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moves.c
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/*
* moves.c - Move generation and checking
*
* Copyright 1991 by Digital Equipment Corporation, Maynard,
* Massachusetts.
*
* Enhancements Copyright 1992-2001, 2002, 2003, 2004, 2005, 2006,
* 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015 Free Software Foundation, Inc.
*
* Enhancements Copyright 2005 Alessandro Scotti
*
* The following terms apply to Digital Equipment Corporation's copyright
* interest in XBoard:
* ------------------------------------------------------------------------
* All Rights Reserved
*
* Permission to use, copy, modify, and distribute this software and its
* documentation for any purpose and without fee is hereby granted,
* provided that the above copyright notice appear in all copies and that
* both that copyright notice and this permission notice appear in
* supporting documentation, and that the name of Digital not be
* used in advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
*
* DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
* ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
* DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
* ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
* WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
* ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
* SOFTWARE.
* ------------------------------------------------------------------------
*
* The following terms apply to the enhanced version of XBoard
* distributed by the Free Software Foundation:
* ------------------------------------------------------------------------
*
* GNU XBoard is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or (at
* your option) any later version.
*
* GNU XBoard is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see http://www.gnu.org/licenses/. *
*
*------------------------------------------------------------------------
** See the file ChangeLog for a revision history. */
#include "config.h"
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#if HAVE_STRING_H
# include <string.h>
#else /* not HAVE_STRING_H */
# include <strings.h>
#endif /* not HAVE_STRING_H */
#include "common.h"
#include "backend.h"
#include "moves.h"
#include "parser.h"
int WhitePiece P((ChessSquare));
int BlackPiece P((ChessSquare));
int SameColor P((ChessSquare, ChessSquare));
int PosFlags(int index);
extern signed char initialRights[BOARD_FILES]; /* [HGM] all rights enabled, set in InitPosition */
int quickFlag;
char *pieceDesc[EmptySquare];
char *defaultDesc[EmptySquare] = {
"fmWfceFifmnD", "N", "B", "R", "Q",
"F", "A", "BN", "RN", "W", "K",
"mRcpR", "N0", "BW", "RF", "gQ",
"", "", "QN", "", "N", "",
"", "", "", "", "",
"", "", "", "", "", "",
"", "", "", "", "",
"", "", "", "", "", "K"
};
int
WhitePiece (ChessSquare piece)
{
return (int) piece >= (int) WhitePawn && (int) piece < (int) BlackPawn;
}
int
BlackPiece (ChessSquare piece)
{
return (int) piece >= (int) BlackPawn && (int) piece < (int) EmptySquare;
}
#if 0
int
SameColor (ChessSquare piece1, ChessSquare piece2)
{
return ((int) piece1 >= (int) WhitePawn && /* [HGM] can be > King ! */
(int) piece1 < (int) BlackPawn &&
(int) piece2 >= (int) WhitePawn &&
(int) piece2 < (int) BlackPawn)
|| ((int) piece1 >= (int) BlackPawn &&
(int) piece1 < (int) EmptySquare &&
(int) piece2 >= (int) BlackPawn &&
(int) piece2 < (int) EmptySquare);
}
#else
#define SameColor(piece1, piece2) (piece1 < EmptySquare && piece2 < EmptySquare && (piece1 < BlackPawn) == (piece2 < BlackPawn) || piece1 == DarkSquare || piece2 == DarkSquare)
#endif
unsigned char pieceToChar[EmptySquare+1] = {
'P', 'N', 'B', 'R', 'Q', 'F', 'E', 'A', 'C', 'W', 'M',
'O', 'H', 'I', 'J', 'G', 'D', 'V', 'L', 'S', 'U', 'K',
'p', 'n', 'b', 'r', 'q', 'f', 'e', 'a', 'c', 'w', 'm',
'o', 'h', 'i', 'j', 'g', 'd', 'v', 'l', 's', 'u', 'k',
'x' };
unsigned char pieceNickName[EmptySquare];
char
PieceToChar (ChessSquare p)
{
int c;
if((int)p < 0 || (int)p >= (int)EmptySquare) return('x'); /* [HGM] for safety */
c = pieceToChar[(int) p];
if(c & 128) c = c & 63 | 64;
return c;
}
char
PieceSuffix (ChessSquare p)
{
int c;
