SDL  2.0
SDL_sensor.h File Reference
#include "SDL_stdinc.h"
#include "SDL_error.h"
#include "begin_code.h"
#include "close_code.h"
+ Include dependency graph for SDL_sensor.h:
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Go to the source code of this file.

Macros

#define SDL_STANDARD_GRAVITY   9.80665f
 

Typedefs

typedef Sint32 SDL_SensorID
 

Enumerations

enum  SDL_SensorType {
  SDL_SENSOR_INVALID = -1,
  SDL_SENSOR_UNKNOWN,
  SDL_SENSOR_ACCEL,
  SDL_SENSOR_GYRO
}
 

Functions

int SDL_NumSensors (void)
 Count the number of sensors attached to the system right now. More...
 
const char * SDL_SensorGetDeviceName (int device_index)
 Get the implementation dependent name of a sensor. More...
 
SDL_SensorType SDL_SensorGetDeviceType (int device_index)
 Get the type of a sensor. More...
 
int SDL_SensorGetDeviceNonPortableType (int device_index)
 Get the platform dependent type of a sensor. More...
 
SDL_SensorID SDL_SensorGetDeviceInstanceID (int device_index)
 Get the instance ID of a sensor. More...
 
SDL_Sensor * SDL_SensorOpen (int device_index)
 Open a sensor for use. More...
 
SDL_Sensor * SDL_SensorFromInstanceID (SDL_SensorID instance_id)
 
const char * SDL_SensorGetName (SDL_Sensor *sensor)
 Get the implementation dependent name of a sensor. More...
 
SDL_SensorType SDL_SensorGetType (SDL_Sensor *sensor)
 Get the type of a sensor. More...
 
int SDL_SensorGetNonPortableType (SDL_Sensor *sensor)
 Get the platform dependent type of a sensor. More...
 
SDL_SensorID SDL_SensorGetInstanceID (SDL_Sensor *sensor)
 Get the instance ID of a sensor. More...
 
int SDL_SensorGetData (SDL_Sensor *sensor, float *data, int num_values)
 
void SDL_SensorClose (SDL_Sensor *sensor)
 
void SDL_SensorUpdate (void)
 

Detailed Description

Include file for SDL sensor event handling

Definition in file SDL_sensor.h.

Macro Definition Documentation

◆ SDL_STANDARD_GRAVITY

#define SDL_STANDARD_GRAVITY   9.80665f

Accelerometer sensor

The accelerometer returns the current acceleration in SI meters per second squared. This includes gravity, so a device at rest will have an acceleration of SDL_STANDARD_GRAVITY straight down.

values[0]: Acceleration on the x axis values[1]: Acceleration on the y axis values[2]: Acceleration on the z axis

For phones held in portrait mode, the axes are defined as follows: -X ... +X : left ... right -Y ... +Y : bottom ... top -Z ... +Z : farther ... closer

The axis data is not changed when the phone is rotated.

See also
SDL_GetDisplayOrientation()

Definition at line 97 of file SDL_sensor.h.

