game.c

   1
   2 /**
   3  *
   4  * Tennix! SDL Port
   5  * Copyright (C) 2003, 2007, 2008 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
  34 GameState *gamestate_new() {
  35     int x, y, z;
  36     GameState *s;
  37
  38     GameState template = {
  39         { 0, 0, 0.0, 0.0, 0.0 },
  40         { 0, 0, 0, 0, 0 },
  41         { GAME_X_MIN-RACKET_X_MID*2, GAME_Y_MID, 0, 0, 1, DESIRE_NORMAL, PLAYER_TYPE_HUMAN, GAME_Y_MID, false, 0, {0}, 0, 0, PLAYER_ACCEL_DEFAULT, true },
  42         { GAME_X_MAX+RACKET_X_MID*2, GAME_Y_MID, 0, 0, 0, DESIRE_NORMAL, PLAYER_TYPE_AI, GAME_Y_MID, false, 0, {0}, 0, 0, PLAYER_ACCEL_DEFAULT, true },
  43         0,
  44         0,
  45         0,
  46         true,
  47         "welcome to tennix " VERSION,
  48         { 0 },
  49         { 0 },
  50         REFEREE_NORMAL,
  51         0,
  52         WINNER_NONE,
  53         false,
  54         GR_CTT_GRASS,
  55         -1,
  56         { 0 },
  57         0,
  58         false,
  59         { { { 0 } } },
  60         0.0,
  61         SOUND_MAX,
  62         0.0,
  63         0.0,
  64         0,
  65         0
  66     };
  67
  68     s = (GameState*)malloc(sizeof(GameState));
  69     if (s == NULL) abort();
  70
  71     memcpy(s, &template, sizeof(GameState));
  72
  73     game_setup_serve(s);
  74
  75     /* smoothen n-gram */
  76     for( x = 0; x<NGRAM_STEPS; x++) {
  77         for( y = 0; y<NGRAM_STEPS; y++) {
  78             for( z = 0; z<NGRAM_STEPS; z++) {
  79                 s->ngram[x][y][z] = 1;
  80             }
  81         }
  82     }
  83
  84     return s;
  85 }
  86
  87
  88 void gameloop(GameState *s) {
  89     strcpy(s->game_score_str, format_game(s));
  90     strcpy(s->sets_score_str, format_sets(s));
  91
  92     Uint32 ot = SDL_GetTicks();
  93     Uint32 nt;
  94     Uint32 dt = GAME_TICKS;
  95     Uint32 diff;
  96     Uint32 accumulator = 0;
  97     bool quit = false;
  98
  99 #ifdef ENABLE_FPS_LIMIT
 100     Uint32 ft, frames; /* frame timer and frames */
 101 #endif
 102
 103     play_sample_loop(SOUND_AUDIENCE);
 104     /* Reset the court type, so it is redrawn on first display */
 105     s->old_court_type = -1;
 106
 107 #ifdef ENABLE_FPS_LIMIT
 108     frames = 0;
 109     ft = SDL_GetTicks();
 110 #endif
 111     while( !quit) {
 112         nt = SDL_GetTicks();
 113         diff = nt-ot;
 114         if( diff > 2000) {
 115             diff = 0;
 116         }
 117
 118         accumulator += diff;
 119         ot = nt;
 120
 121         while( accumulator >= dt) {
 122             quit = step(s);
 123             s->time += dt;
 124             accumulator -= dt;
 125
 126             if( s->was_stopped) {
 127                 ot = SDL_GetTicks();
 128                 s->was_stopped = false;
 129             }
 130         }
 131
 132 #ifdef ENABLE_FPS_LIMIT
 133         while (frames*1000.0/((float)(SDL_GetTicks()-ft+1))>(float)(DEFAULT_FPS)) {
 134             SDL_Delay(10);
 135         }
 136         frames++;
 137 #endif
 138
 139         render(s);
 140     }
 141
 142     clear_screen();
 143     store_screen();
 144
 145     stop_sample(SOUND_AUDIENCE);
 146 }
 147
 148 bool step( GameState* s) {
 149     Uint8 *keys;
 150     SDL_Event e;
 151
 152     if( get_phase( s) < 1.0) {
 153         if( !s->ground.jump) {
 154             s->play_sound = SOUND_GROUND;
 155
 156             if( IS_OUT_Y( s->ball.y)) {
 157                 /* out - responsibilities stay the same */
 158                 s->status = "out!";
 159                 s->play_sound = SOUND_OUT;
