BMQuadtree+Search.swift

/// Nearest neigbour to a defined point.
let nearest = tree.element(nearestTo: float2(0, 0))

/// You may filter for different types (classes) when performing 
/// a nearest element search.
let nearestLocation = tree.element(
  nearestTo: float2(0, 0), 
  type: CLLocation.self)

/// All of the elements in the quadtree node this point would be placed in.
let elementsAtPoint = tree.elements(at: float2(0, 0))

/// All of the elements that resides in quadtree nodes which intersect 
/// the given quad. Recursively check if the earch quad contains the points 
/// in the quad.
let searchQuad = BMQuad(
  quadMin: float2(-10, -10), 
  quadMax: float2(10, 10))

let elementsInQuad = tree.elements(in: searchQuad)