game.c

   1
   2 /**
   3  *
   4  * Tennix! SDL Port
   5  * Copyright (C) 2003, 2007 Thomas Perl <thp@perli.net>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version 2
  10  * of the License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  20  * MA  02110-1301, USA.
  21  *
  22  **/
  23
  24 #include <stdio.h>
  25 #include <math.h>
  26
  27 #include "tennix.h"
  28 #include "game.h"
  29 #include "graphics.h"
  30 #include "input.h"
  31 #include "sound.h"
  32
  33 void game( bool singleplayer) {
  34     GameState s = {
  35         { 0, 0, 0.0, 0.0, 0.0 },
  36         { 0, 0, 0, 0, 0 },
  37         { GAME_X_MIN-RACKET_X_MID*2, GAME_Y_MID, 0, 0, 1, DESIRE_NORMAL, PLAYER_TYPE_HUMAN, false, 0, 0 },
  38         { GAME_X_MAX+RACKET_X_MID*2, GAME_Y_MID, 0, 0, 0, DESIRE_NORMAL, PLAYER_TYPE_HUMAN, false, 0, 0 },
  39         0,
  40         0,
  41         0,
  42         true,
  43         "welcome to tennix " VERSION,
  44         { 0 },
  45         { 0 },
  46         REFEREE_NORMAL,
  47         0,
  48         WINNER_NONE,
  49         false,
  50         GR_CTT_GRASS,
  51         -1,
  52         { 0 },
  53         0,
  54         false,
  55         { { { 0 } } },
  56         0.0,
  57         SOUND_MAX,
  58         0.0,
  59         0.0,
  60         0
  61     };
  62
  63     strcpy( s.game_score_str, format_game( &s));
  64     strcpy( s.sets_score_str, format_sets( &s));
  65
  66     Uint32 ot = SDL_GetTicks();
  67     Uint32 nt;
  68     Uint32 dt = GAME_TICKS;
  69     Uint32 diff;
  70     Uint32 accumulator = 0;
  71     bool quit = false;
  72     int x, y, z;
  73
  74     if( singleplayer) {
  75 #ifdef DEBUG
  76         s.player1.type = PLAYER_TYPE_AI;
  77 #endif
  78         s.player2.type = PLAYER_TYPE_AI;
  79     }
  80
  81     game_setup_serve( &s);
  82
  83     /* smoothen n-gram */
  84     for( x = 0; x<NGRAM_STEPS; x++) {
  85         for( y = 0; y<NGRAM_STEPS; y++) {
  86             for( z = 0; z<NGRAM_STEPS; z++) {
  87                 s.ngram[x][y][z] = 1;
  88             }
  89         }
  90     }
  91
  92     while( !quit) {
  93         nt = SDL_GetTicks();
  94         diff = nt-ot;
  95         if( diff > 2000) {
  96             diff = 0;
  97         }
  98
  99         accumulator += diff;
 100         ot = nt;
 101
 102         while( accumulator >= dt) {
 103             quit = step( &s);
 104             s.time += dt;
 105             accumulator -= dt;
 106
 107             if( s.was_stopped) {
 108                 ot = SDL_GetTicks();
 109                 s.was_stopped = false;
 110             }
 111         }
 112
 113         render( &s);
 114     }
 115
 116 }
 117
 118 bool step( GameState* s) {
 119     Uint8 *keys;
 120     SDL_Event e;
 121
 122     if( get_phase( s) < 1.0) {
 123         if( !s->ground.jump) {
 124             s->play_sound = SOUND_GROUND;
 125
 126             if( IS_OUT_Y( s->ball.y)) {
 127                 /* out - responsibilities stay the same */
 128                 s->status = "out!";
 129                 s->play_sound = SOUND_OUT;
 130                 s->referee = REFEREE_OUT;
 131             } else {
 132                 /* not out - responsibilities change */
 133                 s->player1.responsible = !(s->player2.responsible = !s->player2.responsible);
