The angle needs to be added to the start angle.
Add tests to cover this:
* Check end point is correct
* Check midpoints are within tolerance
This would have prevented the bug fixed in 5813164d1,
as well as the bug fixed in this commit.
As well as failed tests, this manifests when routing across
Edge.Cuts arcs (unless they happen to start at 0 degrees
staritng angle).
Expose as expected failure to prove tests catch it.
Fix to follow in separate commit.
Prevent a divide-by-zero bug in SHAPE_ARC::ConvertToPolyline.
When the radius is zero, just use the initial angle (it makes
no different anyway, the result is the centre point, which is
the start point.
Add unit test of SHAPE_ARC::ConvertToPolyline.
This function has a bug when the arc is of zero radius. This
test shows the bug, but does not fix it yet.
Test a few "centre-point-angle" cases and add some
generic geom code for testing vectors and boxes are within
tolerance (since rounding often creeps in).
Much of the arc-checking code will be useful to other
construction methods (e.g. point-point-point).
There are expected failures for the bbox code when
the arc passes though, but does not end on, a quadrant point
(0, 90, 180, 270). This is due to a defective
implementation of SHAPE_ARC::BBox() that does not take
into account the quadrant points. This will be fixed
as a follow-up.