 160                 s->referee = REFEREE_OUT;
 161             } else {
 162                 /* not out - responsibilities change */
 163                 s->player1.responsible = !(s->player2.responsible = !s->player2.responsible);
 164                 s->status = format_status( s);
 165                 s->referee = REFEREE_NORMAL;
 166             }
 167         }
 168         s->ground.jump = 3;
 169         s->ground.x = s->ball.x;
 170         s->ground.y = s->ball.y;
 171     } else {
 172         if( s->ground.jump && !(s->time%5)) s->ground.jump--;
 173     }
 174
 175     if( IS_OUT_X(s->ball.x) || IS_OFFSCREEN_Y(s->ball.y)) {
 176         if( IS_OFFSCREEN( s->ball.x, s->ball.y)) {
 177             s->player1_serves = s->player1.responsible;
 178
 179             score_game( s, s->player2.responsible);
 180             strcpy( s->game_score_str, format_game( s));
 181             strcpy( s->sets_score_str, format_sets( s));
 182
 183             if( s->player1.responsible) {
 184                 if( s->player1.type == PLAYER_TYPE_HUMAN && s->player2.type == PLAYER_TYPE_AI) {
 185                     s->status = "computer scores";
 186                 } else {
 187                     s->status = "player 2 scores";
 188                 }
 189                 s->referee = REFEREE_PLAYER2;
 190             } else {
 191                 if( s->player1.type == PLAYER_TYPE_HUMAN && s->player2.type == PLAYER_TYPE_AI) {
 192                     s->status = "player scores";
 193                 } else {
 194                     s->status = "player 1 scores";
 195                 }
 196                 s->referee = REFEREE_PLAYER1;
 197             }
 198
 199             game_setup_serve( s);
 200             s->play_sound = SOUND_APPLAUSE;
 201             SDL_Delay( 500);
 202             s->was_stopped = true;
 203             s->history_size = 0;
 204             s->history_is_locked = 0;
 205             s->ngram_prediction = 0.0;
 206 #ifdef DEBUG
 207             printf( "-- game reset --\n");
 208 #endif
 209         }
 210
 211         if( IS_OUT_X(s->ball.x)) {
 212             if( !s->history_is_locked && s->referee != REFEREE_OUT) {
 213                 s->history[s->history_size] = (int)(NGRAM_STEPS*s->ball.y/HEIGHT);
 214                 s->history_size++;
 215                 if( s->history_size == 3) {
 216                     s->ngram[s->history[0]][s->history[1]][s->history[2]] += 10;
 217 #ifdef DEBUG
 218                     printf( "history: %d, %d, %d\n", s->history[0], s->history[1], s->history[2]);
 219 #endif
 220                     s->ngram_prediction = ngram_predictor( s);
 221                     s->history[0] = s->history[1];
 222                     s->history[1] = s->history[2];
 223                     s->history_size--;
 224                 }
 225                 s->history_is_locked = true;
 226             }
 227             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) {
 228                 s->ball.x = GAME_X_MIN;
 229                 if( s->player1.state == PLAYER_STATE_MAX) {
 230                     s->ball.move_x = PLAYER_POWERSHOT;
 231                 } else {
 232                     s->ball.move_x = 2.5 + 2.0*s->player1.state/PLAYER_STATE_MAX;
 233                 }
 234                 s->ball.move_y = get_move_y( s, 1);
 235                 s->player2.responsible = !(s->player1.responsible = 1);
 236                 s->ball.jump += 1.0-2.0*(s->player1.state<5);
 237                 s->play_sound = SOUND_RACKET;
 238                 pan_sample(SOUND_RACKET, 0.4);