if((int)p < 0 || (int)p >= (int)EmptySquare) return 0; /* [HGM] for safety */
c = pieceToChar[(int) p];
if(c < 128) return 0;
return SUFFIXES[c - 128 >> 6];
}
int
PieceToNumber (ChessSquare p) /* [HGM] holdings: count piece type, ignoring non-participating piece types */
{
int i=0;
ChessSquare start = (int)p >= (int)BlackPawn ? BlackPawn : WhitePawn;
while(start++ != p) if(pieceToChar[start-1] != '.' && pieceToChar[start-1] != '+') i++;
return i;
}
ChessSquare
CharToPiece (int c)
{
int i;
if(c == '.') return EmptySquare;
for(i=0; i< (int) EmptySquare; i++)
if(pieceNickName[i] == c) return (ChessSquare) i;
for(i=0; i< (int) EmptySquare; i++)
if(pieceToChar[i] == c) return (ChessSquare) i;
return EmptySquare;
}
void
CopyBoard (Board to, Board from)
{
int i, j;
for (i = 0; i < BOARD_HEIGHT; i++)
for (j = 0; j < BOARD_WIDTH; j++)
to[i][j] = from[i][j];
for (j = 0; j < BOARD_FILES; j++) // [HGM] gamestate: copy castling rights and ep status
to[VIRGIN][j] = from[VIRGIN][j],
to[CASTLING][j] = from[CASTLING][j];
to[HOLDINGS_SET] = 0; // flag used in ICS play
}
int
CompareBoards (Board board1, Board board2)
{
int i, j;
for (i = 0; i < BOARD_HEIGHT; i++)
for (j = 0; j < BOARD_WIDTH; j++) {
if (board1[i][j] != board2[i][j])
return FALSE;
}
return TRUE;
}
char defaultName[] = "PNBRQ......................................K" // white
"pnbrq......................................k"; // black
char shogiName[] = "PNBRLS...G.++++++..........................K" // white
"pnbrls...g.++++++..........................k"; // black
char xqName[] = "PH.R.AE..K.C................................" // white
"ph.r.ae..k.c................................"; // black
char *
CollectPieceDescriptors ()
{ // make a line of piece descriptions for use in the PGN Piece tag:
// dump all engine defined pieces, and pieces with non-standard names,
// but suppress black pieces that are the same as their white counterpart
ChessSquare p;
static char buf[MSG_SIZ];
char *m, c, d, *pieceName = defaultName;
int len;
*buf = NULLCHAR;
if(!pieceDefs) return "";
if(gameInfo.variant == VariantChu) return ""; // for now don't do this for Chu Shogi
if(gameInfo.variant == VariantShogi) pieceName = shogiName;
if(gameInfo.variant == VariantXiangqi) pieceName = xqName;
for(p=WhitePawn; p<EmptySquare; p++) {
if((c = pieceToChar[p]) == '.' || c == '~') continue; // does not participate
m = pieceDesc[p]; d = (c == '+' ? pieceToChar[DEMOTED p] : c);
if(p >= BlackPawn && pieceToChar[BLACK_TO_WHITE p] == toupper(c)
&& (c != '+' || pieceToChar[DEMOTED BLACK_TO_WHITE p] == d)) { // black member of normal pair
char *wm = pieceDesc[BLACK_TO_WHITE p];
if(!m && !wm || m && wm && !strcmp(wm, m)) continue; // moves as a white piece
} else // white or unpaired black
if((p < BlackPawn || CharToPiece(toupper(d)) != EmptySquare) && // white or lone black
!pieceDesc[p] /*&& pieceName[p] == c*/) continue; // orthodox piece known by its usual name
// TODO: listing pieces because of unusual name can only be done if we have accurate Betza of all defaults
if(!m) m = defaultDesc[p];
len = strlen(buf);
snprintf(buf+len, MSG_SIZ-len, "%s%s%c:%s", len ? ";" : "", c == '+' ? "+" : "", d, m);
}
return buf;
}
// [HGM] gen: configurable move generation from Betza notation sent by engine.
// Some notes about two-leg moves: GenPseudoLegal() works in two modes, depending on whether a 'kill-
// square has been set: without one is generates all moves, and a global int legNr flags in bits 0 and 1
// if the move has 1 or 2 legs. Only the marking of squares makes use of this info, by only marking
// target squares of leg 1 (rejecting null move). A dummy move with MoveType 'FirstLeg' to the relay square
// is generated, so a cyan marker can be put there, and other functions can ignore such a move. When the
// user selects this square, it becomes the kill-square. Once a kill-square is set, only 2-leg moves are
// generated that use that square as relay, plus 1-leg moves, so the 1-leg move that goes to the kill-square
// can be marked during 2nd-leg entry to terminate the move there. For judging the pseudo-legality of the
// 2nd leg, the from-square has to be considered empty, although the moving piece is still on it.
