检查纬度和经度的公式是在没有Google Maps Api的区域内

Question

I have this Example Map:

I make Boundary Polygon shape,

-6.875165174925262, 107.56293296813965
-6.882663904407988, 107.66730308532715
-6.980818117491586, 107.67210960388184
-6.97093546084682, 107.54508018493652

How can I check if the given (Lat, Lng) -6.935884,107.611592 is inside that Boundary Polygon?

I need to do it without Google Maps API, because the program will be offline and must check more often than Google API's free service will allow.

Is there any geometric formula I can use for this? With PHP or Python if possible.

Answer 1

Finally i got the answer ... Detect Point in Polygon

this function help me alot ... and works great... others function sometime give false result whether point in or outside polygon