The cut-off frequency of the lowpass filter was too high
for the sampling rate used by DELAY_NORMAL.
Now we use the same filters used for the gravity vector
(cascaded biquad at 1.5 Hz)
Change-Id: Iac290a716cc47a78337a8f0e45b103e49b4d9d78
whether a physical sensor needed to be active or not was managed by
a simpe reference counter; unfortunatelly nothing prevented it to
get out of sync if a sensor was disabled more than once.
sensorservice already maintainted a list of all the "clients"
connected to a physical sensor; we now use that list to determine if
a sensor should be enabled. This can never be "out-of-sync" since
this is the only data structure linking a sensor to a user of that
sensor.
also removed the isEnabled() method, which was never used and
implemented wrongly (since it didn't take into account that a sensor
could be disabled for a client but not of another).
Change-Id: I789affb877728ca957e99f7ba749def37c4db1c7
- upadte documentation for rotation vector
- update method dealing with rotation vector to deal with 4 components
- virtual rotation-vector sensor reports all four components
- improve SensorManager documentation layout
Whent he 4-th component of the rotation-vector is present, we can save
a square-root when computing the quaternion or rotation matrix from it.
Change-Id: Ia84d278dd5f0909fab1c5ba050f8df2679e2c7c8
indeed, by construction of the rotation matrix, it is
guaranteed to have a length of 1.
moreover, the normalization code was missing a square-root,
fortunatelly, since the length is 1, this didn't cause any
damage (since sqrt(1) = 1).
Change-Id: I9facd668caaf5bb3bfccb139ab872f2bb2066365
Rework sensorservice to allow "virtual sensors", that is
sensors that report a synthetized value based on real sensors.
the main change to sensorservice is around managing which real
sensor need to be activated and which rate to use.
The logic for all this has been moved into SensorDevice, which
essentially wraps the sensor HAL but adds two features to it:
- it keeps track of which sensors need to be activated
- it keeps track of what rate needs to be used
For this purpose an "identity" is associated with each real sensor
activation, so we can track them.
On start-up we check for gravity, linear-acceleration and
rotation-vector sensors, if they're not present in the HAL, we
synthetize them in sensor-service.
Change-Id: I841db2c1b37ef127ed571efa21732ecc5adf1800
