add kono and fox-and-hounds (#628)

diff --git a/src/movegen.cpp b/src/movegen.cpp
index 6c852aa..b33d986 100644 (file)
--- a/src/movegen.cpp
+++ b/src/movegen.cpp
@@ -388,7 +388,7 @@ namespace {
                 target = pos.checkers();
         }
 
-        // Remove inaccesible squares (outside board + wall squares)
+        // Remove inaccessible squares (outside board + wall squares)
         target &= pos.board_bb();
 
         moveList = generate_pawn_moves<Us, Type>(pos, moveList, target);

diff --git a/src/position.cpp b/src/position.cpp
index 72afba8..03b0a9d 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -2675,15 +2675,15 @@ bool Position::is_immediate_game_end(Value& result, int ply) const {
   // capture the flag
   if (   capture_the_flag_piece()
       && flag_move()
-      && (capture_the_flag(sideToMove) & pieces(sideToMove, capture_the_flag_piece())))
+      && (popcount(capture_the_flag(sideToMove) & pieces(sideToMove, capture_the_flag_piece()))>=flag_piece_count()))
   {
-      result =  (capture_the_flag(~sideToMove) & pieces(~sideToMove, capture_the_flag_piece()))
+      result =  (popcount(capture_the_flag(~sideToMove) & pieces(~sideToMove, capture_the_flag_piece()))>=flag_piece_count())
               && sideToMove == WHITE ? VALUE_DRAW : mate_in(ply);
       return true;
   }
   if (   capture_the_flag_piece()
       && (!flag_move() || capture_the_flag_piece() == KING)
-      && (capture_the_flag(~sideToMove) & pieces(~sideToMove, capture_the_flag_piece())))
+      && (popcount(capture_the_flag(~sideToMove) & pieces(~sideToMove, capture_the_flag_piece()))>=flag_piece_count()) )
   {
       bool gameEnd = true;
       // Check whether king can move to CTF zone

diff --git a/src/position.h b/src/position.h
index 7fe9951..6e179c8 100644 (file)
--- a/src/position.h
+++ b/src/position.h
@@ -201,6 +201,7 @@ public:
   Bitboard capture_the_flag(Color c) const;
   bool flag_move() const;
   bool check_counting() const;
+  int flag_piece_count() const;
   int connect_n() const;
   CheckCount checks_remaining(Color c) const;
   MaterialCounting material_counting() const;
@@ -930,6 +931,11 @@ inline bool Position::flag_move() const {
   return var->flagMove;
 }
 
+inline int Position::flag_piece_count() const {
+  assert(var != nullptr);
+  return var->flagPieceCount;
+}
+
 inline bool Position::check_counting() const {
   assert(var != nullptr);
   return var->checkCounting;

diff --git a/src/variant.cpp b/src/variant.cpp
index 8196915..fd8564f 100644 (file)
--- a/src/variant.cpp
+++ b/src/variant.cpp
@@ -542,6 +542,32 @@ namespace {
         return v;
     }
 
+    Variant* kono_variant() { //https://en.wikipedia.org/wiki/Five_Field_Kono
+        Variant* v = chess_variant_base()->init();
+        v->maxRank = RANK_5;
+        v->maxFile = FILE_E;
+        v->reset_pieces();
+        v->add_piece(CUSTOM_PIECE_1, 'p', "mF"); //diagonally, no capture
+        v->startFen = "ppppp/p3p/5/P3P/PPPPP w - - 0 1";
+        v->flagPiece = CUSTOM_PIECE_1;
+        v->flagRegion[WHITE] = make_bitboard(SQ_A5, SQ_B5, SQ_C5, SQ_D5, SQ_E5, SQ_A4, SQ_E4);
+        v->flagRegion[BLACK] = make_bitboard(SQ_A1, SQ_B1, SQ_C1, SQ_D1, SQ_E1, SQ_A2, SQ_E2);
+        v->flagPieceCount = 7;
+        return v;
+    }
+
+    Variant* fox_and_hounds_variant() { //https://boardgamegeek.com/boardgame/148180/fox-and-hounds
+        Variant* v = chess_variant_base()->init();
+        v->reset_pieces();
+        v->add_piece(CUSTOM_PIECE_1, 'h', "mfF"); //Hound
+        v->add_piece(CUSTOM_PIECE_2, 'f', "mF"); //Fox
+        v->startFen = "1h1h1h1h/8/8/8/8/8/8/4F3 w - - 0 1";
+        v->stalemateValue = -VALUE_MATE;
+        v->flagPiece = CUSTOM_PIECE_2;
+        v->flagRegion[WHITE] = Rank8BB;
+        return v;
+    }
+
     // Three-check chess
     // Check the king three times to win
     // https://lichess.org/variant/threeCheck
@@ -1789,6 +1815,8 @@ void VariantMap::init() {
     add("isolation", isolation_variant());
     add("isolation7x7", isolation7x7_variant());
     add("snailtrail", snailtrail_variant());
+    add("fox-and-hounds", fox_and_hounds_variant());
+    add("kono", kono_variant());
 #ifdef ALLVARS
     add("duck", duck_variant());
 #endif

diff --git a/src/variant.h b/src/variant.h
index e1a460a..c7df2f7 100644 (file)
--- a/src/variant.h
+++ b/src/variant.h
@@ -143,6 +143,7 @@ struct Variant {
   int extinctionOpponentPieceCount = 0;
   PieceType flagPiece = NO_PIECE_TYPE;
   Bitboard flagRegion[COLOR_NB] = {};
+  int flagPieceCount = 1;
   bool flagMove = false;
   bool checkCounting = false;
   int connectN = 0;

diff --git a/src/variants.ini b/src/variants.ini
index 85be25b..c6f5dd6 100644 (file)
--- a/src/variants.ini
+++ b/src/variants.ini
@@ -250,6 +250,7 @@
 # flagRegionBlack: black's target region for capture the flag win rule [Bitboard] (default: )
 # flagMove: black gets one more move after white captures the flag [bool] (default: false)
 # checkCounting: enable check count win rule (check count is communicated via FEN, see 3check) [bool] (default: false)
+# flagPieceCount: number of flag pieces that have to be in the flag zone [int] (default: 1)
 # connectN: number of aligned pieces for win [int] (default: 0)
 # materialCounting: enable material counting rules [MaterialCounting] (default: none)
 # countingRule: enable counting rules [CountingRule] (default: none)