/*
*******************************************************************************
* *
* SetBoard() is used to set up the board in any position desired. It uses *
* a forsythe-like string of characters to describe the board position. *
* *
* The standard piece codes p,n,b,r,q,k are used to denote the type of piece *
* on a square, upper/lower case are used to indicate the side (program/opp.)*
* of the piece. *
* *
* The pieces are entered with square a8 first, then b8, ... until the full *
* 8th rank is completed. A "/" terminates that rank. This is repeated for *
* each of the 8 ranks, with the last (1st) rank not needing a terminating *
* "/". For empty squares, a number between 1 and 8 can be used to indicate *
* the number of adjacent empty squares. *
* *
* That board description must be followed by a "b" or "w" to indicate which *
* side is on move. *
* *
* Next, up to 4 characters are used to indicate which side can castle and *
* to which side. An uppercase K means white can castle kingside, while a *
* lowercase q means black can castle queenside. *
* *
* Finally, if there is an enpassant capture possible (the last move was a *
* double pawn move and there was an enemy pawn that could capture it. The *
* square is the square the capturing pawn ends up on. *
* *
* K2R/PPP////q/5ppp/7k/ b - - *
* *
* this assumes that k represents a white king and -q represents a black *
* queen. *
* *
* k * * r * * * * *
* p p p * * * * * *
* * * * * * * * * *
* * * * * * * * * *
* * * * * * * * * *
* -q * * * * * * * *
* * * * * * -p -p -p *
* * * * * * * * -k *
* *
*******************************************************************************
*/
void SetBoard(TREE * tree, int nargs, char *args[], int special) {
int twtm, i, match, num, pos, square, tboard[64];
int bcastle, ep, wcastle, error = 0;
char input[80];
static const char bdinfo[] =
{ 'k', 'q', 'r', 'b', 'n', 'p', '*', 'P', 'N', 'B',
'R', 'Q', 'K', '*', '1', '2', '3', '4',
'5', '6', '7', '8', '/'
};
static const char status[13] =
{ 'K', 'Q', 'k', 'q', 'a', 'b', 'c', 'd', 'e', 'f', 'g',
'h', ' '
};
int whichsq;
static const int firstsq[8] = { 56, 48, 40, 32, 24, 16, 8, 0 };
if (special)
strcpy(input, initial_position);
else
strcpy(input, args[0]);
for (i = 0; i < 64; i++)
tboard[i] = 0;
/*
************************************************************
* *
* Scan the input string searching for pieces, numbers *
* [empty squares], slashes [end-of-rank] and a blank *
* [end of board, start of castle status]. *
* *
************************************************************
*/
whichsq = 0;
square = firstsq[whichsq];
num = 0;
for (pos = 0; pos < (int) strlen(args[0]); pos++) {
for (match = 0; match < 23 && args[0][pos] != bdinfo[match]; match++);
if (match > 22)
break;
/*
"/" -> end of this rank.
*/
else if (match == 22) {
num = 0;
if (whichsq > 6)
break;
square = firstsq[++whichsq];
}
/*
"1-8" -> empty squares.
*/
else if (match >= 14) {
num += match - 13;
square += match - 13;
if (num > 8) {
printf("more than 8 squares on one rank\n");
error = 1;
break;
}
continue;
}
/*
piece codes.
*/
else {
if (++num > 8) {
printf("more than 8 squares on one rank\n");
error = 1;
break;
}
tboard[square++] = match - 6;
}
}
/*
************************************************************
* *
* Now extract (a) side to move [w/b], (b) castle status *
* [KkQq for white/black king-side ok, white/black queen- *
* side ok], (c) enpassant target square. *
* *
************************************************************
*/
twtm = 0;
ep = 0;
wcastle = 0;
bcastle = 0;
/*
************************************************************
* *
* Side to move. *
* *
************************************************************
*/
if (args[1][0] == 'w')
twtm = 1;
else if (args[1][0] == 'b')
twtm = 0;
else {
printf("side to move is bad\n");
error = 1;
}
/*
************************************************************
* *
* Castling/enpassant status. *
* *
************************************************************
*/
if (nargs > 2 && strlen(args[2])) {
if (strcmp(args[2], "-")) {
for (pos = 0; pos < (int) strlen(args[2]); pos++) {
for (match = 0; (match < 13) && (args[2][pos] != status[match]);
match++);
