private OsmWorldData ToWorld(OsmResponse response, float s, float w, float n, float e)
{
var nodes = new List <OsmNode>();
var ways = new List <OsmWay>();
var others = new List <OsmElement>();
foreach (var element in response.elements)
{
switch (element.type)
{
case "way":
ways.Add(OsmWay.FromElement(element));
break;
case "node":
nodes.Add(OsmNode.FromElement(element));
break;
default:
others.Add(element);
break;
}
}
return(new OsmWorldData(response.version, response.generator, new OsmRect(s, w, n, e), response.osm3s, ways,
nodes, others));
}
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);
}
