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-rw-r--r--src/bitboard.c64
-rw-r--r--src/bitboard.h32
-rw-r--r--src/main.c4
-rw-r--r--src/search.h9
-rw-r--r--src/search/moves.c13
-rw-r--r--src/search/pawn_moves.c47
6 files changed, 150 insertions, 19 deletions
diff --git a/src/bitboard.c b/src/bitboard.c
index 05b370b..ce994c5 100644
--- a/src/bitboard.c
+++ b/src/bitboard.c
@@ -1,25 +1,71 @@
#include "bitboard.h"
+#include <stdio.h>
+#include <inttypes.h>
+#include <assert.h>
-position starting_position() {
- return (position) {
+position_t position_starting() {
+ return (position_t) {
.bitboards = {
+ 16ULL,
+ 8ULL,
+ 129ULL,
+ 36ULL,
+ 66ULL,
+ 65280ULL,
1152921504606846976ULL,
576460752303423488ULL,
9295429630892703744ULL,
- 4755801206503243776ULL,
2594073385365405696ULL,
+ 4755801206503243776ULL,
71776119061217280ULL,
- 16ULL,
- 8ULL,
- 129ULL,
- 66ULL,
- 36ULL,
- 65280ULL
},
.castling =
(1 << WHITE_SHORT_CASTLE) |
(1 << WHITE_LONG_CASTLE) |
(1 << BLACK_SHORT_CASTLE) |
(1 << BLACK_LONG_CASTLE),
+ .turn = WHITE_TURN,
};
}
+
+void assert_valid_position(position_t position) {
+ assert(position.castling <=
+ (
+ (1 << WHITE_SHORT_CASTLE) |
+ (1 << WHITE_LONG_CASTLE) |
+ (1 << BLACK_SHORT_CASTLE) |
+ (1 << BLACK_LONG_CASTLE)
+ )
+ );
+ assert(position.turn == WHITE_TURN || position.turn == BLACK_TURN);
+}
+
+bitboard_t whites(position_t position) {
+ return
+ position.bitboards[WHITE_KING] |
+ position.bitboards[WHITE_QUEEN] |
+ position.bitboards[WHITE_ROOK] |
+ position.bitboards[WHITE_BISHOP] |
+ position.bitboards[WHITE_KNIGHT] |
+ position.bitboards[WHITE_PAWN];
+}
+
+bitboard_t blacks(position_t position) {
+ return
+ position.bitboards[BLACK_KING] |
+ position.bitboards[BLACK_QUEEN] |
+ position.bitboards[BLACK_ROOK] |
+ position.bitboards[BLACK_BISHOP] |
+ position.bitboards[BLACK_KNIGHT] |
+ position.bitboards[BLACK_PAWN];
+}
+
+void print_bitboard(bitboard_t bitboard) {
+ printf("Bitboard(%" PRIu64 ")\n", bitboard);
+ for (int i = 7; i >= 0; i--) {
+ for (int j = 0; j < 8; j++) {
+ printf("%" PRIu64 "", (bitboard >> (8 * i + j)) & 1);
+ }
+ printf("\n");
+ }
+}
diff --git a/src/bitboard.h b/src/bitboard.h
index b92d67f..a816ea6 100644
--- a/src/bitboard.h
+++ b/src/bitboard.h
@@ -28,11 +28,39 @@ enum {
BLACK_LONG_CASTLE,
};
+enum {
+ WHITE_TURN,
+ BLACK_TURN,
+};
+
+#define BITMASK_RANK_A 255ULL
+#define BITMASK_RANK_B 65280ULL
+#define BITMASK_RANK_C 16711680ULL
+#define BITMASK_RANK_D 4278190080ULL
+#define BITMASK_RANK_E 1095216660480ULL
+#define BITMASK_RANK_F 280375465082880ULL
+#define BITMASK_RANK_G 71776119061217280ULL
+#define BITMASK_RANK_H 18374686479671623680ULL
+#define BITMASK_COLM_1 72340172838076673ULL
+#define BITMASK_COLM_2 144680345676153346ULL
+#define BITMASK_COLM_3 289360691352306692ULL
+#define BITMASK_COLM_4 578721382704613384ULL
+#define BITMASK_COLM_5 1157442765409226768ULL
+#define BITMASK_COLM_6 2314885530818453536ULL
+#define BITMASK_COLM_7 4629771061636907072ULL
+#define BITMASK_COLM_8 9259542123273814144ULL
+
typedef struct {
bitboard_t bitboards[PIECE_TYPE_COUNT];
u8 castling;
-} position;
+ u8 turn;
+} position_t;
+
+position_t position_starting();
+void assert_valid_position(position_t position);
+bitboard_t whites(position_t position);
+bitboard_t blacks(position_t position);
-position starting_position();
+void print_bitboard(bitboard_t bitboard);
#endif // !BITBOARD_H
diff --git a/src/main.c b/src/main.c
index 297ef20..6c05aa2 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,7 +1,11 @@
#include <stdio.h>
#include "bitboard.h"
