From 6f7cfbfcde39a57a59db17882339fa26055b75a0 Mon Sep 17 00:00:00 2001
From: eug-vs <eugene@eug-vs.xyz>
Date: Wed, 14 Sep 2022 05:27:30 +0300
Subject: feat: precompute king attack tables

---
 src/main.c | 43 ++++++++++++++++++++++++++++++-------------
 1 file changed, 30 insertions(+), 13 deletions(-)

(limited to 'src/main.c')

diff --git a/src/main.c b/src/main.c
index 5f19585..c8c82cf 100644
--- a/src/main.c
+++ b/src/main.c
@@ -6,7 +6,16 @@ int main() {
     start_test_section("Bitboards");
     unit_test(pop_count(0b01110) == 3, "Pop count of 01110 is 3");
   }
-
+  {
+    start_test_section("Default FEN string");
+    Board board = parse_FEN("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1");
+    unit_test(pop_count(board.pieces[PAWN] | board.pieces[PAWN | BLACK]) == 16, "There are 16 pawns total");
+    unit_test(pop_count(board.pieces[ROOK]) == 2, "There are 2 white rooks");
+    // TODO
+    unit_test(board.side == WHITE, "Side to move is white");
+    unit_test(board.castling_rights == 0, "Both sides can castle");
+    unit_test(board.en_passant_square == 0, "No en passant move is avaialble");
+  }
   {
     start_test_section("Test knight attacks");
     Bitboard attacks[64];
@@ -19,25 +28,33 @@ int main() {
     }
     unit_test(max_attacks == 8, "Max amount of knight attacks should be 8");
 
+    unit_test(
+        attacks[b7] == ((BIT << d8) | (BIT << d6) | (BIT << c5) | (BIT << a5)),
+        "Knight on b7 attacks only d8, d6, c5, a5"
+    );
+  }
+  {
+    start_test_section("Test king attacks");
+    Bitboard attacks[64];
+    precompute_king_attack_table(attacks);
+
+    int max_attacks = 0;
+    for (int i = 0; i < 64; i++) {
+      int attack_count = pop_count(attacks[i]);
+      if (attack_count > max_attacks) max_attacks = attack_count;
+    }
+    unit_test(max_attacks == 8, "Max amount of king attacks should be 8");
+
     {
       U64 bit = 1;
       unit_test(
-          attacks[b7] == ((bit << d8) | (bit << d6) | (bit << c5) | (bit << a5)),
-          "Knight on b7 attacks only d8, d6, c5, a5"
+          attacks[h2] == ((BIT << h1) | (BIT << g1) | (BIT << g2) | (BIT << g3) | (BIT << h3)),
+          "King on h2 attacks only h1, g1, g2, g3, h3"
       );
     }
   }
 
-  {
-    start_test_section("Default FEN string");
-    Board board = parse_FEN("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1");
-    unit_test(pop_count(board.pieces[PAWN] | board.pieces[PAWN | BLACK]) == 16, "There are 16 pawns total");
-    unit_test(pop_count(board.pieces[ROOK]) == 2, "There are 2 white rooks");
-    // TODO
-    unit_test(board.side == WHITE, "Side to move is white");
-    unit_test(board.castling_rights == 0, "Everyone can castle");
-    unit_test(board.en_passant_square == 0, "No en passant move is avaialble");
-  }
+
 
   report();
   return 0;
-- 
cgit v1.2.3