src/joystick/SDL_joystick.c

   1 /*
   2     SDL - Simple DirectMedia Layer
   3     Copyright (C) 1997-2006 Sam Lantinga
   4
   5     This library is free software; you can redistribute it and/or
   6     modify it under the terms of the GNU Lesser General Public
   7     License as published by the Free Software Foundation; either
   8     version 2.1 of the License, or (at your option) any later version.
   9
  10     This library is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13     Lesser General Public License for more details.
  14
  15     You should have received a copy of the GNU Lesser General Public
  16     License along with this library; if not, write to the Free Software
  17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18
  19     Sam Lantinga
  20     slouken@libsdl.org
  21 */
  22 #include "SDL_config.h"
  23
  24 /* This is the joystick API for Simple DirectMedia Layer */
  25
  26 #include "SDL_events.h"
  27 #include "SDL_sysjoystick.h"
  28 #include "SDL_joystick_c.h"
  29 #if !SDL_EVENTS_DISABLED
  30 #include "../events/SDL_events_c.h"
  31 #endif
  32
  33 /* This is used for Quake III Arena */
  34 #if SDL_EVENTS_DISABLED
  35 #define SDL_Lock_EventThread()
  36 #define SDL_Unlock_EventThread()
  37 #endif
  38
  39 Uint8 SDL_numjoysticks = 0;
  40 SDL_Joystick **SDL_joysticks = NULL;
  41 static SDL_Joystick *default_joystick = NULL;
  42
  43 int SDL_JoystickInit(void)
  44 {
  45         int arraylen;
  46         int status;
  47
  48         SDL_numjoysticks = 0;
  49         status = SDL_SYS_JoystickInit();
  50         if ( status >= 0 ) {
  51                 arraylen = (status+1)*sizeof(*SDL_joysticks);
  52                 SDL_joysticks = (SDL_Joystick **)SDL_malloc(arraylen);
  53                 if ( SDL_joysticks == NULL ) {
  54                         SDL_numjoysticks = 0;
  55                 } else {
  56                         SDL_memset(SDL_joysticks, 0, arraylen);
  57                         SDL_numjoysticks = status;
  58                 }
  59                 status = 0;
  60         }
  61         default_joystick = NULL;
  62         return(status);
  63 }
  64
  65 /*
  66  * Count the number of joysticks attached to the system
  67  */
  68 int SDL_NumJoysticks(void)
  69 {
  70         return SDL_numjoysticks;
  71 }
  72
  73 /*
  74  * Get the implementation dependent name of a joystick
  75  */
  76 const char *SDL_JoystickName(int device_index)
  77 {
  78         if ( (device_index < 0) || (device_index >= SDL_numjoysticks) ) {
  79                 SDL_SetError("There are %d joysticks available",
  80                              SDL_numjoysticks);
  81                 return(NULL);
  82         }
  83         return(SDL_SYS_JoystickName(device_index));
  84 }
  85
  86 /*
  87  * Open a joystick for use - the index passed as an argument refers to
  88  * the N'th joystick on the system.  This index is the value which will
  89  * identify this joystick in future joystick events.
  90  *
  91  * This function returns a joystick identifier, or NULL if an error occurred.
