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I use this in my app to determine if a vehicle is within a defined zone made of 5 or more lat/lon coordinates. Point 1 is also Point 5 (first point and last point are same value). A simple box shows...
link: dear @Harris, sorry that i turned your thread to this chaos :D i hope you forgive me :)...
link: centroid(1) End Sub this gives me the center of the polygon and now i can set the origin and scale...
link: Central point for a square works because of its simmetry. Also would work for regular polygons. Not...

Hello, I am using this code found in this topic post 6 : https://www.b4x.com/android/forum/threads/geo-zone-determination-point-in-polygon.53929/#post-427417 Sub CheckPointInPolygone(polx...
link: you give them, but they must be coherent. If the coordinates of polx and poly are meters the result is in...
link: Did you have a look at THIS post? The link is in the first line in the post you are referring to...
link: Yeah I missed it. Thanks !...

Running this SQL in the spatialite gui application: SELECT ID FROM P_POINTS WHERE Within(GEOMETRY....163287 52.604595, -2.165476 52.604321)', 4326)) = 1 Geometry is the column in P_POINTS holding lat...
link: (MakePoint(-2, 52, 4326)) || " & _ "', Polygon: ' || hex(polygonfromtext...
link: Point and Polygon: Point...
link: Running this SQL in the spatialite gui application: SELECT ID FROM P_POINTS WHERE Within(GEOMETRY...

it working. Perfomance is good. Processing time ... it can be much better. With a huge file of points (>3000) the program might give a stackoverflow. the PointInPolygon function has some issues. Or points are outside the polygon and the function return False. Or the function returns True so...For those interested in convex/concave processing: Based on the article Adriano Moreira and Maribel Yasmina Santos i feeded the suggest pseudo code into ChatGPT and asked to build the B4j program...

). But I do know how holes in font characters work, and perhaps it's the same here? If so, it's only a matter of making sure that the points in the inner polygon goes in the other direction from the outer polygon. Meaning, if the outer polygon has its points clockwise, the inner one should have its points counterclockwise....
link: involves the creation of polygons with a hole inside, passing as parameters the list of points...

1. You cannot hide parts of the map. 2. https://www.b4x.com/android/forum/pages/results/?query=point+in+polygon...
link: -determination-point-in-polygon.53929/#content...

. And at last, add the starting point to close the polygon. Remember to add the points in the correct... the first point at last to close the polygon Private gpm as GPSPolyMap gpm.Initialize(PolyPoints) Sub...With this class, you can check if the GPS location coordinate is inside a polygon. You can use...
link: info: year 2015 https://www.b4x.com/android/forum/threads/geo-zone-determination-point-in-polygon...
link: info: year 2015 https://www.b4x.com/android/forum/threads/geo-zone-determination-point-in-polygon...

O anche questo https://www.b4x.com/android/forum/threads/geo-zone-determination-point-in-polygon.53929/...
link: O anche questo https://www.b4x.com/android/forum/threads/geo-zone-determination-point-in-polygon...

Do you want to know when a user clicks inside the polygon? As far as I am aware there is no automated way to do this However, you can use this code. https://www.b4x.com/android/forum/threads/geo-zone-determination-point-in-polygon.53929/ I have used this code to monitor clicks in over 100 polygons and the performance is fine....

Check this: https://www.b4x.com/android/forum/threads/geo-zone-determination-point-in-polygon.53929/#content...
link: with convex shapes. Type Point (X As Double, Y As Double) Public Sub IsPointInPolygon(p As Point, pList...
link: Source: https://stackoverflow.com/questions/41203225/check-if-point-is-in-polygon-with-google-maps...