SDL 2.0
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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 , SDL_SENSOR_ACCEL_L , SDL_SENSOR_GYRO_L , SDL_SENSOR_ACCEL_R , SDL_SENSOR_GYRO_R } |
Functions | |
void | SDL_LockSensors (void) |
void | SDL_UnlockSensors (void) |
int | SDL_NumSensors (void) |
const char * | SDL_SensorGetDeviceName (int device_index) |
SDL_SensorType | SDL_SensorGetDeviceType (int device_index) |
int | SDL_SensorGetDeviceNonPortableType (int device_index) |
SDL_SensorID | SDL_SensorGetDeviceInstanceID (int device_index) |
SDL_Sensor * | SDL_SensorOpen (int device_index) |
SDL_Sensor * | SDL_SensorFromInstanceID (SDL_SensorID instance_id) |
const char * | SDL_SensorGetName (SDL_Sensor *sensor) |
SDL_SensorType | SDL_SensorGetType (SDL_Sensor *sensor) |
int | SDL_SensorGetNonPortableType (SDL_Sensor *sensor) |
SDL_SensorID | SDL_SensorGetInstanceID (SDL_Sensor *sensor) |
int | SDL_SensorGetData (SDL_Sensor *sensor, float *data, int num_values) |
int | SDL_SensorGetDataWithTimestamp (SDL_Sensor *sensor, Uint64 *timestamp, float *data, int num_values) |
void | SDL_SensorClose (SDL_Sensor *sensor) |
void | SDL_SensorUpdate (void) |
Include file for SDL sensor event handling
Definition in file SDL_sensor.h.
#define SDL_STANDARD_GRAVITY 9.80665f |
Accelerometer sensor
The accelerometer returns the current acceleration in SI meters per second squared. This measurement includes the force of gravity, so a device at rest will have an value of SDL_STANDARD_GRAVITY away from the center of the earth, which is a positive Y value.
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 and game controllers held in front of you, 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.
Definition at line 103 of file SDL_sensor.h.
typedef struct _SDL_Sensor SDL_Sensor |
Definition at line 52 of file SDL_sensor.h.
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.
enum SDL_SensorType |
Definition at line 69 of file SDL_sensor.h.
void SDL_LockSensors | ( | void | ) |
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 (pitch) values[1]: Angular speed around the y axis (yaw) values[2]: Angular speed around the z axis (roll)
For phones held in portrait mode and game controllers held in front of you, 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 or controller is rotated.
If you are using the sensor API or handling events from multiple threads you should use these locking functions to protect access to the sensors.
In particular, you are guaranteed that the sensor list won't change, so the API functions that take a sensor index will be valid, and sensor events will not be delivered.
int SDL_NumSensors | ( | void | ) |
Count the number of sensors attached to the system right now.
void SDL_SensorClose | ( | SDL_Sensor * | sensor | ) |
Close a sensor previously opened with SDL_SensorOpen().
sensor | The SDL_Sensor object to close |
SDL_Sensor * SDL_SensorFromInstanceID | ( | SDL_SensorID | instance_id | ) |
Return the SDL_Sensor associated with an instance id.
instance_id | The sensor from instance id |
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.
sensor | The SDL_Sensor object to query |
data | A pointer filled with the current sensor state |
num_values | The number of values to write to data |
int SDL_SensorGetDataWithTimestamp | ( | SDL_Sensor * | sensor, |
Uint64 * | timestamp, | ||
float * | data, | ||
int | num_values | ||
) |
Get the current state of an opened sensor with the timestamp of the last update.
The number of values and interpretation of the data is sensor dependent.
sensor | The SDL_Sensor object to query |
timestamp | A pointer filled with the timestamp in microseconds of the current sensor reading if available, or 0 if not |
data | A pointer filled with the current sensor state |
num_values | The number of values to write to data |
SDL_SensorID SDL_SensorGetDeviceInstanceID | ( | int | device_index | ) |
Get the instance ID of a sensor.
device_index | The sensor to get instance id from |
device_index
is out of range.const char * SDL_SensorGetDeviceName | ( | int | device_index | ) |
Get the implementation dependent name of a sensor.
device_index | The sensor to obtain name from |
device_index
is out of range.int SDL_SensorGetDeviceNonPortableType | ( | int | device_index | ) |
Get the platform dependent type of a sensor.
device_index | The sensor to check |
device_index
is out of range.SDL_SensorType SDL_SensorGetDeviceType | ( | int | device_index | ) |
Get the type of a sensor.
device_index | The sensor to get the type from |
SDL_SENSOR_INVALID
if device_index
is out of range.SDL_SensorID SDL_SensorGetInstanceID | ( | SDL_Sensor * | sensor | ) |
Get the instance ID of a sensor.
sensor | The SDL_Sensor object to inspect |
sensor
is NULL.const char * SDL_SensorGetName | ( | SDL_Sensor * | sensor | ) |
Get the implementation dependent name of a sensor
sensor | The SDL_Sensor object |
sensor
is NULL.int SDL_SensorGetNonPortableType | ( | SDL_Sensor * | sensor | ) |
Get the platform dependent type of a sensor.
sensor | The SDL_Sensor object to inspect |
sensor
is NULL.SDL_SensorType SDL_SensorGetType | ( | SDL_Sensor * | sensor | ) |
Get the type of a sensor.
sensor | The SDL_Sensor object to inspect |
SDL_SENSOR_INVALID
if sensor
is NULL.SDL_Sensor * SDL_SensorOpen | ( | int | device_index | ) |
Open a sensor for use.
device_index | The sensor to open |
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.
void SDL_UnlockSensors | ( | void | ) |