Parse halfmove clock and fullmove number from FEN

[stockfish] / src / position.cpp

diff --git a/src/position.cpp b/src/position.cpp
index 2d1e476391c19db02f1f26cdcc5c25a7a45ac3c0..71556a566e49072d37023c5a07b74613e043303f 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -152,9 +152,9 @@ Position::Position(const Position& pos, int th) {
   nodes = 0;
 }
 
-Position::Position(const string& fen, int th) {
+Position::Position(const string& fen, bool isChess960, int th) {
 
-  from_fen(fen);
+  from_fen(fen, isChess960);
   threadID = th;
 }
 
@@ -175,7 +175,7 @@ void Position::detach() {
 /// string. This function is not very robust - make sure that input FENs are
 /// correct (this is assumed to be the responsibility of the GUI).
 
-void Position::from_fen(const string& fen) {
+void Position::from_fen(const string& fen, bool c960) {
 /*
    A FEN string defines a particular position using only the ASCII character set.
 
@@ -264,7 +264,15 @@ void Position::from_fen(const string& fen) {
           st->epSquare = fenEpSquare;
   }
 
-  // 5-6. Halfmove clock and fullmove number are not parsed
+  // 5. Halfmove clock
+  int hmc;
+  if (ss >> hmc)
+      st->rule50 = hmc;
+
+  // 6. Fullmove number
+  int fmn;
+  if (ss >> fmn)
+      startPosPlyCounter = (fmn - 1) * 2 + int(sideToMove == BLACK);
 
   // Various initialisations
   castleRightsMask[make_square(initialKFile,  RANK_1)] ^= WHITE_OO | WHITE_OOO;
@@ -274,10 +282,7 @@ void Position::from_fen(const string& fen) {
   castleRightsMask[make_square(initialQRFile, RANK_1)] ^= WHITE_OOO;
   castleRightsMask[make_square(initialQRFile, RANK_8)] ^= BLACK_OOO;
 
-  isChess960 =   initialKFile  != FILE_E
-              || initialQRFile != FILE_A
-              || initialKRFile != FILE_H;
-
+  isChess960 = c960;
   find_checkers();
 
   st->key = compute_key();
@@ -527,7 +532,7 @@ Bitboard Position::attacks_from(Piece p, Square s) const {
   case WB: case BB: return attacks_from<BISHOP>(s);
   case WR: case BR: return attacks_from<ROOK>(s);
   case WQ: case BQ: return attacks_from<QUEEN>(s);
-  default: return StepAttackBB[p][s];
+  default: return NonSlidingAttacksBB[p][s];
   }
 }
 
@@ -540,7 +545,7 @@ Bitboard Position::attacks_from(Piece p, Square s, Bitboard occ) {
   case WB: case BB: return bishop_attacks_bb(s, occ);
   case WR: case BR: return rook_attacks_bb(s, occ);
   case WQ: case BQ: return bishop_attacks_bb(s, occ) | rook_attacks_bb(s, occ);
-  default: return StepAttackBB[p][s];
+  default: return NonSlidingAttacksBB[p][s];
   }
 }
 
@@ -638,9 +643,9 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const {
 
   // A non-king move is legal if and only if it is not pinned or it
   // is moving along the ray towards or away from the king.
-  return (   !pinned
-          || !bit_is_set(pinned, from)
-          || (direction_between_squares(from, king_square(us)) == direction_between_squares(move_to(m), king_square(us))));
+  return   !pinned
+        || !bit_is_set(pinned, from)
+        ||  squares_aligned(from, move_to(m), king_square(us));
 }
 
 
@@ -698,7 +703,7 @@ bool Position::move_is_check(Move m, const CheckInfo& ci) const {
   {
       // For pawn and king moves we need to verify also direction
       if (  (pt != PAWN && pt != KING)
-          ||(direction_between_squares(from, ci.ksq) != direction_between_squares(to, ci.ksq)))
+          || !squares_aligned(from, to, ci.ksq))
           return true;
   }