Contempt factor: use DrawValue also in case of stealmates

[stockfish] / src / movegen.cpp

diff --git a/src/movegen.cpp b/src/movegen.cpp
index 0b46298b9c80f9ca770e88766d4b6d74d20f1fa3..be848cf1a6acb370e1ddf262b4f79762ba187f56 100644 (file)
--- a/src/movegen.cpp
+++ b/src/movegen.cpp
@@ -31,7 +31,7 @@
                                          (*mlist++).move = make_move(to - (d), to); }
 namespace {
 
-  template<CastlingSide Side, bool Checks>
+  template<CastlingSide Side, bool Checks, bool Chess960>
   MoveStack* generate_castle(const Position& pos, MoveStack* mlist, Color us) {
 
     if (pos.castle_impeded(us, Side) || !pos.can_castle(make_castle_right(us, Side)))
@@ -46,16 +46,18 @@ namespace {
 
     assert(!pos.in_check());
 
-    for (Square s = kto; s != kfrom; s += (Square)(Side == KING_SIDE ? -1 : 1))
+    const int K = Chess960 ? kto > kfrom ? -1 : 1
+                           : Side == KING_SIDE ? -1 : 1;
+
+    for (Square s = kto; s != kfrom; s += (Square)K)
         if (pos.attackers_to(s) & enemies)
             return mlist;
 
     // Because we generate only legal castling moves we need to verify that
     // when moving the castling rook we do not discover some hidden checker.
     // For instance an enemy queen in SQ_A1 when castling rook is in SQ_B1.
-    if (    pos.is_chess960()
-        && (pos.attackers_to(kto, pos.pieces() ^ rfrom) & enemies))
-            return mlist;
+    if (Chess960 && (pos.attackers_to(kto, pos.pieces() ^ rfrom) & enemies))
+        return mlist;
 
     (*mlist++).move = make<CASTLE>(kfrom, rfrom);
 
@@ -273,8 +275,16 @@ namespace {
 
     if (Type != CAPTURES && Type != EVASIONS && pos.can_castle(us))
     {
-        mlist = generate_castle<KING_SIDE,  Type == QUIET_CHECKS>(pos, mlist, us);
-        mlist = generate_castle<QUEEN_SIDE, Type == QUIET_CHECKS>(pos, mlist, us);
+        if (pos.is_chess960())
+        {
+            mlist = generate_castle<KING_SIDE,  Type == QUIET_CHECKS, true>(pos, mlist, us);
+            mlist = generate_castle<QUEEN_SIDE, Type == QUIET_CHECKS, true>(pos, mlist, us);
+        }
+        else
+        {
+            mlist = generate_castle<KING_SIDE,  Type == QUIET_CHECKS, false>(pos, mlist, us);
+            mlist = generate_castle<QUEEN_SIDE, Type == QUIET_CHECKS, false>(pos, mlist, us);
+        }
     }
 
     return mlist;
@@ -420,11 +430,13 @@ MoveStack* generate<LEGAL>(const Position& pos, MoveStack* mlist) {
 
   MoveStack *end, *cur = mlist;
   Bitboard pinned = pos.pinned_pieces();
+  Square ksq = pos.king_square(pos.side_to_move());
 
   end = pos.in_check() ? generate<EVASIONS>(pos, mlist)
                        : generate<NON_EVASIONS>(pos, mlist);
   while (cur != end)
-      if (!pos.pl_move_is_legal(cur->move, pinned))
+      if (   (pinned || from_sq(cur->move) == ksq || type_of(cur->move) == ENPASSANT)
+          && !pos.pl_move_is_legal(cur->move, pinned))
           cur->move = (--end)->move;
       else
           cur++;