Boolean pieceDefs;
// alphabet "abcdefghijklmnopqrstuvwxyz"
char symmetry[] = "FBNW.FFW.NKN.NW.QR....W..N";
char xStep[] = "2110.130.102.10.00....0..2";
char yStep[] = "2132.133.313.20.11....1..3";
char dirType[] = "01000104000200000260050000";
char upgrade[] = "AFCD.BGH.JQL.NO.KW....R..Z";
char rotate[] = "DRCA.WHG.JKL.NO.QB....F..Z";
// alphabet "a b c d e f g h i j k l m n o p q r s t u v w x y z "
int dirs1[] = { 0,0x3C,0,0,0,0xC3,0,0, 0,0,0,0xF0,0,0,0,0,0,0x0F,0 ,0,0,0 ,0,0,0,0 };
int dirs2[] = { 0,0x18,0,0,0,0x81,0,0xFF,0,0,0,0x60,0,0,0,0,0,0x06,0x66,0,0,0x99,0,0,0,0 };
int dirs3[] = { 0,0x38,0,0,0,0x83,0,0xFF,0,0,0,0xE0,0,0,0,0,0,0x0E,0xEE,0,0,0xBB,0,0,0,0 };
int dirs4[] = { 0,0x10,0,0,0,0x01,0,0xFF,0,0,0,0x40,0,0,0,0,0,0x04,0x44,0,0,0x11,0,0,0,0 };
int rot[][4] = { // rotation matrices for each direction
{ 1, 0, 0, 1 },
{ 0, 1, 1, 0 },
{ 0, 1,-1, 0 },
{ 1, 0, 0,-1 },
{-1, 0, 0,-1 },
{ 0,-1,-1, 0 },
{ 0,-1, 1, 0 },
{-1, 0, 0, 1 }
};
void
OK (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR cl)
{
(*(int*)cl)++;
}
void
MovesFromString (Board board, int flags, int f, int r, int tx, int ty, int angle, char *desc, MoveCallback cb, VOIDSTAR cl)
{
char buf[80], *p = desc, *atom = NULL;
int mine, his, dir, bit, occup, i, ep, promoRank = -1;
ChessMove promo= NormalMove; ChessSquare pc = board[r][f];
if(pc == DarkSquare) return; // this is not a piece, but a 'hole' in the board
if(flags & F_WHITE_ON_MOVE) his = 2, mine = 1; else his = 1, mine = 2;
if(pc == WhitePawn || pc == WhiteLance) promo = WhitePromotion, promoRank = BOARD_HEIGHT-1; else
if(pc == BlackPawn || pc == BlackLance) promo = BlackPromotion, promoRank = 0;
while(*p) { // more moves to go
int expo = 1, dx, dy, x, y, mode, dirSet, ds2=0, retry=0, initial=0, jump=1, skip = 0, all = 0;
char *cont = NULL;
if(*p == 'i') initial = 1, desc = ++p;
while(islower(*p)) p++; // skip prefixes
if(!isupper(*p)) return; // syntax error: no atom
dx = xStep[*p-'A'] - '0';// step vector of atom
dy = yStep[*p-'A'] - '0';
dirSet = 0; // build direction set based on atom symmetry
switch(symmetry[*p-'A']) {
case 'B': expo = 0; // bishop, slide
case 'F': all = 0xAA; // diagonal atom (degenerate 4-fold)
if(tx >= 0) goto king; // continuation legs specified in K/Q system!
while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
int b = dirs1[*desc-'a']; // use wide version
if( islower(desc[1]) &&
((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim)
b = dirs1[*desc-'a'] & dirs1[desc[1]-'a']; // intersect wide & perp wide
desc += 2;
} else desc++;
dirSet |= b;
}
dirSet &= 0xAA; if(!dirSet) dirSet = 0xAA;
break;
case 'R': expo = 0; // rook, slide
case 'W': all = 0x55; // orthogonal atom (non-deg 4-fold)
if(tx >= 0) goto king; // continuation legs specified in K/Q system!
while(islower(*desc) && (dirType[*desc-'a'] & ~4) != '0') dirSet |= dirs2[*desc++-'a'];
dirSet &= 0x55; if(!dirSet) dirSet = 0x55;
dirSet = (dirSet << angle | dirSet >> 8-angle) & 255; // re-orient direction system
break;
case 'N': all = 0xFF; // oblique atom (degenerate 8-fold)
if(tx >= 0) goto king; // continuation legs specified in K/Q system!