 134                 s->status = format_status( s);
 135                 s->referee = REFEREE_NORMAL;
 136             }
 137         }
 138         s->ground.jump = 3;
 139         s->ground.x = s->ball.x;
 140         s->ground.y = s->ball.y;
 141     } else {
 142         if( s->ground.jump && !(s->time%5)) s->ground.jump--;
 143     }
 144
 145     if( IS_OUT_X(s->ball.x) || IS_OFFSCREEN_Y(s->ball.y)) {
 146         if( IS_OFFSCREEN( s->ball.x, s->ball.y)) {
 147             s->player1_serves = s->player1.responsible;
 148
 149             score_game( s, s->player2.responsible);
 150             strcpy( s->game_score_str, format_game( s));
 151             strcpy( s->sets_score_str, format_sets( s));
 152
 153             if( s->player1.responsible) {
 154                 if( s->player1.type == PLAYER_TYPE_HUMAN && s->player2.type == PLAYER_TYPE_AI) {
 155                     s->status = "computer scores";
 156                 } else {
 157                     s->status = "player 2 scores";
 158                 }
 159                 s->referee = REFEREE_PLAYER2;
 160             } else {
 161                 if( s->player1.type == PLAYER_TYPE_HUMAN && s->player2.type == PLAYER_TYPE_AI) {
 162                     s->status = "player scores";
 163                 } else {
 164                     s->status = "player 1 scores";
 165                 }
 166                 s->referee = REFEREE_PLAYER1;
 167             }
 168
 169             game_setup_serve( s);
 170             s->play_sound = SOUND_APPLAUSE;
 171             SDL_Delay( 500);
 172             start_fade();
 173             s->was_stopped = true;
 174             s->history_size = 0;
 175             s->history_is_locked = 0;
 176             s->ngram_prediction = 0.0;
 177 #ifdef DEBUG
 178             printf( "-- game reset --\n");
 179 #endif
 180         }
 181
 182         if( IS_OUT_X(s->ball.x)) {
 183             if( !s->history_is_locked && s->referee != REFEREE_OUT) {
 184                 s->history[s->history_size] = (int)(NGRAM_STEPS*s->ball.y/HEIGHT);
 185                 s->history_size++;
 186                 if( s->history_size == 3) {
 187                     s->ngram[s->history[0]][s->history[1]][s->history[2]] += 10;
 188 #ifdef DEBUG
 189                     printf( "history: %d, %d, %d\n", s->history[0], s->history[1], s->history[2]);
 190 #endif
 191                     s->ngram_prediction = ngram_predictor( s);
 192                     s->history[0] = s->history[1];
 193                     s->history[1] = s->history[2];
 194                     s->history_size--;
 195                 }
 196                 s->history_is_locked = true;
 197             }
 198             if( s->ball.move_x <= 0 && IS_NEAR_X( s->player1.x, s->ball.x) && IS_NEAR_Y( s->player1.y, s->ball.y) && s->player1.state && s->referee != REFEREE_OUT) {
 199                 s->ball.x = GAME_X_MIN;
 200                 if( s->player1.state == PLAYER_STATE_MAX) {
 201                     s->ball.move_x = PLAYER_POWERSHOT;
 202                 } else {
 203                     s->ball.move_x = 2.5 + 2.0*s->player1.state/PLAYER_STATE_MAX;
 204                 }
 205                 s->ball.move_y = get_move_y( s, 1);
 206                 s->player2.responsible = !(s->player1.responsible = 1);