  92  */
  93 SDL_Joystick *SDL_JoystickOpen(int device_index)
  94 {
  95         int i;
  96         SDL_Joystick *joystick;
  97
  98         if ( (device_index < 0) || (device_index >= SDL_numjoysticks) ) {
  99                 SDL_SetError("There are %d joysticks available",
 100                              SDL_numjoysticks);
 101                 return(NULL);
 102         }
 103
 104         /* If the joystick is already open, return it */
 105         for ( i=0; SDL_joysticks[i]; ++i ) {
 106                 if ( device_index == SDL_joysticks[i]->index ) {
 107                         joystick = SDL_joysticks[i];
 108                         ++joystick->ref_count;
 109                         return(joystick);
 110                 }
 111         }
 112
 113         /* Create and initialize the joystick */
 114         joystick = (SDL_Joystick *)SDL_malloc((sizeof *joystick));
 115         if ( joystick != NULL ) {
 116                 SDL_memset(joystick, 0, (sizeof *joystick));
 117                 joystick->index = device_index;
 118                 if ( SDL_SYS_JoystickOpen(joystick) < 0 ) {
 119                         SDL_free(joystick);
 120                         joystick = NULL;
 121                 } else {
 122                         if ( joystick->naxes > 0 ) {
 123                                 joystick->axes = (Sint16 *)SDL_malloc
 124                                         (joystick->naxes*sizeof(Sint16));
 125                         }
 126                         if ( joystick->nhats > 0 ) {
 127                                 joystick->hats = (Uint8 *)SDL_malloc
 128                                         (joystick->nhats*sizeof(Uint8));
 129                         }
 130                         if ( joystick->nballs > 0 ) {
 131                                 joystick->balls = (struct balldelta *)SDL_malloc
 132                                   (joystick->nballs*sizeof(*joystick->balls));
 133                         }
 134                         if ( joystick->nbuttons > 0 ) {
 135                                 joystick->buttons = (Uint8 *)SDL_malloc
 136                                         (joystick->nbuttons*sizeof(Uint8));
 137                         }
 138                         if ( ((joystick->naxes > 0) && !joystick->axes)
 139                           || ((joystick->nhats > 0) && !joystick->hats)
 140                           || ((joystick->nballs > 0) && !joystick->balls)
 141                           || ((joystick->nbuttons > 0) && !joystick->buttons)) {
 142                                 SDL_OutOfMemory();
 143                                 SDL_JoystickClose(joystick);
 144                                 joystick = NULL;
 145                         }
 146                         if ( joystick->axes ) {
 147                                 SDL_memset(joystick->axes, 0,
 148                                         joystick->naxes*sizeof(Sint16));
 149                         }
 150                         if ( joystick->hats ) {
 151                                 SDL_memset(joystick->hats, 0,
 152                                         joystick->nhats*sizeof(Uint8));
 153                         }
 154                         if ( joystick->balls ) {
 155                                 SDL_memset(joystick->balls, 0,
 156                                   joystick->nballs*sizeof(*joystick->balls));
 157                         }
 158                         if ( joystick->buttons ) {
 159                                 SDL_memset(joystick->buttons, 0,
 160                                         joystick->nbuttons*sizeof(Uint8));
 161                         }
 162                 }
 163         }
 164         if ( joystick ) {
 165                 /* Add joystick to list */
 166                 ++joystick->ref_count;
 167                 SDL_Lock_EventThread();
 168                 for ( i=0; SDL_joysticks[i]; ++i )
 169                         /* Skip to next joystick */;
 170                 SDL_joysticks[i] = joystick;
 171                 SDL_Unlock_EventThread();
 172         }
 173         return(joystick);
 174 }
 175
 176 /*
 177  * Returns 1 if the joystick has been opened, or 0 if it has not.
 178  */
 179 int SDL_JoystickOpened(int device_index)
 180 {
 181         int i, opened;
 182
 183         opened = 0;
 184         for ( i=0; SDL_joysticks[i]; ++i ) {
 185                 if ( SDL_joysticks[i]->index == (Uint8)device_index ) {
 186                         opened = 1;
 187                         break;
 188                 }
 189         }
 190         return(opened);
 191 }
 192
 193 static int ValidJoystick(SDL_Joystick **joystick)
 194 {
 195         int valid;
 196
 197         if ( *joystick == NULL ) {
 198                 *joystick = default_joystick;
 199         }
 200         if ( *joystick == NULL ) {
 201                 SDL_SetError("Joystick hasn't been opened yet");
 202                 valid = 0;
 203         } else {
 204                 valid = 1;
 205         }
 206         return valid;
 207 }
 208
 209 /*
 210  * Get the device index of an opened joystick.
