Simplifying FlightSeparations: removal of some possibilities

[jdaw1]

FlightSeparations has possibilities that are ugly and have been superseded.

The basic line construct has straights meeting at sharp turns. These can be softened with the new (March 2021) /Arc control, which replaces the sharp turn with a part-circle.

• The old (Sep 2010) /Curve inserts a Bézier curve made with the PostScript command curveto, the two middle knot points both being where the straight lines would meet. The end knots points are not necessarily equidistant from this, so the curve can look lopsided. Too often it’s ugly.

• There’s also a possibly of clinging to the outside of the circle with /Clockwise or /Widdershins (older: Nov 2009). Optically, these more than minimally interfere with the Circlearrays, and so have never looked good. The existence of these necessitated /HorizontalLeftwards, /HorizontalRightwards, /VerticalDown, and /VerticalUp.

Ugly; superseded. Hence the proposal is to remove support for all of:

• /Curve,
• /Clockwise,
• /Widdershins,
• FlightSeparationArcRadiusControl (which affects only /Clockwise and /Widdershins),
• /HorizontalLeftwards,
• /HorizontalRightwards,
• /VerticalDown, and
• /VerticalUp.

Objections?

[jdaw1]

Email from Glenn E., Sat 10 Apr 2021, replying to a question asking whether he objected: “I do not; safe to remove.”

[jdaw1]

FlightSeparations have been used only rarely. FTR, and as mind food, I find six past uses:

• Niepoort, 12 Nov 2010;
• Olympic, 25 July 2012;
• 1997s, 16 June 2014;
• 1985s, 26 Feb 2016;
• Sercial, 30 Apr 2016;
• Sixties, 08 May 2018.

Also, one possible forthcoming use:

• 1994s, 16 Nov 2021.

[jdaw1]

Decision: at a convenient moment, I will do this simplification. Doing so will: remove a possible ugliness; make the documentation easier to digest; and make the code itself easier to read and maintain.

[jdaw1]

Done.