Get Location Address W.r.t The Polygon I Am In

I have over 200 polygons to create and I get the location by LocationListenerOnChanged() but I would like to know which polygon I am in based on the current location . How wil

Solution 1:

There is no direct method in android api v2 to know if a latlng lies within a polygon. So you need to do a mathemetical calculation known as point inside polygon check. You can check out the below two methods suggested in earlier posts:

1, Raycasting method

2, Winding number method

If in your case, checking a point against all 200 or more polygons is slowing your app, you can consider reducing the number of polygons to be checked. First of all , for each polygon, other than their vertices, also store an approximate geometric center. Then when you get a new location for checking, find the distance between this location and the geometric center of all the polygons. Now take only few polygons ( say 8) whose centers are closest to the point and then do any of the above point inside polygon check for those chosen polygons.