pieces_legmoves.c

// This file is a part of the GiuChess Project.
//
// Copyright (c) 2005 Giuliano Ippoliti aka JSorel (ippo@linuxmail.org)
//
// This program 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 2 of the License, or (at your option) any later version.
//
// This program 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, write to the Free Software
// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

#include "pieces_legmoves.h" 

BITMASK rook_legmovs(int order, piece *friends, piece *enem) {
	int row, col, i;
	BITMASK bm_pos, bm_work, focc, eocc, bm_result;
	
	focc = eocc = 0;		//bmasks for busy squares
	for (i=0; i<=15; i++) {
		eocc = eocc | enem[i].bm_pos;	//no probmem with king
		focc = focc | friends[i].bm_pos;
	}
		
	bm_pos = friends[order].bm_pos;
	focc = focc & (bm_pos ^ RET_ERR);
	
	bm_result = 0;
	
	if ( (bm_pos & LEFT) == 0) {	//left
		bm_work = bm_pos;
		
		while (1) {
			bm_work = bm_work >> 1;
			if ((bm_work & focc) != 0)
				break;
			if ((bm_work & eocc) != 0) {
				if (is_legal_mov(order, friends, enem, bm_work))
					bm_result = bm_result | bm_work;
				break;
			}
			if (is_legal_mov(order, friends, enem, bm_work))
				bm_result = bm_result | bm_work;
//mettere un else?
//se andando a sin. non è legale a un certo punto, puo` essere che continuando sia legale? si` se mangia un cavallo, ad es.
			if ( (bm_work & LEFT) != 0)
				break;
		}
	}
	
	if ( (bm_pos & RIGHT) == 0) {	//right
		bm_work = bm_pos;
		
		while (1) {
			bm_work = bm_work << 1;
			if ((bm_work & focc) != 0)
				break;
			if ((bm_work & eocc) != 0) {
				if (is_legal_mov(order, friends, enem, bm_work))
					bm_result = bm_result | bm_work;
				break;
			}
			if (is_legal_mov(order, friends, enem, bm_work))
				bm_result = bm_result | bm_work;
			if ( (bm_work & RIGHT) != 0)
				break;
		}
	}
	
	if ( (bm_pos & BOTTOM) == 0) {	//bottom
		bm_work = bm_pos;
		
		while (1) {
			bm_work = bm_work >> 8;
			if ((bm_work & focc) != 0)
				break;
			if ((bm_work & eocc) != 0) {
				if (is_legal_mov(order, friends, enem, bm_work))
					bm_result = bm_result | bm_work;
				break;
			}
			if (is_legal_mov(order, friends, enem, bm_work))
				bm_result = bm_result | bm_work;
			if ( (bm_work & BOTTOM) != 0)
				break;
		}
	}

	if ( (bm_pos & TOP) == 0) {	//top
		bm_work = bm_pos;
		
		while (1) {
			bm_work = bm_work << 8;
			if ((bm_work & focc) != 0)
				break;
			if ((bm_work & eocc) != 0) {
				if (is_legal_mov(order, friends, enem, bm_work))
					bm_result = bm_result | bm_work;
				break;
			}
			if (is_legal_mov(order, friends, enem, bm_work))
				bm_result = bm_result | bm_work;
			if ( (bm_work & TOP) != 0)
				break;
		}
	}

	return bm_result;
}
		
BITMASK bishop_legmovs(int order, piece *friends, piece *enem) {
	int i;
	BITMASK bm_pos, bm_work, focc, eocc, bm_result;

	focc = eocc = 0;		//bmasks for busy squares
	for (i=0; i<=15; i++) {
		eocc = eocc | enem[i].bm_pos;
		focc = focc | friends[i].bm_pos;
	}
	
	bm_pos = friends[order].bm_pos;
	focc = focc & (bm_pos ^ RET_ERR);
	bm_result = 0;
	
	if ( (bm_pos & TOPLEFT) == 0) {
		bm_work = bm_pos;
		while (1) {
			bm_work = bm_work << 7;		// top left
			if ((bm_work & focc) != 0)
				break;
			if ((bm_work & eocc) != 0) {
				if (is_legal_mov(order, friends, enem, bm_work))
					bm_result = bm_result | bm_work;
				break;
			}
			if (is_legal_mov(order, friends, enem, bm_work))
				bm_result = bm_result | bm_work;
			if ( (bm_work & TOPLEFT) != 0) 	//border
				break;
		}
	}

