include/SDL_sensor.h
author Ryan C. Gordon <icculus@icculus.org>
Mon, 14 Jan 2019 19:43:25 -0500
changeset 12548 1ae839748d02
parent 12503 806492103856
permissions -rw-r--r--
evdev: don't debug log on a BTN_TOUCH from a non-touch device.
     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 /**
    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  *  \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: */