Stellarium / stellarium / 9316146993

11%

Build Type

push

github

Committed by 10110111

Commit Message

Rewrite generation of shadow limits

Previous version didn't quite match the rise-set curve, crossing it or
failing to reach instead of touching. The crossing was likely due to a
bad approximation for taking into account Earth flattening, and the
failure to reach the final point was due to the fact that a single point
in time may generate two points of a single limit curve, while the
iteration in the original implementation (and the one in the book) are
only capable of generating one.

The new implementation goes a very different route: a single equation is
derived for all the limit points at a given time, and these points are
then found by Newton's method of locating roots.

This is not completely robust, so I there may be cases when this fails
due to Newton's method's lack of guarantees of convergence. When this
happens, we'll see discontinuities in the curves. But from what I
tested, these discontinuities, when present (particularly when the lines
naturally have multiple branches), are not critical due to refinement
being done at their ends.

Run Details

0 of 283 new or added lines in 1 file covered. (0.0%)

396 existing lines in 1 file now uncovered.

14429 of 117659 relevant lines covered (12.26%)

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