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brchess/src/move.c

503 lines
15 KiB
C

/* move.c - move management.
*
* Copyright (C) 2021 Bruno Raoult ("br")
* Licensed under the GNU General Public License v3.0 or later.
* Some rights reserved. See COPYING.
*
* You should have received a copy of the GNU General Public License along with this
* program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.htmlL>.
*
* SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
*
*/
#include <malloc.h>
#include <ctype.h>
#include "chessdefs.h"
#include "piece.h"
#include "move.h"
#include "list.h"
#include "debug.h"
static pool_t *moves_pool;
static struct vector {
unsigned char ndirs;
char slide;
char dir[8];
} vectors[] = {
[KNIGHT] = { 8, 0, { -33, -31, -18, -14, 14, 18, 31, 33 }},
[BISHOP] = { 4, 1, { -15, -17, 15, 17 }},
[ROOK] = { 4, 1, { -1, -16, 1, 16 }},
[QUEEN] = { 8, 1, { -1, -16, 1, 16, -15, -17, 15, 17 }},
[KING] = { 8, 0, { -1, -16, 1, 16, -15, -17, 15, 17 }}
};
/* squares needed to be empty & not controlled by opponent for castle.
* For black castle, same values 7 rows higher (>> 7*8)
*/
static struct can_castle {
bitboard_t controlled[2];
bitboard_t occupied[2];
} castle_squares[2] = {
/* Queen side King side Queen side King side */
{ { C1|D1|E1, E1|F1|G1, }, { B1|C1|D1, F1|G1 } },
{ { C8|D8|E8, E8|F8|G8, }, { B8|C8|D8, F8|G8 } }
};
pool_t *moves_pool_init()
{
if (!moves_pool)
moves_pool = pool_init("moves", 128, sizeof(move_t));
return moves_pool;
}
int move_print(move_t *move, move_flags_t flags)
{
if (flags & M_PR_CAPT && !(move->flags & M_CAPTURE)) {
# ifdef DEBUG_MOVE
log_i(5, "capture & %#04x\n", move->flags);
# endif
return 0;
}
if (flags & M_PR_NCAPT && move->flags & M_CAPTURE) {
# ifdef DEBUG_MOVE
log_i(5, "!capture & %#04x\n", move->flags);
# endif
return 0;
}
if (move->flags & M_CASTLE_K) {
printf("O-O");
goto end;
} else if (move->flags & M_CASTLE_Q) {
printf("O-O-O");
goto end;
} else {
printf("%s%c%c", P_SYM(move->piece),
FILE2C(GET_F(move->from)),
RANK2C(GET_R(move->from)));
if (move->taken) {
printf("x");
if (flags & M_PR_LONG)
printf("%s", P_SYM(move->taken));
} else {
printf("-");
}
printf("%c%c",
FILE2C(GET_F(move->to)),
RANK2C(GET_R(move->to)));
if (flags & M_PR_LONG && move->flags & M_EN_PASSANT)
printf("e.p.");
if (move->promotion)
printf("=%s", P_SYM(move->promotion));
end:
printf(" ");
}
return 1;
}
void moves_print(pos_t *pos, move_flags_t flags)
{
struct list_head *p_cur, *tmp;
move_t *move;
int i = 0;
move_flags_t details = flags & M_PR_LONG;
printf("%s pseudo-moves:\n\t", pos->turn == WHITE? "White": "Black");
if (! (flags & M_PR_SEPARATE)) {
list_for_each_safe(p_cur, tmp, &pos->moves) {
move = list_entry(p_cur, move_t, list);
