engine.cpp

   1 /***************************************************************************
   2                           engine.cpp  -  description
   3                              -------------------
   4     begin                : mer ott 23 2002
   5     copyright            : (C) 2002-2005 by Maurizio Monge
   6     email                : monge@linuz.sns.it
   7  ***************************************************************************/
   8
   9 /***************************************************************************
  10  *                                                                         *
  11  *   This program is free software; you can redistribute it and/or modify  *
  12  *   it under the terms of the GNU General Public License as published by  *
  13  *   the Free Software Foundation; either version 2 of the License, or     *
  14  *   (at your option) any later version.                                   *
  15  *                                                                         *
  16  ***************************************************************************/
  17
  18 #include "engine.h"
  19 #include "utils.h"
  20 #include "commands.h"
  21 #include <string.h>
  22
  23 Engine* Engine::instance = NULL;
  24
  25 Engine* Engine::eng()
  26 {
  27     return instance;
  28 }
  29
  30 Engine::Engine()
  31 {
  32     instance = this;
  33
  34     mv_done             = new Move[400];
  35
  36     create_hash();
  37     reset_hash();
  38
  39     mv_done_num         = 0;
  40     analysis_limit      = TIME_LIMIT;
  41     time_fixed          = 2;
  42
  43     st_computer_color   = BLACK;
  44     status              = PLAYING;
  45     eng_status          = PLAYING;
  46     thinking            = false;
  47     status_string       = NULL;
  48     post                = true;//false;
  49     ponder              = false;
  50
  51     io_xboard           = false;
  52     io_san              = false;
  53     io_colors           = false;
  54
  55     /* register engine commands */
  56     register_commands();
  57
  58     /* register engine variables */
  59     register_variables();
  60
  61     /* open log file */
  62     log = fopen("rattatechess.log", "w");
  63
  64     /* open the book */
  65     book_mmap = NULL;
  66     if(!open_book("ratta.book"))
  67     if(!open_book("../ratta.book"))
  68     {
  69         char buf[1024];
  70         snprintf(buf, 1024, "%s/ratta.book", getenv("HOME"));
  71         open_book(buf);
  72     }
  73
  74     /* open the play lines */
  75     if(!open_lines("ratta.lines"))
  76     if(!open_lines("../ratta.lines"))
  77     {
  78         char buf[1024];
  79         snprintf(buf, 1024, "%s/ratta.lines", getenv("HOME"));
  80         open_lines(buf);
  81     }
  82
  83     srand(time(NULL));
  84     board.set_as_default();
  85 }
  86
  87 unsigned char Engine::color_to_move()
  88 {
  89     return board.color_to_move;
  90 }
  91
  92 unsigned char Engine::computer_color()
  93 {
  94     return st_computer_color;
  95 }
  96
  97 int Engine::get_status()
  98 {
  99     return status;
 100 }
 101
 102 int Engine::move_number()
 103 {
 104     return board.num_moves;
 105 }
 106
 107 void Engine::start()
 108 {
 109     st_computer_color = board.color_to_move;
 110     status = PLAYING;
 111     status_string = NULL;
 112     eng_status = PLAYING;
 113     //output("starting!\n");
 114     if(thinking)
 115         longjmp(back, 1);
 116 }
 117
 118 void Engine::start(unsigned char color)
 119 {
 120     st_computer_color = color;
 121     status = PLAYING;
 122     status_string = NULL;
 123     eng_status = PLAYING;
 124     if(thinking)
 125         longjmp(back, 1);
 126 }
 127
 128 void Engine::force()
 129 {
 130     st_computer_color = 0;
 131     eng_status = FORCING;
 132     if(thinking)
 133         longjmp(back, 1);
 134 }
 135
 136 void Engine::analyze()
 137 {
 138     st_computer_color = 0;
 139     HashKey h = board.hash;
 140     find_best_move();
 141
 142     /* exited analyzing without any move being done?
 143         (because of a near mate or a book entry found) */
 144     while(eng_status==ANALYZING && h == board.hash)
 145         process_input();
 146 }
 147
 148 void Engine::do_ponder()
 149 {
 150     HashKey h = board.hash;
 151     find_best_move();
 152
 153     /* exited pondering without any move being done?
