On Dec 28, 10:44 am, Will <[email protected]> wrote: > Hi, > > I'd like to know how i can determine between which markers the user > clicked on the polygon. so if i have a polygon A ---- B ----- C and > the user clicks on the line between B and C, now the polygon event > gives me a GLatLng but how can figure out that the Glatlng is between > B and C?
There are at least three methods; but which you choose depends on how you are drawing your line. Let's call the click point Q. You could use a straight-line graph (y=mx+c), calculate the straight line connecting B and C and then find whether point Q lies on that line. That will be reasonably accurate for short distances. You could also do this in pixels if B and C are both on the map: if Q is on the line BC as drawn in pixels, it will get the result which matches the map shown. Or you could use the formulae at http://www.movable-type.co.uk/scripts/latlong.html -- find the bearing of point C from B. Then find the bearing of point Q from B. If the bearings are the same, Q lies on the line BC. Because this method uses great circles drawn on a sphere, it will look right if you use geodesic lines, but may not match the map if you use straight lines. Andrew -- 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.
