stellar

commit 29568808a50e6f13021dcc79acdfc864fbcdefea
parent a1e1fde71226015465fd0dacbf438af066a8f5c7
Author: Dimitrije Dobrota <mail@dimitrijedobrota.com>
Date:   Mon, 19 Sep 2022 20:09:53 +0200

Bishop attack mask

Diffstat:
M
src/engine.c
 | 
30
++++++++++++++++++++++++++----

1 file changed, 26 insertions(+), 4 deletions(-)
diff --git a/src/engine.c b/src/engine.c
@@ -8,18 +8,22 @@
 
 /* DEFINITIONS */
 
+// useful macros
+#define MAX(a, b) ((a > b) ? a : b)
+#define MIN(a, b) ((a < b) ? a : b)
+
 typedef unsigned long long U64;           // define bitboard data type
 #define C64(constantU64) constantU64##ULL // define shorthand for constants
 
-// usefull bit patterns
+// useful bit patterns
 const U64 universe = C64(0xffffffffffffffff); //
 const U64 notAFile = C64(0xfefefefefefefefe); // ~0x0101010101010101
 const U64 notHFile = C64(0x7f7f7f7f7f7f7f7f); // ~0x8080808080808080
 
 // useful bit operations
-#define bit_get(bitboard, square) ((bitboard >> square) & C64(1))
-#define bit_set(bitboard, square) (bitboard |= C64(1) << square)
-#define bit_pop(bitboard, square) (bitboard &= ~(C64(1) << square))
+#define bit_get(bitboard, square) (((bitboard) >> (square)) & C64(1))
+#define bit_set(bitboard, square) ((bitboard) |= C64(1) << (square))
+#define bit_pop(bitboard, square) ((bitboard) &= ~(C64(1) << (square)))
 
 // squares
 // clang-format off
@@ -165,6 +169,24 @@ U64 mask_king_attacks(int square) {
   return attacks;
 }
 
+U64 mask_bishup_attacks(int square) {
+  U64 bitboard = C64(0), attacks = C64(0), tmp;
+  int tr = square / 8, tf = square % 8, i;
+
+  bit_set(bitboard, square);
+
+  for (i = 0, tmp = bitboard; i < MIN(7 - tf, 7 - tr) - 1; i++)
+    attacks |= tmp = noEaOne(tmp);
+  for (i = 0, tmp = bitboard; i < MIN(tf, 7 - tr) - 1; i++)
+    attacks |= tmp = noWeOne(tmp);
+  for (i = 0, tmp = bitboard; i < MIN(7 - tf, tr) - 1; i++)
+    attacks |= tmp = soEaOne(tmp);
+  for (i = 0, tmp = bitboard; i < MIN(tf, tr) - 1; i++)
+    attacks |= tmp = soWeOne(tmp);
+
+  return attacks;
+}
+
 void init_leapers_attacks(void) {
   for (int square = 0; square < 64; square++) {
     pawn_attacks[WHITE][square] = mask_pawn_attacks(WHITE, square);