	if ( (bm_pos & TOPRIGHT) == 0) {
		bm_work = bm_pos;
		while (1) {
			bm_work = bm_work << 9;		// top right
			if ((bm_work & focc) != 0)
				break;
			if ((bm_work & eocc) != 0) {
				if (is_legal_mov(order, friends, enem, bm_work))
					bm_result = bm_result | bm_work;
				break;
			}
			if (is_legal_mov(order, friends, enem, bm_work))
				bm_result = bm_result | bm_work;
			if ( (bm_work & TOPRIGHT) != 0) 	//border
				break;
		}
	}

	if ( (bm_pos & BOTTOMRIGHT) == 0) {
		bm_work = bm_pos;
		while (1) {
			bm_work = bm_work >> 7;		// bottom right
			if ((bm_work & focc) != 0)
				break;
			if ((bm_work & eocc) != 0) {
				if (is_legal_mov(order, friends, enem, bm_work))
					bm_result = bm_result | bm_work;
				break;
			}
			if (is_legal_mov(order, friends, enem, bm_work))
				bm_result = bm_result | bm_work;
			if ( (bm_work & BOTTOMRIGHT) != 0) 	//border
				break;
		}
	}
				
	if ( (bm_pos & BOTTOMLEFT) == 0) {
		bm_work = bm_pos;
		while (1) {
			bm_work = bm_work >> 9;		// bottom left
			if ((bm_work & focc) != 0)
				break;
			if ((bm_work & eocc) != 0) {
				if (is_legal_mov(order, friends, enem, bm_work))
					bm_result = bm_result | bm_work;
				break;
			}
			if (is_legal_mov(order, friends, enem, bm_work))
				bm_result = bm_result | bm_work;
			if ( (bm_work & BOTTOMLEFT) != 0) 	//border
				break;
		}
	}
	
	return bm_result;
}

BITMASK queen_legmovs(int order, piece *friends, piece *enem) {
	BITMASK bm_pos, bm_result, bm_work;
	
	bm_work = rook_legmovs(order, friends, enem);
	bm_result = bm_work;
		
	bm_work = bishop_legmovs(order, friends, enem);
	bm_result = bm_result | bm_work;
		
	return bm_result;
}
	
BITMASK knight_legmovs(int order, piece *friends, piece *enem) {
	int row, col, i;
	BITMASK bm_pos, bm_work, focc, eocc, bm_result;

	focc = eocc = 0;		//bmasks for busy squares
	for (i=0; i<=15; i++) {
		eocc = eocc | enem[i].bm_pos;
		focc = focc | friends[i].bm_pos;
	}
	
	bm_pos = friends[order].bm_pos;
	focc = focc & (bm_pos ^ RET_ERR);
	conv_bm_cases(bm_pos, &row, &col);
	
	bm_result = 0;

	if ( ((row+2) <= 7) && ((col+1) <= 7) ) {
		bm_work = bm_pos << 17;
		if ((bm_work & focc) == 0) {
			if (is_legal_mov(order, friends, enem, bm_work))
				bm_result = bm_result | bm_work;
		}
	}
	if ( ((row+1) <= 7) && ((col+2) <= 7) ) {
		bm_work = bm_pos << 10;
		if ((bm_work & focc) == 0) {
			if (is_legal_mov(order, friends, enem, bm_work))
				bm_result = bm_result | bm_work;
		}
	}
	if ( ((row-1) >= 0) && ((col+2) <= 7) ) {
		bm_work = bm_pos >> 6;
		if ((bm_work & focc) == 0) {
			if (is_legal_mov(order, friends, enem, bm_work))
				bm_result = bm_result | bm_work;
		}
	}
	if ( ((row-2) >= 0) && ((col+1) <= 7) ) {
		bm_work = bm_pos >> 15;
		if ((bm_work & focc) == 0) {
			if (is_legal_mov(order, friends, enem, bm_work))
				bm_result = bm_result | bm_work;
		}
	}
	if ( ((row-2) >= 0) && ((col-1) >= 0) ) {
		bm_work = bm_pos >> 17;
		if ((bm_work & focc) == 0) {
			if (is_legal_mov(order, friends, enem, bm_work))
				bm_result = bm_result | bm_work;
		}
	}
	if ( ((row-1) >= 0) && ((col-2) >= 0) ) {
		bm_work = bm_pos >> 10;
		if ((bm_work & focc) == 0) {
			if (is_legal_mov(order, friends, enem, bm_work))
				bm_result = bm_result | bm_work;
		}
	}
	if ( ((row+1) <= 7) && ((col-2) >= 0) ) {
		bm_work = bm_pos << 6;
		if ((bm_work & focc) == 0) {
			if (is_legal_mov(order, friends, enem, bm_work))
				bm_result = bm_result | bm_work;
		}
	}
	if ( ((row+2) <= 7) && ((col-1) >= 0) ) {
		bm_work = bm_pos << 15;
		if ((bm_work & focc) == 0) {
			if (is_legal_mov(order, friends, enem, bm_work))
				bm_result = bm_result | bm_work;
		}
	}

