For interpolators defined with a path, PathInterpolator is more accurate
and likely less costly for longer animations than what are currently
using as a substiute - LUTInterpolator.
Test: manual test and added a unit test
BUG: 32830741
Change-Id: I867c7a28e4261392cce9c45a2992ab4fd120c496
Get rid of compuation of the intersection for penumbra and convex hull for umbra.
Use simple circle / normal to compute the penumbra and simple intersection for umbra.
The new way could be 2x to 4x faster from rectangle to round shape.
And this part is roughly half of the shadow computation, or 2/3 of spot shadow
computation.
This improve the spot shadow spikeness too.
b/16712006
b/14976551
Change-Id: I02911784868731369efa73f76fc915bc08248600