Typedef Documentation

◆ SDL_SensorID

SDL_PRINTF_FORMAT_STRING const char int SDL_PRINTF_FORMAT_STRING const char int SDL_PRINTF_FORMAT_STRING const char int SDL_PRINTF_FORMAT_STRING const char const char SDL_SCANF_FORMAT_STRING const char return SDL_ThreadFunction const char void return Uint32 return Uint32 SDL_AssertionHandler void SDL_SpinLock SDL_atomic_t int int return SDL_atomic_t return void void void return void return int return SDL_AudioSpec SDL_AudioSpec return int int return return int SDL_RWops int SDL_AudioSpec Uint8 Uint32 return SDL_AudioCVT SDL_AudioFormat Uint8 int SDL_AudioFormat Uint8 int return Uint8 const Uint8 Uint32 int const char return return return return return return return return Uint32 return Uint32 SDL_Event return SDL_Event int return SDL_EventFilter void SDL_EventFilter void SDL_EventFilter void int return const char const char return SDL_JoystickGUID return int return int return SDL_GameController return int return const char return SDL_GameController SDL_GameControllerAxis return const char return SDL_GameController SDL_GameControllerButton return SDL_GameController SDL_RWops return SDL_TouchID SDL_RWops return int return int return return SDL_Joystick return SDL_Haptic SDL_Haptic return SDL_Haptic return SDL_Haptic SDL_HapticEffect return SDL_Haptic int Uint32 return SDL_Haptic int SDL_Haptic int return SDL_Haptic return SDL_Haptic return SDL_Haptic return SDL_Haptic return const char const char return const char SDL_HintCallback void int return SDL_Joystick return SDL_Joystick return const char return SDL_Joystick return SDL_Joystick return SDL_Joystick return int return SDL_Joystick int return SDL_Joystick int return return return SDL_Scancode return SDL_Scancode return SDL_Keycode return return const char return void int SDL_LogPriority SDL_LogOutputFunction void Uint32 const char const char SDL_Window return int int return SDL_Window int int return SDL_Surface int int return SDL_Cursor return int return SDL_mutex return SDL_mutex return Uint32 return SDL_sem return SDL_sem Uint32 return SDL_sem return SDL_cond SDL_cond return SDL_cond SDL_mutex Uint32 return Uint32 int Uint32 Uint32 Uint32 Uint32 return Uint32 return int return SDL_Palette const SDL_Color int int return const SDL_PixelFormat Uint8 Uint8 Uint8 return Uint32 const SDL_PixelFormat Uint8 Uint8 Uint8 float Uint16 int int return const SDL_Rect const SDL_Rect SDL_Rect return const SDL_Point int const SDL_Rect SDL_Rect return return int int Uint32 SDL_Window SDL_Renderer return SDL_Surface return SDL_Renderer SDL_RendererInfo return SDL_Renderer Uint32 int int int return SDL_Texture Uint32 int int int return SDL_Texture Uint8 Uint8 Uint8 return SDL_Texture Uint8 return SDL_Texture SDL_BlendMode return SDL_Texture const SDL_Rect const Uint8 int const Uint8 int const Uint8 int return SDL_Texture SDL_Renderer SDL_Texture return SDL_Renderer int int return SDL_Renderer const SDL_Rect return SDL_Renderer const SDL_Rect return SDL_Renderer float float return SDL_Renderer Uint8 Uint8 Uint8 Uint8 return SDL_Renderer SDL_BlendMode return SDL_Renderer return SDL_Renderer const SDL_Point int return SDL_Renderer const SDL_Point int return SDL_Renderer const SDL_Rect int return SDL_Renderer const SDL_Rect int return SDL_Renderer SDL_Texture const SDL_Rect const SDL_Rect const double const SDL_Point const SDL_RendererFlip return SDL_Renderer SDL_Renderer SDL_Texture return void int return return SDL_RWops return SDL_RWops return SDL_RWops return SDL_RWops return SDL_RWops Uint16 return SDL_RWops Uint32 return SDL_RWops Uint64 return const char unsigned int unsigned int unsigned int unsigned int Uint32 return SDL_Window SDL_Surface SDL_WindowShapeMode return size_t return void size_t return const char return void size_t size_t int(*) a int return int return int size_t return size_t return const wchar_t return const wchar_t size_t return const char size_t return const char size_t return char return char return const char int return int char int return long char int return Sint64 char int return const char return const char char int return const char char int return const char char return const char const char size_t return const char const char size_t return double return double return double return double return double return double return double int return float return const char const char return SDL_iconv_t const char size_t char size_t return Uint32 int int int Uint32 Uint32 Uint32 Uint32 return SDL_Surface SDL_Surface return SDL_RWops int return SDL_Surface int return SDL_Surface Uint32 return SDL_Surface Uint8 Uint8 Uint8 return SDL_Surface Uint8 return SDL_Surface SDL_BlendMode return SDL_Surface SDL_Rect SDL_Surface Uint32 Uint32 return SDL_Surface const SDL_Rect Uint32 return SDL_Surface const SDL_Rect SDL_Surface SDL_Rect return SDL_Surface const SDL_Rect SDL_Surface const SDL_Rect return SDL_Surface SDL_Rect SDL_Surface SDL_Rect return SDL_Thread return SDL_Thread return SDL_Thread int return SDL_TLSID const void void(*) return return Uint32 SDL_TimerID return int return SDL_TouchID int return return return const char return return int return int return int SDL_DisplayMode return int const SDL_DisplayMode SDL_DisplayMode return SDL_Window const SDL_DisplayMode return SDL_Window return const void return Uint32 return SDL_Window const char SDL_Window SDL_Surface SDL_Window const char return SDL_Window int int SDL_Window int int SDL_Window int int SDL_Window int int SDL_Window SDL_Window SDL_Window SDL_Window Uint32 return SDL_Window return SDL_Window SDL_bool SDL_Window float return SDL_Window const Uint16 const Uint16 const Uint16 return SDL_Window const char return SDL_GLattr int return SDL_Window return return SDL_Window int int return SDL_GLContext SDL_RWops int return return void return int int return double return SDL_bool return int int return SDL_AudioDeviceID const void Uint32 return SDL_AudioDeviceID int float float float return SDL_JoystickID return int SDL_Rect return SDL_Window float return SDL_Window return SDL_Renderer SDL_bool return SDL_AudioDeviceID void Uint32 return Uint32 int int int Uint32 return const char SDL_bool return int return SDL_Joystick return SDL_Joystick return SDL_GameController return return return SDL_Joystick int Sint16 return SDL_Joystick return const char return const wchar_t const wchar_t return SDL_Surface return return SDL_Window unsigned int const char return SDL_Window int int SDL_malloc_func SDL_calloc_func SDL_realloc_func SDL_free_func return const SDL_AudioFormat const Uint8 const int const SDL_AudioFormat const Uint8 const int return SDL_AudioStream void int return SDL_AudioStream return SDL_AudioStream return float return float float return float float return float return float float return double double return SDL_YUV_CONVERSION_MODE int int return SDL_Renderer return float return return float return SDL_GameController Uint16 Uint16 Uint32 return return int return int return SDL_SensorID

