Compiling Stockfish to disable own castling while allowing opponent castling

Question

For artistic purposes, I would like to create and study engine games in which only one side is able to castle.

For this, I need to compile a version of Stockfish which never castles, and doesn't consider its own castling in its calculations, whereas calculates with castling for the opponent.

I have gone through the types.h file and found the following:

enum MoveType {
  NORMAL,
  PROMOTION = 1 << 14,
  ENPASSANT = 2 << 14,
  CASTLING  = 3 << 14
};

enum CastlingRights {
  NO_CASTLING,
  WHITE_OO,
  WHITE_OOO = WHITE_OO << 1,
  BLACK_OO  = WHITE_OO << 2,
  BLACK_OOO = WHITE_OO << 3,

  KING_SIDE      = WHITE_OO  | BLACK_OO,
  QUEEN_SIDE     = WHITE_OOO | BLACK_OOO,
  WHITE_CASTLING = WHITE_OO  | WHITE_OOO,
  BLACK_CASTLING = BLACK_OO  | BLACK_OOO,
  ANY_CASTLING   = WHITE_CASTLING | BLACK_CASTLING,

  CASTLING_RIGHT_NB = 16
};

What can I do to disable castling in moves and calculations of Stockfish?

Answer 1

There is no need to compile your own version of Stockfish for this. Instead you can just start from a position that omits castling rights for one side or the other. The FEN for the initial position without castling rights for White is

rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w kq - 0 1

and the FEN for the initial position without castling rights for Black is

rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQ - 0 1

The FEN can be entered into Stockfish using the UCI command

position fen FEN

where FEN should be replaced by the FEN in question.

Answer 2

Without reviewing the complete code (which is probably humongous), it is difficult to give a proven right answer.

However, it should work if you replace the lines for the black castling possibilities by BLACK_00 = 0, BLACK_000 = 0, (or respectively for the white, if you want). This should lead to all tests in the code returning 'black castling not possible', which is the intention.