SDL_sensor.h File Reference

#include "SDL_stdinc.h"
#include "SDL_error.h"
#include "begin_code.h"
#include "close_code.h"

Go to the source code of this file.

Macros
#define	SDL_STANDARD_GRAVITY   9.80665f

Typedefs
typedef struct _SDL_Sensor	SDL_Sensor
typedef Sint32	SDL_SensorID

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

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

typedef struct _SDL_Sensor SDL_Sensor

Definition at line 52 of file SDL_sensor.h.

SDL_SensorID

typedef Sint32 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

enum 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.

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

Function Documentation

SDL_NumSensors()

DECLSPEC int SDLCALL 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()

SDL_SensorClose()

DECLSPEC void SDLCALL SDL_SensorClose

(

SDL_Sensor *

sensor

)

Close a sensor previously opened with SDL_SensorOpen()

SDL_SensorFromInstanceID()

DECLSPEC SDL_Sensor* SDLCALL SDL_SensorFromInstanceID

(

SDL_SensorID

instance_id

)

Return the SDL_Sensor associated with an instance id.

SDL_SensorGetData()

DECLSPEC int SDLCALL 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

sensor	The sensor to query
data	A pointer filled with the current sensor state
num_values	The number of values to write to data

Returns

0 or -1 if an error occurred.

SDL_SensorGetDeviceInstanceID()

DECLSPEC SDL_SensorID SDLCALL 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.

SDL_SensorGetDeviceName()

DECLSPEC const char* SDLCALL 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.

SDL_SensorGetDeviceNonPortableType()

DECLSPEC int SDLCALL 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.

SDL_SensorGetDeviceType()

DECLSPEC SDL_SensorType SDLCALL 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.

SDL_SensorGetInstanceID()

DECLSPEC SDL_SensorID SDLCALL 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.

SDL_SensorGetName()

DECLSPEC const char* SDLCALL SDL_SensorGetName

(

SDL_Sensor *

sensor

)

Get the implementation dependent name of a sensor.

Returns

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

SDL_SensorGetNonPortableType()

DECLSPEC int SDLCALL 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.

SDL_SensorGetType()

DECLSPEC SDL_SensorType SDLCALL 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.

SDL_SensorOpen()

DECLSPEC SDL_Sensor* SDLCALL 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.

SDL_SensorUpdate()

DECLSPEC void SDLCALL 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.