public static string AgentPath(MapAgentPath path, bool addBoundingBoxex = true)
{
var result = new GeoJsonMultiLine();
for(int i = 0; i < path.Points.Count - 2; i++)
{
var p0 = path.Points[i];
var p1 = path.Points[i + 1];
var segment = new List<List<double>>
{
new List<double> { p0.Lon, p0.Lat },
new List<double> { p1.Lon, p1.Lat }
};
result.Coordinates.Add(segment);
}
if (addBoundingBoxex)
{
foreach (var tileId in path.TileIds)
{
var bbox = new List<List<double>>();
var (lon0, lat0, lon1, lat1) = TileMath.GetTileBounds(tileId, WorldGraph.Zoom);
bbox.Add(new List<double> { lon0, lat0 });
bbox.Add(new List<double> { lon1, lat0 });
bbox.Add(new List<double> { lon1, lat1 });
bbox.Add(new List<double> { lon0, lat1 });
bbox.Add(new List<double> { lon0, lat0 });
result.Coordinates.Add(bbox);
}
}
return JsonSerializer.Serialize(result, SerializerOptions);
}
void AddTile(WayTile tile)
{
if (_tiles.Any(t => t.Id == tile.Id))
{
return;
}
_tiles.Add(tile);
var(lon0, lat0, lon1, lat1) = TileMath.GetTileBounds(tile.Id, Zoom);
foreach (var node in tile.Nodes)
{
node.TileId = tile.Id;
node.VisitCount = 0;
if (_nodeLut.TryGetValue(node.Id, out WayTileNode existingNode))
{
// It is possible that both nodes are inside their own tile if they are exactly on the border. Which one wins doesn't matter.
var insideNode = existingNode.Inside.HasValue ? existingNode : node;
var outsideNode = existingNode.Inside.HasValue ? node : existingNode;
// Node id already exists. This is a link between two tiles. The existing node should be outside its tile
// and the new one should be inside. Otherwise something is wrong.
// 1) Let the node inside its own tile inherit the connections of the other
var tileLinkConnections = outsideNode.Conn.Where(id => insideNode.Conn.Any(idOther => idOther == id)).ToList();
insideNode.Conn.AddRange(tileLinkConnections);
// 2) Overwrite the old one with the new one in the LUT.
_nodeLut[node.Id] = insideNode;
}
else
{
_nodeLut[node.Id] = node;
}
}
var outside = _nodeLut.Values.Where(v => !v.Inside.HasValue).ToList();
int loaded = 0;
int notLoaded = 0;
foreach (var n in outside)
{
if (!n.Inside.HasValue)
{
long tileId = TileMath.GetTileId(n.Point.Lon, n.Point.Lat, Zoom);
if (_tiles.Any(t => t.Id == tileId))
{
loaded++;
}
else
{
notLoaded++;
}
}
// all outside nodes should be in tiles NOT loaded.
}
}
public async Task <WayTile> GetTile(long tileId, int zoom)
{
var bbox = TileMath.GetTileBounds(tileId, zoom);
string dbgMsg = $"TileId {tileId}, zoom: {zoom}, bbox: ({bbox.lon0}, {bbox.lat0}, {bbox.lon1}, {bbox.lat1})";
_logger.LogInformation($"Loading: {dbgMsg}");
// https://wiki.openstreetmap.org/wiki/Bounding_Box
// The order of values in the bounding box used by Overpass API is (South, West, North, East):
// minimum latitude, minimum longitude, maximum latitude, maximum longitude
string cmd = $"[out: json];way(if:is_tag(\"highway\") || is_tag(\"route\"))({NumberStr(bbox.lat1)}, {NumberStr(bbox.lon0)}, {NumberStr(bbox.lat0)}, {NumberStr(bbox.lon1)});out qt;node(w);out skel qt;";
var client = new HttpClient();
var content = new StringContent(cmd);
OsmResponse osmResponse = null;
string body = "";
HttpResponseMessage httpRes = null;
int attempt = 0;
while (true)
{
try
{
var sw = Stopwatch.StartNew();
httpRes = await client.PostAsync(_currentUrl, content);
body = await httpRes.Content.ReadAsStringAsync();
long elapsed = sw.ElapsedMilliseconds;
osmResponse = JsonSerializer.Deserialize <OsmResponse>(body, SerializerOptions);
_logger.LogInformation($"Loaded (ms: {elapsed}, chars: {body.Length}, elements: {osmResponse.Elements.Count}): {dbgMsg}, url: {_currentUrl}");
break;
}
catch (Exception e)
{
if (++attempt > 3)
{
_logger.LogWarning($"Giving up getting tile: {dbgMsg}, exception: {e}");
return(null);
}
// Try switching URL on errors
_currentUrl = _currentUrl == UrlPrimary ? UrlSecondary : UrlPrimary;
_logger.LogInformation($"Retrying tile: {dbgMsg}, url: {_currentUrl}, exception: {e}");
await Task.Delay(200);
}
}
var osmNodes = osmResponse.Elements.Where(e => e.Type == "node").ToList();
var osmWays = osmResponse.Elements.Where(e => e.Type == "way").ToList();
var result = new WayTile();
result.Id = tileId;
var nodeLut = new Dictionary <long, WayTileNode>();
// First create all nodes...
foreach (var osmNode in osmNodes)
{
var node = new WayTileNode();
node.Id = osmNode.Id;
node.Point = new GeoCoord(osmNode.Lon, osmNode.Lat);
node.Inside = TileMath.IsInsideBounds(osmNode.Lon, osmNode.Lat, bbox) ? (byte?)1 : null;
nodeLut[osmNode.Id] = node;
result.Nodes.Add(node);
}
// ...then add connections between them
foreach (var osmWay in osmWays)
{
int nodeCount = osmWay.Nodes.Count;
for (int i = 0; i < nodeCount - 1; ++i)
{
var wayPointA = osmWay.Nodes[i];
var wayPointB = osmWay.Nodes[i + 1];
nodeLut.TryGetValue(wayPointA, out WayTileNode nodeA);
nodeLut.TryGetValue(wayPointB, out WayTileNode nodeB);
if (nodeA != null && nodeB != null)
{
// Skip connection if both nodes are out of bounds
bool withinBoundsA = TileMath.IsInsideBounds(nodeA.Point.Lon, nodeA.Point.Lat, bbox);
bool withinBoundsB = TileMath.IsInsideBounds(nodeB.Point.Lon, nodeB.Point.Lat, bbox);
if (withinBoundsA || withinBoundsB)
{
nodeA.Conn.Add(wayPointB);
nodeB.Conn.Add(wayPointA);
}
}
}
}
// Remove orphaned nodes outside of bounds
result.Nodes = result.Nodes.Where(n => n.Conn.Count > 0).ToList();
_logger.LogInformation($"Parsed (nodes: {result.Nodes.Count}): {dbgMsg}");
return(result);
}
