SDL  2.0
SDL_sysjoystick.c
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1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2019 Sam Lantinga <slouken@libsdl.org>
4 
5  This software is provided 'as-is', without any express or implied
6  warranty. In no event will the authors be held liable for any damages
7  arising from the use of this software.
8 
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12 
13  1. The origin of this software must not be misrepresented; you must not
14  claim that you wrote the original software. If you use this software
15  in a product, an acknowledgment in the product documentation would be
16  appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18  misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20 */
21 
22 #include "../../SDL_internal.h"
23 
24 #ifdef SDL_JOYSTICK_EMSCRIPTEN
25 
26 #include <stdio.h> /* For the definition of NULL */
27 #include "SDL_error.h"
28 #include "SDL_events.h"
29 
30 #include "SDL_joystick.h"
31 #include "SDL_assert.h"
32 #include "SDL_timer.h"
33 #include "SDL_log.h"
34 #include "SDL_sysjoystick_c.h"
35 #include "../SDL_joystick_c.h"
36 
37 static SDL_joylist_item * JoystickByIndex(int index);
38 
39 static SDL_joylist_item *SDL_joylist = NULL;
40 static SDL_joylist_item *SDL_joylist_tail = NULL;
41 static int numjoysticks = 0;
42 static int instance_counter = 0;
43 
44 static EM_BOOL
45 Emscripten_JoyStickConnected(int eventType, const EmscriptenGamepadEvent *gamepadEvent, void *userData)
46 {
47  int i;
48 
49  SDL_joylist_item *item;
50 
51  if (JoystickByIndex(gamepadEvent->index) != NULL) {
52  return 1;
53  }
54 
55  item = (SDL_joylist_item *) SDL_malloc(sizeof (SDL_joylist_item));
56  if (item == NULL) {
57  return 1;
58  }
59 
60  SDL_zerop(item);
61  item->index = gamepadEvent->index;
62 
63  item->name = SDL_strdup(gamepadEvent->id);
64  if ( item->name == NULL ) {
65  SDL_free(item);
66  return 1;
67  }
68 
69  item->mapping = SDL_strdup(gamepadEvent->mapping);
70  if ( item->mapping == NULL ) {
71  SDL_free(item->name);
72  SDL_free(item);
73  return 1;
74  }
75 
76  item->naxes = gamepadEvent->numAxes;
77  item->nbuttons = gamepadEvent->numButtons;
78  item->device_instance = instance_counter++;
79 
80  item->timestamp = gamepadEvent->timestamp;
81 
82  for( i = 0; i < item->naxes; i++) {
83  item->axis[i] = gamepadEvent->axis[i];
84  }
85 
86  for( i = 0; i < item->nbuttons; i++) {
87  item->analogButton[i] = gamepadEvent->analogButton[i];
88  item->digitalButton[i] = gamepadEvent->digitalButton[i];
89  }
90 
91  if (SDL_joylist_tail == NULL) {
92  SDL_joylist = SDL_joylist_tail = item;
93  } else {
94  SDL_joylist_tail->next = item;
95  SDL_joylist_tail = item;
96  }
97 
98  ++numjoysticks;
99 
100  SDL_PrivateJoystickAdded(item->device_instance);
101 
102 #ifdef DEBUG_JOYSTICK
103  SDL_Log("Number of joysticks is %d", numjoysticks);
104 #endif
105 
106 #ifdef DEBUG_JOYSTICK
107  SDL_Log("Added joystick with index %d", item->index);
108 #endif
109 
110  return 1;
111 }
112 
113 static EM_BOOL
114 Emscripten_JoyStickDisconnected(int eventType, const EmscriptenGamepadEvent *gamepadEvent, void *userData)
115 {
116  SDL_joylist_item *item = SDL_joylist;
117  SDL_joylist_item *prev = NULL;
118 
119  while (item != NULL) {
120  if (item->index == gamepadEvent->index) {
121  break;
122  }
123  prev = item;
124  item = item->next;
125  }
126 
127  if (item == NULL) {
128  return 1;
129  }
130 
131  if (item->joystick) {
132  item->joystick->hwdata = NULL;
133  }
134 
135  if (prev != NULL) {
136  prev->next = item->next;
137  } else {
138  SDL_assert(SDL_joylist == item);
139  SDL_joylist = item->next;
140  }
141  if (item == SDL_joylist_tail) {
142  SDL_joylist_tail = prev;
143  }
144 