This is a unique ID for a sensor for the time it is connected to the system, and is never reused for the lifetime of the application.

The ID value starts at 0 and increments from there. The value -1 is an invalid ID.

Definition at line 60 of file SDL_sensor.h.

Enumeration Type Documentation

◆ SDL_SensorType

Enumerator
SDL_SENSOR_INVALID 

Returned for an invalid sensor

SDL_SENSOR_UNKNOWN 

Unknown sensor type

SDL_SENSOR_ACCEL 

Accelerometer

SDL_SENSOR_GYRO 

Gyroscope

Definition at line 69 of file SDL_sensor.h.

70 {
71  SDL_SENSOR_INVALID = -1, /**< Returned for an invalid sensor */
72  SDL_SENSOR_UNKNOWN, /**< Unknown sensor type */
73  SDL_SENSOR_ACCEL, /**< Accelerometer */
74  SDL_SENSOR_GYRO /**< Gyroscope */
SDL_SensorType
Definition: SDL_sensor.h:69

Function Documentation

◆ SDL_NumSensors()

int SDL_NumSensors ( void  )

Count the number of sensors attached to the system right now.

Gyroscope sensor

The gyroscope returns the current rate of rotation in radians per second. The rotation is positive in the counter-clockwise direction. That is, an observer looking from a positive location on one of the axes would see positive rotation on that axis when it appeared to be rotating counter-clockwise.

values[0]: Angular speed around the x axis values[1]: Angular speed around the y axis values[2]: Angular speed around the z axis

For phones held in portrait mode, the axes are defined as follows: -X ... +X : left ... right -Y ... +Y : bottom ... top -Z ... +Z : farther ... closer

The axis data is not changed when the phone is rotated.