 211  */
 212 int SDL_JoystickIndex(SDL_Joystick *joystick)
 213 {
 214         if ( ! ValidJoystick(&joystick) ) {
 215                 return(-1);
 216         }
 217         return(joystick->index);
 218 }
 219
 220 /*
 221  * Get the number of multi-dimensional axis controls on a joystick
 222  */
 223 int SDL_JoystickNumAxes(SDL_Joystick *joystick)
 224 {
 225         if ( ! ValidJoystick(&joystick) ) {
 226                 return(-1);
 227         }
 228         return(joystick->naxes);
 229 }
 230
 231 /*
 232  * Get the number of hats on a joystick
 233  */
 234 int SDL_JoystickNumHats(SDL_Joystick *joystick)
 235 {
 236         if ( ! ValidJoystick(&joystick) ) {
 237                 return(-1);
 238         }
 239         return(joystick->nhats);
 240 }
 241
 242 /*
 243  * Get the number of trackballs on a joystick
 244  */
 245 int SDL_JoystickNumBalls(SDL_Joystick *joystick)
 246 {
 247         if ( ! ValidJoystick(&joystick) ) {
 248                 return(-1);
 249         }
 250         return(joystick->nballs);
 251 }
 252
 253 /*
 254  * Get the number of buttons on a joystick
 255  */
 256 int SDL_JoystickNumButtons(SDL_Joystick *joystick)
 257 {
 258         if ( ! ValidJoystick(&joystick) ) {
 259                 return(-1);
 260         }
 261         return(joystick->nbuttons);
 262 }
 263
 264 /*
 265  * Get the current state of an axis control on a joystick
 266  */
 267 Sint16 SDL_JoystickGetAxis(SDL_Joystick *joystick, int axis)
 268 {
 269         Sint16 state;
 270
 271         if ( ! ValidJoystick(&joystick) ) {
 272                 return(0);
 273         }
 274         if ( axis < joystick->naxes ) {
 275                 state = joystick->axes[axis];
 276         } else {
 277                 SDL_SetError("Joystick only has %d axes", joystick->naxes);
 278                 state = 0;
 279         }
 280         return(state);
 281 }
 282
 283 /*
 284  * Get the current state of a hat on a joystick
 285  */
 286 Uint8 SDL_JoystickGetHat(SDL_Joystick *joystick, int hat)
 287 {
 288         Uint8 state;
 289
 290         if ( ! ValidJoystick(&joystick) ) {
 291                 return(0);
 292         }
 293         if ( hat < joystick->nhats ) {
 294                 state = joystick->hats[hat];
 295         } else {
 296                 SDL_SetError("Joystick only has %d hats", joystick->nhats);
 297                 state = 0;
 298         }
 299         return(state);
 300 }
 301
 302 /*
 303  * Get the ball axis change since the last poll
 304  */
 305 int SDL_JoystickGetBall(SDL_Joystick *joystick, int ball, int *dx, int *dy)
 306 {
 307         int retval;
 308
 309         if ( ! ValidJoystick(&joystick) ) {
 310                 return(-1);
 311         }
 312
 313         retval = 0;
 314         if ( ball < joystick->nballs ) {
 315                 if ( dx ) {
 316                         *dx = joystick->balls[ball].dx;
 317                 }
 318                 if ( dy ) {
 319                         *dy = joystick->balls[ball].dy;
 320                 }
 321                 joystick->balls[ball].dx = 0;
 322                 joystick->balls[ball].dy = 0;
 323         } else {
 324                 SDL_SetError("Joystick only has %d balls", joystick->nballs);
 325                 retval = -1;
 326         }
 327         return(retval);
 328 }
 329
 330 /*
 331  * Get the current state of a button on a joystick
 332  */
 333 Uint8 SDL_JoystickGetButton(SDL_Joystick *joystick, int button)
 334 {
 335         Uint8 state;
 336
 337         if ( ! ValidJoystick(&joystick) ) {
 338                 return(0);
 339         }
 340         if ( button < joystick->nbuttons ) {
 341                 state = joystick->buttons[button];
 342         } else {
 343                 SDL_SetError("Joystick only has %d buttons",joystick->nbuttons);
 344                 state = 0;
 345         }
 346         return(state);
 347 }
 348
 349 /*
