For comparison purposes, port the legacy velocity tracker
algorithm as it behaved prior to ICS.
Bug: 6413587
Change-Id: I7e8e56584dcdb1a3c660ca9d8f9c5bd5d868e449
This algorithm better tolerates certain kinds of errors in the
touch input than the least squares strategy but it may underestimate
the velocity of accelerating movements. This algorithm is
mainly of interest as a baseline for testing and comparison with the
least squares algorithm, which remains the default.
Bug: 6413587
Change-Id: I8ddb50084e44875e234717907e5b06d03f59788c
This change is very useful for testing purposes because it makes it
easy to compare different implementations to see how they behave.
There is no change to the current default strategy.
Bug: 6413587
Change-Id: I4d8567aa4160571ba9fa397ce419882cd9366749
Some input devices do not generate ACTION_MOVE events while all
pointers have stopped, thereby lulling the VelocityTracker into
a false sense of complacency. Before handling the following sample,
reset the VelocityTracker state so as not to be influenced by
earlier samples before the pointer stopped. The velocity after
stopping is assumed to be discontinuous.
Bug: 6413587
Change-Id: I6387bc036ff141d083d3d17a89e37eeaa3188349
VelocityTracker was implicitly assuming that the pointer ids in
a MotionEvent were ordered. That is not necessarily the case
so we need to be careful while copying the pointer coordinates out.
Bug: 6413587
Change-Id: I3b23a954f893eebdf786f2a94207149b092ef036
