Absolute path length since swipe start (|step| per axis).
Current pointer position.
Offset from start to current (angle is accumulated).
Total displacement in movement space (rubber + snap applied).
Previous pointer position.
Movement on the previous frame (movement space, after rubber and snap).
Current scaling modifier
Pointer position at swipe start.
Offset from prev to current.
Last event timestamp (ms).
Snapshot exposed on swipe callbacks and accessors.
Pointer space:
start,prev,current,diff,step,accum. Movement space:movement(after bounds rubber and snap; use for transforms).