 350  * Close a joystick previously opened with SDL_JoystickOpen()
 351  */
 352 void SDL_JoystickClose(SDL_Joystick *joystick)
 353 {
 354         int i;
 355
 356         if ( ! ValidJoystick(&joystick) ) {
 357                 return;
 358         }
 359
 360         /* First decrement ref count */
 361         if ( --joystick->ref_count > 0 ) {
 362                 return;
 363         }
 364
 365         /* Lock the event queue - prevent joystick polling */
 366         SDL_Lock_EventThread();
 367
 368         if ( joystick == default_joystick ) {
 369                 default_joystick = NULL;
 370         }
 371         SDL_SYS_JoystickClose(joystick);
 372
 373         /* Remove joystick from list */
 374         for ( i=0; SDL_joysticks[i]; ++i ) {
 375                 if ( joystick == SDL_joysticks[i] ) {
 376                         SDL_memcpy(&SDL_joysticks[i], &SDL_joysticks[i+1],
 377                                (SDL_numjoysticks-i)*sizeof(joystick));
 378                         break;
 379                 }
 380         }
 381
 382         /* Let the event thread keep running */
 383         SDL_Unlock_EventThread();
 384
 385         /* Free the data associated with this joystick */
 386         if ( joystick->axes ) {
 387                 SDL_free(joystick->axes);
 388         }
 389         if ( joystick->hats ) {
 390                 SDL_free(joystick->hats);
 391         }
 392         if ( joystick->balls ) {
 393                 SDL_free(joystick->balls);
 394         }
 395         if ( joystick->buttons ) {
 396                 SDL_free(joystick->buttons);
 397         }
 398         SDL_free(joystick);
 399 }
 400
 401 void SDL_JoystickQuit(void)
 402 {
 403         /* Stop the event polling */
 404         SDL_Lock_EventThread();
 405         SDL_numjoysticks = 0;
 406         SDL_Unlock_EventThread();
 407
 408         /* Quit the joystick setup */
 409         SDL_SYS_JoystickQuit();
 410         if ( SDL_joysticks ) {
 411                 SDL_free(SDL_joysticks);
 412                 SDL_joysticks = NULL;
 413         }
 414 }
 415
 416
 417 /* These are global for SDL_sysjoystick.c and SDL_events.c */
 418
 419 int SDL_PrivateJoystickAxis(SDL_Joystick *joystick, Uint8 axis, Sint16 value)
 420 {
 421         int posted;
 422
 423         /* Update internal joystick state */
 424         joystick->axes[axis] = value;
 425
 426         /* Post the event, if desired */
 427         posted = 0;
 428 #if !SDL_EVENTS_DISABLED
 429         if ( SDL_ProcessEvents[SDL_JOYAXISMOTION] == SDL_ENABLE ) {
 430                 SDL_Event event;
 431                 event.type = SDL_JOYAXISMOTION;
 432                 event.jaxis.which = joystick->index;
 433                 event.jaxis.axis = axis;
 434                 event.jaxis.value = value;
 435                 if ( (SDL_EventOK == NULL) || (*SDL_EventOK)(&event) ) {
 436                         posted = 1;
 437                         SDL_PushEvent(&event);
 438                 }
 439         }
 440 #endif /* !SDL_EVENTS_DISABLED */
 441         return(posted);
 442 }
 443
 444 int SDL_PrivateJoystickHat(SDL_Joystick *joystick, Uint8 hat, Uint8 value)
 445 {
 446         int posted;
 447
 448         /* Update internal joystick state */
 449         joystick->hats[hat] = value;
 450
 451         /* Post the event, if desired */
 452         posted = 0;
 453 #if !SDL_EVENTS_DISABLED
 454         if ( SDL_ProcessEvents[SDL_JOYHATMOTION] == SDL_ENABLE ) {
 455                 SDL_Event event;
 456                 event.jhat.type = SDL_JOYHATMOTION;
 457                 event.jhat.which = joystick->index;
 458                 event.jhat.hat = hat;
 459                 event.jhat.value = value;
 460                 if ( (SDL_EventOK == NULL) || (*SDL_EventOK)(&event) ) {
 461                         posted = 1;
 462                         SDL_PushEvent(&event);
 463                 }
 464         }