	return bm_result;
}

BITMASK white_pawn_legmovs(int order, piece *w, piece *b) {
	int row, col, i;
	BITMASK bm_pos, bm_work, focc, eocc, bm_result;

	focc = eocc = 0;		//bmasks for busy squares
	for (i=0; i<=15; i++) {
		eocc = eocc | b[i].bm_pos;
		focc = focc | w[i].bm_pos;
	}
	
	bm_pos = w[order].bm_pos;
	focc = focc & (bm_pos ^ RET_ERR);
	bm_result = 0;
	
	bm_work = bm_pos << 8;

	if ( ((bm_work & focc) == 0) && ((bm_work & eocc) == 0) ) {	//free square
		if (is_pawn_legal_mov(order, w, b, bm_work))
			bm_result = bm_result | bm_work;

		if ((bm_pos & ROW2) != 0) {				//never moved
			bm_work = bm_pos << 16;
			if ( ((bm_work & focc) == 0) && ((bm_work & eocc) == 0) )
				if (is_pawn_legal_mov(order, w, b, bm_work))
					bm_result = bm_result | bm_work;
		}
	}
	
	if ((bm_pos & COL1) == 0) {				//pas sur LEFT
		bm_work = bm_pos << 7;
		if ((bm_work & eocc) != 0)
			if (is_pawn_legal_mov(order, w, b, bm_work))
				bm_result = bm_result | bm_work;
	}

	if ((bm_pos & COL8) == 0) {			//pas sur RIGHT
		bm_work = bm_pos << 9;
		if ((bm_work & eocc) != 0)
			if (is_pawn_legal_mov(order, w, b, bm_work))
				bm_result = bm_result | bm_work;
	}

	//en passant
	if ((bm_pos & ROW5) != 0) {
		get_column_from_bm(bm_pos, &col);
//conv_bm_cases(bm_pos, &row, &col);
		if (col != 7) {
			if (b[8+col+1].last_double_move == 1) {
				bm_work = bm_pos << 9;
				if (is_pawn_legal_mov(order, w, b, bm_work))
					bm_result = bm_result | bm_work;
			}
		}
		if (col != 0) {
			if (b[8+col-1].last_double_move == 1) {
				bm_work = bm_pos << 7;
				if (is_pawn_legal_mov(order, w, b, bm_work))
					bm_result = bm_result | bm_work;
			}
		}
	}

	return bm_result;
}


BITMASK black_pawn_legmovs(int order, piece *w, piece *b) {
	int row, col, i;
	BITMASK bm_pos, bm_work, focc, eocc, bm_result;

	focc = eocc = 0;		//bmasks for busy squares
	for (i=0; i<=15; i++) {
		eocc = eocc | w[i].bm_pos;
		focc = focc | b[i].bm_pos;
	}
	
	bm_pos = b[order].bm_pos;
	focc = focc & (bm_pos ^ RET_ERR);
	bm_result = 0;
	
	bm_work = bm_pos >> 8;
	if ( ((bm_work & focc) == 0) && ((bm_work & eocc) == 0) ) {	//free square
		if (is_pawn_legal_mov(order, b, w, bm_work))
			bm_result = bm_result | bm_work;
		if ((bm_pos & ROW7) != 0) {				//never moved
			bm_work = bm_pos >> 16;
			if ( ((bm_work & focc) == 0) && ((bm_work & eocc) == 0) )
				if (is_pawn_legal_mov(order, b, w, bm_work))
					bm_result = bm_result | bm_work;
		}
	}

	if ((bm_pos & COL1) == 0) {				//pas sur LEFT
		bm_work = bm_pos >> 9;
		if ((bm_work & eocc) != 0)
			if (is_pawn_legal_mov(order, b, w, bm_work))
				bm_result = bm_result | bm_work;
	}

	if ((bm_pos & COL8) == 0) {			//pas sur RIGHT
		bm_work = bm_pos >> 7;
		if ((bm_work & eocc) != 0)
			if (is_pawn_legal_mov(order, b, w, bm_work))
				bm_result = bm_result | bm_work;
	}

