add square attackers fct

Makefile

@@ -41,7 +41,7 @@ TSTSRC    := $(wildcard $(TSTDIR)/*.c)
 
 LIB       := br_$(shell uname -m)			    # library name
 
-DEP_FN    := $(SRC_FN) $(LIBSRC_FN)
+DEP_FN    := $(SRC_FN)
 DEP       := $(addprefix $(DEPDIR)/,$(DEP_FN:.c=.d))
 
 TARGET_FN := brchess
@@ -66,6 +66,7 @@ CPPFLAGS  += -DDEBUG_DEBUG                                  # enable log() funct
 #CPPFLAGS  += -DDEBUG_DEBUG_C                                # enable log() settings
 CPPFLAGS  += -DDEBUG_POOL                                   # memory pools management
 #CPPFLAGS  += -DDEBUG_FEN                                    # FEN decoding
+#CPPFLAGS  += -DDEBUG_POS				    # position.c
 CPPFLAGS  += -DDEBUG_MOVE                                   # move generation
 CPPFLAGS  += -DDEBUG_EVAL                                   # eval functions
 CPPFLAGS  += -DDEBUG_PIECE                                  # piece list management
@@ -76,7 +77,7 @@ CPPFLAGS  := $(strip $(CPPFLAGS))
 
 ##################################### compiler flags
 CFLAGS    := -std=gnu11
-CFLAGS    += -O3
+CFLAGS    += -O1
 CFLAGS    += -g
 CFLAGS    += -Wall
 CFLAGS    += -Wextra
@@ -263,23 +264,35 @@ memcheck: targets
 	@$(VALGRIND) $(VALGRINDFLAGS) $(BINDIR)/brchess
 
 ##################################### test binaries
-TEST           = bin/fen-test bin/bitboard-test
+TEST           = bin/fen-test bin/bitboard-test bin/movegen-test \
+	bin/mktestdata
 
 FENTESTOBJS    = obj/fen.o obj/position.o obj/piece.o obj/bitboard.o \
 	obj/board.o obj/util.o
 BITBOARDOBJS   = obj/fen.o obj/position.o obj/piece.o obj/bitboard.o \
 	obj/board.o obj/hyperbola-quintessence.o
+MOVEGENOBJS    = obj/fen.o obj/position.o obj/piece.o obj/bitboard.o \
+	obj/board.o obj/hyperbola-quintessence.o obj/move.o obj/movegen.o
+MKTESTDATAOBJS = obj/fen.o obj/position.o obj/piece.o obj/bitboard.o \
+	obj/board.o obj/hyperbola-quintessence.o obj/move.o
 
 testing: $(TEST)
 
 bin/fen-test: test/fen-test.c $(FENTESTOBJS)
-	$(CC) $(DEPFLAGS) $(CPPFLAGS) $(CFLAGS) $< $(FENTESTOBJS)  $(LDFLAGS) $(LIBS) -o $@
+	@echo compiling $@ executable.
+	@$(CC) $(DEPFLAGS) $(CPPFLAGS) $(CFLAGS) $< $(FENTESTOBJS)  $(LDFLAGS) $(LIBS) -o $@
 
 bin/bitboard-test: test/bitboard-test.c $(BITBOARDOBJS)
-	echo all=$^
-	$(CC) $(DEPFLAGS) $(CPPFLAGS) $(CFLAGS) $< $(BITBOARDOBJS) $(LDFLAGS) $(LIBS) -o $@
+	@echo compiling $@ executable.
+	@$(CC) $(DEPFLAGS) $(CPPFLAGS) $(CFLAGS) $< $(BITBOARDOBJS) $(LDFLAGS) $(LIBS) -o $@
 
+bin/movegen-test: test/movegen-test.c $(MOVEGENOBJS)
+	@echo compiling $@ executable.
+	@$(CC) $(DEPFLAGS) $(CPPFLAGS) $(CFLAGS) $< $(MOVEGENOBJS) $(LDFLAGS) $(LIBS) -o $@
 
+bin/mktestdata: test/mktestdata.c $(MKTESTDATAOBJS)
+	@echo compiling $@ executable.
+	@$(CC) $(DEPFLAGS) $(CPPFLAGS) $(CFLAGS) $< $(MKTESTDATAOBJS) $(LDFLAGS) $(LIBS) -o $@
 ##################################### Makefile debug
 .PHONY: showflags wft
 

src/attack.c

@@ -0,0 +1,67 @@
+/* attack.c - attack functions.
+ *
+ * Copyright (C) 2024 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.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#include "chessdefs.h"
+#include "bitboard.h"
+#include "position.h"
+#include "hyperbola-quintessence.h"
+
+/**
+ * square_attackers() - find attackers on a square
+ * @pos: position
+ * @sq:  square to test
+ * @c:   attacker color
+ *
+ * Find all @c attacks on @sq. En-passant is not considered.
+ *
+ * Algorithm:  We perform a reverse attack, and check if any given
+ * piece type on @sq can attack a @c piece of same type.
+ *
+ * For example, if @c is white, we test for all T in P,N,B,R,Q,K if
+ * T on @sq could attack a white T piece.
+ *
+ * @Return: a bitboard of attackers.
+ *
+ */
+bitboard_t sq_attackers(pos_t *pos, square_t sq, color_t c)
+{
+    bitboard_t attackers = 0;
+    bitboard_t from = mask(sq);
+    bitboard_t c_pieces = pos->bb[c][ALL_PIECES];
+    bitboard_t occ = c_pieces | pos->bb[OPPONENT(c)][ALL_PIECES];
+    bitboard_t to;
+
+    /* pawn */
+    to =  pos->bb[c][PAWN];
+    attackers |= pawn_push_upleft(from, c) & to;
+    attackers |= pawn_push_upright(from, c) & to;
+
+    /* knight & king */
+    to = pos->bb[c][KNIGHT];
+    attackers |= bb_knight_moves(c_pieces, from);
+    to = pos->bb[c][KING];
+    attackers |= bb_king_moves(c_pieces, from);
+
+    /* bishop / queen */
+    to = pos->bb[c][BISHOP] | pos->bb[c][QUEEN];
+    attackers |= hyperbola_bishop_moves(occ, from) & to;
+
+    /* rook / queen */
+    to = pos->bb[c][ROOK] | pos->bb[c][QUEEN];
+    attackers |= hyperbola_rook_moves(occ, from) & to;
+
+    return attackers;
+}

src/attack.h

@@ -0,0 +1,22 @@
+/* attack.h - attack functions.
+ *
+ * Copyright (C) 2024 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.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef _ATTACK_H
+#define _ATTACK_H
+
+#include "chessdefs.h"
+#include "bitboard.h"
+
+extern bitboard_t sq_attackers(pos_t *pos, square_t sq, color_t c);
+
+#endif