[Solved]OpenStreetMap coordinates to tiles

https://wiki.openstreetmap.org/wiki/Slippy_map_tilenames#C.23

Using the docs I have

Code (CSharp):

1. public PointF WorldToTilePos(double lon, double lat, int zoom)
2.     {
3.         PointF p = new Point();
4.         p.X = (float)((lon + 180.0) / 360.0 * (1 << zoom));
5.         p.Y = (float)((1.0 - Math.Log(Math.Tan(lat * Math.PI / 180.0) +
6.             1.0 / Math.Cos(lat * Math.PI / 180.0)) / Math.PI) / 2.0 * (1 << zoom));
7.  
8.         return p;
9.     }

this gives me a very long float that I somehow need to use in a webrequest.

Code (CSharp):

1. string url = "http://d.tile.stamen.com/watercolor/"+zoom+"/"+x+"/"+y+".jpg";

kind of stuck however. Not sure the step inbetween to get the correct index/ int of the tile from the PointF value

 

Was trying

Code (CSharp):

1. string url = "http://d.tile.stamen.com/watercolor/"+zoom+"/"+(int)x+"/"+(int)y+".jpg";

but it gave me weird offsets.


Maybe this is the explanation... still a bit confusing tho.

 

Oh, duh. I was using the https://docs.mapbox.com/help/interactive-tools/static-api-playground/ and it was centering created maps on the Coordinates.
In open street the tiles are pre rendered so each tile has 4 "subtiles" per zoom level. So when I zoom in a level I need to recenter the map on my coordinates since the map at any scale will be chosen simply if the coordinates are contained within it (thanks to my rounding).

Code (CSharp):

1. string url = "http://d.tile.stamen.com/watercolor/"+zoom+"/"+(int)x+"/"+(int)y+".jpg";