1
0
Fork 0
mirror of https://github.com/sockspls/badfish synced 2025-05-01 17:19:36 +00:00

Use standard naming conventions in book.cpp

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba 2011-05-08 10:40:30 +01:00
parent d5f0b91c06
commit de58594b0f
2 changed files with 33 additions and 30 deletions

View file

@ -35,7 +35,7 @@ using namespace std;
namespace { namespace {
// Random numbers from PolyGlot, used to compute book hash keys // Random numbers from PolyGlot, used to compute book hash keys
const uint64_t Random64[781] = { const Key PolyGlotRandoms[781] = {
0x9D39247E33776D41ULL, 0x2AF7398005AAA5C7ULL, 0x44DB015024623547ULL, 0x9D39247E33776D41ULL, 0x2AF7398005AAA5C7ULL, 0x44DB015024623547ULL,
0x9C15F73E62A76AE2ULL, 0x75834465489C0C89ULL, 0x3290AC3A203001BFULL, 0x9C15F73E62A76AE2ULL, 0x75834465489C0C89ULL, 0x3290AC3A203001BFULL,
0x0FBBAD1F61042279ULL, 0xE83A908FF2FB60CAULL, 0x0D7E765D58755C10ULL, 0x0FBBAD1F61042279ULL, 0xE83A908FF2FB60CAULL, 0x0D7E765D58755C10ULL,
@ -299,55 +299,54 @@ namespace {
0xF8D626AAAF278509ULL 0xF8D626AAAF278509ULL
}; };
// Indices to the Random64[] array // Offsets to the PolyGlotRandoms[] array of zobrist keys
const int PieceIdx = 0; const Key* ZobPiece = PolyGlotRandoms + 0;
const int CastleIdx = 768; const Key* ZobCastle = PolyGlotRandoms + 768;
const int EnPassantIdx = 772; const Key* ZobEnPassant = PolyGlotRandoms + 772;
const int TurnIdx = 780; const Key* ZobTurn = PolyGlotRandoms + 780;
// Piece offset is calculated as 64 * (PolyPiece ^ 1) where
// PolyPiece is: BP = 0, WP = 1, BN = 2, WN = 3 ... BK = 10, WK = 11
const int PieceOfs[] = { 0, 64, 192, 320, 448, 576, 704, 0,
0, 0, 128, 256, 384, 512, 640 };
// book_key() builds up a PolyGlot hash key out of a position // book_key() builds up a PolyGlot hash key out of a position
uint64_t book_key(const Position& pos) { uint64_t book_key(const Position& pos) {
// Piece offset is calculated as (64 * PolyPieceType + square), where
// PolyPieceType is: BP = 0, WP = 1, BN = 2, WN = 3 .... BK = 10, WK = 11
static const int PieceToPoly[] = { 0, 1, 3, 5, 7, 9, 11, 0, 0, 0, 2, 4, 6, 8, 10 };
uint64_t result = 0; uint64_t result = 0;
Bitboard b = pos.occupied_squares(); Bitboard b = pos.occupied_squares();
while (b) while (b)
{ {
Square s = pop_1st_bit(&b); Square s = pop_1st_bit(&b);
int p = PieceToPoly[int(pos.piece_on(s))]; result ^= ZobPiece[PieceOfs[pos.piece_on(s)] + s];
result ^= Random64[PieceIdx + 64 * p + int(s)];
} }
if (pos.can_castle_kingside(WHITE)) if (pos.can_castle_kingside(WHITE))
result ^= Random64[CastleIdx + 0]; result ^= ZobCastle[0];
if (pos.can_castle_queenside(WHITE)) if (pos.can_castle_queenside(WHITE))
result ^= Random64[CastleIdx + 1]; result ^= ZobCastle[1];
if (pos.can_castle_kingside(BLACK)) if (pos.can_castle_kingside(BLACK))
result ^= Random64[CastleIdx + 2]; result ^= ZobCastle[2];
if (pos.can_castle_queenside(BLACK)) if (pos.can_castle_queenside(BLACK))
result ^= Random64[CastleIdx + 3]; result ^= ZobCastle[3];
if (pos.ep_square() != SQ_NONE) if (pos.ep_square() != SQ_NONE)
result ^= Random64[EnPassantIdx + square_file(pos.ep_square())]; result ^= ZobEnPassant[square_file(pos.ep_square())];
if (pos.side_to_move() == WHITE) if (pos.side_to_move() == WHITE)
result ^= Random64[TurnIdx]; result ^= ZobTurn[0];
return result; return result;
} }
} }
/// Book c'tor. Make random number generation less deterministic, for book moves /// Book c'tor. Make random number generation less deterministic, for book moves