if(*desc == 'h') { // chiral direction sets 'hr' and 'hl'
dirSet = (desc[1] == 'r' ? 0x55 : 0xAA); desc += 2;
} else
while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
int b = dirs2[*desc-'a']; // when alone, use narrow version
if(desc[1] == 'h') b = dirs1[*desc-'a'], desc += 2; // dirs1 is wide version
else if(*desc == desc[1] || islower(desc[1]) && i < '4'
&& ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim or same)
b = dirs1[*desc-'a'] & dirs2[desc[1]-'a']; // intersect wide & perp narrow
desc += 2;
} else desc++;
dirSet |= b;
}
if(!dirSet) dirSet = 0xFF;
break;
case 'Q': expo = 0; // queen, slide
case 'K': all = 0xFF; // non-deg (pseudo) 8-fold
king:
while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
int b = dirs4[*desc-'a']; // when alone, use narrow version
if(desc[1] == *desc) desc++; // doubling forces alone
else if(islower(desc[1]) && i < '4'
&& ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim or same)
b = dirs3[*desc-'a'] & dirs3[desc[1]-'a']; // intersect wide & perp wide
desc += 2;
} else desc++;
dirSet |= b;
}
if(!dirSet) dirSet = (tx < 0 ? 0xFF // default is all directions, but in continuation leg
: all == 0xFF ? 0xEF : 0x45); // omits backward, and for 4-fold atoms also diags
dirSet = (dirSet << angle | dirSet >> 8-angle) & 255; // re-orient direction system
ds2 = dirSet & 0xAA; // extract diagonal directions
if(dirSet &= 0x55) // start with orthogonal moves, if present
retry = 1, dx = 0; // and schedule the diagonal moves for later
else dx = dy, dirSet = ds2; // if no orthogonal directions, do diagonal immediately
break; // should not have direction indicators
default: return; // syntax error: invalid atom
}
if(mine == 2 && tx < 0) dirSet = dirSet >> 4 | dirSet << 4 & 255; // invert black moves
mode = 0; // build mode mask
if(*desc == 'm') mode |= 4, desc++; // move to empty
if(*desc == 'c') mode |= his, desc++; // capture foe
if(*desc == 'd') mode |= mine, desc++; // destroy (capture friend)
if(*desc == 'e') mode |= 8, desc++; // e.p. capture last mover
if(*desc == 't') mode |= 16, desc++; // exclude enemies as hop platform ('test')
if(*desc == 'p') mode |= 32, desc++; // hop over occupied
if(*desc == 'g') mode |= 64, desc++; // hop and toggle range
if(*desc == 'o') mode |= 128, desc++; // wrap around cylinder board
if(*desc == 'y') mode |= 512, desc++; // toggle range on empty square
if(*desc == 'n') jump = 0, desc++; // non-jumping
while(*desc == 'j') jump++, desc++; // must jump (on B,R,Q: skip first square)
if(*desc == 'a') cont = ++desc; // move again after doing what preceded it
if(isdigit(*++p)) expo = atoi(p++); // read exponent
if(expo > 9) p++; // allow double-digit
desc = p; // this is start of next move
if(initial && (board[r][f] != initialPosition[r][f] ||
r == 0 && board[TOUCHED_W] & 1<<f ||
r == BOARD_HEIGHT-1 && board[TOUCHED_B] & 1<<f ) ) continue;
if(expo > 1 && dx == 0 && dy == 0) { // castling indicated by O + number
mode |= 1024; dy = 1;
}
if(!cont) {
if(!(mode & 15)) mode |= his + 4; // no mode spec, use default = mc
} else {
strncpy(buf, cont, 80); cont = buf; // copy next leg(s), so we can modify
atom = buf; while(islower(*atom)) atom++; // skip to atom
if(mode & 32) mode ^= 256 + 32; // in non-final legs 'p' means 'pass through'
if(mode & 64 + 512) {
mode |= 256; // and 'g' too, but converts leaper <-> slider
if(mode & 512) mode ^= 0x304; // and 'y' is m-like 'g'
*atom = upgrade[*atom-'A']; // replace atom, BRQ <-> FWK
atom[1] = atom[2] = '\0'; // make sure any old range is stripped off
if(expo == 1) atom[1] = '0'; // turn other leapers into riders
}
if(!(mode & 0x30F)) mode |= 4; // and default of this leg = m
}
if(dy == 1) skip = jump - 1, jump = 1; // on W & F atoms 'j' = skip first square
do {
for(dir=0, bit=1; dir<8; dir++, bit += bit) { // loop over directions
int i = expo, j = skip, hop = mode, vx, vy, loop = 0;
if(!(bit & dirSet)) continue; // does not move in this direction
if(dy != 1 || mode & 1024) j = 0; //
vx = dx*rot[dir][0] + dy*rot[dir][1]; // rotate step vector
vy = dx*rot[dir][2] + dy*rot[dir][3];
if(tx < 0) x = f, y = r; // start square
else x = tx, y = ty; // from previous to-square if continuation
do { // traverse ray
x += vx; y += vy; // step to next square
if(y < 0 || y >= BOARD_HEIGHT) break; // vertically off-board: always done
if(x < BOARD_LEFT) { if(mode & 128) x += BOARD_RGHT - BOARD_LEFT, loop++; else break; }
if(x >= BOARD_RGHT) { if(mode & 128) x -= BOARD_RGHT - BOARD_LEFT, loop++; else break; }
if(board[y][x] == DarkSquare) break; // black squares are supposed to be off board
if(j) { j--; continue; } // skip irrespective of occupation
if(!jump && board[y - vy + vy/2][x - vx + vx/2] != EmptySquare) break; // blocked
if(jump > 1 && board[y - vy + vy/2][x - vx + vx/2] == EmptySquare) break; // no hop
if(x == f && y == r && !loop) occup = 4; else // start square counts as empty (if not around cylinder!)
