John and Neil, I have another question and hope you guys can enlight me a little. Because I am going to cover the whole united states. I have to use many big images(5120 X 5120). How do I connect 2 lat/lon pairs that on different images? Any one of you have the function already done that?
Thanks Qin On Mar 12, 9:44 pm, zoogle <[email protected]> wrote: > Thanks Neil! > > On Mar 11, 4:21 pm, "neil.young" <[email protected]> wrote: > > > > > See below. Use: > > > TileCoordinate c = new TileCoordinate(lat, lon, zoom); > > if (c.locationCoord()) { > > // Do whatever > > > } > > > whereas lat, lon is the geocoordinate (e.g. 52.123, 13.123) and zoom is > > the Google zoom stage (0...17). The resulting x,y is the image > > coordinate within the big, fat picture, Google draws for us. The int > > part may be used directly to obtain the tiles (Attention: Illegal) using > > a URL formed like this: > > > String.Format("http://mt.google.com/mt?x={0}&y={1}&zoom={2}";, c.x, c.y, > > 17-zoom) > > > The fractional part times 256 is the pixel coordinate within the tile > > itself. > > > Regards > > > using System; > > using System.Collections.Generic; > > using System.Text; > > > namespace TileRequest { > > class TileCoordinate { > > public TileCoordinate(double lat, double lon, int zoom) { > > this.lat = lat; > > this.lon = lon; > > this.zoom = zoom; > > } > > public double y; > > public double x; > > > public double lat; > > public double lon; > > public int zoom; > > > public bool locationCoord() { > > if (System.Math.Abs(this.lat) > 85.0511287798066) > > return false; > > double sin_phi = System.Math.Sin(this.lat * System.Math.PI / > > 180); > > double norm_x = this.lon / 180; > > double norm_y = (0.5 * System.Math.Log((1 + sin_phi) / (1 - > > sin_phi))) / System.Math.PI; > > this.y = System.Math.Pow(2, this.zoom) * ((1 - norm_y) / 2); > > this.x = System.Math.Pow(2, this.zoom) * ((norm_x + 1) / 2); > > return true; > > } > > } > > > }- Hide quoted text - > > > - Show quoted text -- Hide quoted text - > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Maps API" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/Google-Maps-API?hl=en -~----------~----~----~----~------~----~------~--~---