See also
SDL_GetDisplayOrientation()

Definition at line 97 of file SDL_sensor.c.

References SDL_SensorDriver::GetCount, i, SDL_arraysize, SDL_LockSensors(), and SDL_UnlockSensors().

98 {
99  int i, total_sensors = 0;
100  SDL_LockSensors();
101  for (i = 0; i < SDL_arraysize(SDL_sensor_drivers); ++i) {
102  total_sensors += SDL_sensor_drivers[i]->GetCount();
103  }
105  return total_sensors;
106 }
static void SDL_LockSensors(void)
Definition: SDL_sensor.c:52
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
static SDL_SensorDriver * SDL_sensor_drivers[]
Definition: SDL_sensor.c:35
static void SDL_UnlockSensors(void)
Definition: SDL_sensor.c:60
#define SDL_arraysize(array)
Definition: SDL_stdinc.h:115
int(* GetCount)(void)
Definition: SDL_syssensor.h:60

◆ SDL_SensorClose()

void SDL_SensorClose ( SDL_Sensor *  sensor)

Close a sensor previously opened with SDL_SensorOpen()

Definition at line 390 of file SDL_sensor.c.

References NULL, SDL_free, SDL_LockSensors(), SDL_PrivateSensorValid(), SDL_sensors, SDL_UnlockSensors(), and SDL_updating_sensor.

Referenced by SDL_SensorQuit(), and SDL_SensorUpdate().

391 {
392  SDL_Sensor *sensorlist;
393  SDL_Sensor *sensorlistprev;
394 
395  if (!SDL_PrivateSensorValid(sensor)) {
396  return;
397  }
398 
399  SDL_LockSensors();
400 
401  /* First decrement ref count */
402  if (--sensor->ref_count > 0) {
404  return;
405  }
406 
407  if (SDL_updating_sensor) {
409  return;
410  }
411 
412  sensor->driver->Close(sensor);
413  sensor->hwdata = NULL;
414 
415  sensorlist = SDL_sensors;
416  sensorlistprev = NULL;
417  while (sensorlist) {
418  if (sensor == sensorlist) {
419  if (sensorlistprev) {
420  /* unlink this entry */
421  sensorlistprev->next = sensorlist->next;
422  } else {
423  SDL_sensors = sensor->next;
424  }
425  break;
426  }
427  sensorlistprev = sensorlist;
428  sensorlist = sensorlist->next;
429  }
430 
431  SDL_free(sensor->name);
432 
433  /* Free the data associated with this sensor */
434  SDL_free(sensor);
435 
437 }
static void SDL_LockSensors(void)
Definition: SDL_sensor.c:52
#define SDL_free
static SDL_bool SDL_updating_sensor
Definition: SDL_sensor.c:47
static SDL_Sensor * SDL_sensors
Definition: SDL_sensor.c:46
#define NULL
Definition: begin_code.h:164
static void SDL_UnlockSensors(void)
Definition: SDL_sensor.c:60
static int SDL_PrivateSensorValid(SDL_Sensor *sensor)
Definition: SDL_sensor.c:305

◆ SDL_SensorFromInstanceID()

SDL_Sensor* SDL_SensorFromInstanceID ( SDL_SensorID  instance_id)

Return the SDL_Sensor associated with an instance id.

Definition at line 287 of file SDL_sensor.c.

References SDL_LockSensors(), SDL_sensors, and SDL_UnlockSensors().

288 {
289  SDL_Sensor *sensor;
290 
291  SDL_LockSensors();
292  for (sensor = SDL_sensors; sensor; sensor = sensor->next) {
293  if (sensor->instance_id == instance_id) {
294  break;
295  }
296  }
298  return sensor;
299 }
static void SDL_LockSensors(void)
Definition: SDL_sensor.c:52
static SDL_Sensor * SDL_sensors
Definition: SDL_sensor.c:46
static void SDL_UnlockSensors(void)
Definition: SDL_sensor.c:60

◆ SDL_SensorGetData()

int SDL_SensorGetData ( SDL_Sensor *  sensor,
float *  data,
int  num_values 
)

Get the current state of an opened sensor.