Book::Book() { Book::Book() : bookSize(0) {
for (int i = abs(get_system_time() % 10000); i > 0; i--) for (int i = abs(get_system_time() % 10000); i > 0; i--)
RKiss.rand<unsigned>(); RKiss.rand<unsigned>();
@ -371,6 +370,7 @@ void Book::close() {
bookFile.close(); bookFile.close();
bookName = ""; bookName = "";
bookSize = 0;
} }
@ -408,7 +408,7 @@ void Book::open(const string& fileName) {
Move Book::get_move(const Position& pos, bool findBestMove) { Move Book::get_move(const Position& pos, bool findBestMove) {
if (!bookFile.is_open() || bookSize == 0) if (!bookSize || !bookFile.is_open())
return MOVE_NONE; return MOVE_NONE;
BookEntry entry; BookEntry entry;
@ -417,7 +417,7 @@ Move Book::get_move(const Position& pos, bool findBestMove) {
uint64_t key = book_key(pos); uint64_t key = book_key(pos);
// Choose a book move among the possible moves for the given position // Choose a book move among the possible moves for the given position
for (int idx = find_entry(key); idx < bookSize; idx++) for (int idx = first_entry(key); idx < bookSize; idx++)
{ {
entry = read_entry(idx); entry = read_entry(idx);
@ -429,8 +429,8 @@ Move Book::get_move(const Position& pos, bool findBestMove) {
if (!findBestMove) if (!findBestMove)
{ {
// Choose book move according to its score. If a move has a very // Choose book move according to its score. If a move has a very
// high score it has more probability to be choosen then a one with // high score it has higher probability to be choosen than a move
// lower score. Note that first entry is always chosen. // with lower score. Note that first entry is always chosen.
scoresSum += score; scoresSum += score;
if (RKiss.rand<unsigned>() % scoresSum < score) if (RKiss.rand<unsigned>() % scoresSum < score)
bookMove = entry.move; bookMove = entry.move;
@ -442,6 +442,9 @@ Move Book::get_move(const Position& pos, bool findBestMove) {
} }
} }
if (!bookMove)
return MOVE_NONE;
// A PolyGlot book move is encoded as follows: // A PolyGlot book move is encoded as follows:
// //
// bit 0- 5: destination square (from 0 to 63) // bit 0- 5: destination square (from 0 to 63)
@ -469,16 +472,16 @@ Move Book::get_move(const Position& pos, bool findBestMove) {
} }
/// Book::find_entry() takes a book key as input, and does a binary search /// Book::first_entry() takes a book key as input, and does a binary search
/// through the book file for the given key. The index to the first book /// through the book file for the given key. The index to the first (leftmost)
/// entry with the same key as the input is returned. When the key is not /// book entry with the same key as the input is returned. When the key is not
/// found in the book file, bookSize is returned. /// found in the book file, bookSize is returned.
int Book::find_entry(uint64_t key) { int Book::first_entry(uint64_t key) {
int left, right, mid; int left, right, mid;
// Binary search (finds the leftmost entry) // Binary search (finds the leftmost entry with given key)
left = 0; left = 0;
right = bookSize - 1; right = bookSize - 1;

View file

@ -51,7 +51,7 @@ private:
template<typename T> Book& operator>>(T& n); template<typename T> Book& operator>>(T& n);
BookEntry read_entry(int idx); BookEntry read_entry(int idx);
int find_entry(uint64_t key); int first_entry(uint64_t key);
std::ifstream bookFile; std::ifstream bookFile;
std::string bookName; std::string bookName;