Merge pull request #62 from emilio-zuniga/search

Search

src/gamemanager/evaluation/heatmaps.rs

@@ -10,8 +10,8 @@ pub struct Heatmap {
 }
 
 impl Default for Heatmap {
-    /// Returns the heatmaps for white.
-    /// Use .rev() to get the heatmaps for black.
+    /// Returns the heatmaps for black.
+    /// Use .rev() to get the heatmaps for white.
     fn default() -> Self {
         let pawns_start = [
             0, 0, 0, 0, 0, 0, 0, 0, 50, 50, 50, 50, 50, 50, 50, 50, 10, 10, 20, 30, 30, 20, 10, 10,
@@ -79,8 +79,8 @@ impl Default for Heatmap {
 }
 
 impl Heatmap {
-    /// Returns the heatmap for black, if the provided
-    /// heatmap is for white, and vice versa.
+    /// Returns the heatmap for white, if the provided
+    /// heatmap is for black, and vice versa.
     pub fn rev(&self) -> Self {
         Self {
             pawns_start: reverse_array(self.pawns_start),

src/gamemanager/evaluation/mod.rs

@@ -19,26 +19,28 @@ impl GameManager {
     pub fn evaluate(&self, movetype: MoveType) -> i32 {
         if self.white_to_move {
             // Evaluate for black; better or worse after its move?
-            let mass_score = self.bitboard.piece_mass(Color::Black) + movetype_weight(movetype);
+            let mass_score = self.bitboard.piece_mass(Color::Black);
             let heatmap = heatmaps::Heatmap::default();
 
-            let endgame_weight = mass_score * 100 / START_MASS;
+            // endgame_weight shows how close we are to the endgame. The more pieces our side has, the further
+            // it is from the end of the game, and the fewer, the closer to the end of the game.
+            let endgame_weight = (mass_score / START_MASS) * 100;
 
             let position_score =
                 eval_heatmaps(Color::Black, self.bitboard, heatmap, endgame_weight);
 
-            position_score + mass_score
+            position_score + mass_score + movetype_weight(movetype)
         } else {
             // Ditto for white.
-            let mass_score = self.bitboard.piece_mass(Color::White) + movetype_weight(movetype);
+            let mass_score = self.bitboard.piece_mass(Color::White);
             let heatmap = heatmaps::Heatmap::default().rev();
 
-            let endgame_weight = mass_score * 100 / START_MASS;
+            let endgame_weight = (mass_score / START_MASS) * 100;
 
             let position_score =
                 eval_heatmaps(Color::White, self.bitboard, heatmap, endgame_weight);
 
-            position_score + mass_score
+            position_score + mass_score + movetype_weight(movetype)
         }
     }
 }
@@ -55,8 +57,7 @@ fn movetype_weight(mt: MoveType) -> i32 {
         BPromoCapture => Bishop as i32 + 50,
         NPromotion => Knight as i32,
         NPromoCapture => Knight as i32 + 50,
-        EPCapture => Pawn as i32,
-        Capture => 400,
+        Capture => 500,
         _ => 0,
     }
 }

src/gamemanager/legal_moves/search.rs

@@ -30,14 +30,20 @@ pub fn root_negamax(depth: u16, gm: GameManager, tbl: &NoArc<MoveTable>) -> (Mov
         .map(|(s, movetuple)| (s, (movetuple.0, movetuple.1)))
         .collect();
 
-    scored_moves.sort_by(|a, b| a.0.cmp(&b.0));
+    if depth % 2 == 0 {
+        scored_moves.sort_by(|a, b| a.0.cmp(&b.0));
+    } else {
+        scored_moves.sort_by(|a, b| a.0.cmp(&b.0));
+    }
 
-    // Little bit of debugging code.
-    let _ = scored_moves
-        .iter()
-        .for_each(|m| println!("{}: {}{}", m.0, m.1 .0 .1.to_str(), m.1 .0 .2.to_str()));
+    let best = scored_moves
+        .into_iter()
+        .inspect(|m| println!("{}: {}{}", m.0, m.1 .0 .1.to_str(), m.1 .0 .2.to_str()))
+        .last()
+        .expect("Should be a move here!");
 
-    scored_moves.pop().expect("There'll be a move!").1
+    println!("Best score: {}", best.0);
+    best.1
 }
 
 fn negamax(
@@ -54,22 +60,19 @@ fn negamax(
         let moves = gm.legal_moves(tbl);
 
         if moves.len() == 0 {
-            return i32::MIN + 1; // It's a pretty bad outcome to have no moves,
-                                 // but stalemates shouldn't count so hard against us.
+            return i32::MIN + 1; // Return value of node.
         }
 
+        let mut score = i32::MIN + 1;
         for mv in moves {
             // Call negamax and negate it's return value. Enemy's alpha is our -beta & v.v.
-            let score = -negamax(depth - 1, -beta, -alpha, mv.3, &mv.4, tbl);
-
-            if score >= beta {
-                return beta;
-            }
-            if score > alpha {
-                alpha = score;
+            score = score.max(-negamax(depth - 1, -beta, -alpha, mv.3, &mv.4, tbl));
+            alpha = alpha.max(score);
+            if alpha >= beta {
+                break;
             }
         }
-        alpha
+        score
     }
 }
 

src/main.rs

@@ -7,7 +7,16 @@ mod ucimanager;
 mod enginemanager;
 
 fn main() {
+
+    let tbl = noarc::NoArc::new(MoveTable::default());
+
+    let gm =
+        GameManager::from_fen_str("rn1b1k1r/p4ppp/1pp5/8/2B5/3n4/PPP1N1PP/RNBQ1K1R w - - 0 11");
+    let bestmove = root_negamax(4, gm, &tbl).0;
+    println!("Best move: {}{}", bestmove.1.to_str(), bestmove.2.to_str())
+
     ucimanager::communicate();
+
 }
 
 #[cfg(test)]

src/types.rs

@@ -5,7 +5,7 @@ use std::fmt::Display;
 #[derive(Debug, Clone, Eq, Hash, PartialEq)]
 pub enum PieceType {
     King,
-    Queen = 900,
+    Queen = 1000,
     Rook = 500,
     Bishop = 320,
     Knight = 300,