 239             } 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) {
 240                 s->ball.x = GAME_X_MAX;
 241                 if( s->player2.state == PLAYER_STATE_MAX) {
 242                     s->ball.move_x = -PLAYER_POWERSHOT;
 243                 } else {
 244                     s->ball.move_x = -(2.5 + 2.0*s->player2.state/PLAYER_STATE_MAX);
 245                 }
 246                 s->ball.move_y = get_move_y( s, 2);
 247                 s->player1.responsible = !(s->player2.responsible = 1);
 248                 s->ball.jump += 1.0-2.0*(s->player2.state<5);
 249                 s->play_sound = SOUND_RACKET;
 250                 pan_sample(SOUND_RACKET, 0.6);
 251             }
 252         }
 253     } else {
 254         s->history_is_locked = false;
 255     }
 256
 257     SDL_PollEvent( &e);
 258     keys = SDL_GetKeyState( NULL);
 259     switch(e.type) {
 260         case SDL_JOYAXISMOTION:
 261             if (e.jaxis.axis == JOYSTICK_Y_AXIS) {
 262                 s->joystick_y = JOYSTICK_PERCENTIZE(e.jaxis.value);
 263             } else if (e.jaxis.axis == JOYSTICK_X_AXIS) {
 264                 s->joystick_x = JOYSTICK_PERCENTIZE(e.jaxis.value);
 265             }
 266             break;
 267         case SDL_JOYBUTTONUP: case SDL_JOYBUTTONDOWN:
 268             if (e.jbutton.button == JOYSTICK_BUTTON_A) {
 269                 s->joystick_a = (e.jbutton.state == SDL_PRESSED);
 270             }
 271             break;
 272     }
 273
 274     if( s->time%50==0) {
 275         /**
 276          * Maemo keys:
 277          * F7 = "Decrease" key
 278          * F8 = "Increase" key
 279          **/
 280         if (keys['c'] || keys[SDLK_F8]) {
 281             s->court_type++;
 282         } else if (keys[SDLK_F7]) {
 283             s->court_type--;
 284         }
 285         if (keys['r']) {
 286             s->rain += 10;
 287         }
 288         if( s->court_type > GR_CTT_LAST) {
 289             s->court_type = GR_CTT_FIRST;
 290         } else if (s->court_type < GR_CTT_FIRST) {
 291             s->court_type = GR_CTT_LAST;
 292         }
 293     }
 294
 295     if( !is_fading() && !s->is_over) {
 296         if( s->player1.type == PLAYER_TYPE_HUMAN) {
 297            input_human( &s->player1,
 298                    keys['w'] || keys[SDLK_UP] || s->joystick_y < -JOYSTICK_TRESHOLD,
 299                    keys['s'] || keys[SDLK_DOWN] || s->joystick_y > JOYSTICK_TRESHOLD,
 300                    keys['d'] || keys[SDLK_SPACE] || keys[SDLK_LCTRL] || keys[SDLK_RETURN] || s->joystick_a,
 301 #ifdef ENABLE_MOUSE
 302                    true,
 303 #else
 304                    false,
 305 #endif
 306                    s);
 307         } else {
 308             input_ai( &s->player1, &s->ball, &s->player2, s);
 309         }
 310
 311         if( s->player2.type == PLAYER_TYPE_HUMAN) {
 312             input_human( &s->player2, keys['o'], keys['l'], keys['k'], false, s);
 313         } else {
 314             input_ai( &s->player2, &s->ball, &s->player1, s);
 315         }
 316     }
 317
 318     /* Maemo: The "F6" button is the "Fullscreen" button */
 319     if( keys['f'] || keys[SDLK_F6]) SDL_WM_ToggleFullScreen( screen);
 320     if( keys['y']) SDL_SaveBMP( screen, "screenshot.bmp");
 321
 322     /* Maemo: The "F4" button is the "Open menu" button */
 323     if( keys['p'] || keys[SDLK_F4]) {
 324         while( keys['p'] || keys[SDLK_F4]) {
 325             SDL_PollEvent( &e);
 326             keys = SDL_GetKeyState( NULL);
 327             SDL_Delay( 10);
 328         }
 329         while( (keys['p'] || keys[SDLK_F4]) == 0) {
