Square control evaluation (#29)

Aryan1508 · web-flow · commit ac12ddbcbb89 · 2021-06-07T20:31:22.000+05:30
Bench: 68794192
diff --git a/Bit-Genie/src/eval.cpp b/Bit-Genie/src/eval.cpp
@@ -22,18 +22,25 @@
 #include "board.h"
 #include "evalscores.h"
 #include <cstring>
+#include <math.h>
+
 struct EvalData
 {
     int king_attackers_count[2] = {0};
     int king_attackers_weight[2] = {0};
     uint64_t king_ring[2] = {0};
+    int attackers_count[2];
 
     void init(Position const &position)
     {
         std::memset(this, 0, sizeof(EvalData));
         king_ring[White] = Attacks::king(get_lsb(position.pieces.get_piece_bb<King>(White)));
         king_ring[Black] = Attacks::king(get_lsb(position.pieces.get_piece_bb<King>(Black)));
     }
+    void update_attackers_count(uint64_t attacks, Color by)
+    {
+        attackers_count[by] += popcount64(attacks);
+    }
 };
 
 template <PieceType pt, bool safe = false>
@@ -42,6 +49,8 @@ static constexpr int calculate_moblity(Position const &position, EvalData &data,
     uint64_t occupancy = position.total_occupancy();
     uint64_t attacks = Attacks::generate(pt, sq, occupancy);
 
+    data.update_attackers_count(attacks, us);
+
     if constexpr (!safe)
     {
         if (attacks & data.king_ring[!us])
@@ -133,14 +142,16 @@ static Square psqt_sq(Square sq, Color color)
     return color == White ? flip_square(sq) : sq;
 }
 
-static int evaluate_pawn(Position const &position, EvalData, Square sq, Color us)
+static int evaluate_pawn(Position const &position, EvalData& data, Square sq, Color us)
 {
     int score = 0;
     uint64_t enemy_pawns = position.pieces.get_piece_bb<Pawn>(!us);
     uint64_t friend_pawns = position.pieces.get_piece_bb<Pawn>(us);
     uint64_t enemy = position.pieces.get_occupancy(!us);
     uint64_t ahead_squares = BitMask::passed_pawn[us][sq] & BitMask::files[sq];
 
+    data.update_attackers_count(BitMask::pawn_attacks[us][sq], us);
+
     score += PawnEval::psqt[psqt_sq(sq, us)];
     score += pawn_is_isolated(friend_pawns, sq) * PawnEval::isolated;
     score += pawn_is_stacked(friend_pawns, sq) * PawnEval::stacked;
@@ -157,8 +168,6 @@ static int evaluate_pawn(Position const &position, EvalData, Square sq, Color us
         if (BitMask::pawn_attacks[!us][sq] & friend_pawns)
             score += PawnEval::passed_connected;
     }
-
-
     return score;
 }
 
@@ -295,6 +304,8 @@ static int eval_king(Position const &position, EvalData &data, Color us)
     int score = KingEval::psqt[psqt_sq(sq, us)];
     Color enemy = !us;
 
+    data.update_attackers_count(BitMask::king_attacks[sq], us);
+
     if (data.king_attackers_count[enemy] >= 2)
     {
         int weight = data.king_attackers_weight[enemy];
@@ -308,6 +319,12 @@ static int eval_king(Position const &position, EvalData &data, Color us)
     return score;
 }
 
+template<Color us>
+static inline int evaluate_control(EvalData& data)
+{
+    return MiscEval::control * (data.attackers_count[us] - data.attackers_count[!us]);    
+}
+
 static inline int scale_score(Position const &position, int score)
 {
 #define mg_score(s) ((int16_t)((uint16_t)((unsigned)((s)))))
@@ -336,6 +353,9 @@ int eval_position(Position const &position)
     score += eval_king(position, data, White);
     score -= eval_king(position, data, Black);
 
+    score += evaluate_control<White>(data);
+    score -= evaluate_control<Black>(data);
+
     score = scale_score(position, score);
 
     return position.side == White ? score : -score;
diff --git a/Bit-Genie/src/evalscores.h b/Bit-Genie/src/evalscores.h
@@ -227,3 +227,7 @@ namespace KingEval
         S(-400, -400), S(-400, -400), S(-400, -400), S(-400, -400),
     };
 }
+namespace MiscEval
+{
+    constexpr int control = S(0, 27);
+}
diff --git a/Bit-Genie/src/uci.cpp b/Bit-Genie/src/uci.cpp
@@ -25,7 +25,7 @@
 #include "benchmark.h"
 #include "searchinit.h"
 
-const char *version = "5.2";
+const char *version = "5.25";
 
 namespace
 {

Original file line number	Diff line number	Diff line change
`@@ -227,3 +227,7 @@ namespace KingEval`
`227`	`227`	`S(-400, -400), S(-400, -400), S(-400, -400), S(-400, -400),`
`228`	`228`	`};`
`229`	`229`	`}`
	`230`	`+namespace MiscEval`
	`231`	`+{`
	`232`	`+ constexpr int control = S(0, 27);`
	`233`	`+}`
Original file line number	Diff line number	Diff line change
`@@ -25,7 +25,7 @@`
`25`	`25`	`#include "benchmark.h"`
`26`	`26`	`#include "searchinit.h"`
`27`	`27`
`28`		`-const char *version = "5.2";`
	`28`	`+const char *version = "5.25";`
`29`	`29`
`30`	`30`	`namespace`
`31`	`31`	`{`