 465 #endif /* !SDL_EVENTS_DISABLED */
 466         return(posted);
 467 }
 468
 469 int SDL_PrivateJoystickBall(SDL_Joystick *joystick, Uint8 ball,
 470                                         Sint16 xrel, Sint16 yrel)
 471 {
 472         int posted;
 473
 474         /* Update internal mouse state */
 475         joystick->balls[ball].dx += xrel;
 476         joystick->balls[ball].dy += yrel;
 477
 478         /* Post the event, if desired */
 479         posted = 0;
 480 #if !SDL_EVENTS_DISABLED
 481         if ( SDL_ProcessEvents[SDL_JOYBALLMOTION] == SDL_ENABLE ) {
 482                 SDL_Event event;
 483                 event.jball.type = SDL_JOYBALLMOTION;
 484                 event.jball.which = joystick->index;
 485                 event.jball.ball = ball;
 486                 event.jball.xrel = xrel;
 487                 event.jball.yrel = yrel;
 488                 if ( (SDL_EventOK == NULL) || (*SDL_EventOK)(&event) ) {
 489                         posted = 1;
 490                         SDL_PushEvent(&event);
 491                 }
 492         }
 493 #endif /* !SDL_EVENTS_DISABLED */
 494         return(posted);
 495 }
 496
 497 int SDL_PrivateJoystickButton(SDL_Joystick *joystick, Uint8 button, Uint8 state)
 498 {
 499         int posted;
 500 #if !SDL_EVENTS_DISABLED
 501         SDL_Event event;
 502
 503         switch ( state ) {
 504                 case SDL_PRESSED:
 505                         event.type = SDL_JOYBUTTONDOWN;
 506                         break;
 507                 case SDL_RELEASED:
 508                         event.type = SDL_JOYBUTTONUP;
 509                         break;
 510                 default:
 511                         /* Invalid state -- bail */
 512                         return(0);
 513         }
 514 #endif /* !SDL_EVENTS_DISABLED */
 515
 516         /* Update internal joystick state */
 517         joystick->buttons[button] = state;
 518
 519         /* Post the event, if desired */
 520         posted = 0;
 521 #if !SDL_EVENTS_DISABLED
 522         if ( SDL_ProcessEvents[event.type] == SDL_ENABLE ) {
 523                 event.jbutton.which = joystick->index;
 524                 event.jbutton.button = button;
 525                 event.jbutton.state = state;
 526                 if ( (SDL_EventOK == NULL) || (*SDL_EventOK)(&event) ) {
 527                         posted = 1;
 528                         SDL_PushEvent(&event);
 529                 }
 530         }
 531 #endif /* !SDL_EVENTS_DISABLED */
 532         return(posted);
 533 }
 534
 535 void SDL_JoystickUpdate(void)
 536 {
 537         int i;
 538
 539         for ( i=0; SDL_joysticks[i]; ++i ) {
 540                 SDL_SYS_JoystickUpdate(SDL_joysticks[i]);
 541         }
 542 }
 543
 544 int SDL_JoystickEventState(int state)
 545 {
 546 #if SDL_EVENTS_DISABLED
 547         return SDL_IGNORE;
 548 #else
 549         const Uint8 event_list[] = {
 550                 SDL_JOYAXISMOTION, SDL_JOYBALLMOTION, SDL_JOYHATMOTION,
 551                 SDL_JOYBUTTONDOWN, SDL_JOYBUTTONUP,
 552         };
 553         unsigned int i;
 554
 555         switch (state) {
 556                 case SDL_QUERY:
 557                         state = SDL_IGNORE;
 558                         for ( i=0; i<SDL_arraysize(event_list); ++i ) {
 559                                 state = SDL_EventState(event_list[i],SDL_QUERY);
 560                                 if ( state == SDL_ENABLE ) {
 561                                         break;
 562                                 }
 563                         }
 564                         break;
 565                 default:
 566                         for ( i=0; i<SDL_arraysize(event_list); ++i ) {
 567                                 SDL_EventState(event_list[i], state);
 568                         }
 569                         break;
 570         }
 571         return(state);
 572 #endif /* SDL_EVENTS_DISABLED */
 573 }