 330             SDL_PollEvent( &e);
 331             keys = SDL_GetKeyState( NULL);
 332             SDL_Delay( 10);
 333         }
 334         while( keys['p'] || keys[SDLK_F4]) {
 335             SDL_PollEvent( &e);
 336             keys = SDL_GetKeyState( NULL);
 337             SDL_Delay( 10);
 338         }
 339         s->was_stopped = true;
 340     }
 341
 342     if( keys[SDLK_ESCAPE] || keys['q']) return true;
 343
 344     limit_value( &s->player1.y, PLAYER_Y_MIN, PLAYER_Y_MAX);
 345     limit_value( &s->player2.y, PLAYER_Y_MIN, PLAYER_Y_MAX);
 346     limit_value( &s->ball.jump, BALL_JUMP_MIN, BALL_JUMP_MAX);
 347
 348     /* Update ball_dest for debugging purposes */
 349     get_move_y(s, 1);
 350     get_move_y(s, 2);
 351
 352     s->ball.x += s->ball.move_x;
 353     s->ball.y += s->ball.move_y;
 354
 355     if(s->player1.state) s->player1.state--;
 356     if(s->player2.state) s->player2.state--;
 357
 358     return false;
 359 }
 360
 361 void render( GameState* s) {
 362     int i, x, y;
 363     if (s->play_sound != SOUND_MAX) {
 364         play_sample(s->play_sound);
 365         s->play_sound = SOUND_MAX;
 366     }
 367     if( s->winner != WINNER_NONE) {
 368         if( !s->is_over) {
 369             start_fade();
 370             s->is_over = true;
 371         }
 372         clear_screen();
 373         store_screen();
 374         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);
 375         sprintf( s->game_score_str, "player %d wins the match with %s", s->winner, format_sets( s));
 376         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);
 377         updatescr();
 378         return;
 379     }
 380     if (s->old_court_type != s->court_type) {
 381         clear_screen();
 382         fill_image(s->court_type, 120, 120, 400, 250);
 383         show_image(GR_COURT, 0, 0, 255);
 384         s->old_court_type = s->court_type;
 385         store_screen();
 386     }
 387     show_sprite( GR_REFEREE, s->referee, 4, 250, 10, 255);
 388     show_image( GR_SHADOW, s->ball.x-BALL_X_MID, s->ball.y + get_phase( s) - BALL_Y_MID, 255);
 389
 390     show_sprite( GR_RACKET, (!s->player1.state), 4, s->player1.x-RACKET_X_MID, s->player1.y-RACKET_Y_MID, 255);
 391     show_sprite( GR_RACKET, (!s->player2.state)+2, 4, s->player2.x-RACKET_X_MID, s->player2.y-RACKET_Y_MID, 255);
 392
 393     if( s->ball.move_x > 0) {
 394         show_sprite( GR_BALL, (s->time/500)%4, 4, s->ball.x-BALL_X_MID, s->ball.y-BALL_Y_MID, 255);
 395     } else if( s->ball.move_x < 0) {
 396         show_sprite( GR_BALL, 3-(s->time/500)%4, 4, s->ball.x-BALL_X_MID, s->ball.y-BALL_Y_MID, 255);
 397     } else {
 398         show_sprite( GR_BALL, 0, 4, s->ball.x-BALL_X_MID, s->ball.y-BALL_Y_MID, 255);
 399     }
 400
 401     /* Player 1's mouse rectangle */
 402     if (!(s->player1.mouse_locked)) {
 403         rectangle(s->player1.x-2+5, s->player1.mouse_y-2, 4, 4, 255, 255, 255);
 404         rectangle(s->player1.x-1+5, s->player1.mouse_y-1, 2, 2, 0, 0, 0);
 405     }
 406
 407     font_draw_string( GR_DKC2_FONT, s->game_score_str, 14, 14, 0, ANIMATION_NONE);
 408     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);
 409
 410     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);
 411
 412     for (i=0; i<s->rain; i++) {
 413         x = rand()%WIDTH;
 414         y = rand()%HEIGHT;
 415         draw_line_faded(x, y, x+10, y+30, 0, 0, 255, 100, 200, 255);
 416     }
 417     if (s->rain) {
 418         /**
 419          * Cheap-ish update of the whole screen. This can
 420          * probably be optimized.
