I don't know relevant keywords about this algorithm.
I can show you visually
Any ideas are appreciated
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3$\begingroup$ ("scan|sweep line" or "line|plane scan|scanning|sweep|sweeping" and "polar coordinates"?) Are you looking for terminology or algorithm? Tag accordingly! $\endgroup$– greybeardFeb 25, 2020 at 9:11
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1$\begingroup$ Take a look at stackoverflow.com/questions/6989100/… $\endgroup$– ciamejFeb 25, 2020 at 17:12
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1$\begingroup$ This reminds me of parts of the Jarvis March algorithm or Graham scan for convex hull calculation. Maybe these articles will give you some additional wording clues. $\endgroup$– Nobody moving away from SEFeb 25, 2020 at 22:38
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2 Answers
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For each of your points in the field, calculate the red angle:
Then sort all the (point, angle)-tuples by the angle.
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Here's a way to sort points by angle in Swift:
let radarSortedPoints: [CGPoint] = points.sorted { pointA, pointB -> Bool in
atan2(pointA.y, pointA.x) < atan2(pointB.y, pointB.x)
}
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4$\begingroup$ Just a note, the use of atan2 is not necessary, see github.com/Laakeri/contestlib/blob/master/src/geometry/… for an implementation that is exact for integers. $\endgroup$– LaakeriFeb 25, 2020 at 9:55
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$\begingroup$ @Laakeri Isyourspacekeybroken? lol why would you type def something as clear as
complex<long long>to something as arbitrary and cryptic asco? $\endgroup$ Feb 25, 2020 at 23:37