富豪的に。
| vertices center pi thetaOf |
vertices := {100@100. 200@100. 200@200. 100@200} shuffled. "任意順に与えられた四座標"
center := (vertices min + vertices max) / 2.
pi := Float pi.
thetaOf := [:point | ((point - center) theta - pi) \\ (2 * pi)].
^ vertices sort: [:aa :bb | (thetaOf value: aa) < (thetaOf value: bb)]
同じ方針で、コの字にこだわらない（匚の字でもいい）のなら…。
| vertices center |
vertices := {100@100. 200@100. 200@200. 100@200} shuffled.
center := (vertices min + vertices max) / 2.
^ vertices sort: [:aa :bb | (aa - center) theta < (bb - center) theta]=> #(200@200 100@200 100@100 200@100)
小市民的に。
| vertices rect |
vertices := {100@100. 200@100. 200@200. 100@200} shuffled.
rect := vertices min corner: vertices max.
^ {rect topLeft. rect topRight. rect bottomRight. rect bottomLeft}
同じく、コの字にこだわらない（凵の字でもいい）のなら…。
| vertices |
vertices := {100@100. 200@100. 200@200. 100@200} shuffled.
^ (vertices min corner: vertices max) corners=> #(100@100 100@200 200@200 200@100)
