Example #1
0
        private IObservable <T> Search(IEnvelop envelope, int zoomLevel)
        {
            var minMargin = ZoomHelper.GetMinMargin(zoomLevel);

            return(Observable.Create <T>(observer =>
            {
                var node = Root;
                if (!envelope.Intersects(node.Envelope))
                {
                    observer.OnCompleted();
                    return Disposable.Empty;
                }

                var nodesToSearch = new Stack <RTreeNode>();

                while (node != null && node.Envelope != null)
                {
                    if (node.Children != null)
                    {
                        foreach (var child in node.Children)
                        {
                            var childEnvelope = child.Envelope;
                            if (envelope.Intersects(childEnvelope))
                            {
                                if (node.IsLeaf && childEnvelope.Margin >= minMargin)
                                {
                                    observer.OnNext(child.Data);
                                }
                                else if (envelope.Contains(childEnvelope))
                                {
                                    Collect(child, minMargin, observer);
                                }
                                else
                                {
                                    nodesToSearch.Push(child);
                                }
                            }
                        }
                    }
                    node = nodesToSearch.TryPop();
                }
                observer.OnCompleted();
                return Disposable.Empty;
            }));
        }