 207                 s->ball.jump += 1.0-2.0*(s->player1.state<5);
 208                 s->play_sound = SOUND_RACKET;
 209                 pan_sample(SOUND_RACKET, 0.4);
 210             } else if( s->ball.move_x >= 0 && IS_NEAR_X( s->player2.x, s->ball.x) && IS_NEAR_Y( s->player2.y, s->ball.y) && s->player2.state && s->referee != REFEREE_OUT) {
 211                 s->ball.x = GAME_X_MAX;
 212                 if( s->player2.state == PLAYER_STATE_MAX) {
 213                     s->ball.move_x = -PLAYER_POWERSHOT;
 214                 } else {
 215                     s->ball.move_x = -(2.5 + 2.0*s->player2.state/PLAYER_STATE_MAX);
 216                 }
 217                 s->ball.move_y = get_move_y( s, 2);
 218                 s->player1.responsible = !(s->player2.responsible = 1);
 219                 s->ball.jump += 1.0-2.0*(s->player2.state<5);
 220                 s->play_sound = SOUND_RACKET;
 221                 pan_sample(SOUND_RACKET, 0.6);
 222             }
 223         }
 224     } else {
 225         s->history_is_locked = false;
 226     }
 227
 228     /* Update ball_dest for debugging purposes */
 229     get_move_y( s, 1);
 230     get_move_y( s, 2);
 231
 232     s->ball.x += s->ball.move_x;
 233     s->ball.y += s->ball.move_y;
 234
 235     if( s->player1.state) s->player1.state--;
 236     if( s->player2.state) s->player2.state--;
 237
 238     SDL_PollEvent( &e);
 239     keys = SDL_GetKeyState( NULL);
 240     switch(e.type) {
 241         case SDL_JOYAXISMOTION:
 242             if (e.jaxis.axis == JOYSTICK_Y_AXIS) {
 243                 s->joystick_y = JOYSTICK_PERCENTIZE(e.jaxis.value);
 244             } else if (e.jaxis.axis == JOYSTICK_X_AXIS) {
 245                 s->joystick_x = JOYSTICK_PERCENTIZE(e.jaxis.value);
 246             }
 247             break;
 248         case SDL_JOYBUTTONUP: case SDL_JOYBUTTONDOWN:
 249             if (e.jbutton.button == JOYSTICK_BUTTON_A) {
 250                 s->joystick_a = (e.jbutton.state == SDL_PRESSED);
 251             }
 252             break;
 253     }
 254
 255     if( keys['c'] && s->time%50==0) {
 256         s->court_type++;
 257         if( s->court_type > GR_CTT_LAST) {
 258             s->court_type = GR_CTT_FIRST;
 259         }
 260     }
 261
 262     if( !is_fading() && !s->is_over) {
 263         if( s->player1.type == PLAYER_TYPE_HUMAN) {
 264            input_human( &s->player1,
 265                    keys['w'] || keys[SDLK_UP] || s->joystick_y < -JOYSTICK_TRESHOLD,
 266                    keys['s'] || keys[SDLK_DOWN] || s->joystick_y > JOYSTICK_TRESHOLD,
 267                    keys['d'] || keys[SDLK_SPACE] || keys[SDLK_LCTRL] || s->joystick_a,
 268                    ENABLE_MOUSE,
 269                    s);
 270         } else {
 271             input_ai( &s->player1, &s->ball, &s->player2, s);
 272         }
 273
 274         if( s->player2.type == PLAYER_TYPE_HUMAN) {
 275             input_human( &s->player2, keys['o'], keys['l'], keys['k'], false, s);
 276         } else {
 277             input_ai( &s->player2, &s->ball, &s->player1, s);
 278         }
 279     }
 280
 281     if( keys['f']) SDL_WM_ToggleFullScreen( screen);
 282     if( keys['y']) SDL_SaveBMP( screen, "screenshot.bmp");
 283
 284     if( keys['p']) {
 285         while( keys['p']) {
