// Get map package which is neighbour for given in specified direction.
public MapPackage getNeighbourMapPkg(MapPackage pkg, Point direction, int zoom)
{
if (direction.X != -1 && direction.X != 0 && direction.X != 1 ||
direction.Y != -1 && direction.Y != 0 && direction.Y != 1)
{
throw new MapNotFoundException("Bad direction!");
}
double topLeftLongitude = pkg.getTopLeftLongitude();
double topLeftLatitude = pkg.getTopLeftLatitude();
double bottomRightLongitude = pkg.getBottomRightLongitude();
double bottomRightLatitude = pkg.getBottomRightLatitude();
double longitude = (topLeftLongitude + bottomRightLongitude) / 2;
double latitude = (topLeftLatitude + bottomRightLatitude) / 2;
switch (direction.X)
{
case 1:
longitude = bottomRightLongitude + 0.000001;
break;
case -1:
longitude = topLeftLongitude - 0.000001;
break;
}
// NOTE: y has inverted direction in map context
switch (direction.Y)
{
case 1:
latitude = bottomRightLatitude - 0.000001;
break;
case -1:
latitude = topLeftLatitude + 0.000001;
break;
}
return(getMapPkg(latitude, longitude, zoom));
}