 421          **/
 422         update_rect(0, 0, WIDTH, HEIGHT);
 423     }
 424
 425 #ifdef DEBUG
 426     line_horiz( s->player1.y, 255, 0, 0);
 427     line_horiz( s->player2.y, 0, 0, 255);
 428     line_horiz( s->ball.y, 0, 255, 0);
 429
 430     line_vert( s->player1.x, 255, 0, 0);
 431     line_vert( s->player2.x, 0, 0, 255);
 432     line_vert( s->ball.x, 0, 255, 0);
 433
 434     line_horiz( s->player1.ball_dest, 255, 0, 255);
 435     line_horiz( s->player2.ball_dest, 0, 255, 255);
 436
 437     line_horiz( GAME_Y_MIN, 100, 100, 100);
 438     line_horiz( GAME_Y_MAX, 100, 100, 100);
 439 #endif
 440
 441     updatescr();
 442 }
 443
 444 void limit_value( float* value, float min, float max) {
 445     if( *value < min) {
 446         *value = min;
 447     } else if( *value > max) {
 448         *value = max;
 449     }
 450 }
 451
 452 float get_phase( GameState* s) {
 453     float pos, fract;
 454     float x, min, max, direction;
 455
 456     x = s->ball.x;
 457     min = GAME_X_MIN;
 458     max = GAME_X_MAX;
 459     direction = s->ball.move_x;
 460
 461     pos = (direction>0)?(1-GROUND_PHASE):(GROUND_PHASE);
 462
 463     fract = (x-min)/(max-min);
 464
 465     if( fract < pos) {
 466         fract = fract/pos;
 467         return fabsf( cosf(PI*fract/2))*PHASE_AMP*s->ball.jump;
 468     } else {
 469         fract = (pos-fract)/(1-pos);
 470         return fabsf( sinf(PI*fract/2))*PHASE_AMP*s->ball.jump;
 471     }
 472 }
 473
 474 float get_move_y( GameState* s, unsigned char player) {
 475     float pct, dest, x_len, y_len;
 476     float py, by, pa, move_x;
 477
 478     py = (player==1)?(s->player1.y):(s->player2.y);
 479     by = s->ball.y;
 480     pa = RACKET_Y_MID*2;
 481     move_x = s->ball.move_x;
 482
 483     /* -1.0 .. 1.0 for racket hit position */
 484     pct = (by-py)/(pa/2);
 485     limit_value( &pct, -1.0, 1.0);
 486
 487     /* Y destination for ball */
 488     dest = GAME_Y_MID + pct*(GAME_Y_MAX-GAME_Y_MIN);
 489     if( player == 1) {
 490         s->player1.ball_dest = dest;
 491     } else {
 492         s->player2.ball_dest = dest;
 493     }
 494
 495     /* lengths for the ball's journey */
 496     if( player == 1) {
 497         x_len = fabsf(GAME_X_MAX - s->ball.x);
 498         y_len = dest - by + MOVE_Y_SEED-rand()%MOVE_Y_SEED*2;
 499     } else {
 500         x_len = s->ball.x - GAME_X_MIN;
 501         y_len = by - dest + MOVE_Y_SEED-rand()%MOVE_Y_SEED*2;
 502     }
 503
 504     /* return the should-be value for move_y */
 505     return (y_len*move_x)/(x_len);
 506 }
 507
 508 void input_human( Player* player, bool up, bool down, bool hit, bool use_mouse, GameState* s) {
 509     int diff = PLAYER_MOVE_Y;
 510     int mb;
 511
 512     /**
 513      * Only use mouse control if the user isn't pressing any buttons
 514      * this way, keyboard control still works when mouse control is
 515      * enabled.