 286             SDL_PollEvent( &e);
 287             keys = SDL_GetKeyState( NULL);
 288             SDL_Delay( 10);
 289         }
 290         while( keys['p'] == 0) {
 291             SDL_PollEvent( &e);
 292             keys = SDL_GetKeyState( NULL);
 293             SDL_Delay( 10);
 294         }
 295         while( keys['p']) {
 296             SDL_PollEvent( &e);
 297             keys = SDL_GetKeyState( NULL);
 298             SDL_Delay( 10);
 299         }
 300         s->was_stopped = true;
 301     }
 302
 303     if( keys[SDLK_ESCAPE] || keys['q']) return true;
 304
 305     limit_value( &s->player1.y, PLAYER_Y_MIN, PLAYER_Y_MAX);
 306     limit_value( &s->player2.y, PLAYER_Y_MIN, PLAYER_Y_MAX);
 307     limit_value( &s->ball.jump, BALL_JUMP_MIN, BALL_JUMP_MAX);
 308
 309     return false;
 310 }
 311
 312 void render( GameState* s) {
 313     if (s->play_sound != SOUND_MAX) {
 314         play_sample(s->play_sound);
 315         s->play_sound = SOUND_MAX;
 316     }
 317     if( s->winner != WINNER_NONE) {
 318         if( !s->is_over) {
 319             start_fade();
 320             s->is_over = true;
 321         }
 322         clear_screen();
 323         store_screen();
 324         show_sprite( GR_RACKET, 2*(s->winner-1), 4, WIDTH/2 - get_image_width( GR_RACKET)/8, HEIGHT/2 - get_image_height( GR_RACKET), 255);
 325         sprintf( s->game_score_str, "player %d wins the match with %s", s->winner, format_sets( s));
 326         font_draw_string( GR_DKC2_FONT, s->game_score_str, (WIDTH-font_get_string_width( GR_DKC2_FONT, s->game_score_str))/2, HEIGHT/2 + 30, s->time/20, ANIMATION_WAVE | ANIMATION_BUNGEE);
 327         updatescr();
 328         return;
 329     }
 330     if (s->old_court_type != s->court_type) {
 331         clear_screen();
 332         fill_image(s->court_type, 120, 120, 400, 250);
 333         show_image(GR_COURT, 0, 0, 255);
 334         s->old_court_type = s->court_type;
 335         store_screen();
 336     }
 337     show_sprite( GR_REFEREE, s->referee, 4, 250, 10, 255);
 338     show_image( GR_SHADOW, s->ball.x-BALL_X_MID, s->ball.y + get_phase( s) - BALL_Y_MID, 255);
 339
 340     show_sprite( GR_RACKET, (!s->player1.state), 4, s->player1.x-RACKET_X_MID, s->player1.y-RACKET_Y_MID, 255);
 341     show_sprite( GR_RACKET, (!s->player2.state)+2, 4, s->player2.x-RACKET_X_MID, s->player2.y-RACKET_Y_MID, 255);
 342
 343     if( s->ground.jump) {
 344         show_sprite( GR_GROUND, s->ground.jump-1, 3, s->ground.x - BALL_X_MID, s->ground.y - BALL_Y_MID, 128);
 345     }
 346
 347     if( s->ball.move_x > 0) {
 348         show_sprite( GR_BALL, (s->time/500)%4, 4, s->ball.x-BALL_X_MID, s->ball.y-BALL_Y_MID, 255);
 349     } else if( s->ball.move_x < 0) {
 350         show_sprite( GR_BALL, 3-(s->time/500)%4, 4, s->ball.x-BALL_X_MID, s->ball.y-BALL_Y_MID, 255);
 351     } else {
 352         show_sprite( GR_BALL, 0, 4, s->ball.x-BALL_X_MID, s->ball.y-BALL_Y_MID, 255);
 353     }
 354
 355
 356     font_draw_string( GR_DKC2_FONT, s->game_score_str, 14, 14, 0, ANIMATION_NONE);
 357     font_draw_string( GR_DKC2_FONT, s->sets_score_str, (WIDTH-font_get_string_width( GR_DKC2_FONT, s->sets_score_str))-14, 14, 0, ANIMATION_NONE);
 358
 359     font_draw_string( GR_DKC2_FONT, s->status, (WIDTH-font_get_string_width( GR_DKC2_FONT, s->status))/2, HEIGHT-50, s->time/30, ANIMATION_WAVE);
