
         }),
         transform: Transform {
-            translation: Vec3::new(x, y, 0.0),
+            translation: Vec3::new(x, y, 1.),
             ..Default::default()
         },
         ..Default::default()
@@ -150,19 +161,21 @@ pub fn process_inputs (
     score: ResMut<Score>,
 ) {
 
+    let mover = |dir: MoveDirection| move_field(dir, field, score);
+
     for key in kb.get_just_pressed() {
         match key {
             KeyCode::ArrowUp | KeyCode::KeyW => {
-                return move_field(MoveDirection::Up, field, score);
+                return mover(MoveDirection::Up);
             },
             KeyCode::ArrowDown | KeyCode::KeyS => {
-                return move_field(MoveDirection::Down, field, score);
+                return mover(MoveDirection::Down);
             },
             KeyCode::ArrowLeft | KeyCode::KeyA => {
-                return move_field(MoveDirection::Left, field, score);
+                return mover(MoveDirection::Left);
             },
             KeyCode::ArrowRight | KeyCode::KeyD => {
-                return move_field(MoveDirection::Right, field, score);
+                return mover(MoveDirection::Right);
             },
             _ => ()
         }
@@ -179,28 +192,89 @@ pub fn process_inputs (
         // controls (with custom actuation point)
         // https://bevy-cheatbook.github.io/input/gamepad.html#gamepad-settings
         if icgbp(GBT::DPadLeft) {
-            return move_field(MoveDirection::Left, field, score);
+            return mover(MoveDirection::Left);
         } else if icgbp(GBT::DPadRight) {
-            return move_field(MoveDirection::Right, field, score);
+            return mover(MoveDirection::Right);
         } else if icgbp(GBT::DPadUp) {
-            return move_field(MoveDirection::Up, field, score);
+            return mover(MoveDirection::Up);
         } else if icgbp(GBT::DPadDown) {
-            return move_field(MoveDirection::Down, field, score);
+            return mover(MoveDirection::Down);
         }
 
 
     }
 }
 
-pub fn move_field (
+fn move_field (
     direction: MoveDirection,
-    field: ResMut<Field>,
-    score: ResMut<Score>
+    mut field: ResMut<Field>,
+    mut score: ResMut<Score>,
 ) {
-
-    println!("{:?} {:?}", direction, score);
+    let (new, score_incr) = calculate_move(&field.0, field.1, direction);
+    if new != field.0 {
+        field.0 = new;
+        score.0 += score_incr;
+        spawn_new_square(field);
+    }
 }
 
-pub fn redraw_field () {
+fn calculate_move (source: &[u8], size: usize, dir: MoveDirection) -> (Vec<u8>, usize)  {
+    let mut score_changes = vec![];
+    let mut target = vec![0; source.len()];
 
+    let mut qs = Vec::with_capacity(size);
+
+    for x in 0..size {
+        let mut col = Vec::with_capacity(size);
+        for y in 0..size {
+            if dir == MoveDirection::Up || dir == MoveDirection::Down {
+                col.push(y * size + x);
+            } else {
+                col.push(x * size + y);
+            }
+        }
+
+        if dir == MoveDirection::Down || dir == MoveDirection::Right {
+            col.reverse();
+        }
+
+        qs.push(col);
+    }
+
+
+    for q in qs {
+        let mut write_cursor = 0;
+        let mut cursor = 0;
+        let _in = q.iter().map(|&idx| source[idx]).filter(|&e| e != 0).collect_vec();
+
+        while let Some(&cur) = _in.get(cursor) {
+            let next = _in.get(cursor + 1);
+
+            match (cur, next) {
+                (a, Some(b)) if a == *b => {
+                    target[q[write_cursor]] = cur + 1;
+                    score_changes.push(cur as usize);
+                    write_cursor += 1;
+                    cursor += 2;
+                },
+                _ => {
+                    target[q[write_cursor]] = cur;
+                    write_cursor += 1;
+                    cursor += 1;
+                }
+            }
+        }
+
+    }
+
+    (target, score_changes.iter().sum())
+}
+
+fn spawn_new_square (mut field: ResMut<Field>) {
+    let rng = &mut thread_rng();
+    let Some(empty) = field.0.iter().enumerate().filter(|&(_, &val)| val == 0).map(|(idx, _)| idx).choose(rng) else { return };
+    let choices = [1, 2, 3];
+    let weights = [8, 4, 1];
+    let Ok(index) = WeightedIndex::new(&weights) else { return };
+    field.0[empty] = choices[index.sample(rng)];
 }

src/main.rs

@@ -17,12 +17,13 @@ impl Plugin for SqPlugin {
             .insert_state(State4096::Game)
             .insert_state(InGameState::Static)
             .insert_resource(Score(0))
-            .insert_resource(Field(vec![]))
+            .insert_resource(Field(vec![], 0))
+            .insert_resource(PrevField(vec![]))
             .add_systems(Startup, setup::setup)
-            .add_systems(Update, (game::update_scoreboard, game::process_inputs).run_if(in_state(State4096::Game)))
+            .add_systems(Update, (game::render_field, game::update_scoreboard, game::process_inputs).run_if(in_state(State4096::Game)))
             .add_systems(Update, (menu::actions, common::button_system).run_if(in_state(State4096::Menu)))
             .add_systems(OnEnter(State4096::Menu), menu::enter)
-            .add_systems(OnExit(State4096::Menu), common::despawn_screen::<menu::Menu>)
+            .add_systems(OnExit(State4096::Menu), common::despawn_screen_move::<menu::Menu>)
             .add_systems(OnEnter(State4096::Game), game::enter)
             ;
     }

src/prelude.rs

@@ -9,7 +9,10 @@ pub struct ScoreboardUi;
 
 
 #[derive(Resource, Deref, DerefMut)]
-pub struct Field (pub Vec<u32>);
+pub struct Field (#[deref] pub Vec<u8>, pub usize);
+
+#[derive(Resource, Deref, DerefMut)]
+pub struct PrevField (pub Vec<u8>);
 
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub enum MoveDirection {