- Added uci.cpp and ucioptions.cpp for aspiration window tuning (instead of rebuilding which takes time)

- Enhanced timestamp in TT
- Rewritten the alpha-beta pruning search due to clutters of copied code :)
- Fixed some bugs of eval.cpp
- Modified SEE in move_ordering.cpp to use basic quiescence search itself (with some modifications)

Author: winapiadmin

CMakeLists.txt

@@ -18,7 +18,9 @@ set(SOURCES
     eval.cpp
     search.cpp
     tt.cpp
-    move_ordering.cpp
+    move_ordering.cpp 
+    uci.cpp
+    ucioptions.cpp
 )
 
 # Define the executable

Makefile

@@ -2,7 +2,7 @@
 CXX = g++
 
 # Source files and object files
-SRC = main.cpp eval.cpp search.cpp tt.cpp move_ordering.cpp
+SRC = main.cpp eval.cpp search.cpp tt.cpp move_ordering.cpp uci.cpp ucioptions.cpp
 OBJ = $(SRC:.cpp=.o)
 
 # Output file

eval.cpp

@@ -135,7 +135,6 @@ namespace chess
 #define MATE(i) MAX_MATE-i
 #define MATE_DISTANCE(i) (i - MAX_MATE)
 int16_t eval(const chess::Position &board);
-constexpr int16_t ASPIRATION_DELTA = 30;
 int16_t piece_value(chess::PieceType p);
 int16_t passed(const chess::Position &pos);
 void trace(const chess::Position& pos);

eval.h

@@ -3,222 +3,17 @@
 #include "eval.h"
 #include "search.hpp"
 #include "tt.hpp"
-
-#include <atomic>
-#include <chrono>
-#include <iostream>
-#include <limits>
-#include <sstream>
-#include <string>
-#include <thread>
+#include "ucioptions.hpp" // this only handles options
+#include "uci.h"
 
 using namespace std;
 
-// Constants
-#define IS_MATE_SCORE(score) (abs(score) >= MAX_SCORE_CP)
-constexpr unsigned INFINITE_TIME = std::numeric_limits<unsigned>::max();
-
-// Thread handle
-static std::thread search_thread;
-
-// Search function
-void run_search(chess::Position board, int depth, unsigned time_limit_ms, bool infinite)
-{
-    int prev_score = 0;
-    search::nodes=0;
-    search::tt.newSearch();
-    search::start_time = std::chrono::high_resolution_clock::now();
-    search::time_limit = std::chrono::milliseconds((int)(time_limit_ms * 0.01));
-    search::PV stablePV;
-
-    for (int d = 1; (depth == -1 || d <= depth) && !search::stop_requested.load(); ++d)
-    {
-        int alpha = prev_score - ASPIRATION_DELTA;
-        int beta = prev_score + ASPIRATION_DELTA;
-
-        int16_t score = search::alphaBeta(board, alpha, beta, d);
-
-        if (score <= alpha)
-        {
-            alpha = -MATE(0);
-            beta = prev_score + ASPIRATION_DELTA;
-            score = search::alphaBeta(board, alpha, beta, d);
-        }
-        else if (score >= beta)
-        {
-            alpha = prev_score - ASPIRATION_DELTA;
-            beta = MATE(0);
-            score = search::alphaBeta(board, alpha, beta, d);
-        }
-        if (!infinite && search::check_time())
-            break;
-    }
-
-    chess::Move best = search::pv.argmove[0];
-    chess::Move ponder = search::pv.argmove[1];
-
-    if (best != chess::Move())
-    {
-        cout << "bestmove " << best;
-        if (ponder != chess::Move())
-            cout << " ponder " << ponder;
-        cout << endl;
-    }
-    else
-    {
-        cout << "bestmove (none)" << endl;
-    }
-}
 
