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module SF::Sensor #

Give access to the real-time state of the sensors

SF::Sensor provides an interface to the state of the various sensors that a device provides. It only contains static functions, so it's not meant to be instantiated.

This module allows users to query the sensors values at any time and directly, without having to deal with a window and its events. Compared to the Event::SensorChanged event, SF::Sensor can retrieve the state of a sensor at any time (you don't need to store and update its current value on your side).

Depending on the OS and hardware of the device (phone, tablet, ...), some sensor types may not be available. You should always check the availability of a sensor before trying to read it, with the SF::Sensor.available? function.

You may wonder why some sensor types look so similar, for example Type::Accelerometer and Type::Gravity / Type::UserAcceleration. The first one is the raw measurement of the acceleration, and takes into account both the earth gravity and the user movement. The others are more precise: they provide these components separately, which is usually more useful. In fact they are not direct sensors, they are computed internally based on the raw acceleration and other sensors. This is exactly the same for Gyroscope vs Orientation.

Because sensors consume a non-negligible amount of current, they are all disabled by default. You must call SF::Sensor.set_enabled for each sensor in which you are interested.

Usage example: 

if SF::Sensor.available?(SF::Sensor::Gravity)
  # gravity sensor is available
end

# enable the gravity sensor
SF::Sensor.set_enabled(SF::Sensor::Gravity, true)

# get the current value of gravity
gravity = SF::Sensor.get_value(SF::Sensor::Gravity)

Class methods#

.available?(sensor : Sensor::Type) : Bool#

Check if a sensor is available on the underlying platform

  • sensor - Sensor to check

Returns: True if the sensor is available, false otherwise

View source

.get_value(sensor : Sensor::Type) : Vector3f#

Get the current sensor value

  • sensor - Sensor to read

Returns: The current sensor value

View source

.set_enabled(sensor : Sensor::Type, enabled : Bool)#

Enable or disable a sensor

All sensors are disabled by default, to avoid consuming too much battery power. Once a sensor is enabled, it starts sending events of the corresponding type.

This function does nothing if the sensor is unavailable.

  • sensor - Sensor to enable
  • enabled - True to enable, false to disable
View source