I need to process millions of latitude/longitude points every day to see if they are located within a defined lat/lon bounded polygon. The polygon may be rectangular, or it may be some irregular 3.. n sided shape. The points of the polygons will all be straight lines between points defined by lat/lon, no curves to complicate things. Allowing for great circle would be great. Many of the polygons will transit the anti-meridian or meridian. Every approach that I have tried so far fails with anti-meridian crossing and some don't handle meridian crossings.
I'm completely useless with mathematics and probably not trainable at this point so classical math notation will fly directly over my head.
The math functions that are available in my environment include all the standard geometry elements (a full list of available math functions can be seen at this link
I don't expect anyone to write code for me, but I'm hoping that someone can show me an algorithmic example in the pseudo-code like form of: (ignore the content, it's meaningless)
c = atan2(lon) * 4800 ca = sin(c)
Something like that would be really helpful.