rorystephenson / supercluster_dart Goto Github PK

// Clusters must be global functions
// dynamic radius calculation, zoom is saved in poi point
SuperclusterImmutable<POIPoint> _calculateClusters(List<POIPoint> data) {
  if (data.isEmpty) {
    return SuperclusterImmutable<POIPoint>(radius: 50, getX: (m) => m.longitude!, getY: (m) => m.latitude!);
  }

  const int minZoom = 2, maxZoom = 20;
  const int minRadius = 7, maxRadius = 75;
  const int minExtent = 51, maxExtent = 512;
  double currentZoom = data.first.zoomLevel ?? 10;

  int radius = calculateRadius(currentZoom, minZoom, maxZoom, minRadius, maxRadius);
  int extent = calculateExtent(currentZoom, minZoom, maxZoom, minExtent, maxExtent);

  debugPrint('Radius/Zoom/Extent: $radius $currentZoom $extent');

  final cluster = SuperclusterImmutable<POIPoint>(
    radius: radius,
    extent: extent,
    getX: (m) => m.longitude!,
    getY: (m) => m.latitude!,
    minZoom: minZoom,
    maxZoom: maxZoom,
  )..load(data);

  return cluster;
}

int calculateRadius(double currentZoom, int minZoom, int maxZoom, int minRadius, int maxRadius) {
  int radius;
  if (currentZoom <= minZoom) {
    radius = maxRadius;
  } else if (currentZoom >= maxZoom) {
    radius = minRadius;
  } else if (currentZoom < 13.5) {
    radius = ((maxRadius - minRadius) * (maxZoom - currentZoom) / (maxZoom - minZoom) + minRadius).round();
  } else {
    radius = ((maxRadius - minRadius) * (maxZoom - currentZoom) / (maxZoom - minZoom) + minRadius - 15).round();
  }
  return radius < minRadius ? minRadius : radius;
}

int calculateExtent(double currentZoom, int minZoom, int maxZoom, int minExtent, int maxExtent) {
  int extent;
  if (currentZoom <= minZoom) {
    extent = maxExtent;
  } else if (currentZoom >= maxZoom) {
    extent = minExtent;
  } else if (currentZoom < 13.5) {
    extent = ((maxExtent - minExtent) * (currentZoom - minZoom) / (maxZoom - minZoom) + minExtent).round();
  } else {
    extent = ((maxExtent - minExtent) * (currentZoom - minZoom) / (maxZoom - minZoom) + minExtent - 100).round();
  }
  return extent < minExtent ? minExtent : extent;
}

Future ComputePoints() async {
  await updatePoints();
  CombinedProvider.cluster = await compute(_calculateClusters, CombinedProvider.poiPoints.values.toList());
}

calculateClusters() async {
  int start = DateTime.now().millisecond;
  List<Map<String, dynamic>> clusterDatas = [];
  //Search all map
  var clusterSearch = CombinedProvider.cluster!
      .search(180, -90, 180, 90, _mlMapController.cameraPosition!.zoom.toInt())
      .map((e) => e.map(cluster: (c) {
            clusterDatas.add({
              'marker': true,
              'lat': c.latitude,
              'lng': c.longitude,
              'zoom': CalculationUtil.zoomMore(c.highestZoom + 0),
            });
            return getClusterSymbol(c);
          }, point: (p) {
            clusterDatas.add({
              'poi': p.originalPoint.toJson(),
              'lat': p.originalPoint.latitude,
              'lng': p.originalPoint.longitude,
            });
            return getPOISymbol(p);
          }));
  int end = DateTime.now().millisecond;
  CombinedProvider().updateAllSymbols(clusterSearch.toList(), clusterDatas);
  debugPrint('clusterSearch took ${end - start}ms: ${clusterSearch.length}/${CombinedProvider.cluster!.length}');
  _lastClusterCalculateCameraPos = _mlMapController.cameraPosition;
  redrawPOISymbols();
}