fix(editor): a curve laid from a free end on a curve, or to one, goes on from its curvature: traced (Tab) from the end of the diverging track of a switch it begins right at P4 at the radius of the switch, not on a straight nor with a transition from a curvature of 0. The design of the line takes the curve of the adjoining track at each end (start_curved/end_curved with the radius, the side and the cant, kept with it in the scenery): the curve of the first vertex turning its way, or of the last one, begins right at the end, its transition going from that curvature and cant to those of its first arc, as between the arcs of a compound curve, none where it goes on at its radius; the radius of its arcs is the one which begins it there, solved for the tangent, the curves next to it making room on the straight. A curve traced next to such an end is fitted by its transitions alone, with none between the curves where the points keep to that as well, or laid from a straight there where it doesn't go on from it or that keeps to the points much closer: eased out of the curve of a plain track by the transition of the norms, the line beginning at its end, or right from P4, as a switch goes on with a straight. A bend of straights turning the way of the curve gets its curve going on from it with the transitions and the cant of the norms; the other way, or a straight, as before: eased out of the curve of a plain track, the jump of the curvature kept at a switch, as at its start, and not warned of. The cant of the adjoining track goes on into the curve with no ramp at that end; the norms ask for the transition between the curves only where the curvature differs by more than 5 % or the cant by 5 mm. The readout by the cursor, the status after laying and the plan tell the curve going on from the track, the plan with a box to go on or not. Dragged back to P4 from a point the curve goes on from its radius too. Selftests laywalk, laybends, curvejoint, endcurves; unit tests of a curve going on from a switch and into a free end, its cant, traced, through a transition into a larger radius, and of a bend of straights after such an end

application/editormodeselftest.cpp

@@ -129,6 +129,11 @@ editor_mode::selftest_result editor_mode::selftest_dispatch(std::string const &c
 //   layclicks <layout 0..3> <radius> <x> <z>...   clicks of the lay tool at the points, a free end within 3 m joined
 //   layspeed <km/h> <own 0|1>            the speed set for the laying, and whether it goes also on from a track with its own
 //   laymode <straights|curve>, layradius <R from> <R to>, laytrace <radii 0..3> <straights between 0|1>   as the panel of the laying sets them
+//   endcurves                            logs every free end of the rails: where, the way out and the curvature its track goes on with
+//   curvejoint <x> <z>                   logs the paths meeting at the end nearest the point, the curvature of each and its jump from the ones before to the ones after
+//   laywalk <from|into> <x> <z> <spacing> <noise> <k0> <k1> <L>...   a line of known curves on from the free end nearest the point,
+//                                        the points along it clicked in the mode of a curve, from the end or towards it (see the command)
+//   laybends <x> <z> <distance> <degrees> ... <distance>   the bends of straights clicked from the free end nearest the point
 //   layp <x> <z>...                      the points clicked in the mode set, on the ground, a free end within 3 m reached
 //   layreport <label>                    logs the line the points clicked make, as Enter would lay it: its bends and curves, warnings, traces
 //   layenter, layback, laycancel         as Enter, Backspace and Esc while laying