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

Include dependency graph for SDL_sensor.h:

This graph shows which files directly or indirectly include 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.
const char *	SDL_SensorGetDeviceName (int device_index)
	Get the implementation dependent name of a sensor.
SDL_SensorType	SDL_SensorGetDeviceType (int device_index)
	Get the type of a sensor.
int	SDL_SensorGetDeviceNonPortableType (int device_index)
	Get the platform dependent type of a sensor.
SDL_SensorID	SDL_SensorGetDeviceInstanceID (int device_index)
	Get the instance ID of a sensor.
SDL_Sensor *	SDL_SensorOpen (int device_index)
	Open a sensor for use.
SDL_Sensor *	SDL_SensorFromInstanceID (SDL_SensorID instance_id)
const char *	SDL_SensorGetName (SDL_Sensor *sensor)
	Get the implementation dependent name of a sensor.
SDL_SensorType	SDL_SensorGetType (SDL_Sensor *sensor)
	Get the type of a sensor.
int	SDL_SensorGetNonPortableType (SDL_Sensor *sensor)
	Get the platform dependent type of a sensor.
SDL_SensorID	SDL_SensorGetInstanceID (SDL_Sensor *sensor)
	Get the instance ID of a sensor.
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

#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

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

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,    /**< Returned for an invalid sensor */
    SDL_SENSOR_UNKNOWN,         /**< Unknown sensor type */
    SDL_SENSOR_ACCEL,           /**< Accelerometer */
    SDL_SENSOR_GYRO             /**< Gyroscope */
} SDL_SensorType;

Function Documentation

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().

{
    int i, total_sensors = 0;
    SDL_LockSensors();
    for (i = 0; i < SDL_arraysize(SDL_sensor_drivers); ++i) {
        total_sensors += SDL_sensor_drivers[i]->GetCount();
    }
    SDL_UnlockSensors();
    return total_sensors;
}

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.

{
    SDL_Sensor *sensorlist;
    SDL_Sensor *sensorlistprev;
    if (!SDL_PrivateSensorValid(sensor)) {
        return;
    }
    SDL_LockSensors();
    /* First decrement ref count */
    if (--sensor->ref_count > 0) {
        SDL_UnlockSensors();
        return;
    }
    if (SDL_updating_sensor) {
        SDL_UnlockSensors();
        return;
    }
    sensor->driver->Close(sensor);
    sensor->hwdata = NULL;
    sensorlist = SDL_sensors;
    sensorlistprev = NULL;
    while (sensorlist) {
        if (sensor == sensorlist) {
            if (sensorlistprev) {
                /* unlink this entry */
                sensorlistprev->next = sensorlist->next;
            } else {
                SDL_sensors = sensor->next;
            }
            break;
        }
        sensorlistprev = sensorlist;
        sensorlist = sensorlist->next;
    }
    SDL_free(sensor->name);
    /* Free the data associated with this sensor */
    SDL_free(sensor);
    SDL_UnlockSensors();
}

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().

{
    SDL_Sensor *sensor;
    SDL_LockSensors();
    for (sensor = SDL_sensors; sensor; sensor = sensor->next) {
        if (sensor->instance_id == instance_id) {
            break;
        }
    }
    SDL_UnlockSensors();
    return sensor;
}

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

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.

Definition at line 375 of file SDL_sensor.c.

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

{
    if (!SDL_PrivateSensorValid(sensor)) {
        return -1;
    }
    num_values = SDL_min(num_values, SDL_arraysize(sensor->data));
    SDL_memcpy(data, sensor->data, num_values*sizeof(*data));
    return 0;
}

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().

{
    SDL_SensorDriver *driver;
    SDL_SensorID instance_id = -1;
    SDL_LockSensors();
    if (SDL_GetDriverAndSensorIndex(device_index, &driver, &device_index)) {
        instance_id = driver->GetDeviceInstanceID(device_index);
    }
    SDL_UnlockSensors();
    return instance_id;
}

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().

{
    SDL_SensorDriver *driver;
    const char *name = NULL;
    SDL_LockSensors();
    if (SDL_GetDriverAndSensorIndex(device_index, &driver, &device_index)) {
        name = driver->GetDeviceName(device_index);
    }
    SDL_UnlockSensors();
    /* FIXME: Really we should reference count this name so it doesn't go away after unlock */
    return name;
}

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().