	//en passant
	if ((bm_pos & ROW4) != 0) {
		get_column_from_bm(bm_pos, &col);
//conv_bm_cases(bm_pos, &row, &col);
		if (col != 7) {
			if (w[8+col+1].last_double_move == 1) {
				bm_work = bm_pos >> 7;
				if (is_pawn_legal_mov(order, b, w, bm_work))
					bm_result = bm_result | bm_work;
			}
		}
		if (col != 0) {
			if (w[8+col-1].last_double_move == 1) {
				bm_work = bm_pos >> 9;
				if (is_pawn_legal_mov(order, b, w, bm_work))
					bm_result = bm_result | bm_work;
			}
		}
	}

	return bm_result;
}


BITMASK king_legmovs(int order, piece *friends, piece *enems) {
	int row, col, i;
	BITMASK bm_pos, bm_work, focc, eocc, bm_result;

	focc = eocc = 0;
	for (i=0; i<=15; i++) {
		eocc = eocc | enems[i].bm_pos;
		focc = focc | friends[i].bm_pos;
	}

	bm_pos = friends[order].bm_pos;
	focc = focc & (bm_pos ^ RET_ERR);
	bm_result = 0;

	if ((bm_pos & ROW1) == 0)  {
		bm_work = bm_pos >> 8;
		if ((bm_work & focc) == 0) {			// no friend in that case
			if (is_legal_mov(order, friends, enems, bm_work))
				bm_result = bm_result | bm_work;
		}
			
		if ((bm_pos & COL1) == 0)  {
			bm_work = bm_pos >> 9;
			if ((bm_work & focc) == 0) {
				if (is_legal_mov(order, friends, enems, bm_work))
					bm_result = bm_result | bm_work;
			}
		}
	}

	if ((bm_pos & COL1) == 0)  {
		bm_work = bm_pos >> 1;
		if ((bm_work & focc) == 0) {
			if (is_legal_mov(order, friends, enems, bm_work))
				bm_result = bm_result | bm_work;
		}
			
		if ((bm_pos & ROW8) == 0)  {
			bm_work = bm_pos << 7;
			if ((bm_work & focc) == 0) {
				if (is_legal_mov(order, friends, enems, bm_work))
					bm_result = bm_result | bm_work;
			}
		}
	}

	if ((bm_pos & ROW8) == 0)  {
		bm_work = bm_pos << 8;
		if ((bm_work & focc) == 0) {
			if (is_legal_mov(order, friends, enems, bm_work))
				bm_result = bm_result | bm_work;
		}
			
		if ((bm_pos & COL8) == 0)  {
			bm_work = bm_pos << 9;
			if ((bm_work & focc) == 0) {
				if (is_legal_mov(order, friends, enems, bm_work))
					bm_result = bm_result | bm_work;
			}
		}
	}

	if ((bm_pos & COL8) == 0)  {
		bm_work = bm_pos << 1;
		if ((bm_work & focc) == 0) {
			if (is_legal_mov(order, friends, enems, bm_work))
				bm_result = bm_result | bm_work;
		}
			
		if ((bm_pos & ROW1) == 0)  {
			bm_work = bm_pos >> 7;
			if ((bm_work & focc) == 0) {
				if (is_legal_mov(order, friends, enems, bm_work))
					bm_result = bm_result | bm_work;
			}
		}
	}

	//general castle
	//already moved
	if (friends[order].deja_moved == 1)
		return bm_result;
		
	//short castle
	do {
		bm_work = bm_pos << 1;
		if ((bm_work & bm_result) == 0)	// "e1f1" not in move list
			continue;
			
		if (friends[order+3].deja_moved == 1)  //rook has already moved
			continue;
		
		if (friends[order+3].bm_pos == 0)
			continue;

		bm_work = bm_pos << 2;
		if ((bm_work & (focc | eocc)) != 0)
			continue;
			
		//under check: last test!
		if (friends[order].under_check == 1)
			return bm_result;
			
		if (is_legal_mov(order, friends, enems, bm_work))
			bm_result = bm_result | bm_work;	
	} while(0);
	
	//long castle
	do {
		bm_work = bm_pos >> 1;
		if ((bm_work & bm_result) == 0)	// "e1c1" not in move list
			continue;	
	
		if (friends[order-4].deja_moved == 1)     //rook has already moved
			continue;
			
		if (friends[order-4].bm_pos == 0)
			continue;

		bm_work = bm_pos >> 3;
		if ((bm_work & (focc | eocc)) != 0)
			continue;
			
		bm_work = bm_pos >> 2;
		if ((bm_work & (focc | eocc)) != 0)
			continue;
			
		if (friends[order].under_check == 1)
			return bm_result;

		if (is_legal_mov(order, friends, enems, bm_work))
			bm_result = bm_result | bm_work;
	} while(0);
	
	return bm_result;
}