QTR

A simple QuadTree in Swift, along with some useful tools to help create and work with a spatial index.

Some code based on pseudocode from Wikipedia

##Usage##

• Create a QTRNodePointobject for User.
• Create a QTRBBox with the bounding box for the total area to be searched. (TODO: Update this to be calculated based on the input data.)
• Create an Array of QTRNodePoint for locations/landmarks.
• Initialize QTRNode with the above array and set the number of points in each bucket.
• Call nearestNeighbours() to query the QuadTree.

let userPoint: QTRNodePoint = QTRNodePoint(longitude, latitude, name)
let bbox: QTRBBox = QTRBBox(withArray: boundingArray)
let pointArray: [QTRNodePoint] = [pointa, pointb, pointc]

let node: QTRNode? = QTRNode(pointArray, bbox, bucketCount)

// Traverses the tree and prints elements in nodes that are closest to userPoint.
nearestNeighboursAlternate(toPoint: userPoint, startingAt: node!, canUseParent: true, andApply: { (nd: QTRNodePoint) -> () in
    print(nd.name)
})

##Note##

QuadTree.swift : Last tested in Xcode 7.2.1

QuadTree.playground : Contains an updated, more concise QuadTree that uses Swift 3. Last tested in Xcode 8.2.1.

##License## See included LICENSE file.