i += move_print(move, details);
}
printf("\n\tTotal moves = %d\n", i);
} else {
printf("captures: ");
list_for_each_safe(p_cur, tmp, &pos->moves) {
move = list_entry(p_cur, move_t, list);
i += move_print(move, details | M_PR_CAPT);
}
printf("\n\tothers : ");
list_for_each_safe(p_cur, tmp, &pos->moves) {
move = list_entry(p_cur, move_t, list);
i += move_print(move, details | M_PR_NCAPT);
}
printf("\n\tTotal moves = %d\n", i);
}
}
static move_t *move_add(pos_t *pos, piece_t piece, square_t from,
square_t to)
{
board_t *board = pos->board;
move_t *move;
# ifdef DEBUG_MOVE
log_i(3, "piece_color=%d turn=%d from=%c%c to=%c%c\n",
COLOR(piece), pos->turn,
FILE2C(GET_F(from)),
RANK2C(GET_R(from)),
FILE2C(GET_F(to)),
RANK2C(GET_R(to)));
# endif
if (COLOR(piece) != pos->turn)
return NULL;
if (!(move = pool_get(moves_pool)))
return NULL;
move->piece = piece;
move->from = from;
move->to = to;
move->taken = board[to].piece;
move->flags = M_NORMAL;
if (move->taken)
move->flags |= M_CAPTURE;
list_add(&move->list, &pos->moves);
# ifdef DEBUG_MOVE
log_i(3, "added move from %c%c to %c%c\n",
FILE2C(GET_F(move->from)),
RANK2C(GET_R(move->from)),
FILE2C(GET_F(move->to)),
RANK2C(GET_R(move->to)));
# endif
return move;
}
/* TODO: return nmoves */
static move_t *move_pawn_add(pos_t *pos, piece_t piece, square_t from,
square_t to, unsigned char rank7)
{
move_t *move;
piece_t promote;
unsigned char color = COLOR(piece);
if (color != pos->turn)
return NULL;
if (RANK88(from) == rank7) { /* promotion */
for (promote = QUEEN; promote > PAWN; promote >>= 1) {
if ((move = move_add(pos, piece, from, to))) {
move->flags |= M_PROMOTION;
move->promotion = promote | color;
}
}
} else {
move = move_add(pos, piece, from, to);
}
return move;
}
/* pawn moves. We do not test for valid destination square here,
* assuming position is valid. Is that correct ?
*/
int pseudo_moves_pawn(pos_t *pos, piece_list_t *ppiece, bool doit)
{
piece_t piece = PIECE(ppiece->piece);
unsigned char color = COLOR(ppiece->piece);
unsigned char vcolor = VCOLOR(ppiece->piece);
square_t square = ppiece->square, new;
board_t *board = pos->board;
unsigned char rank2, rank7, rank5;
move_t *move = NULL;
char dir;
int count = 0;
/* setup direction */
if (IS_WHITE(color)) {
dir = 1;
rank2 = 1;
rank7 = 6;
rank5 = 4;
} else {
dir = -1;
rank2 = 6;
rank7 = 1;
rank5 = 3;
}
# ifdef DEBUG_MOVE
log_f(3, "pos:%p turn:%s piece:%d [%s %s] dir:%d at %#04x[%c%c]\n",
pos,
IS_WHITE(pos->turn)? "white": "black",
piece,
IS_WHITE(color)? "white": "black",
P_NAME(piece),
dir,
square,
FILE2C(GET_F(square)), RANK2C(GET_R(square)));
# endif
/* normal push. We do not test for valid destination square here,
* assuming position is valid. Is that correct ?