 516      **/
 517     if (use_mouse && (down || up || hit)) {
 518         /**
 519          * this is here so if the user decides to play
 520          * with keyboard controls, we will lock the
 521          * mouse and disable displaying the mouse cursor
 522          **/
 523         player->mouse_locked = true;
 524     }
 525     if (use_mouse && !down && !up && !hit) {
 526         mb = SDL_GetMouseState(&(player->mouse_x), &(player->mouse_y));
 527         if (mb&SDL_BUTTON(SDL_BUTTON_LEFT)) {
 528             if (player->mouse_y < player->y) {
 529                 down = false;
 530                 up = true;
 531                 diff = (player->y-player->mouse_y<diff)?(player->y-player->mouse_y):(diff);
 532             } else if (player->mouse_y > player->y) {
 533                 up = false;
 534                 down = true;
 535                 diff = (player->mouse_y-player->y<diff)?(player->mouse_y-player->y):(diff);
 536             }
 537             player->mouse_locked = false;
 538         } else if (!player->mouse_locked) {
 539             hit = true;
 540         }
 541     }
 542
 543     if (fabsf(s->joystick_y) > JOYSTICK_TRESHOLD) {
 544         diff = PLAYER_MOVE_Y*fabsf(s->joystick_y)/40.0;
 545         if (diff > PLAYER_MOVE_Y) {
 546             diff = PLAYER_MOVE_Y;
 547         }
 548     }
 549
 550     if (up) {
 551         player->y -= fminf(diff, diff*player->accelerate);
 552         player->accelerate *= PLAYER_ACCEL_INCREASE;
 553     } else if (down) {
 554         player->y += fminf(diff, diff*player->accelerate);
 555         player->accelerate *= PLAYER_ACCEL_INCREASE;
 556     } else {
 557         player->accelerate = PLAYER_ACCEL_DEFAULT;
 558     }
 559
 560     if( hit) {
 561         if( !player->state && !player->state_locked) {
 562             player->state = PLAYER_STATE_MAX;
 563             player->state_locked = true;
 564         }
 565     } else {
 566         player->state_locked = false;
 567     }
 568 }
 569
 570 void input_ai( Player* player, Ball* ball, Player* opponent, GameState* s) {
 571     float fact = 1.7;
 572     float target;
 573
 574     if( fabsf( player->y - ball->y) > RACKET_Y_MID*5) {
 575         fact = 3.5;
 576     }
 577
 578     target = GAME_Y_MID + (opponent->ball_dest - GAME_Y_MID)/5;
 579
 580     if( player->responsible) {
 581         if( player->desire == DESIRE_NORMAL && !IS_NEAR_Y_AI( player->y, ball->y)) {
 582             if( player->y < ball->y) {
 583                 player->y += fmin( 2*fact, ball->y - player->y);
 584             } else if( player->y > ball->y) {
 585                 player->y -= fmin( 2*fact, player->y - ball->y);
 586             }
 587         }
 588
 589         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) {
 590             player->state = PLAYER_STATE_MAX;
 591         }
 592     } else if( ball->move_x == 0) {
 593         if( player->desire == DESIRE_NORMAL && !IS_NEAR_Y_AI( player->y, target)) {
 594             if( player->y < target) {
 595                 player->y += fmin( fact, (target-player->y)/40.0);
 596             } else if( player->y > target) {
 597                 player->y -= fmin( fact, (player->y-target)/40.0);
 598             }
 599         }
 600     } else if( s->ngram_prediction > 0.0) {
 601         target = s->ngram_prediction*((float)HEIGHT)/((float)(NGRAM_STEPS));
 602         target = GAME_Y_MID + (target-GAME_Y_MID)*1.5;
 603
 604         if( player->desire == DESIRE_NORMAL && !IS_NEAR_Y_AI( player->y, target)) {
 605             if( player->y < target) {
 606                 player->y += fmin( fact, (target-player->y)/40.0);
 607             } else if( player->y > target) {
 608                 player->y -= fmin( fact, (player->y-target)/40.0);
 609             }
 610         }
 611     } else {/*
 612         if( player->desire == DESIRE_NORMAL) {
 613             if( !IS_NEAR_Y_AI( player->y, target)) {
 614                 player->y += (target - player->y)/40.0;
 615             }