The number of values and interpretation of the data is sensor dependent.

Parameters
sensorThe sensor to query
dataA pointer filled with the current sensor state
num_valuesThe number of values to write to data
Returns
0 or -1 if an error occurred.

Definition at line 375 of file SDL_sensor.c.

References SDL_arraysize, SDL_memcpy, SDL_min, and SDL_PrivateSensorValid().

376 {
377  if (!SDL_PrivateSensorValid(sensor)) {
378  return -1;
379  }
380 
381  num_values = SDL_min(num_values, SDL_arraysize(sensor->data));
382  SDL_memcpy(data, sensor->data, num_values*sizeof(*data));
383  return 0;
384 }
#define SDL_min(x, y)
Definition: SDL_stdinc.h:406
GLint GLenum GLsizei GLsizei GLsizei GLint GLsizei const GLvoid * data
Definition: SDL_opengl.h:1974
#define SDL_memcpy
#define SDL_arraysize(array)
Definition: SDL_stdinc.h:115
static int SDL_PrivateSensorValid(SDL_Sensor *sensor)
Definition: SDL_sensor.c:305

◆ SDL_SensorGetDeviceInstanceID()

SDL_SensorID SDL_SensorGetDeviceInstanceID ( int  device_index)

Get the instance ID of a sensor.

This can be called before any sensors are opened.

Returns
The sensor instance ID, or -1 if device_index is out of range.

Definition at line 193 of file SDL_sensor.c.

References SDL_SensorDriver::GetDeviceInstanceID, SDL_GetDriverAndSensorIndex(), SDL_LockSensors(), and SDL_UnlockSensors().

194 {
195  SDL_SensorDriver *driver;
196  SDL_SensorID instance_id = -1;
197 
198  SDL_LockSensors();
199  if (SDL_GetDriverAndSensorIndex(device_index, &driver, &device_index)) {
200  instance_id = driver->GetDeviceInstanceID(device_index);
201  }
203 
204  return instance_id;
205 }
SDL_SensorID(* GetDeviceInstanceID)(int device_index)
Definition: SDL_syssensor.h:75
Sint32 SDL_SensorID
Definition: SDL_sensor.h:60
static void SDL_LockSensors(void)
Definition: SDL_sensor.c:52
static SDL_bool SDL_GetDriverAndSensorIndex(int device_index, SDL_SensorDriver **driver, int *driver_index)
Definition: SDL_sensor.c:122
static void SDL_UnlockSensors(void)
Definition: SDL_sensor.c:60

◆ SDL_SensorGetDeviceName()

const char* SDL_SensorGetDeviceName ( int  device_index)

Get the implementation dependent name of a sensor.

This can be called before any sensors are opened.

Returns
The sensor name, or NULL if device_index is out of range.

Definition at line 147 of file SDL_sensor.c.

References SDL_SensorDriver::GetDeviceName, NULL, SDL_GetDriverAndSensorIndex(), SDL_LockSensors(), and SDL_UnlockSensors().

148 {
149  SDL_SensorDriver *driver;
150  const char *name = NULL;
151 
152  SDL_LockSensors();
153  if (SDL_GetDriverAndSensorIndex(device_index, &driver, &device_index)) {
154  name = driver->GetDeviceName(device_index);
155  }
157 
158  /* FIXME: Really we should reference count this name so it doesn't go away after unlock */
159  return name;
160 }
const char *(* GetDeviceName)(int device_index)
Definition: SDL_syssensor.h:66
GLuint const GLchar * name
static void SDL_LockSensors(void)
Definition: SDL_sensor.c:52
#define NULL
Definition: begin_code.h:164
static SDL_bool SDL_GetDriverAndSensorIndex(int device_index, SDL_SensorDriver **driver, int *driver_index)
Definition: SDL_sensor.c:122
static void SDL_UnlockSensors(void)
Definition: SDL_sensor.c:60

◆ SDL_SensorGetDeviceNonPortableType()

int SDL_SensorGetDeviceNonPortableType ( int  device_index)

Get the platform dependent type of a sensor.