 154         (because of a near mate or a book entry found) */
 155     while(ponder && eng_status==PLAYING &&
 156          st_computer_color == board.other_color && h == board.hash)
 157         process_input();
 158 }
 159
 160 void Engine::move_now()
 161 {
 162     if(!thinking)
 163     {
 164         output("You cannot use this command now!\n");
 165         return;
 166     }
 167
 168     longjmp(back, 1);
 169 }
 170
 171 /* do the move and update a couple of things */
 172 void Engine::move(Move mv)
 173 {
 174     /* save the move in the stack of played moves (from the starting position) */
 175     mv_done[mv_done_num++] = mv;
 176
 177     board.do_move(mv);
 178
 179     if(insufficient_material())
 180     {
 181         status=_12;
 182         status_string = "Insufficient material";
 183         return;
 184     }
 185
 186     /* 50mvs rule */
 187     if(board.fifty >= 100)
 188     {
 189         status=_12;
 190         status_string = "Drawn by 50-move rule";
 191         return;
 192     }
 193
 194     /* for the latest reversible moves check if the hash value
 195         (for this player) is the same         */
 196     int first_candidate = MAX(board.num_old_hashes-(board.fifty/2)*2, 0);
 197     int repeat = 1;
 198     for(int i=board.num_old_hashes-4;i>=first_candidate;i-=2)
 199     {
 200         if(board.hash == board.old_hashes[i])
 201             repeat++;
 202         if(repeat>=3)
 203         {
 204             status = _12;
 205             status_string = "Drawn by 3-fold repetition";
 206             return;
 207         }
 208     }
 209
 210     Move mvs[250];
 211     if(board.find_moves(mvs)==0)      //mate or stalemate...
 212     {
 213         if(board.under_check)
 214         {
 215             if(board.color_to_move==WHITE)
 216             {
 217                 status = _01;
 218                 status_string = "Black mates";
 219             }
 220             else
 221             {
 222                 status = _10;
 223                 status_string = "White mates";
 224             }
 225         }
 226         else
 227         {
 228             status = _12;
 229             status_string = "Stalemate";
 230         }
 231         return;
 232     }
 233 }
 234
 235 void Engine::retract_move()
 236 {
 237     if(mv_done_num>1)
 238         board.undo_move(mv_done[--mv_done_num]);
 239     board.undo_move(mv_done[--mv_done_num]);
 240 }
 241
 242 void Engine::undo()
 243 {
 244     if(mv_done_num>0)
 245         board.undo_move(mv_done[--mv_done_num]);
 246     status = PLAYING;
 247 }
 248
 249 void Engine::new_game()
 250 {
 251     mv_done_num     = 0;
 252     analysis_limit  = TIME_LIMIT;
 253     time_fixed      = 2;
 254     st_computer_color   = BLACK;
 255     status          = PLAYING;
 256     eng_status      = PLAYING;
 257
 258     strcpy(opponent, "<unknown>");
 259     w_rating  = 0;
 260     b_rating  = 0;
 261
 262     board.set_as_default();
 263     reset_hash();
 264 }
 265
 266 void Engine::set_depth(int d)
 267 {
 268     analysis_limit  = DEPTH_LIMIT;
 269     st_depth        = d;
 270 }
 271
 272 void Engine::set_max_nodes(int d)
 273 {
 274     analysis_limit  = NODES_LIMIT;
 275     st_nodes        = d;
 276 }
 277
 278 void Engine::set_time_fixed(int t)
 279 {
 280     analysis_limit  = TIME_LIMIT;
 281     time_fixed      = t;
 282 }
 283
 284 void Engine::set_time_control(int mps, int basesec, int inc)
 285 {
 286     analysis_limit  = TIME_LIMIT;
 287     time_fixed      = 0;
 288     time_mps        = mps;
 289     time_base       = basesec;
 290     time_inc        = inc;
 291     time_clock_csec = time_base*100;
 292 }
 293
 294 void Engine::set_my_clock(int t)
 295 {
 296     time_clock_csec = t;
 297 }
 298
 299 void Engine::set_other_clock(int t)
 300 {
 301     time_oth_clock_csec = t;
 302 }
 303
 304 void Engine::print_board()
 305 {
 306     board.print_board();
 307 }
 308
 309 void Engine::read_board(char* brd, char* color, char* castle,
 310                         char* passing, int moves_to_draw, int num_moves)
 311 {
 312     board.read_board(brd, color,castle,passing,moves_to_draw,num_moves);
 313     mv_done_num     = 0;
 314     reset_hash();
 315     if(thinking)
 316         longjmp(back, 1);
 317 }
 318
 319 void Engine::read_board(char* str)
 320 {