*/
new = square + dir * 16;
if (!board[new].piece) {
# ifdef DEBUG_MOVE
log_i(4, "pushing pawn %#04x\n", square);
# endif
//log_f(4, "pawn move mobility\n");
pos->mobility[vcolor]++;
if (doit && (move = move_pawn_add(pos, piece | color, square, new, rank7)))
count++;
/* push 2 squares */
if (move && RANK88(square) == rank2) {
new += dir * 16;
if (SQ88_OK(new) && !board[new].piece) {
# ifdef DEBUG_MOVE
log_i(4, "pushing pawn %#04x 2 squares\n", square);
# endif
//log_f(2, "pawn move2 mobility\n");
pos->mobility[vcolor]++;
if (doit && (move = move_pawn_add(pos, piece | color, square, new, rank7)))
count++;
}
}
}
/* en passant - not accounted for mobility. Correct ? */
if (doit && pos->en_passant && RANK88(square) == rank5) {
unsigned char ep_file = FILE88(pos->en_passant);
unsigned char sq_file = FILE88(square);
# ifdef DEBUG_MOVE
log_i(4, "possible en passant on rank %#x (current = %#0x)\n", ep_file,
sq_file);
# endif
if (sq_file == ep_file - 1 || sq_file == ep_file + 1) {
square_t taken = board[SQUARE(ep_file, rank5)].piece;
move = move_pawn_add(pos, piece | color , square, pos->en_passant, rank7);
count++;
move->flags |= M_EN_PASSANT | M_CAPTURE;
move->taken = taken;
count++;
}
}
/* capture */
int two=0;
for (new = square + dir * 15; two < 2; new = square + dir * 17, two++) {
# ifdef DEBUG_MOVE
log_i(4, "pawn capture %#04x %#04x\n", square, new);
# endif
if (SQ88_NOK(new))
continue;
pos->controlled[vcolor] |= SQ88_2_BB(new);
if (board[new].piece && COLOR(board[new].piece) != color) {
//log_f(2, "pawn capture mobility\n");
pos->mobility[vcolor]++;
if (doit &&
((move = move_pawn_add(pos, piece | color, square, new, rank7))))
count++;
}
}
return count;
}
int pseudo_moves_castle(pos_t *pos)
{
unsigned char color = pos->turn;
board_t *board = pos->board;
unsigned char rank1, castle_K, castle_Q;
move_t *move = NULL;
unsigned short count=0;
struct can_castle *can_castle;
bitboard_t controlled;
bitboard_t occupied = pos->occupied[WHITE] | pos->occupied[BLACK];
# ifdef DEBUG_MOVE
log_f(2, "pos:%p turn:%s\n",
pos,
IS_WHITE(pos->turn)? "white": "black");
# endif
if (IS_WHITE(color)) {
rank1 = 0;
castle_K = pos->castle & CASTLE_WK;
castle_Q = pos->castle & CASTLE_WQ;
can_castle = castle_squares+WHITE;
controlled = pos->controlled[BLACK];
} else {
rank1 = 7;
castle_K = pos->castle & CASTLE_BK;
castle_Q = pos->castle & CASTLE_BQ;
can_castle = castle_squares+BLACK;
controlled = pos->controlled[WHITE];
}
if (castle_K) {
if (occupied & can_castle->occupied[1]) {
printf("Cannot castle K side: occupied\n");
goto next;
}
if (controlled & can_castle->controlled[1]) {
printf("Cannot castle K side: controlled\n");
goto next;
}
move = move_add(pos, board[SQUARE(4, rank1)].piece,
SQUARE(4, rank1), SQUARE(6, rank1));
if (move) {
move->flags |= M_CASTLE_K;
count++;
}
}
next:
if (castle_Q) {
if (occupied & can_castle->occupied[0]) {
printf("Cannot castle Q side: occupied\n");
goto end;
}
if (controlled & can_castle->controlled[0]) {
printf("Cannot castle Q side: controlled\n");
goto end;
}
move = move_add(pos, board[SQUARE(4, rank1)].piece,
SQUARE(4, rank1), SQUARE(2, rank1));
if (move) {
move->flags |= M_CASTLE_Q;
count++;
}
}
end:
return count;
}
/* general rule moves for non pawn pieces