This can be called before any sensors are opened.

Returns
The sensor platform dependent type, or -1 if device_index is out of range.

Definition at line 178 of file SDL_sensor.c.

References SDL_SensorDriver::GetDeviceNonPortableType, SDL_GetDriverAndSensorIndex(), SDL_LockSensors(), and SDL_UnlockSensors().

179 {
180  SDL_SensorDriver *driver;
181  int type = -1;
182 
183  SDL_LockSensors();
184  if (SDL_GetDriverAndSensorIndex(device_index, &driver, &device_index)) {
185  type = driver->GetDeviceNonPortableType(device_index);
186  }
188 
189  return type;
190 }
int(* GetDeviceNonPortableType)(int device_index)
Definition: SDL_syssensor.h:72
static void SDL_LockSensors(void)
Definition: SDL_sensor.c:52
static SDL_bool SDL_GetDriverAndSensorIndex(int device_index, SDL_SensorDriver **driver, int *driver_index)
Definition: SDL_sensor.c:122
GLuint GLuint GLsizei GLenum type
Definition: SDL_opengl.h:1571
static void SDL_UnlockSensors(void)
Definition: SDL_sensor.c:60

◆ SDL_SensorGetDeviceType()

SDL_SensorType SDL_SensorGetDeviceType ( int  device_index)

Get the type of a sensor.

This can be called before any sensors are opened.

Returns
The sensor type, or SDL_SENSOR_INVALID if device_index is out of range.

Definition at line 163 of file SDL_sensor.c.

References SDL_SensorDriver::GetDeviceType, SDL_GetDriverAndSensorIndex(), SDL_LockSensors(), SDL_SENSOR_INVALID, and SDL_UnlockSensors().

164 {
165  SDL_SensorDriver *driver;
167 
168  SDL_LockSensors();
169  if (SDL_GetDriverAndSensorIndex(device_index, &driver, &device_index)) {
170  type = driver->GetDeviceType(device_index);
171  }
173 
174  return type;
175 }
SDL_SensorType(* GetDeviceType)(int device_index)
Definition: SDL_syssensor.h:69
static void SDL_LockSensors(void)
Definition: SDL_sensor.c:52
SDL_SensorType
Definition: SDL_sensor.h:69
static SDL_bool SDL_GetDriverAndSensorIndex(int device_index, SDL_SensorDriver **driver, int *driver_index)
Definition: SDL_sensor.c:122
GLuint GLuint GLsizei GLenum type
Definition: SDL_opengl.h:1571
static void SDL_UnlockSensors(void)
Definition: SDL_sensor.c:60

◆ SDL_SensorGetInstanceID()

SDL_SensorID SDL_SensorGetInstanceID ( SDL_Sensor *  sensor)

Get the instance ID of a sensor.

This can be called before any sensors are opened.

Returns
The sensor instance ID, or -1 if the sensor is NULL.

Definition at line 362 of file SDL_sensor.c.

References SDL_PrivateSensorValid().

363 {
364  if (!SDL_PrivateSensorValid(sensor)) {
365  return -1;
366  }
367 
368  return sensor->instance_id;
369 }
static int SDL_PrivateSensorValid(SDL_Sensor *sensor)
Definition: SDL_sensor.c:305

◆ SDL_SensorGetName()

const char* SDL_SensorGetName ( SDL_Sensor *  sensor)

Get the implementation dependent name of a sensor.

Returns
The sensor name, or NULL if the sensor is NULL.

Definition at line 323 of file SDL_sensor.c.

References NULL, and SDL_PrivateSensorValid().