+#include "search.h"
int main() {
+ moves_t moves = moves_init();
+ position_t position = position_starting();
+ get_pawn_moves(&moves, position);
printf("Hello World\n");
return 0;
}
diff --git a/src/search.h b/src/search.h
index 153b865..f613294 100644
--- a/src/search.h
+++ b/src/search.h
@@ -2,6 +2,7 @@
#define SEARCH_H
#include "ints.h"
+#include "bitboard.h"
typedef u8 square_t;
@@ -16,9 +17,11 @@ typedef struct {
u32 capacity;
} moves_t;
-moves_t init_moves();
-moves_t init_moves_wcapacity(u32 capacity);
-moves_t empty_moves();
+moves_t moves_init();
+moves_t moves_init_wcapacity(u32 capacity);
+moves_t moves_empty();
void add_move(moves_t* moves, square_t from, square_t to);
+void get_pawn_moves(moves_t* moves, position_t position);
+
#endif // !SEARCH_H
diff --git a/src/search/moves.c b/src/search/moves.c
index 57797e7..7089886 100644
--- a/src/search/moves.c
+++ b/src/search/moves.c
@@ -1,11 +1,12 @@
#include "../search.h"
+#include <assert.h>
#include <stdlib.h>
-moves_t init_moves() {
- return init_moves_wcapacity(16);
+moves_t moves_init() {
+ return moves_init_wcapacity(16);
}
-moves_t init_moves_wcapacity(u32 capacity) {
+moves_t moves_init_wcapacity(u32 capacity) {
move_t* moves = malloc(capacity * sizeof(*moves));
return (moves_t) {
.moves = moves,
@@ -14,7 +15,7 @@ moves_t init_moves_wcapacity(u32 capacity) {
};
}
-moves_t empty_moves() {
+moves_t moves_empty() {
return (moves_t) {
.moves = 0,
.capacity = 0,
@@ -28,7 +29,9 @@ int min(int a, int b) {
}
void add_move(moves_t* moves, square_t from, square_t to) {
- if (moves->moves == 0) return;
+ assert(moves->moves != 0);
+ assert(from != to);
+
if (moves->length + 1 >= moves->capacity) {
moves->capacity += min(32, moves->capacity);
moves->moves = realloc(
diff --git a/src/search/pawn_moves.c b/src/search/pawn_moves.c
index e69de29..58eac83 100644
--- a/src/search/pawn_moves.c
+++ b/src/search/pawn_moves.c
@@ -0,0 +1,47 @@
+#include "../search.h"
+#include <assert.h>
+
+void get_white_pawn_moves(moves_t* moves, position_t position) {
+ bitboard_t enemy_bitboard = blacks(position);
+ bitboard_t friendly_pieces =
+ position.bitboards[WHITE_KING] |
+ position.bitboards[WHITE_QUEEN] |
+ position.bitboards[WHITE_ROOK] |
+ position.bitboards[WHITE_BISHOP] |
+ position.bitboards[WHITE_KNIGHT];
+ bitboard_t friendly_pawns = position.bitboards[WHITE_PAWN];
+ bitboard_t y = friendly_pieces | enemy_bitboard;
+ bitboard_t x = ~((friendly_pawns << 8) & y) & (friendly_pawns << 8);
+ bitboard_t first_move_x = x | BITMASK_RANK_C;
+
+ first_move_x |= (first_move_x << 8) & (~y);
+ x |= first_move_x;
+
+ print_bitboard(x);
+}
+void get_black_pawn_moves(moves_t* moves, position_t position) {
+ bitboard_t enemy_bitboard = whites(position);
+ bitboard_t friendly_pieces =
+ position.bitboards[BLACK_KING] |
+ position.bitboards[BLACK_QUEEN] |
+ position.bitboards[BLACK_ROOK] |
+ position.bitboards[BLACK_BISHOP] |
+ position.bitboards[BLACK_KNIGHT];
+ bitboard_t friendly_pawns = position.bitboards[BLACK_PAWN];
+ bitboard_t y = friendly_pieces | enemy_bitboard;
+ bitboard_t x = ~((friendly_pawns << 8) & y) & (friendly_pawns << 8);
+ bitboard_t first_move_x = x | BITMASK_RANK_F;
+
+ first_move_x |= (first_move_x >> 8) & (~y);
+ x |= first_move_x;
+}
+
+void get_pawn_moves(moves_t* moves, position_t position) {
+ assert_valid_position(position);
+
+ if (position.turn == WHITE_TURN) {
+ get_white_pawn_moves(moves, position);
+ } else {
+ get_black_pawn_moves(moves, position);
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2026-08-24 21:34:59 +0000