making fen parser be self contained

3 files changed, 34 insertions, 5 deletions

diff --git a/src/board/board.cpp b/src/board/board.cpp
index 676a7de..c02aac5 100644
--- a/src/board/board.cpp
+++ b/src/board/board.cpp
@@ -324,6 +324,3 @@ void UpdateHelpers(Game *g) {
   }
   g->PieceBitboard = g->WhitePieceBitboard | g->BlackPieceBitboard;
 }
-void SetPiece(int i, PieceType type, bool color, Game *g) {
-  g->pieces[i] = {.color = color, .type = type};
-}
diff --git a/src/board/board.hpp b/src/board/board.hpp
index 50d38ed..d93f6ae 100644
--- a/src/board/board.hpp
+++ b/src/board/board.hpp
@@ -106,5 +106,4 @@ void UnMakeMove(UndoMove undo, Game *g);
 
 Position FindKing(Game *g, bool white);
 void UpdateHelpers(Game *g);
-void SetPiece(int i, PieceType type, bool color, Game *g);
 #endif /* SRC_BOARD_H_ */
diff --git a/src/board/fen.cpp b/src/board/fen.cpp
index c4c5e7a..5f27e68 100644
--- a/src/board/fen.cpp
+++ b/src/board/fen.cpp
@@ -3,6 +3,7 @@
 #include <cassert>
 #include <cctype>
 #include <cstdlib>
+#include <cstring>
 #include <print>
 #include <string>
 #include <sys/types.h>
@@ -10,7 +11,39 @@
 bool WHITE = true;
 bool BLACK = false;
 
+static void updateBitboards(Game *g) {
+  g->PieceBitboard = 0;
+  g->WhitePieceBitboard = 0;
+  g->BlackPieceBitboard = 0;
+  std::memset(g->PieceBitboards, 0, sizeof(g->PieceBitboards));
+  for (uint8_t i = 0; i < 64; i++) {
+    Piece piece = g->pieces[i];
+    if (piece.type == NONEPIECE) {
+      continue;
+    }
+    g->PieceBitboards[piece.color][piece.type] |= (1ULL << i);
+
+    if (piece.color) {
+      g->WhitePieceBitboard |= (1ULL << i);
+    } else {
+      g->BlackPieceBitboard |= (1ULL << i);
+    }
+  }
+  g->PieceBitboard = g->WhitePieceBitboard | g->BlackPieceBitboard;
+}
+static void SetPiece(int i, PieceType type, bool color, Game *g) {
+  g->pieces[i] = {.color = color, .type = type};
+}
+
 void setBoardFen(const std::string fen, Game *g) {
+  for (int i = 0; i < 64; ++i) {
+    g->pieces[i] = {.color = false, .type = NONEPIECE};
+  }
+  g->blackCastleKing = false;
+  g->blackCastleQueen = false;
+  g->whiteCastleKing = false;
+  g->whiteCastleQueen = false;
+
   // example fen rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
   int file = 0;
   int rank = 7;
@@ -145,5 +178,5 @@ void setBoardFen(const std::string fen, Game *g) {
     break;
   }
   g->enPassant = enpassant;
-  UpdateHelpers(g);
+  updateBitboards(g);
 }