324 {
325  if (!SDL_PrivateSensorValid(sensor)) {
326  return NULL;
327  }
328 
329  return sensor->name;
330 }
#define NULL
Definition: begin_code.h:164
static int SDL_PrivateSensorValid(SDL_Sensor *sensor)
Definition: SDL_sensor.c:305

◆ SDL_SensorGetNonPortableType()

int SDL_SensorGetNonPortableType ( SDL_Sensor *  sensor)

Get the platform dependent type of a sensor.

This can be called before any sensors are opened.

Returns
The sensor platform dependent type, or -1 if the sensor is NULL.

Definition at line 349 of file SDL_sensor.c.

References SDL_PrivateSensorValid().

350 {
351  if (!SDL_PrivateSensorValid(sensor)) {
352  return -1;
353  }
354 
355  return sensor->non_portable_type;
356 }
static int SDL_PrivateSensorValid(SDL_Sensor *sensor)
Definition: SDL_sensor.c:305

◆ SDL_SensorGetType()

SDL_SensorType SDL_SensorGetType ( SDL_Sensor *  sensor)

Get the type of a sensor.

This can be called before any sensors are opened.

Returns
The sensor type, or SDL_SENSOR_INVALID if the sensor is NULL.

Definition at line 336 of file SDL_sensor.c.

References SDL_PrivateSensorValid(), and SDL_SENSOR_INVALID.

337 {
338  if (!SDL_PrivateSensorValid(sensor)) {
339  return SDL_SENSOR_INVALID;
340  }
341 
342  return sensor->type;
343 }
static int SDL_PrivateSensorValid(SDL_Sensor *sensor)
Definition: SDL_sensor.c:305

◆ SDL_SensorOpen()

SDL_Sensor* SDL_SensorOpen ( int  device_index)

Open a sensor for use.

The index passed as an argument refers to the N'th sensor on the system.

Returns
A sensor identifier, or NULL if an error occurred.

Definition at line 215 of file SDL_sensor.c.

References SDL_SensorDriver::GetDeviceInstanceID, SDL_SensorDriver::GetDeviceName, SDL_SensorDriver::GetDeviceNonPortableType, SDL_SensorDriver::GetDeviceType, NULL, SDL_SensorDriver::Open, SDL_calloc, SDL_free, SDL_GetDriverAndSensorIndex(), SDL_LockSensors(), SDL_OutOfMemory, SDL_sensors, SDL_strdup, SDL_UnlockSensors(), and SDL_SensorDriver::Update.