if(board[y][x] < BlackPawn) occup = 0x101; else
if(board[y][x] < EmptySquare) occup = 0x102; else
occup = 4;
if(cont) { // non-final leg
if(mode&16 && his&occup) occup &= 3;// suppress hopping foe in t-mode
if(occup & mode) { // valid intermediate square, do continuation
char origAtom = *atom;
if(!(bit & all)) *atom = rotate[*atom - 'A']; // orth-diag interconversion to make direction valid
if(occup & mode & 0x104) // no side effects, merge legs to one move
MovesFromString(board, flags, f, r, x, y, dir, cont, cb, cl);
if(occup & mode & 3 && (killX < 0 || killX == x && killY == y)) { // destructive first leg
int cnt = 0;
MovesFromString(board, flags, f, r, x, y, dir, cont, &OK, &cnt); // count possible continuations
if(cnt) { // and if there are
if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); // then generate their first leg
legNr <<= 1;
MovesFromString(board, flags, f, r, x, y, dir, cont, cb, cl);
legNr >>= 1;
}
}
*atom = origAtom; // undo any interconversion
}
if(occup != 4) break; // occupied squares always terminate the leg
continue;
}
if(hop & 32+64) { if(occup != 4) { if(hop & 64 && i != 1) i = 2; hop &= 31; } continue; } // hopper
ep = board[EP_RANK];
if(mode & 8 && occup == 4 && board[EP_FILE] == x && (y == (ep & 127) || y - vy == ep - 128)) { // to e.p. square (or 2nd e.p. square)
cb(board, flags, mine == 1 ? WhiteCapturesEnPassant : BlackCapturesEnPassant, r, f, y, x, cl);
}
if(mode & 1024) { // castling
i = 2; // kludge to elongate move indefinitely
if(occup == 4) continue; // skip empty squares
if((x == BOARD_LEFT + skip || x > BOARD_LEFT + skip && vx < 0 && board[y][x-1-skip] == DarkSquare)
&& board[y][x] == initialPosition[y][x]) { // reached initial corner piece
if(pc != WhiteKing && pc != BlackKing) { // non-royal castling (to be entered as two-leg move via 'Rook')
if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); if(killX < f)
legNr <<= 1, cb(board, flags, NormalMove, r, f, y, f - expo, cl), legNr >>= 1;
} else
cb(board, flags, mine == 1 ? WhiteQueenSideCastle : BlackQueenSideCastle, r, f, y, f - expo, cl);
}
if((x == BOARD_RGHT-1-skip || x < BOARD_RGHT-1-skip && vx > 0 && board[y][x+1+skip] == DarkSquare)
&& board[y][x] == initialPosition[y][x]) {
if(pc != WhiteKing && pc != BlackKing) {
if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); if(killX > f)
legNr <<= 1, cb(board, flags, NormalMove, r, f, y, f + expo, cl), legNr >>= 1;
} else
cb(board, flags, mine == 1 ? WhiteKingSideCastle : BlackKingSideCastle, r, f, y, f + expo, cl);
}
break;
}
if(mode & 16 && (board[y][x] == WhiteKing || board[y][x] == BlackKing)) break; // tame piece, cannot capture royal
if(occup & mode) cb(board, flags, y == promoRank ? promo : NormalMove, r, f, y, x, cl); // allowed, generate
if(occup != 4) break; // not valid transit square
} while(--i);
}
dx = dy; dirSet = ds2; // prepare for diagonal moves of K,Q
} while(retry-- && ds2); // and start doing them
if(tx >= 0) break; // don't do other atoms in continuation legs
}
} // next atom
// [HGM] move generation now based on hierarchy of subroutines for rays and combinations of rays
void
SlideForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
{
int i, rt, ft = ff;
for (i = 1;; i++) {
rt = rf + i;
if (rt >= BOARD_HEIGHT) break;
if (SameColor(board[rf][ff], board[rt][ft])) break;
callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
if (board[rt][ft] != EmptySquare) break;
}
}
void
SlideBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
{
int i, rt, ft = ff;
for (i = 1;; i++) {
rt = rf - i;
if (rt < 0) break;
if (SameColor(board[rf][ff], board[rt][ft])) break;
callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
if (board[rt][ft] != EmptySquare) break;
}
}
void
SlideVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
{
SlideForward(board, flags, rf, ff, callback, closure);
SlideBackward(board, flags, rf, ff, callback, closure);
}
void
SlideSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
{
int i, s, rt = rf, ft;
for(s = -1; s <= 1; s+= 2) {
for (i = 1;; i++) {
ft = ff + i*s;
if (ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
if (SameColor(board[rf][ff], board[rt][ft])) break;
callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
if (board[rt][ft] != EmptySquare) break;
}
}
}
void
SlideDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
{
int i, s, rt, ft;
for(s = -1; s <= 1; s+= 2) {
for (i = 1;; i++) {
rt = rf + i;
ft = ff + i * s;
if (rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
if (SameColor(board[rf][ff], board[rt][ft])) break;
callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
