adding castling

2 files changed, 50 insertions, 6 deletions

diff --git a/src/moves.cpp b/src/moves.cpp
index b07c91b..163bb8c 100644
--- a/src/moves.cpp
+++ b/src/moves.cpp
@@ -2,6 +2,7 @@
 #include <cassert>
 #include <cstdint>
 #include <cstdlib>
+#include <iostream>
 #include <sys/types.h>
 #include <vector>
 
@@ -159,12 +160,12 @@ std::vector<Move> GetPseudoLegalMoves(Game *b, bool GenerateQuietMoves) {
       continue;
     }
 
+    if (piece.type == PAWN) {
+      GeneratePawnMoves(b, i, moves, GenerateQuietMoves);
+    }
     if (piece.type == KNIGHT) {
       GenerateKnightMoves(b, i, moves, GenerateQuietMoves);
     };
-    if (piece.type == KING) {
-      GenerateKingMoves(b, i, moves, GenerateQuietMoves);
-    };
     if (piece.type == BISHOP) {
       GenerateSlidingMoves(b, i, bishop_Moves, moves, GenerateQuietMoves);
     }
@@ -175,9 +176,10 @@ std::vector<Move> GetPseudoLegalMoves(Game *b, bool GenerateQuietMoves) {
       GenerateSlidingMoves(b, i, rook_Moves, moves, GenerateQuietMoves);
       GenerateSlidingMoves(b, i, bishop_Moves, moves, GenerateQuietMoves);
     }
-    if (piece.type == PAWN) {
-      GeneratePawnMoves(b, i, moves, GenerateQuietMoves);
-    }
+    if (piece.type == KING) {
+      GenerateKingMoves(b, i, moves, GenerateQuietMoves);
+      GenerateCastlingMoves(i, b, moves);
+    };
   };
 
   return moves;
@@ -397,3 +399,44 @@ void GenerateSlidingMoves(Game *b, int from,
     }
   };
 };
+void GenerateCastlingMoves(int from, Game *g, std::vector<Move> &moves) {
+  Piece piece = g->pieces[from];
+  if (piece.type != KING) {
+    assert(false && "Calling generate castling moves on non king piece");
+    std::cout << "Internal error\n";
+    exit(1);
+  }
+  if (from != 4 && !g->turn) {
+    return;
+  }
+  if (from != 60 && g->turn) {
+    return;
+  }
+  bool oneToRight = g->PieceBitboard & (1ULL << (from + 1));
+  bool twoToRight = g->PieceBitboard & (1ULL << (from + 2));
+  bool oneToLeft = g->PieceBitboard & (1ULL << (from - 1));
+  bool twoToLeft = g->PieceBitboard & (1ULL << (from - 2));
+  bool threeToLeft = g->PieceBitboard & (1ULL << (from - 3));
+  if (g->turn) {
+    // white
+    if (!oneToRight && !twoToRight && g->whiteCastleKing) {
+      moves.push_back(
+          {.From = IndexToPosition(from), .To = IndexToPosition(from + 2)});
+    }
+    if (!oneToLeft && !twoToLeft && !threeToLeft && g->whiteCastleQueen) {
+      moves.push_back(
+          {.From = IndexToPosition(from), .To = IndexToPosition(from - 2)});
+    }
+  }
+  if (!g->turn) {
+    // black
+    if (!oneToRight && !twoToRight && g->blackCastleKing) {
+      moves.push_back(
+          {.From = IndexToPosition(from), .To = IndexToPosition(from + 2)});
+    }
+    if (!oneToLeft && !twoToLeft && !threeToLeft && g->blackCastleQueen) {
+      moves.push_back(
+          {.From = IndexToPosition(from), .To = IndexToPosition(from - 2)});
+    }
+  }
+}
diff --git a/src/moves.hpp b/src/moves.hpp
index 282cff8..e48d7f8 100644
--- a/src/moves.hpp
+++ b/src/moves.hpp
@@ -16,6 +16,7 @@ void GenerateKnightMoves(Game *b, int from, std::vector<Move> &moves,
                          bool GenerateQuietMoves);
 void GeneratePawnMoves(Game *b, int from, std::vector<Move> &moves,
                        bool GenerateQuietMoves);
+void GenerateCastlingMoves(int from, Game *g, std::vector<Move> &moves);
 bool IsSquareAttacked(Game *g, Position square, bool byWhite);
 GameState GetNewGameState(Game *g);