void chess_game_iterator_init(ChessGameIterator* iter, ChessGame* game)
{
iter->game = game;
chess_position_copy(&game->initial_position, &iter->position);
iter->variation = game->root_variation;
chess_array_init(&iter->unmoves, sizeof(ChessUnmove));
}
static ChessBoolean move_is_legal(const ChessPosition* position, ChessMove move)
{
ChessPosition temp_position;
chess_position_copy(position, &temp_position);
chess_position_make_move(&temp_position, move);
chess_position_set_to_move(&temp_position, chess_position_to_move(position));
return !chess_position_is_check(&temp_position);
}
void chess_game_reset_position(ChessGame* game, const ChessPosition* position)
{
chess_position_copy(position, &game->initial_position);
chess_variation_truncate(game->root_variation);
game->result = chess_position_check_result(position);
chess_string_clear(&game->event);
chess_string_clear(&game->site);
chess_string_clear(&game->date);
chess_string_clear(&game->round);
chess_string_clear(&game->white);
chess_string_clear(&game->black);
cleanup_extra_tags(game);
game->extra = NULL;
}
ChessGame* chess_game_new_position(const ChessPosition* position)
{
ChessGame* game = chess_alloc(sizeof(ChessGame));
memset(game, 0, sizeof(ChessGame));
chess_position_copy(position, &game->initial_position);
game->root_variation = chess_variation_new();
chess_string_init(&game->event);
chess_string_init(&game->site);
chess_string_init(&game->date);
chess_string_init(&game->round);
chess_string_init(&game->white);
chess_string_init(&game->black);
return game;
}
ChessBoolean chess_position_validate(ChessPosition* position)
{
ChessSquare sq, other_king;
ChessRank rank;
ChessPiece pc;
ChessPosition temp_position;
chess_position_copy(position, &temp_position);
temp_position.wking = CHESS_SQUARE_INVALID;
temp_position.bking = CHESS_SQUARE_INVALID;
for (sq = CHESS_SQUARE_A1; sq <= CHESS_SQUARE_H8; ++sq)
{
pc = position->piece[sq];
if (pc == CHESS_PIECE_WHITE_KING)
{
if (temp_position.wking != CHESS_SQUARE_INVALID)
return CHESS_FALSE; /* Too many white kings */
temp_position.wking = sq;
}
else if (pc == CHESS_PIECE_BLACK_KING)
{
if (temp_position.bking != CHESS_SQUARE_INVALID)
return CHESS_FALSE; /* Too many black kings */
temp_position.bking = sq;
}
else if (pc == CHESS_PIECE_WHITE_PAWN || pc == CHESS_PIECE_BLACK_PAWN)
{
rank = chess_square_rank(sq);
if (rank == CHESS_RANK_1 || rank == CHESS_RANK_8)
{
/* Pawn on first or last rank */
return CHESS_FALSE;
}
}
}
if (temp_position.wking == CHESS_SQUARE_INVALID
|| temp_position.bking == CHESS_SQUARE_INVALID)
{
/* No white king or black king */
return CHESS_FALSE;
}
/* Clear any impossible castling states */
if (temp_position.piece[CHESS_SQUARE_E1] != CHESS_PIECE_WHITE_KING)
{
temp_position.castle &= ~CHESS_CASTLE_STATE_WKQ;
}
if (temp_position.piece[CHESS_SQUARE_H1] != CHESS_PIECE_WHITE_ROOK)
{
temp_position.castle &= ~CHESS_CASTLE_STATE_WK;
}
if (temp_position.piece[CHESS_SQUARE_A1] != CHESS_PIECE_WHITE_ROOK)
{
temp_position.castle &= ~CHESS_CASTLE_STATE_WQ;
}
if (temp_position.piece[CHESS_SQUARE_E8] != CHESS_PIECE_BLACK_KING)
{
temp_position.castle &= ~CHESS_CASTLE_STATE_BKQ;
}
if (temp_position.piece[CHESS_SQUARE_H8] != CHESS_PIECE_BLACK_ROOK)
{
temp_position.castle &= ~CHESS_CASTLE_STATE_BK;
}
if (temp_position.piece[CHESS_SQUARE_A8] != CHESS_PIECE_BLACK_ROOK)
{
temp_position.castle &= ~CHESS_CASTLE_STATE_BQ;
}
/* Clear en passant state if it's not valid */
if (temp_position.ep != CHESS_FILE_INVALID)
{
/* Valid would mean that a pawn (possibly) just moved to its 4th rank */
if ((temp_position.to_move == CHESS_COLOR_WHITE &&
temp_position.piece[chess_square_from_fr(temp_position.ep, CHESS_RANK_5)] != CHESS_PIECE_BLACK_PAWN) ||
(temp_position.to_move == CHESS_COLOR_BLACK &&
temp_position.piece[chess_square_from_fr(temp_position.ep, CHESS_RANK_4)] != CHESS_PIECE_WHITE_PAWN))
{
temp_position.ep = CHESS_FILE_INVALID;
}
}
other_king = (temp_position.to_move == CHESS_COLOR_WHITE)
? temp_position.bking : temp_position.wking;
if (chess_generate_is_square_attacked(&temp_position, other_king, temp_position.to_move))
{
/* Opponent's king is en prise */
return CHESS_FALSE;
}
/* All checks passed! */
chess_position_copy(&temp_position, position);
return CHESS_TRUE;
}
void chess_game_iterator_step_to_start(ChessGameIterator* iter)
{
chess_position_copy(&iter->game->initial_position, &iter->position);
iter->variation = iter->game->root_variation;
chess_array_clear(&iter->unmoves);
}
void chess_game_set_initial_position(ChessGame* game, const ChessPosition* position)
{
chess_position_copy(position, &game->initial_position);
chess_variation_truncate(game->root_variation);
}