if (board[rt][ft] != EmptySquare) break;
}
}
}
void
SlideDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
{
int i, s, rt, ft;
for(s = -1; s <= 1; s+= 2) {
for (i = 1;; i++) {
rt = rf - i;
ft = ff + i * s;
if (rt < 0 || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
if (SameColor(board[rf][ff], board[rt][ft])) break;
callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
if (board[rt][ft] != EmptySquare) break;
}
}
}
void
Rook (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
{
SlideVertical(board, flags, rf, ff, callback, closure);
SlideSideways(board, flags, rf, ff, callback, closure);
}
void
Bishop (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
{
SlideDiagForward(board, flags, rf, ff, callback, closure);
SlideDiagBackward(board, flags, rf, ff, callback, closure);
}
void
Sting (Board board, int flags, int rf, int ff, int dy, int dx, MoveCallback callback, VOIDSTAR closure)
{ // Lion-like move of Horned Falcon and Souring Eagle
int ft = ff + dx, rt = rf + dy;
if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
legNr += 2;
if (!SameColor(board[rf][ff], board[rt][ft]))
callback(board, flags, board[rt][ft] != EmptySquare ? FirstLeg : NormalMove, rf, ff, rt, ft, closure);
legNr -= 2;
ft += dx; rt += dy;
if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
legNr += 2;
if (!SameColor(board[rf][ff], board[rt][ft]))
callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
if (!SameColor(board[rf][ff], board[rf+dy][ff+dx]))
callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
legNr -= 2;
}
void
StepForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
{
int ft = ff, rt = rf + 1;
if (rt >= BOARD_HEIGHT) return;
if (SameColor(board[rf][ff], board[rt][ft])) return;
callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
}
void
StepBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
{
int ft = ff, rt = rf - 1;
if (rt < 0) return;
if (SameColor(board[rf][ff], board[rt][ft])) return;
callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
}
void
StepSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
{
int ft, rt = rf;
ft = ff + 1;
if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
ft = ff - 1;
if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
}
void
StepDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
{
int ft, rt = rf + 1;
if (rt >= BOARD_HEIGHT) return;
ft = ff + 1;
if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
ft = ff - 1;
if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
}
void
StepDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
{
int ft, rt = rf - 1;
if(rt < 0) return;
ft = ff + 1;
if (!(rt < 0 || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
ft = ff - 1;
if (!(rt < 0 || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
}
void
StepVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
{
StepForward(board, flags, rf, ff, callback, closure);
StepBackward(board, flags, rf, ff, callback, closure);
}
void
Ferz (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
{
StepDiagForward(board, flags, rf, ff, callback, closure);
StepDiagBackward(board, flags, rf, ff, callback, closure);
}
void
Wazir (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
{
StepVertical(board, flags, rf, ff, callback, closure);
StepSideways(board, flags, rf, ff, callback, closure);
}
void
Knight (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
{
int i, j, s, rt, ft;
for (i = -1; i <= 1; i += 2)
for (j = -1; j <= 1; j += 2)
for (s = 1; s <= 2; s++) {
rt = rf + i*s;
ft = ff + j*(3-s);
if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
&& ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
&& !SameColor(board[rf][ff], board[rt][ft]))
callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
}
}
/* Call callback once for each pseudo-legal move in the given
position, except castling moves. A move is pseudo-legal if it is
legal, or if it would be legal except that it leaves the king in
check. In the arguments, epfile is EP_NONE if the previous move
was not a double pawn push, or the file 0..7 if it was, or
EP_UNKNOWN if we don't know and want to allow all e.p. captures.
Promotion moves generated are to Queen only.
*/
void
GenPseudoLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
// speed: only do moves with this piece type
{
int rf, ff;
int i, j, d, s, fs, rs, rt, ft, m;
int epfile = (signed char)board[EP_STATUS]; // [HGM] gamestate: extract ep status from board
int promoRank = gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess ? 3 : 1;
for (rf = 0; rf < BOARD_HEIGHT; rf++)
for (ff = BOARD_LEFT; ff < BOARD_RGHT; ff++) {