*/
int pseudo_moves_gen(pos_t *pos, piece_list_t *ppiece, bool doit)
{
piece_t piece = PIECE(ppiece->piece);
unsigned char color = COLOR(ppiece->piece);
unsigned char vcolor = VCOLOR(ppiece->piece);
struct vector *vector = vectors+piece;
square_t square = ppiece->square;
unsigned char ndirs = vector->ndirs;
char slide = vector->slide;
board_t *board = pos->board;
move_t *move;
int count = 0;
u64 bb_new;
# ifdef DEBUG_MOVE
log_f(1, "pos:%p turn:%s piece:%d [%s %s] at %#04x[%c%c]\n",
pos,
IS_WHITE(pos->turn)? "white": "black",
piece,
IS_WHITE(color)? "white": "black",
P_NAME(piece),
square,
FILE2C(GET_F(square)), RANK2C(GET_R(square)));
log_i(5, "vector=%ld ndirs=%d slide=%d\n", vector-vectors, ndirs, slide);
# endif
for (int curdir = 0; curdir < ndirs; ++curdir) {
char dir = vector->dir[curdir];
for (square_t new = square + dir; ; new = new + dir) {
/* outside board */
if (SQ88_NOK(new)) {
# ifdef DEBUG_MOVE
log_i(4,"skipping %04x (invalid square)\n", new);
# endif
break;
}
bb_new = SQ88_2_BB(new);
# ifdef DEBUG_MOVE
log_i(2, "trying %#x=%c%c bb=%#lx\n",
new, FILE2C(GET_F(new)), RANK2C(GET_R(new)),
bb_new);
//bitboard_print(new_bitboard);
# endif
pos->controlled[vcolor] |= bb_new;;
/* king: do not move to opponent controlled square */
if (piece == KING && pos->controlled[OPPONENT(vcolor)] & bb_new) {
# ifdef DEBUG_MOVE
log_i(1, "%s king cannot move to %c%c\n",
IS_WHITE(color)? "white": "black",
FILE2C(GET_F(new)), RANK2C(GET_R(new)));
# endif
break;
}
if (bb_new & pos->occupied[vcolor]) {
//bitboard_print(pos->occupied[vcolor]);
//bitboard_print(pos->occupied[OPPONENT(vcolor)]);
# ifdef DEBUG_MOVE
log_i(1, "BB: skipping %#llx [%c%c] (same color piece)\n",
new, FILE2C(GET_F(new)), RANK2C(GET_R(new)));
# endif
break;
}
/* we are sure the move is valid : we create move */
//log_f(2, "piece mobility\n");
pos->mobility[vcolor]++;
if (doit && color == pos->turn) {
if ((move = move_add(pos, ppiece->piece, square, new))) {
count++;
}
}
if (board[new].piece) { /* stopper move */
break;
}
if (!slide)
break;
}
}
return count;
}
int moves_gen(pos_t *pos, bool color, bool doit)
{
struct list_head *p_cur, *tmp, *piece_list;
piece_list_t *piece;
int count = 0;
# ifdef DEBUG_MOVE
log_f(1, "color:%s doit:%d\n", color? "Black": "White", doit);
# endif
piece_list = &pos->pieces[color];
pos->mobility[color]=0;
if (doit)
pseudo_moves_castle(pos);
list_for_each_safe(p_cur, tmp, piece_list) {
piece = list_entry(p_cur, piece_list_t, list);
if (PIECE(piece->piece) != PAWN)
pseudo_moves_gen(pos, piece, doit);
else
pseudo_moves_pawn(pos, piece, doit);
count++;
}
return count;
}
#ifdef BIN_move
#include "fen.h"
int main(int ac, char**av)
{
pos_t *pos;
debug_init(1);
piece_pool_init();
moves_pool_init();
pos_pool_init();
pos = pos_get();
if (ac == 1) {
pos_startpos(pos);
} else {
fen2pos(pos, av[1]);
}
printf("turn = %d opponent = %d\n", pos->turn, OPPONENT(pos->turn));
moves_gen(pos, OPPONENT(pos->turn), false);
moves_gen(pos, pos->turn, true);
pos_print(pos);
pos_pieces_print(pos);
moves_print(pos, M_PR_SEPARATE);
//bitboard_print2(castle_squares[0].controlled, castle_squares[1].controlled);
//bitboard_print2(castle_squares[0].occupied, castle_squares[1].occupied);
}
#endif