// Returns true if the given point is contained by the buffered region,
// i.e. if it is within the given radius of any original shape.
public bool Contains(S2Point p)
{
var target = new S2ClosestEdgeQuery.PointTarget(p);
// Return true if the distance is less than or equal to "radius_".
return(query_.IsDistanceLess(target, radius_successor_));
}
// The implementation is approximate but conservative; it always returns
// "false" if the cell is not contained by the buffered region, but it may
// also return false in some cases where "cell" is in fact contained.
public bool Contains(S2Cell cell)
{
// Return true if the buffered region is guaranteed to cover whole globe.
if (radius_successor_ > S1ChordAngle.Straight)
{
return(true);
}
// To implement this method perfectly would require computing the directed
// Hausdorff distance, which is expensive (and not currently implemented).
// However the following heuristic is almost as good in practice and much
// cheaper to compute.
// Return true if the unbuffered region contains this cell.
if (Index().MakeS2ShapeIndexRegion().Contains(cell))
{
return(true);
}
// Otherwise approximate the cell by its bounding cap.
//
// NOTE(ericv): It would be slightly more accurate to first find the closest
// point in the indexed geometry to the cell, and then measure the actual
// maximum distance from that point to the cell (a poor man's Hausdorff
// distance). But based on actual tests this is not worthwhile.
S2Cap cap = cell.GetCapBound();
if (Radius < cap.Radius)
{
return(false);
}
// Return true if the distance to the cell center plus the radius of the
// cell's bounding cap is less than or equal to "radius_".
var target = new S2ClosestEdgeQuery.PointTarget(cell.Center());
return(query_.IsDistanceLess(target, radius_successor_ - cap.Radius));
}