 360
 361 #ifdef DEBUG
 362     line_horiz( s->player1.y, 255, 0, 0);
 363     line_horiz( s->player2.y, 0, 0, 255);
 364     line_horiz( s->ball.y, 0, 255, 0);
 365
 366     line_vert( s->player1.x, 255, 0, 0);
 367     line_vert( s->player2.x, 0, 0, 255);
 368     line_vert( s->ball.x, 0, 255, 0);
 369
 370     line_horiz( s->player1.ball_dest, 255, 0, 255);
 371     line_horiz( s->player2.ball_dest, 0, 255, 255);
 372
 373     line_horiz( GAME_Y_MIN, 100, 100, 100);
 374     line_horiz( GAME_Y_MAX, 100, 100, 100);
 375 #endif
 376
 377     updatescr();
 378 }
 379
 380 void limit_value( float* value, float min, float max) {
 381     if( *value < min) {
 382         *value = min;
 383     } else if( *value > max) {
 384         *value = max;
 385     }
 386 }
 387
 388 float get_phase( GameState* s) {
 389     float pos, fract;
 390     float x, min, max, direction;
 391
 392     x = s->ball.x;
 393     min = GAME_X_MIN;
 394     max = GAME_X_MAX;
 395     direction = s->ball.move_x;
 396
 397     pos = (direction>0)?(1-GROUND_PHASE):(GROUND_PHASE);
 398
 399     fract = (x-min)/(max-min);
 400
 401     if( fract < pos) {
 402         fract = fract/pos;
 403         return fabsf( cosf(PI*fract/2))*PHASE_AMP*s->ball.jump;
 404     } else {
 405         fract = (pos-fract)/(1-pos);
 406         return fabsf( sinf(PI*fract/2))*PHASE_AMP*s->ball.jump;
 407     }
 408 }
 409
 410 float get_move_y( GameState* s, unsigned char player) {
 411     float pct, dest, x_len, y_len;
 412     float py, by, pa, move_x;
 413
 414     py = (player==1)?(s->player1.y):(s->player2.y);
 415     by = s->ball.y;
 416     pa = RACKET_Y_MID*2;
 417     move_x = s->ball.move_x;
 418
 419     /* -1.0 .. 1.0 for racket hit position */
 420     pct = (by-py)/(pa/2);
 421     limit_value( &pct, -1.0, 1.0);
 422
 423     /* Y destination for ball */
 424     dest = GAME_Y_MID + pct*(GAME_Y_MAX-GAME_Y_MIN);
 425     if( player == 1) {
 426         s->player1.ball_dest = dest;
 427     } else {
 428         s->player2.ball_dest = dest;
 429     }
 430
 431     /* lengths for the ball's journey */
 432     if( player == 1) {
 433         x_len = fabsf(GAME_X_MAX - s->ball.x);
 434         y_len = dest - by + MOVE_Y_SEED-rand()%MOVE_Y_SEED*2;
 435     } else {
 436         x_len = s->ball.x - GAME_X_MIN;
 437         y_len = by - dest + MOVE_Y_SEED-rand()%MOVE_Y_SEED*2;
 438     }
 439
 440     /* return the should-be value for move_y */
 441     return (y_len*move_x)/(x_len);
 442 }
 443
 444 void input_human( Player* player, bool up, bool down, bool hit, bool use_mouse, GameState* s) {
 445     int diff = PLAYER_MOVE_Y;
 446     int mb;
 447
 448     if (use_mouse) {
 449         mb = SDL_GetMouseState(&(player->mouse_x), &(player->mouse_y));
 450         if (mb&SDL_BUTTON(SDL_BUTTON_LEFT)) {
 451             hit = true;
 452         }
 453         if (player->mouse_y < player->y-RACKET_Y_MID-diff) {
 454             down = false;
 455             up = true;
 456         } else if (player->mouse_y > player->y-RACKET_Y_MID+diff) {
 457             up = false;
 458             down = true;
 459         }
 460     }
 461
 462     if (fabsf(s->joystick_y) > JOYSTICK_TRESHOLD) {
 463         diff = PLAYER_MOVE_Y*fabsf(s->joystick_y)/40.0;