 321     board.read_board(str);
 322     mv_done_num     = 0;
 323     reset_hash();
 324     if(thinking)
 325         longjmp(back, 1);
 326 }
 327
 328 void Engine::read_board(FILE* f)
 329 {
 330     char str[256];
 331     fgets(str,256,f);
 332     board.read_board(str);
 333 }
 334
 335 void Engine::write_board(FILE* f)
 336 {
 337     char str[256];
 338     board.write_board(str);
 339     fputs(str,f);
 340 }
 341
 342 bool Engine::check_time()
 343 {
 344     processed_nodes++;
 345     //return false;
 346
 347     if( eng_status == PLAYING &&
 348         analysis_limit == NODES_LIMIT &&
 349         processed_nodes > (unsigned int)st_nodes)
 350     {
 351         rewind_thinking();
 352         longjmp(back, 1);
 353     }
 354
 355     if( (processed_nodes%4096) == 0 )
 356     {
 357         if( eng_status == PLAYING &&
 358             analysis_limit == TIME_LIMIT &&
 359             current_time()>=max_think_time )
 360         {
 361             rewind_thinking();
 362             longjmp(back, 1);
 363         }
 364
 365         if(input_available())
 366         {
 367             rewind_thinking();
 368
 369             int n = mv_done_num;
 370             do
 371             {
 372                 process_input();
 373
 374                 if(n != mv_done_num)
 375                     longjmp(back, 1);
 376
 377                 if(eng_status == PLAYING && !ponder
 378                         && st_computer_color == board.other_color)
 379                     longjmp(back, 1);
 380             }
 381             while(input_available());
 382
 383             restore_thinking();
 384         }
 385     }
 386     return false;
 387 }
 388
 389 //very primitive
 390 void Engine::calc_best_time()
 391 {
 392     if(time_fixed)
 393         time_best_csec = time_fixed * 100;
 394     else
 395     {
 396         int nummoves = (time_mps == 0) ? 30 :
 397                 MAX((time_mps - (board.num_moves % time_mps)), 30);
 398         time_best_csec = time_clock_csec / nummoves + time_inc * 100;
 399         //time_best_csec = time_clock_csec / nummoves * (50 + rand()%300) / 200  + time_inc * 100;
 400     }
 401 }
 402
 403 uint64_t Engine::perft(int lev)
 404 {
 405     Move mv_stack[200];
 406     int num;
 407     num = board.find_moves(mv_stack);
 408
 409     if(lev==1)
 410         return num;
 411     else
 412     {
 413         uint64_t retv=0;
 414         for(int i=0;i<num;i++)
 415         {
 416             board.do_move(mv_stack[i]);
 417             retv+=perft(lev-1);
 418             board.undo_move(mv_stack[i]);
 419         }
 420         return retv;
 421     }
 422 }
 423
 424 void Engine::autotune()
 425 {
 426     struct Tunable { const char* name; int& param; int start; int end; int step; };
 427     Tunable data[] = {
 428         { "v_search_threat_threshold", v_search_threat_threshold, 150, 720, 190 },
 429         { "v_search_threat_extension", v_search_threat_extension, 40, 120, 80 },
 430         { "v_search_null_reduction", v_search_null_reduction, 200, 400, 100 },
 431     };
 432     int numparams = sizeof(data)/sizeof(Tunable);
 433
 434     for(int i=0;i<3;i++)
 435     for(int p=0;p<numparams;p++)
 436     {
 437         int oldv = data[p].param;
 438         int best = 0;
 439         int best_goodness = -1;
 440         int worst_goodness = 99999;
 441
 442         for(data[p].param = data[p].start; data[p].param <= data[p].end; data[p].param += data[p].step)
 443         {
 444             output("\n");
 445             for(int k=0;k<numparams;k++)
 446                 output("%s = %d%s\n", data[k].name, data[k].param, k==p ? " <--" : "");
 447             int goodness = run_epd_prog("self", 1, "epd/abbe.epd");
 448             if(goodness > best_goodness)
 449             {
 450                 best_goodness = goodness;
 451                 best = data[p].param;
 452             }
 453             if(goodness < worst_goodness)
 454                 worst_goodness = goodness;
 455         }
 456
 457         if(worst_goodness == best_goodness)
 458             data[p].param = oldv;
 459         else
 460             data[p].param = best;
 461     }
 462
 463     output("\n");
 464     output("FINAL REPORT:\n");
 465     for(int k=0;k<numparams;k++)
 466         output("%s = %d\n", data[k].name, data[k].param);
 467     exit(0);
 468 }