simple line path calculations that don't suffer from the accumulated
rounding errors that our previous method did.
git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@1434 542714f4-19e9-0310-aa3c-eee0fc999fb1
directions, otherwise movement in one direction will unnecessarily reset
the "move stamp" for the other direction in which we didn't actually move.
git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@1415 542714f4-19e9-0310-aa3c-eee0fc999fb1
follow a path (specifically, I want to allow the media panel to be
"scrolled" along a path).
git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@1409 542714f4-19e9-0310-aa3c-eee0fc999fb1
same math that the scrolling code does to scroll in a straight line.
git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@1377 542714f4-19e9-0310-aa3c-eee0fc999fb1