From 2c2a70b69869f149c0407a62f1bf4c39899027a7 Mon Sep 17 00:00:00 2001
From: Aargh Rai <aargh.rai+git@gmail.com>
Date: Wed, 27 May 2026 18:02:44 +0530
Subject: restructing

---
 src/engine/bitboard.h | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 src/engine/bitboard.h

(limited to 'src/engine/bitboard.h')

diff --git a/src/engine/bitboard.h b/src/engine/bitboard.h
new file mode 100644
index 0000000..912cad0
--- /dev/null
+++ b/src/engine/bitboard.h
@@ -0,0 +1,69 @@
+#ifndef BITBOARD_H
+#define BITBOARD_H
+
+#include "ints.h"
+
+typedef u64 bitboard_t;
+
+enum {
+  WHITE_KING,
+  WHITE_QUEEN,
+  WHITE_ROOK,
+  WHITE_BISHOP,
+  WHITE_KNIGHT,
+  WHITE_PAWN,
+  BLACK_KING,
+  BLACK_QUEEN,
+  BLACK_ROOK,
+  BLACK_BISHOP,
+  BLACK_KNIGHT,
+  BLACK_PAWN,
+  PIECE_TYPE_COUNT,
+};
+
+enum {
+  WHITE_SHORT_CASTLE,
+  WHITE_LONG_CASTLE,
+  BLACK_SHORT_CASTLE,
+  BLACK_LONG_CASTLE,
+};
+
+enum {
+  WHITE_TURN,
+  BLACK_TURN,
+};
+
+#define BITMASK_RANK_1 255ULL
+#define BITMASK_RANK_2 65280ULL
+#define BITMASK_RANK_3 16711680ULL
+#define BITMASK_RANK_4 4278190080ULL
+#define BITMASK_RANK_5 1095216660480ULL
+#define BITMASK_RANK_6 280375465082880ULL
+#define BITMASK_RANK_7 71776119061217280ULL
+#define BITMASK_RANK_8 18374686479671623680ULL
+#define BITMASK_FILE_A 72340172838076673ULL
+#define BITMASK_FILE_B 144680345676153346ULL
+#define BITMASK_FILE_C 289360691352306692ULL
+#define BITMASK_FILE_D 578721382704613384ULL
+#define BITMASK_FILE_E 1157442765409226768ULL
+#define BITMASK_FILE_F 2314885530818453536ULL
+#define BITMASK_FILE_G 4629771061636907072ULL
+#define BITMASK_FILE_H 9259542123273814144ULL
+
+#define occupied_by(bitboard, index) (bitboard & ((bitboard_t)1 << index))
+
+typedef struct {
+  bitboard_t bitboards[PIECE_TYPE_COUNT];
+  u8 castling;
+  u8 turn;
+  u8 passantable_file;
+} 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);
+
+void print_bitboard(bitboard_t bitboard);
+
+#endif // BITBOARD_H
-- 
cgit v1.2.3