216 {
217  SDL_SensorDriver *driver;
218  SDL_SensorID instance_id;
219  SDL_Sensor *sensor;
220  SDL_Sensor *sensorlist;
221  const char *sensorname = NULL;
222 
223  SDL_LockSensors();
224 
225  if (!SDL_GetDriverAndSensorIndex(device_index, &driver, &device_index)) {
227  return NULL;
228  }
229 
230  sensorlist = SDL_sensors;
231  /* If the sensor is already open, return it
232  * it is important that we have a single sensor * for each instance id
233  */
234  instance_id = driver->GetDeviceInstanceID(device_index);
235  while (sensorlist) {
236  if (instance_id == sensorlist->instance_id) {
237  sensor = sensorlist;
238  ++sensor->ref_count;
240  return sensor;
241  }
242  sensorlist = sensorlist->next;
243  }
244 
245  /* Create and initialize the sensor */
246  sensor = (SDL_Sensor *) SDL_calloc(sizeof(*sensor), 1);
247  if (sensor == NULL) {
248  SDL_OutOfMemory();
250  return NULL;
251  }
252  sensor->driver = driver;
253  sensor->instance_id = instance_id;
254  sensor->type = driver->GetDeviceType(device_index);
255  sensor->non_portable_type = driver->GetDeviceNonPortableType(device_index);
256 
257  if (driver->Open(sensor, device_index) < 0) {
258  SDL_free(sensor);
260  return NULL;
261  }
262 
263  sensorname = driver->GetDeviceName(device_index);
264  if (sensorname) {
265  sensor->name = SDL_strdup(sensorname);
266  } else {
267  sensor->name = NULL;
268  }
269 
270  /* Add sensor to list */
271  ++sensor->ref_count;
272  /* Link the sensor in the list */
273  sensor->next = SDL_sensors;
274  SDL_sensors = sensor;
275 
277 
278  driver->Update(sensor);
279 
280  return sensor;
281 }
SDL_SensorID(* GetDeviceInstanceID)(int device_index)
Definition: SDL_syssensor.h:75
Sint32 SDL_SensorID
Definition: SDL_sensor.h:60
int(* GetDeviceNonPortableType)(int device_index)
Definition: SDL_syssensor.h:72
int(* Open)(SDL_Sensor *sensor, int device_index)
Definition: SDL_syssensor.h:81
SDL_SensorType(* GetDeviceType)(int device_index)
Definition: SDL_syssensor.h:69
const char *(* GetDeviceName)(int device_index)
Definition: SDL_syssensor.h:66
void(* Update)(SDL_Sensor *sensor)
Definition: SDL_syssensor.h:88
static void SDL_LockSensors(void)
Definition: SDL_sensor.c:52
#define SDL_free
static SDL_Sensor * SDL_sensors
Definition: SDL_sensor.c:46
#define NULL
Definition: begin_code.h:164
#define SDL_OutOfMemory()
Definition: SDL_error.h:52
#define SDL_calloc
#define SDL_strdup
static SDL_bool SDL_GetDriverAndSensorIndex(int device_index, SDL_SensorDriver **driver, int *driver_index)
Definition: SDL_sensor.c:122
static void SDL_UnlockSensors(void)
Definition: SDL_sensor.c:60

◆ SDL_SensorUpdate()

void SDL_SensorUpdate ( void  )

Update the current state of the open sensors.

This is called automatically by the event loop if sensor events are enabled.

This needs to be called from the thread that initialized the sensor subsystem.

Definition at line 503 of file SDL_sensor.c.

References SDL_SensorDriver::Detect, i, SDL_arraysize, SDL_FALSE, SDL_LockSensors(), SDL_SensorClose(), SDL_sensors, SDL_TRUE, SDL_UnlockSensors(), and SDL_updating_sensor.

504 {
505  int i;
506  SDL_Sensor *sensor;
507 
508  SDL_LockSensors();
509 
510  if (SDL_updating_sensor) {
511  /* The sensors are already being updated */
513  return;
514  }
515 
517 
518  /* Make sure the list is unlocked while dispatching events to prevent application deadlocks */
520 
521  for (sensor = SDL_sensors; sensor; sensor = sensor->next) {
522  sensor->driver->Update(sensor);
523  }
524 
525  SDL_LockSensors();
526 
528 
529  /* If any sensors were closed while updating, free them here */
530  for (sensor = SDL_sensors; sensor; sensor = sensor->next) {
531  if (sensor->ref_count <= 0) {
532  SDL_SensorClose(sensor);
533  }
534  }
535 
536  /* this needs to happen AFTER walking the sensor list above, so that any
537  dangling hardware data from removed devices can be free'd
538  */
539  for (i = 0; i < SDL_arraysize(SDL_sensor_drivers); ++i) {
541  }
542 
544 }
void SDL_SensorClose(SDL_Sensor *sensor)
Definition: SDL_sensor.c:390
static void SDL_LockSensors(void)
Definition: SDL_sensor.c:52
void(* Detect)(void)
Definition: SDL_syssensor.h:63
static SDL_bool SDL_updating_sensor
Definition: SDL_sensor.c:47
static SDL_Sensor * SDL_sensors
Definition: SDL_sensor.c:46
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
static SDL_SensorDriver * SDL_sensor_drivers[]
Definition: SDL_sensor.c:35
static void SDL_UnlockSensors(void)
Definition: SDL_sensor.c:60
#define SDL_arraysize(array)
Definition: SDL_stdinc.h:115