SDL  2.0
SDL_sensor.h
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1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2018 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 /**
23  * \file SDL_sensor.h
24  *
25  * Include file for SDL sensor event handling
26  *
27  */
28 
29 #ifndef _SDL_sensor_h
30 #define _SDL_sensor_h
31 
32 #include "SDL_stdinc.h"
33 #include "SDL_error.h"
34 
35 #include "begin_code.h"
36 /* Set up for C function definitions, even when using C++ */
37 #ifdef __cplusplus
38 /* *INDENT-OFF* */
39 extern "C" {
40 /* *INDENT-ON* */
41 #endif
42 
43 /**
44  * \brief SDL_sensor.h
45  *
46  * In order to use these functions, SDL_Init() must have been called
47  * with the ::SDL_INIT_SENSOR flag. This causes SDL to scan the system
48  * for sensors, and load appropriate drivers.
49  */
50 
51 struct _SDL_Sensor;
52 typedef struct _SDL_Sensor SDL_Sensor;
53 
54 /**
55  * This is a unique ID for a sensor for the time it is connected to the system,
56  * and is never reused for the lifetime of the application.
57  *
58  * The ID value starts at 0 and increments from there. The value -1 is an invalid ID.
59  */
61 
62 /* The different sensors defined by SDL
63  *
64  * Additional sensors may be available, using platform dependent semantics.
65  *
66  * Hare are the additional Android sensors:
67  * https://developer.android.com/reference/android/hardware/SensorEvent.html#values
68  */
69 typedef enum
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 */
76 
77 /**
78  * Accelerometer sensor
79  *
80  * The accelerometer returns the current acceleration in SI meters per
81  * second squared. This includes gravity, so a device at rest will have
82  * an acceleration of SDL_STANDARD_GRAVITY straight down.
83  *
84  * values[0]: Acceleration on the x axis
85  * values[1]: Acceleration on the y axis
86  * values[2]: Acceleration on the z axis
87  *
88  * For phones held in portrait mode, the axes are defined as follows:
89  * -X ... +X : left ... right
90  * -Y ... +Y : bottom ... top
91  * -Z ... +Z : farther ... closer
92  *
93  * The axis data is not changed when the phone is rotated.
94  *
95  * \sa SDL_GetDisplayOrientation()
96  */
97 #define SDL_STANDARD_GRAVITY 9.80665f
98 
99 /**
100  * Gyroscope sensor
101  *
102  * The gyroscope returns the current rate of rotation in radians per second.
103  * The rotation is positive in the counter-clockwise direction. That is,
104  * an observer looking from a positive location on one of the axes would
105  * see positive rotation on that axis when it appeared to be rotating
106  * counter-clockwise.
107  *
108  * values[0]: Angular speed around the x axis
109  * values[1]: Angular speed around the y axis
110  * values[2]: Angular speed around the z axis
111  *
112  * For phones held in portrait mode, the axes are defined as follows:
113  * -X ... +X : left ... right
114  * -Y ... +Y : bottom ... top
115  * -Z ... +Z : farther ... closer
116  *
117  * The axis data is not changed when the phone is rotated.
118  *
119  * \sa SDL_GetDisplayOrientation()
120  */
121 
122 /* Function prototypes */
123 
124 /**
125  * \brief Count the number of sensors attached to the system right now
126  */
127 extern DECLSPEC int SDLCALL SDL_NumSensors(void);
128 
129 /**
130  * \brief Get the implementation dependent name of a sensor.
131  *
132  * This can be called before any sensors are opened.
133  *
134  * \return The sensor name, or NULL if device_index is out of range.
135  */
136 extern DECLSPEC const char *SDLCALL SDL_SensorGetDeviceName(int device_index);
137 
138 /**
139  * \brief Get the type of a sensor.
140  *
141  * This can be called before any sensors are opened.
142  *
143  * \return The sensor type, or SDL_SENSOR_INVALID if device_index is out of range.
144  */
145 extern DECLSPEC SDL_SensorType SDLCALL SDL_SensorGetDeviceType(int device_index);
146 
147 /**
148  * \brief Get the platform dependent type of a sensor.
149  *
150  * This can be called before any sensors are opened.
151  *
152  * \return The sensor platform dependent type, or -1 if device_index is out of range.
153  */
154 extern DECLSPEC int SDLCALL SDL_SensorGetDeviceNonPortableType(int device_index);
155 
156 /**
157  * \brief Get the instance ID of a sensor.
158  *
159  * This can be called before any sensors are opened.
160  *
161  * \return The sensor instance ID, or -1 if device_index is out of range.
162  */
163 extern DECLSPEC SDL_SensorID SDLCALL SDL_SensorGetDeviceInstanceID(int device_index);
164 
165 /**
166  * \brief Open a sensor for use.
167  *
168  * The index passed as an argument refers to the N'th sensor on the system.
169  *
170  * \return A sensor identifier, or NULL if an error occurred.
171  */
172 extern DECLSPEC SDL_Sensor *SDLCALL SDL_SensorOpen(int device_index);
173 
174 /**
175  * Return the SDL_Sensor associated with an instance id.