if (match == 0)
wcastle += 1;
else if (match == 1)
wcastle += 2;
else if (match == 2)
bcastle += 1;
else if (match == 3)
bcastle += 2;
else if (args[2][0] != '-') {
printf("castling status is bad.\n");
error = 1;
}
}
}
}
if (nargs > 3 && strlen(args[3])) {
if (strcmp(args[3], "-")) {
if (args[3][0] >= 'a' && args[3][0] <= 'h' && args[3][1] > '0' &&
args[3][1] < '9') {
ep = (args[3][1] - '1') * 8 + args[3][0] - 'a';
} else if (args[3][0] != '-') {
printf("enpassant status is bad.\n");
error = 1;
}
}
}
for (i = 0; i < 64; i++)
PcOnSq(i) = tboard[i];
Castle(0, white) = wcastle;
Castle(0, black) = bcastle;
EnPassant(0) = 0;
if (ep) {
if (Rank(ep) == RANK6) {
if (PcOnSq(ep - 8) != -pawn)
ep = 0;
} else if (Rank(ep) == RANK3) {
if (PcOnSq(ep + 8) != pawn)
ep = 0;
} else
ep = 0;
if (!ep) {
printf("enpassant status is bad (must be on 3rd/6th rank only.\n");
ep = 0;
error = 1;
}
EnPassant(0) = ep;
}
Rule50Moves(0) = 0;
/*
************************************************************
* *
* Now check the castling status and enpassant status to *
* make sure that the board is in a state that matches *
* these. *
* *
************************************************************
*/
if (((Castle(0, white) & 2) && (PcOnSq(A1) != rook)) ||
((Castle(0, white) & 1) && (PcOnSq(H1) != rook)) ||
((Castle(0, black) & 2) && (PcOnSq(A8) != -rook)) ||
((Castle(0, black) & 1) && (PcOnSq(H8) != -rook))) {
printf("ERROR-- castling status does not match board position\n");
error = 1;
}
/*
************************************************************
* *
* Now set the bitboards so that error tests can be done. *
* *
************************************************************
*/
if ((twtm && EnPassant(0) && (PcOnSq(EnPassant(0) + 8) != -pawn) &&
(PcOnSq(EnPassant(0) - 7) != pawn) &&
(PcOnSq(EnPassant(0) - 9) != pawn)) || (Flip(twtm) && EnPassant(0)
&& (PcOnSq(EnPassant(0) - 8) != pawn) &&
(PcOnSq(EnPassant(0) + 7) != -pawn) &&
(PcOnSq(EnPassant(0) + 9) != -pawn))) {
EnPassant(0) = 0;
}
SetChessBitBoards(tree);
/*
************************************************************
* *
* Now check the position for a sane position, which *
* means no more than 8 pawns, no more than 10 knights, *
* bishops or rooks, no more than 9 queens, no pawns on *
* 1st or 8th rank, etc. *
* *
************************************************************
*/
wtm = twtm;
error += InvalidPosition(tree);
if (!error) {
if (log_file)
DisplayChessBoard(log_file, tree->pos);
tree->rep_index[white] = 0;
tree->rep_index[black] = 0;
Rule50Moves(0) = 0;
if (!special) {
last_mate_score = 0;
InitializeKillers();
last_pv.pathd = 0;
last_pv.pathl = 0;
tree->pv[0].pathd = 0;
tree->pv[0].pathl = 0;
moves_out_of_book = 0;
}
} else {
if (special)
Print(4095, "bad string = \"%s\"\n", initial_position);
else
Print(4095, "bad string = \"%s\"\n", args[0]);
InitializeChessBoard(tree);
Print(4095, "Illegal position, using normal initial chess position\n");
}
}
void InitializeChessBoard(SEARCH_POSITION *new_pos)
{
int i;
if (strlen(initial_position)) {
static char a1[80], a2[16], a3[16], a4[16], a5[16];
static char *args[16]={a1,a2,a3,a4,a5,a5,a5,a5,a5,a5,a5,a5,a5,a5,a5,a5};
int nargs;
nargs=ReadParse(initial_position,args," ;");
SetBoard(nargs,args,1);
}
else {
for(i=0;i<64;i++) search.board[i]=empty;
new_pos->rule_50_moves=0;
opening=1;
middle_game=0;
end_game=0;
largest_positional_score=60;
/*
place pawns
*/
for (i=0;i<8;i++) {
search.board[i+8]=pawn;
search.board[i+48]=-pawn;
}
/*
place knights
*/
search.board[B1]=knight;
search.board[G1]=knight;
search.board[B8]=-knight;
search.board[G8]=-knight;
/*
place bishops
*/
search.board[C1]=bishop;
search.board[F1]=bishop;
search.board[C8]=-bishop;
search.board[F8]=-bishop;
/*
place rooks
*/
search.board[A1]=rook;
search.board[H1]=rook;
search.board[A8]=-rook;
search.board[H8]=-rook;
/*
place queens
*/
search.board[D1]=queen;
search.board[D8]=-queen;
/*
place kings
*/
search.board[E1]=king;
search.board[E8]=-king;
/*
initialize castling status so all castling is legal.
*/
new_pos->w_castle=3;
new_pos->b_castle=3;
/*
initialize enpassant status.
*/
new_pos->enpassant_target=0;
/*
now, set the bit-boards.
*/
SetChessBitBoards(new_pos);
}
}
