On May 4, 9:58 am, nive <[email protected]> wrote: > HI, > > How to determine if a point is within a polygon.
I would use this: Part 12 Using EPoly - extra methods for polygons and polylines. http://econym.org.uk/gmap/epoly.htm .Contains(latlng) Returns true if the GLatLng is inside the poly and false if the GLatLng is outside. The method works for closed or open polygons and polylines. If the shape is open, it considers there to be an additional virtual line from the last point to the first. -- Larry > > I wrote this function > > Private Function inPolygon(ByVal pA As Double(,), ByVal x As Double, > ByVal y As Double) As Boolean > > '-------------------------------------------------------------------' > 'Point inclusion in polygon test > 'Makes use of the ray-casting algorithim (based on the Jordan > Curve > 'Theorem) to determine if a point is within a polygon. > 'Taken from W Randolph Franklin, > 'http://www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/ > pnpoly.html > > '-------------------------------------------------------------------' > > Dim i As Integer = 0 > Dim j As Integer = 0 > Dim c As Boolean = False > > j = pA.GetUpperBound(0) > > For i = 0 To pA.GetUpperBound(0) > If ((((pA(i, 1) <= y) And (y < pA(j, 1))) Or ((pA(j, 1) <= > y) And (y < pA(i, 1)))) _ > And (x < (pA(j, 0) - pA(i, 0)) * (y - pA(i, 1)) / (pA(j, > 1) - pA(i, 1)) + pA(i, 0))) Then > c = Not c > End If > j = i > Next > > Return c > > End Function > > I need to use this function where i am pulling the points from the > databse.I am getting error, can anybody tell me how to do this > > I was using like this, i am not sure if this is correct wa of doing > or not > > Dim dr As OracleClient.OracleDataReader = cmd.ExecuteReader > If dr.HasRows Then > xml = "<?xml version=""1.0"" encoding=""iso-8859-1"" ?>" + > vbNewLine > > xml += "<markers>" + vbNewLine > While dr.Read() > 'If inPolygon(PollyArray(longitude, latitude), dr > ("longitude"), dr("latitude")) Then > xml += "<marker" > > Thanks > Nive --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