176  */
177 extern DECLSPEC SDL_Sensor *SDLCALL SDL_SensorFromInstanceID(SDL_SensorID instance_id);
178 
179 /**
180  * \brief Get the implementation dependent name of a sensor.
181  *
182  * \return The sensor name, or NULL if the sensor is NULL.
183  */
184 extern DECLSPEC const char *SDLCALL SDL_SensorGetName(SDL_Sensor *sensor);
185 
186 /**
187  * \brief Get the type of a sensor.
188  *
189  * This can be called before any sensors are opened.
190  *
191  * \return The sensor type, or SDL_SENSOR_INVALID if the sensor is NULL.
192  */
193 extern DECLSPEC SDL_SensorType SDLCALL SDL_SensorGetType(SDL_Sensor *sensor);
194 
195 /**
196  * \brief Get the platform dependent type of a sensor.
197  *
198  * This can be called before any sensors are opened.
199  *
200  * \return The sensor platform dependent type, or -1 if the sensor is NULL.
201  */
202 extern DECLSPEC int SDLCALL SDL_SensorGetNonPortableType(SDL_Sensor *sensor);
203 
204 /**
205  * \brief Get the instance ID of a sensor.
206  *
207  * This can be called before any sensors are opened.
208  *
209  * \return The sensor instance ID, or -1 if the sensor is NULL.
210  */
211 extern DECLSPEC SDL_SensorID SDLCALL SDL_SensorGetInstanceID(SDL_Sensor *sensor);
212 
213 /**
214  * Get the current state of an opened sensor.
215  *
216  * The number of values and interpretation of the data is sensor dependent.
217  *
218  * \param sensor The sensor to query
219  * \param data A pointer filled with the current sensor state
220  * \param num_values The number of values to write to data
221  *
222  * \return 0 or -1 if an error occurred.
223  */
224 extern DECLSPEC int SDLCALL SDL_SensorGetData(SDL_Sensor * sensor, float *data, int num_values);
225 
226 /**
227  * Close a sensor previously opened with SDL_SensorOpen()
228  */
229 extern DECLSPEC void SDLCALL SDL_SensorClose(SDL_Sensor * sensor);
230 
231 /**
232  * Update the current state of the open sensors.
233  *
234  * This is called automatically by the event loop if sensor events are enabled.
235  *
236  * This needs to be called from the thread that initialized the sensor subsystem.
237  */
238 extern DECLSPEC void SDLCALL SDL_SensorUpdate(void);
239 
240 
241 /* Ends C function definitions when using C++ */
242 #ifdef __cplusplus
243 /* *INDENT-OFF* */
244 }
245 /* *INDENT-ON* */
246 #endif
247 #include "close_code.h"
248 
249 #endif /* _SDL_sensor_h */
250 
251 /* vi: set ts=4 sw=4 expandtab: */
void SDL_SensorUpdate(void)
Definition: SDL_sensor.c:503
Sint32 SDL_SensorID
Definition: SDL_sensor.h:60
GLint GLenum GLsizei GLsizei GLsizei GLint GLsizei const GLvoid * data
Definition: SDL_opengl.h:1974
const char * SDL_SensorGetName(SDL_Sensor *sensor)
Get the implementation dependent name of a sensor.
Definition: SDL_sensor.c:323
const char * SDL_SensorGetDeviceName(int device_index)
Get the implementation dependent name of a sensor.
Definition: SDL_sensor.c:147
void SDL_SensorClose(SDL_Sensor *sensor)
Definition: SDL_sensor.c:390
SDL_SensorID SDL_SensorGetInstanceID(SDL_Sensor *sensor)
Get the instance ID of a sensor.
Definition: SDL_sensor.c:362
#define DECLSPEC
Definition: SDL_internal.h:44
SDL_Sensor * SDL_SensorFromInstanceID(SDL_SensorID instance_id)
Definition: SDL_sensor.c:287
int SDL_SensorGetNonPortableType(SDL_Sensor *sensor)
Get the platform dependent type of a sensor.
Definition: SDL_sensor.c:349
int32_t Sint32
Definition: SDL_stdinc.h:197
SDL_SensorType
Definition: SDL_sensor.h:69
int SDL_SensorGetDeviceNonPortableType(int device_index)
Get the platform dependent type of a sensor.
Definition: SDL_sensor.c:178
SDL_SensorType SDL_SensorGetType(SDL_Sensor *sensor)
Get the type of a sensor.
Definition: SDL_sensor.c:336
SDL_SensorType SDL_SensorGetDeviceType(int device_index)
Get the type of a sensor.
Definition: SDL_sensor.c:163
int SDL_SensorGetData(SDL_Sensor *sensor, float *data, int num_values)
Definition: SDL_sensor.c:375
SDL_SensorID instance_id
Definition: SDL_syssensor.h:35
#define SDLCALL
Definition: SDL_internal.h:45
int SDL_NumSensors(void)
Count the number of sensors attached to the system right now.
Definition: SDL_sensor.c:97
SDL_Sensor * SDL_SensorOpen(int device_index)
Open a sensor for use.
Definition: SDL_sensor.c:215
SDL_SensorID SDL_SensorGetDeviceInstanceID(int device_index)
Get the instance ID of a sensor.
Definition: SDL_sensor.c:193