src/actors/mod.rs

@@ -10,7 +10,6 @@ pub struct State {
     matrix: Matrix,
     active_piece: Option<Tetromino>,
     held_piece: Option<TetrominoType>,
-    line_clears: u32,
 }
 
 impl From<Game> for State {
@@ -21,9 +20,7 @@ impl From<Game> for State {
 
 impl From<&Game> for State {
     fn from(game: &Game) -> Self {
-        let mut state: State = game.playfield().clone().into();
-        state.line_clears = game.line_clears;
-        state
+        game.playfield().clone().into()
     }
 }
 
@@ -33,7 +30,6 @@ impl From<PlayField> for State {
             matrix: playfield.field().clone(),
             active_piece: playfield.active_piece,
             held_piece: playfield.hold_piece().map(|t| t.clone()),
-            line_clears: 0,
         }
     }
 }
@@ -41,14 +37,7 @@ impl From<PlayField> for State {
 pub trait Actor {
     fn get_action(&self, rng: &mut SmallRng, state: &State, legal_actions: &[Action]) -> Action;
 
-    fn update(
-        &mut self,
-        state: State,
-        action: Action,
-        next_state: State,
-        next_legal_actions: &[Action],
-        reward: f64,
-    );
+    fn update(&mut self, state: State, action: Action, next_state: State, reward: f64);
 
     fn set_learning_rate(&mut self, learning_rate: f64);
     fn set_exploration_prob(&mut self, exploration_prob: f64);

src/actors/qlearning.rs

@@ -1,8 +1,5 @@
 use crate::actors::{Actor, State};
-use crate::{
-    game::Action,
-    playfield::{PLAYFIELD_HEIGHT, PLAYFIELD_WIDTH},
-};
+use crate::game::Action;
 use log::debug;
 use rand::rngs::SmallRng;
 use rand::seq::SliceRandom;
@@ -18,10 +15,10 @@ pub struct QLearningAgent {
 
 impl Default for QLearningAgent {
     fn default() -> Self {
-        Self {
-            learning_rate: 0.0,
-            exploration_prob: 0.0,
-            discount_rate: 0.0,
+        QLearningAgent {
+            learning_rate: 0.1,
+            exploration_prob: 0.5,
+            discount_rate: 1.0,
             q_values: HashMap::default(),
         }
     }
@@ -69,14 +66,7 @@ impl Actor for QLearningAgent {
         }
     }
 
