Sittuyin promotion disables rank based promotion

Handle mandatory pawn promotion more naturally by removing
the promotion rank workaround for Sittuyin and instead
explicitly disable rank based promotion in case of sittuyin promotion.

diff --git a/src/movegen.cpp b/src/movegen.cpp
index 7d11d74..e4afd83 100644 (file)
--- a/src/movegen.cpp
+++ b/src/movegen.cpp
@@ -108,8 +108,7 @@ namespace {
     constexpr Direction UpRight  = (Us == WHITE ? NORTH_EAST : SOUTH_WEST);
     constexpr Direction UpLeft   = (Us == WHITE ? NORTH_WEST : SOUTH_EAST);
 
-    Bitboard TRank8BB = pos.mandatory_pawn_promotion() ? rank_bb(relative_rank(Us, pos.promotion_rank(), pos.max_rank()))
-                                                       : zone_bb(Us, pos.promotion_rank(), pos.max_rank());
+    Bitboard TRank8BB = pos.sittuyin_promotion() ? Bitboard(0) : zone_bb(Us, pos.promotion_rank(), pos.max_rank());
     Bitboard TRank7BB = shift<Down>(TRank8BB);
     // Define squares a pawn can pass during a double step
     Bitboard  TRank3BB =  forward_ranks_bb(Us, relative_rank(Us, pos.double_step_rank_min(), pos.max_rank()))

diff --git a/src/pawns.cpp b/src/pawns.cpp
index e8ffe05..a18f653 100644 (file)
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -165,11 +165,11 @@ namespace {
 
         // Passed pawns will be properly scored later in evaluation when we have
         // full attack info.
-        if (passed && is_ok(s + Up) && (r < pos.promotion_rank() || !pos.mandatory_pawn_promotion()))
+        if (passed && is_ok(s + Up) && !pos.sittuyin_promotion())
             e->passedPawns[Us] |= s;
 
         // Score this pawn
-        if ((support | phalanx) && (r < pos.promotion_rank() || !pos.mandatory_pawn_promotion()))
+        if ((support | phalanx) && !pos.sittuyin_promotion())
         {
             int v =  Connected[r] * (2 + bool(phalanx) - bool(opposed)) * (r == RANK_2 && pos.captures_to_hand() ? 3 : 1)
                    + 22 * popcount(support);

diff --git a/src/position.cpp b/src/position.cpp
index 239d961..d5dbd67 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -1170,7 +1170,7 @@ bool Position::pseudo_legal(const Move m) const {
   {
       // We have already handled promotion moves, so destination
       // cannot be on the 8th/1st rank.
-      if (mandatory_pawn_promotion() && rank_of(to) == relative_rank(us, promotion_rank(), max_rank()))
+      if (mandatory_pawn_promotion() && rank_of(to) == relative_rank(us, promotion_rank(), max_rank()) && !sittuyin_promotion())
           return false;
 
       if (   !(pawn_attacks_bb(us, from) & pieces(~us) & to) // Not a capture

diff --git a/src/variant.cpp b/src/variant.cpp
index f6ebc5a..fba1bf7 100644 (file)
--- a/src/variant.cpp
+++ b/src/variant.cpp
@@ -512,7 +512,6 @@ namespace {
         v->whiteDropRegion = Rank1BB | Rank2BB | Rank3BB;
         v->blackDropRegion = Rank8BB | Rank7BB | Rank6BB;
         v->sittuyinRookDrop = true;
-        v->promotionRank = RANK_1; // no regular promotions
         v->sittuyinPromotion = true;
         v->promotionLimit[FERS] = 1;
         v->immobilityIllegal = false;

diff --git a/src/variants.ini b/src/variants.ini
index ae834c9..719653d 100644 (file)
--- a/src/variants.ini
+++ b/src/variants.ini
@@ -281,10 +281,13 @@ blackFlag = d4 e4 d5 e5
 mustCapture = true
 
 # Hybrid variant of makruk and crazyhouse
-[makrukhouse:makruk]
+[makhouse:makruk]
 startFen = rnsmksnr/8/pppppppp/8/8/PPPPPPPP/8/RNSKMSNR[] w - - 0 1
 pieceDrops = true
 capturesToHand = true
+firstRankPawnDrops = true
+promotionZonePawnDrops = true
+immobilityIllegal = true
 
 # Hybrid variant of xiangqi and crazyhouse
 [xiangqihouse:xiangqi]

diff --git a/test.py b/test.py
index cb580b5..8ba1b72 100644 (file)
--- a/test.py
+++ b/test.py
@@ -71,6 +71,14 @@ startFen = rbnkbr/pppppp/6/6/PPPPPP/RBNKBR w KQkq - 0 1
 
 [passchess:chess]
 pass = true
+
+[makhouse:makruk]
+startFen = rnsmksnr/8/pppppppp/8/8/PPPPPPPP/8/RNSKMSNR[] w - - 0 1
+pieceDrops = true
+capturesToHand = true
+firstRankPawnDrops = true
+promotionZonePawnDrops = true
+immobilityIllegal = true
 """
 
 sf.load_variant_config(ini_text)
@@ -286,6 +294,11 @@ class TestPyffish(unittest.TestCase):
         result = sf.legal_moves("janggi", fen, [])
         self.assertEqual(result, ["e10e10"])
 
+        # pawn promotion of dropped pawns beyond promotion rank
+        result = sf.legal_moves("makhouse", "rnsmksnr/8/1ppP1ppp/p3p3/8/PPP1PPPP/8/RNSKMSNR[p] w - - 0 4", [])
+        self.assertIn("d6d7m", result)
+        self.assertNotIn("d6d7", result)
+
     def test_short_castling(self):
         legals = ['f5f4', 'a7a6', 'b7b6', 'c7c6', 'd7d6', 'e7e6', 'i7i6', 'j7j6', 'a7a5', 'b7b5', 'c7c5', 'e7e5', 'i7i5', 'j7j5', 'b8a6', 'b8c6', 'h6g4', 'h6i4', 'h6j5', 'h6f7', 'h6g8', 'h6i8', 'd5a2', 'd5b3', 'd5f3', 'd5c4', 'd5e4', 'd5c6', 'd5e6', 'd5f7', 'd5g8', 'j8g8', 'j8h8', 'j8i8', 'e8f7', 'c8b6', 'c8d6', 'g6g2', 'g6g3', 'g6f4', 'g6g4', 'g6h4', 'g6e5', 'g6g5', 'g6i5', 'g6a6', 'g6b6', 'g6c6', 'g6d6', 'g6e6', 'g6f6', 'g6h8', 'f8f7', 'f8g8', 'f8i8']
         moves = ['b2b4', 'f7f5', 'c2c3', 'g8d5', 'a2a4', 'h8g6', 'f2f3', 'i8h6', 'h2h3']