145  /* Need to decrement the joystick count before we post the event */
146  --numjoysticks;
147 
148  SDL_PrivateJoystickRemoved(item->device_instance);
149 
150 #ifdef DEBUG_JOYSTICK
151  SDL_Log("Removed joystick with id %d", item->device_instance);
152 #endif
153  SDL_free(item->name);
154  SDL_free(item->mapping);
155  SDL_free(item);
156  return 1;
157 }
158 
159 /* Function to perform any system-specific joystick related cleanup */
160 static void
161 EMSCRIPTEN_JoystickQuit(void)
162 {
163  SDL_joylist_item *item = NULL;
164  SDL_joylist_item *next = NULL;
165 
166  for (item = SDL_joylist; item; item = next) {
167  next = item->next;
168  SDL_free(item->mapping);
169  SDL_free(item->name);
170  SDL_free(item);
171  }
172 
173  SDL_joylist = SDL_joylist_tail = NULL;
174 
175  numjoysticks = 0;
176  instance_counter = 0;
177 
178  emscripten_set_gamepadconnected_callback(NULL, 0, NULL);
179  emscripten_set_gamepaddisconnected_callback(NULL, 0, NULL);
180 }
181 
182 /* Function to scan the system for joysticks.
183  * It should return 0, or -1 on an unrecoverable fatal error.
184  */
185 static int
186 EMSCRIPTEN_JoystickInit(void)
187 {
188  int retval, i, numjs;
189  EmscriptenGamepadEvent gamepadState;
190 
191  numjoysticks = 0;
192 
193  retval = emscripten_sample_gamepad_data();
194 
195  /* Check if gamepad is supported by browser */
196  if (retval == EMSCRIPTEN_RESULT_NOT_SUPPORTED) {
197  return SDL_SetError("Gamepads not supported");
198  }
199 
200  numjs = emscripten_get_num_gamepads();
201 
202  /* handle already connected gamepads */
203  if (numjs > 0) {
204  for(i = 0; i < numjs; i++) {
205  retval = emscripten_get_gamepad_status(i, &gamepadState);
206  if (retval == EMSCRIPTEN_RESULT_SUCCESS) {
207  Emscripten_JoyStickConnected(EMSCRIPTEN_EVENT_GAMEPADCONNECTED,
208  &gamepadState,
209  NULL);
210  }
211  }
212  }
213 
214  retval = emscripten_set_gamepadconnected_callback(NULL,
215  0,
216  Emscripten_JoyStickConnected);
217 
218  if(retval != EMSCRIPTEN_RESULT_SUCCESS) {
219  EMSCRIPTEN_JoystickQuit();
220  return SDL_SetError("Could not set gamepad connect callback");
221  }
222 
223  retval = emscripten_set_gamepaddisconnected_callback(NULL,
224  0,
225  Emscripten_JoyStickDisconnected);
226  if(retval != EMSCRIPTEN_RESULT_SUCCESS) {
227  EMSCRIPTEN_JoystickQuit();
228  return SDL_SetError("Could not set gamepad disconnect callback");
229  }
230 
231  return 0;
232 }
233 
234 /* Returns item matching given SDL device index. */
235 static SDL_joylist_item *
236 JoystickByDeviceIndex(int device_index)
237 {
238  SDL_joylist_item *item = SDL_joylist;
239 
240  while (0 < device_index) {
241  --device_index;
242  item = item->next;
243  }
244 
245  return item;
246 }
247 
248 /* Returns item matching given HTML gamepad index. */
249 static SDL_joylist_item *
250 JoystickByIndex(int index)
251 {
252  SDL_joylist_item *item = SDL_joylist;
253 
254  if (index < 0) {
255  return NULL;
256  }
257 
258  while (item != NULL) {
259  if (item->index == index) {
260  break;
261  }
262  item = item->next;
263  }
264 
265  return item;
266 }
267 
268 static int
269 EMSCRIPTEN_JoystickGetCount(void)
270 {
271  return numjoysticks;
272 }
273 
274 static void
275 EMSCRIPTEN_JoystickDetect(void)
276 {
277 }
278 
279 static const char *
280 EMSCRIPTEN_JoystickGetDeviceName(int device_index)
281 {
282  return JoystickByDeviceIndex(device_index)->name;
283 }
284 
285 static int
286 EMSCRIPTEN_JoystickGetDevicePlayerIndex(int device_index)
287 {
288  return -1;
289 }
290 
291 static SDL_JoystickID
292 EMSCRIPTEN_JoystickGetDeviceInstanceID(int device_index)
293 {
294  return JoystickByDeviceIndex(device_index)->device_instance;
295 }
296 
297 /* Function to open a joystick for use.