-    fn update(
-        &mut self,
-        state: State,
-        action: Action,
-        next_state: State,
-        _next_legal_actions: &[Action],
-        reward: f64,
-    ) {
+    fn update(&mut self, state: State, action: Action, next_state: State, reward: f64) {
         let cur_q_val = self.get_q_value(&state, action);
         let new_q_val = cur_q_val
             + self.learning_rate
@@ -105,148 +95,3 @@ impl Actor for QLearningAgent {
         self.discount_rate = discount_rate;
     }
 }
-
-pub struct ApproximateQLearning {
-    pub learning_rate: f64,
-    pub exploration_prob: f64,
-    pub discount_rate: f64,
-    weights: HashMap<String, f64>,
-}
-
-impl Default for ApproximateQLearning {
-    fn default() -> Self {
-        Self {
-            learning_rate: 0.0,
-            exploration_prob: 0.0,
-            discount_rate: 0.0,
-            weights: HashMap::default(),
-        }
-    }
-}
-
-impl ApproximateQLearning {
-    fn get_features(
-        &self,
-        state: &State,
-        _action: &Action,
-        new_state: &State,
-    ) -> HashMap<String, f64> {
-        let mut features = HashMap::default();
-
-        let mut heights = [None; PLAYFIELD_WIDTH];
-        for r in 0..PLAYFIELD_HEIGHT {
-            for c in 0..PLAYFIELD_WIDTH {
-                if heights[c].is_none() && state.matrix[r][c].is_some() {
-                    heights[c] = Some(PLAYFIELD_HEIGHT - r);
-                }
-            }
-        }
-
-        features.insert(
-            "Total Height".into(),
-            heights
-                .iter()
-                .map(|o| o.unwrap_or_else(|| 0))
-                .sum::<usize>() as f64
-                / (PLAYFIELD_HEIGHT * PLAYFIELD_WIDTH) as f64,
-        );
-
-        features.insert(
-            "Bumpiness".into(),
-            heights
-                .iter()
-                .map(|o| o.unwrap_or_else(|| 0) as isize)
-                .fold((0, 0), |(acc, prev), cur| (acc + (prev - cur).abs(), cur))
-                .0 as f64
-                / (PLAYFIELD_WIDTH * 40) as f64,
-        );
-
-        features.insert(
-            "Lines cleared".into(),
-            (new_state.line_clears - state.line_clears) as f64 / 4.0,
-        );
-
-        let mut holes = 0;
-        for r in 1..PLAYFIELD_HEIGHT {
-            for c in 0..PLAYFIELD_WIDTH {
-                if state.matrix[r][c].is_none() && state.matrix[r - 1][c].is_some() {
-                    holes += 1;
-                }
-            }
-        }
-        features.insert("Holes".into(), holes as f64);
-
-        features
-    }
-
-    fn get_q_value(&self, state: &State, action: &Action, next_state: &State) -> f64 {
-        self.get_features(state, action, next_state)
-            .iter()
-            .map(|(key, val)| val * *self.weights.get(key).unwrap_or_else(|| &0.0))
-            .sum()
-    }
-
-    fn get_action_from_q_values(&self, state: &State, legal_actions: &[Action]) -> Action {
-        *legal_actions
-            .iter()
-            .map(|action| (action, self.get_q_value(&state, action, state)))
-            .max_by_key(|(_, q1)| ((q1 * 1_000_000.0) as isize))
-            .expect("Failed to select an action")
-            .0
-    }
-
-    fn get_value(&self, state: &State, legal_actions: &[Action]) -> f64 {
-        legal_actions
-            .iter()
-            .map(|action| self.get_q_value(state, action, state))
-            .max_by_key(|v| (v * 1_000_000.0) as isize)
-            .unwrap_or_else(|| 0.0)
-    }
-}
-
-impl Actor for ApproximateQLearning {
-    fn get_action(&self, rng: &mut SmallRng, state: &State, legal_actions: &[Action]) -> Action {
-        if rng.gen::<f64>() < self.exploration_prob {
-            *legal_actions.choose(rng).unwrap()
-        } else {
-            self.get_action_from_q_values(state, legal_actions)
-        }
-    }
-
-    fn update(
-        &mut self,
-        state: State,
-        action: Action,
-        next_state: State,
-        next_legal_actions: &[Action],
-        reward: f64,
-    ) {
-        let difference = reward
-            + self.discount_rate * self.get_value(&next_state, next_legal_actions)
-            - self.get_q_value(&state, &action, &next_state);
-
-        for (feat_key, feat_val) in self.get_features(&state, &action, &next_state) {
-            self.weights.insert(
-                feat_key.clone(),
-                *self.weights.get(&feat_key).unwrap_or_else(|| &0.0)
-                    + self.learning_rate * difference * feat_val,
-            );
-        }
-    }
-
-    fn set_learning_rate(&mut self, learning_rate: f64) {
-        self.learning_rate = learning_rate;
-    }
-
-    fn set_exploration_prob(&mut self, exploration_prob: f64) {
-        self.exploration_prob = exploration_prob;
-    }
-
-    fn set_discount_rate(&mut self, discount_rate: f64) {
-        self.discount_rate = discount_rate;
-    }
-
-    fn dbg(&self) {
-        dbg!(&self.weights);
-    }
-}

src/cli.rs

@@ -65,15 +65,12 @@ pub struct Train {
     /// Number of episodes to train the agent
     #[clap(short = "n", long = "num", default_value = "10")]
     pub episodes: usize,
-    // #[clap(long = "use-epsilon-decreasing")]
-    // pub epsilon_decreasing: bool,
 }
 
 arg_enum! {
     #[derive(Debug)]
     pub enum Agent {
-        QLearning,
-        ApproximateQLearning,
+        QLearning
     }
 }
 