 464         if (diff > PLAYER_MOVE_Y) {
 465             diff = PLAYER_MOVE_Y;
 466         }
 467     }
 468
 469     if( up) {
 470         player->y -= diff;
 471     }
 472
 473     if( down) {
 474         player->y += diff;
 475     }
 476
 477     if( hit) {
 478         if( !player->state && !player->state_locked) {
 479             player->state = PLAYER_STATE_MAX;
 480             player->state_locked = true;
 481         }
 482     } else {
 483         player->state_locked = false;
 484     }
 485 }
 486
 487 void input_ai( Player* player, Ball* ball, Player* opponent, GameState* s) {
 488     float fact = 1.7;
 489     float target;
 490
 491     if( fabsf( player->y - ball->y) > RACKET_Y_MID*5) {
 492         fact = 3.5;
 493     }
 494
 495     target = GAME_Y_MID + (opponent->ball_dest - GAME_Y_MID)/5;
 496
 497     if( player->responsible) {
 498         if( player->desire == DESIRE_NORMAL && !IS_NEAR_Y_AI( player->y, ball->y)) {
 499             if( player->y < ball->y) {
 500                 player->y += fmin( 2*fact, ball->y - player->y);
 501             } else if( player->y > ball->y) {
 502                 player->y -= fmin( 2*fact, player->y - ball->y);
 503             }
 504         }
 505
 506         if( (ball->move_x != 0 || IS_NEAR_Y_AI( player->y, ball->y)) && IS_NEAR_X_AI( player->x, ball->x) && !player->state && rand()%4) {
 507             player->state = PLAYER_STATE_MAX;
 508         }
 509     } else if( ball->move_x == 0) {
 510         if( player->desire == DESIRE_NORMAL && !IS_NEAR_Y_AI( player->y, target)) {
 511             if( player->y < target) {
 512                 player->y += fmin( fact, (target-player->y)/40.0);
 513             } else if( player->y > target) {
 514                 player->y -= fmin( fact, (player->y-target)/40.0);
 515             }
 516         }
 517     } else if( s->ngram_prediction > 0.0) {
 518         target = s->ngram_prediction*((float)HEIGHT)/((float)(NGRAM_STEPS));
 519         target = GAME_Y_MID + (target-GAME_Y_MID)*1.5;
 520
 521         if( player->desire == DESIRE_NORMAL && !IS_NEAR_Y_AI( player->y, target)) {
 522             if( player->y < target) {
 523                 player->y += fmin( fact, (target-player->y)/40.0);
 524             } else if( player->y > target) {
 525                 player->y -= fmin( fact, (player->y-target)/40.0);
 526             }
 527         }
 528     } else {/*
 529         if( player->desire == DESIRE_NORMAL) {
 530             if( !IS_NEAR_Y_AI( player->y, target)) {
 531                 player->y += (target - player->y)/40.0;
 532             }
 533         }*/
 534     }
 535 }
 536
 537 void game_setup_serve( GameState* s) {
 538     s->ball.jump = 7.5;
 539     s->ball.y = GAME_Y_MID;
 540     s->ball.move_x = 0.0;
 541     s->ball.move_y = 0.0;
 542
 543     if( s->player1_serves) {
 544         s->player1.responsible = true;
 545         s->player1.ball_dest = 0.0;
 546         s->ball.x = GAME_X_MIN-RACKET_X_MID*1.5;
 547     } else {
 548         s->player1.responsible = false;
 549         s->player2.ball_dest = 0.0;
 550         s->ball.x = GAME_X_MAX+RACKET_X_MID*1.5;
 551     }
 552
 553     s->player2.responsible = !(s->player1.responsible);
 554 }
 555
 556 float ngram_predictor( GameState* s) {
 557     unsigned int count = 0;