298  The joystick to open is specified by the device index.
299  This should fill the nbuttons and naxes fields of the joystick structure.
300  It returns 0, or -1 if there is an error.
301  */
302 static int
303 EMSCRIPTEN_JoystickOpen(SDL_Joystick * joystick, int device_index)
304 {
305  SDL_joylist_item *item = JoystickByDeviceIndex(device_index);
306 
307  if (item == NULL ) {
308  return SDL_SetError("No such device");
309  }
310 
311  if (item->joystick != NULL) {
312  return SDL_SetError("Joystick already opened");
313  }
314 
315  joystick->instance_id = item->device_instance;
316  joystick->hwdata = (struct joystick_hwdata *) item;
317  item->joystick = joystick;
318 
319  /* HTML5 Gamepad API doesn't say anything about these */
320  joystick->nhats = 0;
321  joystick->nballs = 0;
322 
323  joystick->nbuttons = item->nbuttons;
324  joystick->naxes = item->naxes;
325 
326  return (0);
327 }
328 
329 /* Function to update the state of a joystick - called as a device poll.
330  * This function shouldn't update the joystick structure directly,
331  * but instead should call SDL_PrivateJoystick*() to deliver events
332  * and update joystick device state.
333  */
334 static void
335 EMSCRIPTEN_JoystickUpdate(SDL_Joystick * joystick)
336 {
337  EmscriptenGamepadEvent gamepadState;
338  SDL_joylist_item *item = (SDL_joylist_item *) joystick->hwdata;
339  int i, result, buttonState;
340 
341  emscripten_sample_gamepad_data();
342 
343  if (item) {
344  result = emscripten_get_gamepad_status(item->index, &gamepadState);
345  if( result == EMSCRIPTEN_RESULT_SUCCESS) {
346  if(gamepadState.timestamp == 0 || gamepadState.timestamp != item->timestamp) {
347  for(i = 0; i < item->nbuttons; i++) {
348  if(item->digitalButton[i] != gamepadState.digitalButton[i]) {
349  buttonState = gamepadState.digitalButton[i]? SDL_PRESSED: SDL_RELEASED;
350  SDL_PrivateJoystickButton(item->joystick, i, buttonState);
351  }
352 
353  /* store values to compare them in the next update */
354  item->analogButton[i] = gamepadState.analogButton[i];
355  item->digitalButton[i] = gamepadState.digitalButton[i];
356  }
357 
358  for(i = 0; i < item->naxes; i++) {
359  if(item->axis[i] != gamepadState.axis[i]) {
360  /* do we need to do conversion? */
361  SDL_PrivateJoystickAxis(item->joystick, i,
362  (Sint16) (32767.*gamepadState.axis[i]));
363  }
364 
365  /* store to compare in next update */
366  item->axis[i] = gamepadState.axis[i];
367  }
368 
369  item->timestamp = gamepadState.timestamp;
370  }
371  }
372  }
373 }
374 
375 /* Function to close a joystick after use */
376 static void
377 EMSCRIPTEN_JoystickClose(SDL_Joystick * joystick)
378 {
379  SDL_joylist_item *item = (SDL_joylist_item *) joystick->hwdata;
380  if (item) {
381  item->joystick = NULL;
382  }
383 }
384 
385 static SDL_JoystickGUID
386 EMSCRIPTEN_JoystickGetDeviceGUID(int device_index)
387 {
389  /* the GUID is just the first 16 chars of the name for now */
390  const char *name = EMSCRIPTEN_JoystickGetDeviceName(device_index);
391  SDL_zero(guid);
392  SDL_memcpy(&guid, name, SDL_min(sizeof(guid), SDL_strlen(name)));
393  return guid;
394 }
395 
396 static int
397 EMSCRIPTEN_JoystickRumble(SDL_Joystick * joystick, Uint16 low_frequency_rumble, Uint16 high_frequency_rumble, Uint32 duration_ms)
398 {
399  return SDL_Unsupported();
400 }
401 
403 {
404  EMSCRIPTEN_JoystickInit,
405  EMSCRIPTEN_JoystickGetCount,