 616         }*/
 617     }
 618 }
 619
 620 void game_setup_serve( GameState* s) {
 621     s->ball.jump = 7.5;
 622     s->ball.y = GAME_Y_MID;
 623     s->ball.move_x = 0.0;
 624     s->ball.move_y = 0.0;
 625
 626     if( s->player1_serves) {
 627         s->player1.responsible = true;
 628         s->player1.ball_dest = 0.0;
 629         s->ball.x = GAME_X_MIN-RACKET_X_MID*1.5;
 630     } else {
 631         s->player1.responsible = false;
 632         s->player2.ball_dest = 0.0;
 633         s->ball.x = GAME_X_MAX+RACKET_X_MID*1.5;
 634     }
 635
 636     s->player2.responsible = !(s->player1.responsible);
 637 }
 638
 639 float ngram_predictor( GameState* s) {
 640     unsigned int count = 0;
 641     unsigned long sum = 0;
 642     int x, y, z;
 643     float result;
 644
 645     if( s->history_size < 3) {
 646         return 0.0;
 647     }
 648
 649     x = s->history[1];
 650     y = s->history[2];
 651
 652     for( z = 0; z<NGRAM_STEPS; z++) {
 653         count += s->ngram[x][y][z];
 654         sum += z * s->ngram[x][y][z];
 655     }
 656
 657     result = ((float)(sum))/((float)(count));
 658 #ifdef DEBUG
 659     printf( "predicting next = %.2f\n", result);
 660 #endif
 661
 662     return result;
 663 }
 664
 665 void score_game( GameState* s, bool player1_scored) {
 666     Player* winner = (player1_scored)?(&(s->player1)):(&(s->player2));
 667     Player* loser = (player1_scored)?(&(s->player2)):(&(s->player1));
 668
 669     if( s->current_set >= SETS_TO_WIN*2-1) {
 670         return;
 671     }
 672
 673     winner->game++;
 674     if( loser->game < winner->game-1) {
 675         if( winner->game >= 4) {
 676             winner->game = loser->game = 0;
 677             winner->sets[s->current_set]++;
 678             /* scoring the set.. */
 679             if( (winner->sets[s->current_set] == 6 && loser->sets[s->current_set] < 5) ||
 680                 winner->sets[s->current_set] == 7) {
 681                 s->current_set++;
 682                 s->winner = game_get_winner( s);
 683             }
 684         }
 685     }
 686 }
 687
 688 char* format_sets( GameState* s) {
 689     static char sets[100];
 690     static char tmp[100];
 691     int i, max = s->current_set;
 692
 693     sets[0] = '\0';
 694
 695     if( s->winner != WINNER_NONE) {
 696         max--;
 697     }
 698     for( i=0; i<=max; i++) {
 699         sprintf( tmp, "%d:%d, ", s->player1.sets[i], s->player2.sets[i]);
 700         strcat( sets, tmp);
 701     }
 702
 703     sets[strlen(sets)-2] = '\0';
 704
 705     return sets;
 706 }
 707
 708 char* format_game( GameState* s) {
 709     static char game[100];
 710     static const int game_scoring[] = { 0, 15, 30, 40 };
 711
 712     if( s->player1.game < 4 && s->player2.game < 4) {
 713         sprintf( game, "%d - %d", game_scoring[s->player1.game], game_scoring[s->player2.game]);
 714     } else if( s->player1.game > s->player2.game) {
 715         strcpy( game, "advantage player 1");
 716     } else if( s->player1.game < s->player2.game) {
 717         strcpy( game, "advantage player 2");
 718     } else {
 719         strcpy( game, "deuce");
 720     }
 721
 722     return game;
 723 }
 724
 725 char* format_status( GameState* s) {
 726     static char status[100];
 727     static const char* set_names[] = { "first", "second", "third", "fourth", "fifth" };
 728
 729     sprintf( status, "%d:%d in %s set", s->player1.sets[s->current_set], s->player2.sets[s->current_set], set_names[s->current_set]);
 730
 731     return status;
 732 }
 733
 734 int game_get_winner( GameState* s) {
 735     int i;
 736     int sets[2] = {0};
 737
 738     for( i=0; i<s->current_set; i++) {
 739         if( s->player1.sets[i] > s->player2.sets[i]) {
 740             sets[0]++;
 741         } else {
 742             sets[1]++;
 743         }
 744     }
 745
 746     if( sets[0] == SETS_TO_WIN) return WINNER_PLAYER1;
 747     if( sets[1] == SETS_TO_WIN) return WINNER_PLAYER2;
 748
 749     return WINNER_NONE;
 750 }
 751