ChessSquare piece;
if(board[rf][ff] == EmptySquare) continue;
if ((flags & F_WHITE_ON_MOVE) != (board[rf][ff] < BlackPawn)) continue; // [HGM] speed: wrong color
m = 0; piece = board[rf][ff];
if(PieceToChar(piece) == '~')
piece = (ChessSquare) ( DEMOTED piece );
if(filter != EmptySquare && piece != filter) continue;
if(pieceDefs && pieceDesc[piece]) { // [HGM] gen: use engine-defined moves
MovesFromString(board, flags, ff, rf, -1, -1, 0, pieceDesc[piece], callback, closure);
continue;
}
if(IS_SHOGI(gameInfo.variant))
piece = (ChessSquare) ( SHOGI piece );
switch ((int)piece) {
/* case EmptySquare: [HGM] this is nonsense, and conflicts with Shogi cases */
default:
/* can't happen ([HGM] except for faries...) */
break;
case WhitePawn:
if(gameInfo.variant == VariantXiangqi) {
/* [HGM] capture and move straight ahead in Xiangqi */
if (rf < BOARD_HEIGHT-1 &&
!SameColor(board[rf][ff], board[rf + 1][ff]) ) {
callback(board, flags, NormalMove,
rf, ff, rf + 1, ff, closure);
}
/* and move sideways when across the river */
for (s = -1; s <= 1; s += 2) {
if (rf >= BOARD_HEIGHT>>1 &&
ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
!WhitePiece(board[rf][ff+s]) ) {
callback(board, flags, NormalMove,
rf, ff, rf, ff+s, closure);
}
}
break;
}
if (rf < BOARD_HEIGHT-1 && board[rf + 1][ff] == EmptySquare) {
callback(board, flags,
rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
rf, ff, rf + 1, ff, closure);
}
if (rf <= (BOARD_HEIGHT>>1)-3 && board[rf+1][ff] == EmptySquare && // [HGM] grand: also on 3rd rank on 10-board
gameInfo.variant != VariantShatranj && /* [HGM] */
gameInfo.variant != VariantCourier && /* [HGM] */
board[rf+2][ff] == EmptySquare ) {
callback(board, flags, NormalMove,
rf, ff, rf+2, ff, closure);
}
for (s = -1; s <= 1; s += 2) {
if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
((flags & F_KRIEGSPIEL_CAPTURE) ||
BlackPiece(board[rf + 1][ff + s]))) {
callback(board, flags,
rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
rf, ff, rf + 1, ff + s, closure);
}
if (rf >= BOARD_HEIGHT+1>>1) {// [HGM] grand: 4th & 5th rank on 10-board
if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
(epfile == ff + s || epfile == EP_UNKNOWN) && rf < BOARD_HEIGHT-3 &&
board[rf][ff + s] == BlackPawn &&
board[rf+1][ff + s] == EmptySquare) {
callback(board, flags, WhiteCapturesEnPassant,
rf, ff, rf+1, ff + s, closure);
}
}
}
break;
case BlackPawn:
if(gameInfo.variant == VariantXiangqi) {
/* [HGM] capture straight ahead in Xiangqi */
if (rf > 0 && !SameColor(board[rf][ff], board[rf - 1][ff]) ) {
callback(board, flags, NormalMove,
rf, ff, rf - 1, ff, closure);
}
/* and move sideways when across the river */
for (s = -1; s <= 1; s += 2) {
if (rf < BOARD_HEIGHT>>1 &&
ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
!BlackPiece(board[rf][ff+s]) ) {
callback(board, flags, NormalMove,
rf, ff, rf, ff+s, closure);
}
}
break;
}
if (rf > 0 && board[rf - 1][ff] == EmptySquare) {
callback(board, flags,
rf <= promoRank ? BlackPromotion : NormalMove,
rf, ff, rf - 1, ff, closure);
}
if (rf >= (BOARD_HEIGHT+1>>1)+2 && board[rf-1][ff] == EmptySquare && // [HGM] grand
gameInfo.variant != VariantShatranj && /* [HGM] */
gameInfo.variant != VariantCourier && /* [HGM] */
board[rf-2][ff] == EmptySquare) {
callback(board, flags, NormalMove,
rf, ff, rf-2, ff, closure);
}
for (s = -1; s <= 1; s += 2) {
if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
((flags & F_KRIEGSPIEL_CAPTURE) ||
WhitePiece(board[rf - 1][ff + s]))) {
callback(board, flags,
rf <= promoRank ? BlackPromotion : NormalMove,
rf, ff, rf - 1, ff + s, closure);
}
if (rf < BOARD_HEIGHT>>1) {
if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
(epfile == ff + s || epfile == EP_UNKNOWN) && rf > 2 &&
board[rf][ff + s] == WhitePawn &&
board[rf-1][ff + s] == EmptySquare) {
callback(board, flags, BlackCapturesEnPassant,
rf, ff, rf-1, ff + s, closure);
}
}
}
break;
case WhiteUnicorn:
case BlackUnicorn:
case WhiteKnight:
case BlackKnight:
for (i = -1; i <= 1; i += 2)
for (j = -1; j <= 1; j += 2)
for (s = 1; s <= 2; s++) {
rt = rf + i*s;
ft = ff + j*(3-s);
if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
&& ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
&& !SameColor(board[rf][ff], board[rt][ft]))
callback(board, flags, NormalMove,
rf, ff, rt, ft, closure);
}
break;
case SHOGI WhiteKnight:
for (s = -1; s <= 1; s += 2) {
if (rf < BOARD_HEIGHT-2 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
!SameColor(board[rf][ff], board[rf + 2][ff + s])) {
callback(board, flags, NormalMove,
rf, ff, rf + 2, ff + s, closure);
}
}
break;
