Move game_phase() to material.cpp

[stockfish] / src / material.cpp

diff --git a/src/material.cpp b/src/material.cpp
index dc2a3a3b550c6eddaf9e8e1d378e5921c77bf72b..d67b95cae96413746d77176e1dcf9bcb31c73b98 100644 (file)
--- a/src/material.cpp
+++ b/src/material.cpp
@@ -58,6 +58,12 @@ namespace {
     24, -32, 107, -51, 117, -9, -126, -21, 31
   };
 
+  // QueenMinorsImbalance[opp_minor_count] is applied when only one side has a queen.
+  // It contains a bonus/malus for the side with the queen.
+  const int QueenMinorsImbalance[13] = {
+    31, -8, -15, -25, -5
+  };
+
   // Endgame evaluation and scaling functions are accessed directly and not through
   // the function maps because they correspond to more than one material hash key.
   Endgame<KXK>    EvaluateKXK[] = { Endgame<KXK>(WHITE),    Endgame<KXK>(BLACK) };
@@ -111,6 +117,10 @@ namespace {
         bonus += pieceCount[Us][pt1] * v;
     }
 
+    // Special handling of Queen vs. Minors
+    if  (pieceCount[Us][QUEEN] == 1 && pieceCount[Them][QUEEN] == 0)
+         bonus += QueenMinorsImbalance[pieceCount[Them][KNIGHT] + pieceCount[Them][BISHOP]];
+
     return bonus;
   }
 
@@ -134,7 +144,13 @@ Entry* probe(const Position& pos) {
   std::memset(e, 0, sizeof(Entry));
   e->key = key;
   e->factor[WHITE] = e->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL;
-  e->gamePhase = pos.game_phase();
+
+  Value npm_w = pos.non_pawn_material(WHITE);
+  Value npm_b = pos.non_pawn_material(BLACK);
+  Value npm = std::max(EndgameLimit, std::min(npm_w + npm_b, MidgameLimit));
+
+  // Map total non-pawn material into [PHASE_ENDGAME, PHASE_MIDGAME]
+  e->gamePhase = Phase(((npm - EndgameLimit) * PHASE_MIDGAME) / (MidgameLimit - EndgameLimit));
 
   // Let's look if we have a specialized evaluation function for this particular
   // material configuration. Firstly we look for a fixed configuration one, then
@@ -171,9 +187,6 @@ Entry* probe(const Position& pos) {
         e->scalingFunction[c] = &ScaleKQKRPs[c];
   }
 
-  Value npm_w = pos.non_pawn_material(WHITE);
-  Value npm_b = pos.non_pawn_material(BLACK);
-
   if (npm_w + npm_b == VALUE_ZERO && pos.pieces(PAWN)) // Only pawns on the board
   {
       if (!pos.count<PAWN>(BLACK))