feat: incrementally update zobrist hash

1 files changed, 8 insertions, 5 deletions

diff --git a/src/board/engine.rs b/src/board/engine.rs
index d00b89b..73c57af 100644
--- a/src/board/engine.rs
+++ b/src/board/engine.rs
@@ -29,6 +29,7 @@ impl Board {
         for mov in moves {
             let ep_target_before = self.ep_target.clone();
             let castling_rights_before = self.castling_rights.clone();
+            let hash_before = self.hash.clone();
             let captured_piece = self.make_move(mov);
             // King can not be in check after our own move
             if !self.is_king_in_check(color) {
@@ -64,7 +65,7 @@ impl Board {
                 result.en_passants += subtree_result.en_passants;
 
             }
-            self.unmake_move(mov, captured_piece, ep_target_before, castling_rights_before);
+            self.unmake_move(mov, captured_piece, ep_target_before, castling_rights_before, hash_before);
         }
 
         if print {
@@ -126,12 +127,13 @@ impl Board {
         for mov in moves {
             let ep_target_before = self.ep_target.clone();
             let castling_rights_before = self.castling_rights.clone();
+            let hash_before = self.hash.clone();
             let captured_piece = self.make_move(mov);
 
             if !self.is_king_in_check(color) {
                 let (mut evaluation, mut subtree_pv) = self.negamax_search(-beta, -alpha, depth_left - 1);
                 evaluation *= -1.;
-                self.unmake_move(mov, captured_piece, ep_target_before, castling_rights_before);
+                self.unmake_move(mov, captured_piece, ep_target_before, castling_rights_before, hash_before);
 
                 if evaluation >= beta {
                     return (beta, principal_variation); // Fail-hard beta-cutoff
@@ -143,7 +145,7 @@ impl Board {
                     principal_variation.append(&mut subtree_pv);
                 }
             } else {
-                self.unmake_move(mov, captured_piece, ep_target_before, castling_rights_before);
+                self.unmake_move(mov, captured_piece, ep_target_before, castling_rights_before, hash_before);
             }
         }
         (alpha, principal_variation)
@@ -167,11 +169,12 @@ impl Board {
         for mov in tactical_moves {
             let ep_target_before = self.ep_target.clone();
             let castling_rights_before = self.castling_rights.clone();
+            let hash_before = self.hash.clone();
             let captured_piece = self.make_move(*mov);
 
             if !self.is_king_in_check(color) {
                 let evaluation = -self.quiscence(-beta, -alpha);
-                self.unmake_move(*mov, captured_piece, ep_target_before, castling_rights_before);
+                self.unmake_move(*mov, captured_piece, ep_target_before, castling_rights_before, hash_before);
 
                 if evaluation >= beta {
                     return beta; // Fail-hard beta-cutoff
@@ -180,7 +183,7 @@ impl Board {
                     alpha = evaluation;
                 }
             } else {
-                self.unmake_move(*mov, captured_piece, ep_target_before, castling_rights_before);
+                self.unmake_move(*mov, captured_piece, ep_target_before, castling_rights_before, hash_before);
             }
         }