public static IPoint TileToWorldPos(long tile_x, long tile_y, long zoom)
{
IPoint p = new PointClass();
double n = Math.PI - ((2.0 * Math.PI * tile_y) / Math.Pow(2.0, zoom));
p.X = (float)((tile_x / Math.Pow(2.0, zoom) * 360.0) - 180.0);
p.Y = (float)(180.0 / Math.PI * Math.Atan(Math.Sinh(n)));
return p;
}