case SHOGI BlackKnight:
for (s = -1; s <= 1; s += 2) {
if (rf > 1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
!SameColor(board[rf][ff], board[rf - 2][ff + s])) {
callback(board, flags, NormalMove,
rf, ff, rf - 2, ff + s, closure);
}
}
break;
case WhiteCannon:
case BlackCannon:
for (d = 0; d <= 1; d++)
for (s = -1; s <= 1; s += 2) {
m = 0;
for (i = 1;; i++) {
rt = rf + (i * s) * d;
ft = ff + (i * s) * (1 - d);
if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
if (m == 0 && board[rt][ft] == EmptySquare)
callback(board, flags, NormalMove,
rf, ff, rt, ft, closure);
if (m == 1 && board[rt][ft] != EmptySquare &&
!SameColor(board[rf][ff], board[rt][ft]) )
callback(board, flags, NormalMove,
rf, ff, rt, ft, closure);
if (board[rt][ft] != EmptySquare && m++) break;
}
}
break;
/* Gold General (and all its promoted versions) . First do the */
/* diagonal forward steps, then proceed as normal Wazir */
case SHOGI (PROMOTED WhitePawn):
if(gameInfo.variant == VariantShogi) goto WhiteGold;
case SHOGI (PROMOTED BlackPawn):
if(gameInfo.variant == VariantShogi) goto BlackGold;
SlideVertical(board, flags, rf, ff, callback, closure);
break;
case SHOGI (PROMOTED WhiteKnight):
if(gameInfo.variant == VariantShogi) goto WhiteGold;
case SHOGI BlackDrunk:
case SHOGI BlackAlfil:
Ferz(board, flags, rf, ff, callback, closure);
StepSideways(board, flags, rf, ff, callback, closure);
StepBackward(board, flags, rf, ff, callback, closure);
break;
case SHOGI (PROMOTED BlackKnight):
if(gameInfo.variant == VariantShogi) goto BlackGold;
case SHOGI WhiteDrunk:
case SHOGI WhiteAlfil:
Ferz(board, flags, rf, ff, callback, closure);
StepSideways(board, flags, rf, ff, callback, closure);
StepForward(board, flags, rf, ff, callback, closure);
break;
case SHOGI WhiteStag:
case SHOGI BlackStag:
if(gameInfo.variant == VariantShogi) goto BlackGold;
SlideVertical(board, flags, rf, ff, callback, closure);
Ferz(board, flags, rf, ff, callback, closure);
StepSideways(board, flags, rf, ff, callback, closure);
break;
case SHOGI (PROMOTED WhiteQueen):
case SHOGI WhiteTokin:
case SHOGI WhiteWazir:
WhiteGold:
StepDiagForward(board, flags, rf, ff, callback, closure);
Wazir(board, flags, rf, ff, callback, closure);
break;
case SHOGI (PROMOTED BlackQueen):
case SHOGI BlackTokin:
case SHOGI BlackWazir:
BlackGold:
StepDiagBackward(board, flags, rf, ff, callback, closure);
Wazir(board, flags, rf, ff, callback, closure);
break;
case WhiteWazir:
case BlackWazir:
Wazir(board, flags, rf, ff, callback, closure);
break;
case SHOGI WhiteMarshall:
case SHOGI BlackMarshall:
Ferz(board, flags, rf, ff, callback, closure);
for (d = 0; d <= 1; d++)
for (s = -2; s <= 2; s += 4) {
rt = rf + s * d;
ft = ff + s * (1 - d);
if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
if (!SameColor(board[rf][ff], board[rt][ft]) )
callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
}
break;
case SHOGI WhiteAngel:
case SHOGI BlackAngel:
Wazir(board, flags, rf, ff, callback, closure);
case WhiteAlfil:
case BlackAlfil:
/* [HGM] support Shatranj pieces */
for (rs = -1; rs <= 1; rs += 2)
for (fs = -1; fs <= 1; fs += 2) {
rt = rf + 2 * rs;
ft = ff + 2 * fs;
if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
&& ( gameInfo.variant != VariantXiangqi ||
board[rf+rs][ff+fs] == EmptySquare && (2*rf < BOARD_HEIGHT) == (2*rt < BOARD_HEIGHT) )
&& !SameColor(board[rf][ff], board[rt][ft]))
callback(board, flags, NormalMove,
rf, ff, rt, ft, closure);
if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
gameInfo.variant == VariantChu || gameInfo.variant == VariantXiangqi) continue; // classical Alfil
rt = rf + rs; // in unknown variant we assume Modern Elephant, which can also do one step
ft = ff + fs;
if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
&& !SameColor(board[rf][ff], board[rt][ft]))
callback(board, flags, NormalMove,
rf, ff, rt, ft, closure);
}
if(gameInfo.variant == VariantSpartan)
for(fs = -1; fs <= 1; fs += 2) {
ft = ff + fs;
if (!(ft < BOARD_LEFT || ft >= BOARD_RGHT) && board[rf][ft] == EmptySquare)
callback(board, flags, NormalMove, rf, ff, rf, ft, closure);
}
break;
/* Make Dragon-Horse also do Dababba moves outside Shogi, for better disambiguation in variant Fairy */
case WhiteCardinal:
case BlackCardinal:
if(gameInfo.variant == VariantChuChess) goto DragonHorse;
for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
for (s = -2; s <= 2; s += 4) {
rt = rf + s * d;
ft = ff + s * (1 - d);
if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
if (SameColor(board[rf][ff], board[rt][ft])) continue;
callback(board, flags, NormalMove, rf, ff, rt, ft, closure);