1 /* 2 Simple DirectMedia Layer 3 Copyright (C) 1997-2020 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 */ 60 typedef Sint32 SDL_SensorID; 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 */ 75 } SDL_SensorType; 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 * Locking for multi-threaded access to the sensor API 126 * 127 * If you are using the sensor API or handling events from multiple threads 128 * you should use these locking functions to protect access to the sensors. 129 * 130 * In particular, you are guaranteed that the sensor list won't change, so 131 * the API functions that take a sensor index will be valid, and sensor 132 * events will not be delivered. 133 */ 134 extern DECLSPEC void SDLCALL SDL_LockSensors(void); 135 extern DECLSPEC void SDLCALL SDL_UnlockSensors(void); 136 137 /** 138 * \brief Count the number of sensors attached to the system right now 139 */ 140 extern DECLSPEC int SDLCALL SDL_NumSensors(void); 141 142 /** 143 * \brief Get the implementation dependent name of a sensor. 144 * 145 * This can be called before any sensors are opened. 146 * 147 * \return The sensor name, or NULL if device_index is out of range. 148 */ 149 extern DECLSPEC const char *SDLCALL SDL_SensorGetDeviceName(int device_index); 150 151 /** 152 * \brief Get the type of a sensor. 153 * 154 * This can be called before any sensors are opened. 155 * 156 * \return The sensor type, or SDL_SENSOR_INVALID if device_index is out of range. 157 */ 158 extern DECLSPEC SDL_SensorType SDLCALL SDL_SensorGetDeviceType(int device_index); 159 160 /** 161 * \brief Get the platform dependent type of a sensor. 162 * 163 * This can be called before any sensors are opened. 164 * 165 * \return The sensor platform dependent type, or -1 if device_index is out of range. 166 */ 167 extern DECLSPEC int SDLCALL SDL_SensorGetDeviceNonPortableType(int device_index); 168 169 /** 170 * \brief Get the instance ID of a sensor. 171 * 172 * This can be called before any sensors are opened. 173 * 174 * \return The sensor instance ID, or -1 if device_index is out of range. 175 */ 176 extern DECLSPEC SDL_SensorID SDLCALL SDL_SensorGetDeviceInstanceID(int device_index); 177 178 /** 179 * \brief Open a sensor for use. 180 * 181 * The index passed as an argument refers to the N'th sensor on the system. 182 * 183 * \return A sensor identifier, or NULL if an error occurred. 184 */ 185 extern DECLSPEC SDL_Sensor *SDLCALL SDL_SensorOpen(int device_index); 186 187 /** 188 * Return the SDL_Sensor associated with an instance id. 189 */ 190 extern DECLSPEC SDL_Sensor *SDLCALL SDL_SensorFromInstanceID(SDL_SensorID instance_id); 191 192 /** 193 * \brief Get the implementation dependent name of a sensor. 194 * 195 * \return The sensor name, or NULL if the sensor is NULL. 196 */ 197 extern DECLSPEC const char *SDLCALL SDL_SensorGetName(SDL_Sensor *sensor); 198 199 /** 200 * \brief Get the type of a sensor. 201 * 202 * This can be called before any sensors are opened. 203 * 204 * \return The sensor type, or SDL_SENSOR_INVALID if the sensor is NULL. 205 */ 206 extern DECLSPEC SDL_SensorType SDLCALL SDL_SensorGetType(SDL_Sensor *sensor); 207 208 /** 209 * \brief Get the platform dependent type of a sensor. 210 * 211 * This can be called before any sensors are opened. 212 * 213 * \return The sensor platform dependent type, or -1 if the sensor is NULL. 214 */ 215 extern DECLSPEC int SDLCALL SDL_SensorGetNonPortableType(SDL_Sensor *sensor); 216 217 /** 218 * \brief Get the instance ID of a sensor. 219 * 220 * This can be called before any sensors are opened. 221 * 222 * \return The sensor instance ID, or -1 if the sensor is NULL. 223 */ 224 extern DECLSPEC SDL_SensorID SDLCALL SDL_SensorGetInstanceID(SDL_Sensor *sensor); 225 226 /** 227 * Get the current state of an opened sensor. 228 * 229 * The number of values and interpretation of the data is sensor dependent. 230 * 231 * \param sensor The sensor to query 232 * \param data A pointer filled with the current sensor state 233 * \param num_values The number of values to write to data 234 * 235 * \return 0 or -1 if an error occurred. 236 */ 237 extern DECLSPEC int SDLCALL SDL_SensorGetData(SDL_Sensor * sensor, float *data, int num_values); 238 239 /** 240 * Close a sensor previously opened with SDL_SensorOpen() 241 */ 242 extern DECLSPEC void SDLCALL SDL_SensorClose(SDL_Sensor * sensor); 243 244 /** 245 * Update the current state of the open sensors. 246 * 247 * This is called automatically by the event loop if sensor events are enabled. 248 * 249 * This needs to be called from the thread that initialized the sensor subsystem. 250 */ 251 extern DECLSPEC void SDLCALL SDL_SensorUpdate(void); 252 253 254 /* Ends C function definitions when using C++ */ 255 #ifdef __cplusplus 256 /* *INDENT-OFF* */ 257 } 258 /* *INDENT-ON* */ 259 #endif 260 #include "close_code.h" 261 262 #endif /* SDL_sensor_h_ */ 263 264 /* vi: set ts=4 sw=4 expandtab: */ 265