// The three things a query has to be handed together: the bodies, the order
// they are swept in, and the height grids some of them stand for.
//
// It is one struct rather than three arguments because every query and the
// character controller need all three, and threading them separately grows a
// parameter list at each layer without ever giving a caller a choice about
// which to pass.
use cratePool;
use Body;
use SweepPrune;
use Heightfields;
/// What a query reads. Borrowed, never owned: a query changes nothing.
pub