1 files changed, 79 insertions, 65 deletions

diff --git a/src/moves.cpp b/src/moves.cpp
index f741b7f..132e79f 100644
--- a/src/moves.cpp
+++ b/src/moves.cpp
@@ -188,113 +188,127 @@ GameState GetNewGameState(Game *g) {
   }
   return TURN;
 }
-
-bool IsSquareAttacked(Game *board, Position square, bool white) {
-  Game temp = *board;
-  temp.turn = white;
-
-  // Moves
-  constexpr std::array<int, 4> bishopMoves{-9, 9, -7, 7};
-  constexpr std::array<int, 4> rookMoves{-8, 8, -1, 1};
-
+bool IsSquareAttacked(Game *g, Position square, bool white) {
   int target = PositionToIndex(square);
 
-  // Pawns (custom because pawn moves != pawn attacks)
-  int pawnDirection = white ? -1 : 1;
+  // Pawn attacks
+  int pawnDir = white ? -1 : 1;
 
-  int pawnRank = square.rank - pawnDirection;
+  int pawnRank = square.rank - pawnDir;
 
   if (pawnRank >= 0 && pawnRank < 8) {
     for (int fileOffset : {-1, 1}) {
-      int pawnFile = square.file + fileOffset;
+      int file = square.file + fileOffset;
 
-      if (pawnFile < 0 || pawnFile >= 8)
+      if (file < 0 || file >= 8)
         continue;
 
-      Piece p = temp.pieces[pawnRank * 8 + pawnFile];
+      Piece p = g->pieces[pawnRank * 8 + file];
 
       if (p.type == PAWN && p.color == white)
         return true;
     }
   }
 
-  // knights
-  for (int i = 0; i < 64; i++) {
-    Piece p = temp.pieces[i];
+  // Knight attacks
+  constexpr std::array<int, 8> knightOffsets{-17, -15, -10, -6, 6, 10, 15, 17};
 
-    if (p.type == KNIGHT && p.color == white) {
-      std::vector<Move> moves;
-      GenerateKnightMoves(&temp, i, moves);
+  for (int offset : knightOffsets) {
+    int from = target + offset;
 
-      for (Move m : moves) {
-        if (PositionToIndex(m.To) == target)
-          return true;
-      }
-    }
-  }
-  for (int i = 0; i < 64; i++) {
-    Piece p = temp.pieces[i];
+    if (from < 0 || from >= 64)
+      continue;
 
-    if (p.type == BISHOP && p.color == white) {
-      std::vector<Move> moves;
-      GenerateSlidingMoves(&temp, i, bishopMoves, moves);
+    int fileDiff = abs((from % 8) - (target % 8));
 
-      for (Move m : moves) {
-        if (PositionToIndex(m.To) == target)
-          return true;
-      }
-    }
+    if (fileDiff != 1 && fileDiff != 2)
+      continue;
+
+    Piece p = g->pieces[from];
+
+    if (p.type == KNIGHT && p.color == white)
+      return true;
   }
 
-  // rook
-  for (int i = 0; i < 64; i++) {
-    Piece p = temp.pieces[i];
+  // King attacks
+  constexpr std::array<int, 8> kingOffsets{-9, -8, -7, -1, 1, 7, 8, 9};
 
-    if (p.type == ROOK && p.color == white) {
-      std::vector<Move> moves;
-      GenerateSlidingMoves(&temp, i, rookMoves, moves);
+  for (int offset : kingOffsets) {
+    int from = target + offset;
 
-      for (Move m : moves) {
-        if (PositionToIndex(m.To) == target)
-          return true;
-      }
-    }
+    if (from < 0 || from >= 64)
+      continue;
+
+    if (abs((from % 8) - (target % 8)) > 1)
+      continue;
+
+    Piece p = g->pieces[from];
+
+    if (p.type == KING && p.color == white)
+      return true;
   }
 
-  // queen
-  for (int i = 0; i < 64; i++) {
-    Piece p = temp.pieces[i];
+  // Sliding pieces
+  constexpr std::array<int, 4> rookDirs{-8, 8, -1, 1};
+
+  constexpr std::array<int, 4> bishopDirs{-9, 9, -7, 7};
+
+  // Rooks + queens
+  for (int dir : rookDirs) {
+    int pos = target;
 
-    if (p.type == QUEEN && p.color == white) {
-      std::vector<Move> moves;
+    while (true) {
+      int next = pos + dir;
 
-      GenerateSlidingMoves(&temp, i, bishopMoves, moves);
-      GenerateSlidingMoves(&temp, i, rookMoves, moves);
+      if (next < 0 || next >= 64)
+        break;
 
-      for (Move m : moves) {
-        if (PositionToIndex(m.To) == target)
+      // horizontal wrap
+      if ((dir == 1 || dir == -1) && next / 8 != pos / 8)
+        break;
+
+      Piece p = g->pieces[next];
+
+      if (p.type != NONEPIECE) {
+        if (p.color == white && (p.type == ROOK || p.type == QUEEN))
           return true;
+
+        break;
       }
+
+      pos = next;
     }
   }
 
-  // --- Kings ---
-  for (int i = 0; i < 64; i++) {
-    Piece p = temp.pieces[i];
+  // Bishops + queens
+  for (int dir : bishopDirs) {
+    int pos = target;
 
-    if (p.type == KING && p.color == white) {
-      std::vector<Move> moves;
-      GenerateKingMoves(&temp, i, moves);
+    while (true) {
+      int next = pos + dir;
+
+      if (next < 0 || next >= 64)
+        break;
+
+      if (abs((next % 8) - (pos % 8)) != 1)
+        break;
 
-      for (Move m : moves) {
-        if (PositionToIndex(m.To) == target)
+      Piece p = g->pieces[next];
+
+      if (p.type != NONEPIECE) {
+        if (p.color == white && (p.type == BISHOP || p.type == QUEEN))
           return true;
+
+        break;
       }
+
+      pos = next;
     }
   }
 
   return false;
 }
+
 Position IndexToPosition(int i) {
   uint8_t rank = i / 8; // 0-7
   uint8_t file = i % 8; // 0-7