1 files changed, 55 insertions, 9 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");
+  }
+}