@@ -90,9 +87,6 @@ pub fn init_verbosity(opts: &Opts) -> Result<(), Box<dyn std::error::Error>> {
     Ok(())
 }
 
-pub fn get_actor(agent: Agent) -> Box<dyn Actor> {
-    match agent {
-        Agent::QLearning => Box::new(qlearning::QLearningAgent::default()),
-        Agent::ApproximateQLearning => Box::new(qlearning::ApproximateQLearning::default()),
-    }
+pub fn get_actor() -> impl Actor {
+    qlearning::QLearningAgent::default()
 }

src/game.rs

@@ -32,7 +32,7 @@ pub struct Game {
     /// The last clear action performed, used for determining if a back-to-back
     /// bonus is needed.
     last_clear_action: ClearAction,
-    pub line_clears: u32,
+    line_clears: u32,
 }
 
 impl fmt::Debug for Game {
@@ -178,7 +178,7 @@ impl Game {
             if cleared_lines > 0 {
                 trace!("Lines were cleared.");
                 self.line_clears += cleared_lines as u32;
-                self.score += (cleared_lines * 100 * self.level as usize) as u32;
+                self.score += (cleared_lines * self.level as usize) as u32;
                 self.level = (self.line_clears / 10) as u8;
                 self.playfield.active_piece = None;
                 self.next_spawn_tick = self.tick + LINE_CLEAR_DELAY;

src/main.rs

@@ -33,7 +33,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     match opts.subcmd {
         SubCommand::Play(sub_opts) => {}
         SubCommand::Train(sub_opts) => {
-            let mut to_train = get_actor(sub_opts.agent);
+            let mut to_train = get_actor();
             to_train.set_learning_rate(sub_opts.learning_rate);
             to_train.set_discount_rate(sub_opts.discount_rate);
             to_train.set_exploration_prob(sub_opts.exploration_prob);
@@ -61,7 +61,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     Ok(())
 }
 
-fn train_actor(episodes: usize, mut actor: Box<dyn Actor>) -> Box<dyn Actor> {
+fn train_actor(episodes: usize, mut actor: impl Actor) -> impl Actor {
     let mut rng = rand::rngs::SmallRng::from_entropy();
     let mut avg = 0.0;
 
@@ -91,16 +91,14 @@ fn train_actor(episodes: usize, mut actor: Box<dyn Actor>) -> Box<dyn Actor> {
             let new_state = (&game).into();
             let mut reward = game.score() as f64 - cur_score as f64;
             if action != Action::Nothing {
-                reward -= 0.0;
+                reward -= 10.0;
             }
 
             if game.is_game_over().is_some() {
-                reward = -1.0;
+                reward = -100.0;
             }
 
-            let new_legal_actions = game.get_legal_actions();
-
-            actor.update(cur_state, action, new_state, &new_legal_actions, reward);
+            actor.update(cur_state, action, new_state, reward);
 
             game.tick();
         }
@@ -111,7 +109,7 @@ fn train_actor(episodes: usize, mut actor: Box<dyn Actor>) -> Box<dyn Actor> {
     actor
 }
 
-async fn play_game(mut actor: Option<Box<dyn Actor>>) -> Result<(), Box<dyn std::error::Error>> {
+async fn play_game(mut actor: Option<impl Actor>) -> Result<(), Box<dyn std::error::Error>> {
     let mut rng = rand::rngs::SmallRng::from_entropy();
     let sdl_context = sdl2::init()?;
     let video_subsystem = sdl_context.video()?;