adding enpassant

1 files changed, 34 insertions, 5 deletions

diff --git a/src/board.cpp b/src/board.cpp
index 877e8c7..a74c5dc 100644
--- a/src/board.cpp
+++ b/src/board.cpp
@@ -35,7 +35,7 @@ Piece createPiece(PieceType type, bool color, bool moved) {
   piece.color = color;
   piece.moved = moved;
   return piece;
-};
+}
 void printBoard(Board *b) {
   std::string line = "  +-----------------+\n";
   std::string whiteLetters = "    a b c d e f g h\n";
@@ -87,6 +87,9 @@ void printBoard(Board *b) {
   assert(b->castle != "");
 
   std::println("Castling: {}", b->castle);
+  std::println("Can enpassant: {}", b->canEnpassant ? "Yes" : "No");
+  std::println("Where enpassant: {}{}", (char)((int)b->enPassant.file + 'A'),
+               8 - (int)b->enPassant.rank);
 }
 
 void PlayMove(Move move, Board *b) {
@@ -98,8 +101,34 @@ void PlayMove(Move move, Board *b) {
       assert(false && "capturing friendly piece error");
     }
   }
-  b->pieces[PositionToIndex(move.To)] = piece;
-  b->pieces[PositionToIndex(move.From)] = {false, NONE, false};
-  return;
-}
+  piece.moved = true;
+  if (piece.type == PAWN || piece2.type == NONE) {
+    b->halfMoveClock = 0;
+  } else {
+    b->halfMoveClock++;
+  }
+  if (piece.type == PAWN && b->canEnpassant && move.To == b->enPassant) {
+    Position capturedPawn = move.To;
+    capturedPawn.rank += piece.color ? 1 : -1;
+    b->pieces[PositionToIndex(capturedPawn)] = {false, NONE, false};
+  }
+
+  b->canEnpassant = false;
+  b->MoveClock++;
+
+  if (piece.type == PAWN) {
+    Position to = move.To;
+    to.rank -= (piece.color ? -2 : 2);
+    if (to == move.From) {
+      b->canEnpassant = true;
+      Position target = move.From;
+      target.rank += piece.color ? -1 : 1;
+      b->enPassant = target;
+    };
+
+    b->pieces[PositionToIndex(move.To)] = piece;
+    b->pieces[PositionToIndex(move.From)] = {false, NONE, false};
+    return;
+  }
+};
 int PositionToIndex(Position i) { return i.rank * 8 + i.file; }