406  EMSCRIPTEN_JoystickDetect,
407  EMSCRIPTEN_JoystickGetDeviceName,
408  EMSCRIPTEN_JoystickGetDevicePlayerIndex,
409  EMSCRIPTEN_JoystickGetDeviceGUID,
410  EMSCRIPTEN_JoystickGetDeviceInstanceID,
411  EMSCRIPTEN_JoystickOpen,
412  EMSCRIPTEN_JoystickRumble,
413  EMSCRIPTEN_JoystickUpdate,
414  EMSCRIPTEN_JoystickClose,
415  EMSCRIPTEN_JoystickQuit,
416 };
417 
418 #endif /* SDL_JOYSTICK_EMSCRIPTEN */
419 
420 /* vi: set ts=4 sw=4 expandtab: */
SDL_zero
#define SDL_zero(x)
Definition: SDL_stdinc.h:416
SDL_events.h
joystick_hwdata::guid
SDL_JoystickGUID guid
Definition: SDL_sysjoystick_c.h:71
numjoysticks
static int numjoysticks
Definition: SDL_sysjoystick.m:83
NULL
#define NULL
Definition: begin_code.h:167
SDL_timer.h
SDL_joystick.h
SDL_error.h
SDL_zerop
#define SDL_zerop(x)
Definition: SDL_stdinc.h:417
SDL_log.h
SDL_PrivateJoystickAdded
void SDL_PrivateJoystickAdded(SDL_JoystickID device_instance)
Definition: SDL_joystick.c:755
joystick_hwdata::joystick
SDL_Joystick * joystick
Definition: SDL_sysjoystick_c.h:42
index
GLuint index
Definition: SDL_opengl_glext.h:660
SDL_RELEASED
#define SDL_RELEASED
Definition: SDL_events.h:49
result
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Definition: SDL_opengl_glext.h:9432
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Definition: SDL_joystick.c:805
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Definition: SDL_joystick.c:833
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int16_t Sint16
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#define SDL_memcpy
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Definition: SDL_dynapi_overrides.h:377
name
GLuint const GLchar * name
Definition: SDL_opengl_glext.h:660
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int SDL_PrivateJoystickButton(SDL_Joystick *joystick, Uint8 button, Uint8 state)
Definition: SDL_joystick.c:966
SDL_assert.h
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#define SDL_min(x, y)
Definition: SDL_stdinc.h:406
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Definition: SDL_assert.h:169
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Definition: SDL_sysjoystick.h:92
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Definition: SDL_sysjoystick_c.h:33
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#define SDL_strdup
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#define SDL_strlen
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Uint32
uint32_t Uint32
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Definition: SDL_error.h:53
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Definition: SDL_dynapi_overrides.h:374
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Definition: SDL_joystick.h:70
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SDL_JoystickDriver SDL_EMSCRIPTEN_JoystickDriver
i
return Display return Display Bool Bool int int int return Display XEvent Bool(*) XPointer return Display return Display Drawable _Xconst char unsigned int unsigned int return Display Pixmap Pixmap XColor XColor unsigned int unsigned int return Display _Xconst char char int char return Display Visual unsigned int int int char unsigned int unsigned int in i)
Definition: SDL_x11sym.h:50
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Definition: SDL_sysjoystick_c.h:46
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Definition: SDL_joystick.h:81