{
    SDL_SensorDriver *driver;
    int type = -1;
    SDL_LockSensors();
    if (SDL_GetDriverAndSensorIndex(device_index, &driver, &device_index)) {
        type = driver->GetDeviceNonPortableType(device_index);
    }
    SDL_UnlockSensors();
    return type;
}

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().

{
    SDL_SensorDriver *driver;
    SDL_SensorType type = SDL_SENSOR_INVALID;
    SDL_LockSensors();
    if (SDL_GetDriverAndSensorIndex(device_index, &driver, &device_index)) {
        type = driver->GetDeviceType(device_index);
    }
    SDL_UnlockSensors();
    return type;
}

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().

{
    if (!SDL_PrivateSensorValid(sensor)) {
        return -1;
    }
    return sensor->instance_id;
}

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().

{
    if (!SDL_PrivateSensorValid(sensor)) {
        return NULL;
    }
    return sensor->name;
}

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().

{
    if (!SDL_PrivateSensorValid(sensor)) {
        return -1;
    }
    return sensor->non_portable_type;
}

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.

{
    if (!SDL_PrivateSensorValid(sensor)) {
        return SDL_SENSOR_INVALID;
    }
    return sensor->type;
}

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.

{
    SDL_SensorDriver *driver;
    SDL_SensorID instance_id;
    SDL_Sensor *sensor;
    SDL_Sensor *sensorlist;
    const char *sensorname = NULL;
    SDL_LockSensors();
    if (!SDL_GetDriverAndSensorIndex(device_index, &driver, &device_index)) {
        SDL_UnlockSensors();
        return NULL;
    }
    sensorlist = SDL_sensors;
    /* If the sensor is already open, return it
     * it is important that we have a single sensor * for each instance id
     */
    instance_id = driver->GetDeviceInstanceID(device_index);
    while (sensorlist) {
        if (instance_id == sensorlist->instance_id) {
                sensor = sensorlist;
                ++sensor->ref_count;
                SDL_UnlockSensors();
                return sensor;
        }
        sensorlist = sensorlist->next;
    }
    /* Create and initialize the sensor */
    sensor = (SDL_Sensor *) SDL_calloc(sizeof(*sensor), 1);
    if (sensor == NULL) {
        SDL_OutOfMemory();
        SDL_UnlockSensors();
        return NULL;
    }
    sensor->driver = driver;
    sensor->instance_id = instance_id;
    sensor->type = driver->GetDeviceType(device_index);
    sensor->non_portable_type = driver->GetDeviceNonPortableType(device_index);
    if (driver->Open(sensor, device_index) < 0) {
        SDL_free(sensor);
        SDL_UnlockSensors();
        return NULL;
    }
    sensorname = driver->GetDeviceName(device_index);
    if (sensorname) {
        sensor->name = SDL_strdup(sensorname);
    } else {
        sensor->name = NULL;
    }
    /* Add sensor to list */
    ++sensor->ref_count;
    /* Link the sensor in the list */
    sensor->next = SDL_sensors;
    SDL_sensors = sensor;
    SDL_UnlockSensors();
    driver->Update(sensor);
    return sensor;
}

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.

{
    int i;
    SDL_Sensor *sensor;
    SDL_LockSensors();
    if (SDL_updating_sensor) {
        /* The sensors are already being updated */
        SDL_UnlockSensors();
        return;
    }
    SDL_updating_sensor = SDL_TRUE;
    /* Make sure the list is unlocked while dispatching events to prevent application deadlocks */
    SDL_UnlockSensors();
    for (sensor = SDL_sensors; sensor; sensor = sensor->next) {
        sensor->driver->Update(sensor);
    }
    SDL_LockSensors();
    SDL_updating_sensor = SDL_FALSE;
    /* If any sensors were closed while updating, free them here */
    for (sensor = SDL_sensors; sensor; sensor = sensor->next) {
        if (sensor->ref_count <= 0) {
            SDL_SensorClose(sensor);
        }
    }
    /* this needs to happen AFTER walking the sensor list above, so that any
       dangling hardware data from removed devices can be free'd
     */
    for (i = 0; i < SDL_arraysize(SDL_sensor_drivers); ++i) {
        SDL_sensor_drivers[i]->Detect();
    }
    SDL_UnlockSensors();
}

Macros

Typedefs

Enumerations

Functions

Detailed Description

Macro Definition Documentation

Typedef Documentation

Enumeration Type Documentation

Function Documentation