 // Main UCI loop
 int main()
 {
     chess::Position board;
-    string line;
-
-    while (getline(cin, line))
-    {
-        istringstream iss(line);
-        string token;
-        iss >> token;
-
-        if (token == "uci")
-        {
-            cout << "id name MyEngine" << endl;
-            cout << "id author YourNameHere" << endl;
-            cout << "uciok" << endl;
-        }
-        else if (token == "isready")
-        {
-            cout << "readyok" << endl;
-        }
-        else if (token == "quit")
-        {
-            search::stop_requested = true;
-            if (search_thread.joinable())
-                search_thread.join();
-            break;
-        }
-        else if (token == "stop")
-        {
-            search::stop_requested = true;
-        }
-        else if (token == "position")
-        {
-            string sub;
-            iss >> sub;
-
-            if (sub == "startpos")
-            {
-                board.setFen(chess::constants::STARTPOS);
-                if (iss >> sub && sub == "moves")
-                {
-                    while (iss >> sub)
-                    {
-                        board.makeMove(chess::uci::uciToMove(board, sub));
-                    }
-                }
-            }
-            else if (sub == "fen")
-            {
-                string fen, temp;
-                int fenParts = 6;
-                while (fenParts-- && iss >> temp)
-                    fen += temp + " ";
-                board.setFen(fen);
-                if (iss >> sub && sub == "moves")
-                {
-                    while (iss >> sub)
-                        board.makeMove(chess::uci::uciToMove(board, sub));
-                }
-            }
-
-            search::tt.clear();
-        }
-        else if (token == "go")
-        {
-            int depth = -1;
-            int movetime = -1;
-            bool infinite = false;
-            bool white = (board.sideToMove() == chess::Color::WHITE);
-
-            string sub;
-            while (iss >> sub)
-            {
-                if (sub == "depth")
-                    iss >> depth;
-                else if (sub == "movetime")
-                    iss >> movetime;
-                else if (sub == "wtime" && white)
-                    iss >> movetime;
-                else if (sub == "btime" && !white)
-                    iss >> movetime;
-                else if (sub == "infinite")
-                {
-                    infinite = true;
-                    depth = MAX_PLY;
-                }
-            }
-
-            if (search_thread.joinable())
-            {
-                search::stop_requested = true;
-                search_thread.join();
-            }
-
-            search::stop_requested = false;
-            unsigned time_limit_ms = INFINITE_TIME;
-            if (!infinite && movetime >= 0)
-            {
-                time_limit_ms = movetime;
-            }
-            chess::Position board_copy = board;
-
-            search_thread = std::thread(run_search, board_copy, depth, time_limit_ms, infinite);
-            search_thread.detach();
-        }
-        else if (token == "d")
-        {
-            cout << board << endl;
-        }
-        else if (token == "bench")
-        {
-            uint64_t nodes=0;
-            std::vector<std::string> fen_list = {"r7/pp3kb1/7p/2nr4/4p3/7P/PP1N1PP1/R1B1K2R b KQ - 1 19",
-                                                 "r1bqk2r/pppp1ppp/2n5/4p3/4P3/2N5/PPPP1PPP/R1BQK2R w KQkq - 0 1",
-                                                 "rnbqkb1r/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1",
-                                                 "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR b KQkq - 0 1",
-                                                 "8/pp3k2/7p/2nR4/4p3/7P/Pb3PP1/6K1 b - - 1 25",
-                                                 "8/p4k2/1p1R3p/2n5/4p3/7P/Pb3PP1/6K1 b - - 1 26",
-                                                 "8/p4k2/1p1R1b1p/2n5/4p3/7P/P4PP1/5K2 b - - 3 27",
-                                                 "8/p3k3/1pR2b1p/2n5/4p3/7P/P4PP1/5K2 b - - 5 28",
-                                                 "1R6/8/1p1knb1p/p7/4p3/7P/P3KPP1/8 b - - 3 32",
-                                                 "3R4/8/1p1k3p/p7/3bp2P/6Pn/P3KP2/8 b - - 2 35",
-                                                 "8/4R3/1p6/p5PP/3b4/2n2K2/P2kp3/8 w - - 1 46",
-                                                 "rnbqkb1r/ppp1pppp/1n6/8/8/2N2N2/PPPP1PPP/R1BQKB1R w KQkq - 2 5",
-                                                 "r2qr1k1/1ppb1pbp/np4p1/3Pp3/4N3/P2B1N1P/1PP2PP1/2RQR1K1 b - - 6 16"};
-            auto start_time = std::chrono::high_resolution_clock::now();
-            for (int i=0;i<fen_list.size();i++)
-            {
-                string fen = fen_list[i];
-                std::cout<<"Position "<<i<<"/"<<fen_list.size()-1<<std::endl;
-                board.setFen(fen);
-                run_search(board, 8, INFINITE_TIME, false);
-                nodes+=search::nodes;
-            }
-            auto end_time = std::chrono::high_resolution_clock::now();
-
-            std::chrono::duration<double> elapsed_seconds = end_time - start_time;
-            printf("===========================\n");
-            printf("Total time (ms) : %d\n", int(elapsed_seconds.count() * 1000));
-            printf("Nodes searched  : %llu\n", nodes);
-            printf("Nodes/second    : %llu\n", (uint64_t)(nodes/elapsed_seconds.count()));
-        }
-        else if (token == "eval")
-        {
-            trace(board);
-        }
-    }
-
+    UCIOptions::addSpin("aspiration_window", 30, 0, 500);
+    uci_loop();
     return 0;
 }