 558     unsigned long sum = 0;
 559     int x, y, z;
 560     float result;
 561
 562     if( s->history_size < 3) {
 563         return 0.0;
 564     }
 565
 566     x = s->history[1];
 567     y = s->history[2];
 568
 569     for( z = 0; z<NGRAM_STEPS; z++) {
 570         count += s->ngram[x][y][z];
 571         sum += z * s->ngram[x][y][z];
 572     }
 573
 574     result = ((float)(sum))/((float)(count));
 575 #ifdef DEBUG
 576     printf( "predicting next = %.2f\n", result);
 577 #endif
 578
 579     return result;
 580 }
 581
 582 void score_game( GameState* s, bool player1_scored) {
 583     Player* winner = (player1_scored)?(&(s->player1)):(&(s->player2));
 584     Player* loser = (player1_scored)?(&(s->player2)):(&(s->player1));
 585
 586     if( s->current_set >= SETS_TO_WIN*2-1) {
 587         return;
 588     }
 589
 590     winner->game++;
 591     if( loser->game < winner->game-1) {
 592         if( winner->game >= 4) {
 593             winner->game = loser->game = 0;
 594             winner->sets[s->current_set]++;
 595             /* scoring the set.. */
 596             if( (winner->sets[s->current_set] == 6 && loser->sets[s->current_set] < 5) ||
 597                 winner->sets[s->current_set] == 7) {
 598                 s->current_set++;
 599                 s->winner = game_get_winner( s);
 600             }
 601         }
 602     }
 603 }
 604
 605 char* format_sets( GameState* s) {
 606     static char sets[100];
 607     static char tmp[100];
 608     int i, max = s->current_set;
 609
 610     sets[0] = '\0';
 611
 612     if( s->winner != WINNER_NONE) {
 613         max--;
 614     }
 615     for( i=0; i<=max; i++) {
 616         sprintf( tmp, "%d:%d, ", s->player1.sets[i], s->player2.sets[i]);
 617         strcat( sets, tmp);
 618     }
 619
 620     sets[strlen(sets)-2] = '\0';
 621
 622     return sets;
 623 }
 624
 625 char* format_game( GameState* s) {
 626     static char game[100];
 627     static const int game_scoring[] = { 0, 15, 30, 40 };
 628
 629     if( s->player1.game < 4 && s->player2.game < 4) {
 630         sprintf( game, "%d - %d", game_scoring[s->player1.game], game_scoring[s->player2.game]);
 631     } else if( s->player1.game > s->player2.game) {
 632         strcpy( game, "advantage player 1");
 633     } else if( s->player1.game < s->player2.game) {
 634         strcpy( game, "advantage player 2");
 635     } else {
 636         strcpy( game, "deuce");
 637     }
 638
 639     return game;
 640 }
 641
 642 char* format_status( GameState* s) {
 643     static char status[100];
 644     static const char* set_names[] = { "first", "second", "third", "fourth", "fifth" };
 645
 646     sprintf( status, "%d:%d in %s set", s->player1.sets[s->current_set], s->player2.sets[s->current_set], set_names[s->current_set]);
 647
 648     return status;
 649 }
 650
 651 int game_get_winner( GameState* s) {
 652     int i;
 653     int sets[2] = {0};
 654
 655     for( i=0; i<s->current_set; i++) {
 656         if( s->player1.sets[i] > s->player2.sets[i]) {
 657             sets[0]++;
 658         } else {
 659             sets[1]++;
 660         }
 661     }
 662
 663     if( sets[0] == SETS_TO_WIN) return WINNER_PLAYER1;
 664     if( sets[1] == SETS_TO_WIN) return WINNER_PLAYER2;
 665
 666     return WINNER_NONE;
 667 }
 668