The terrain under the tracks and the end of Tracks onto the terrain took every chunk along the tracks away and made it again from the model, the changes made by hand with them (79 chunks on test2). The heights while laying are kept under a key of their own, so the fitted ones chosen when they were the default are left behind; fitted stays a choice.
Fitting the grade line took 3 ms for 250 m of track, 30 ms for 1 km, 65 ms for 2 km and 200 ms for 4 km, and the preview of the lay tool and of the drag from a free end fitted it every frame, twice for the drag; on the terrain model the preview of some 800 m took 10 to 17 ms a frame, the cursor standing or not. Now the frame waits under 1.5 ms for 4 km. The formations of the tracks led into the terrain went through every chunk under them 0.3 s after each click, some 50 ms, while the cursor went on to the next point; they wait for the laying to end. The tracks laid and the terrain are the same as before.
Selftests: perf logs the longest frame and those over 33 ms, fittime the time of the fit by length, terrainhash a hash of the chunks in memory.
A deleted track whose read events or track circuit no other track took says so by the cursor, naming the signals and the circuits, and the editor keeps them for the track laid in its place, within a metre of its axis. The read of each signal goes to the piece by the signal, on the list its facing there gives, so a track laid the other way round keeps the trains reading it; the other events go to the piece at its middle, the circuit to a track lying there for the most part, a new track taking it instead of the one of the track it was made from. It happens in the step which lays the track, so Ctrl+Z takes it back and laying it again gets them again; a track which took a circuit over and is removed by another step leaves it to that step, and the events of a signal taken away stay off the tracks.
The SRK panel of a station lists what it and its lines need: signals no track reads, lines broken off where the tracks go on beyond a gap, tracks of a line of the automatic block in no block section, block sections whose tracks are gone. A row shows the place; Repair has the track by each signal read it again, as moving it does, and sets the line signals again where tracks are in no block section. A warning after an operation shows by the cursor in amber, a refusal in red as before. srkcheck counts these too, srkfix repairs, join takes the height of the ends for sceneries far above zero.
A curve laid anew, its radius changed or made compound, or a straight moved: the paths of the chain are cut again where their joints stood, set square onto the new line, each keeping its stretch of the ground, so their events, their track circuits and the cuts of the block sections stay where they were instead of being handed on along the line; the parts between the switches alike, the old even sharing kept where the joints don't follow one another along the new line.
The objects by a track taken for a change go with it by themselves: the signals and the warning discs it or its run reads, the SHP resonators by their events, and the controls of the block sections, the hectometre posts, the W17 markers and the other signs by the track nearest to them, within 12 m. They move square to the new axis keeping their offset and their turn, an object moved by hand meanwhile staying where it was put. Such a binding isn't kept in the scenery nor shown among the bound objects of the infra tool, which can still bind the object for good, and the undo and the redo take the objects back and forth with the tracks. The status of the Plan tells how many objects moved with the tracks. A path taking an object over the other way round keeps it on its side, turned as it was.
A block boundary of a line both ways has, on each track, the block signal of its trains 15 m before the joint and the one of the wrong-track trains 15 m beyond it, named after its twin with N, both on the outside of the line, the templates leaning the other way picked for the N ones, as on the lines of PKP PLK. The mixed block keeps the automatic block for the trains of the track and the semi-automatic one for the wrong-track ones: no N signals, a warning disc the braking distance before the entry signal of the wrong-track trains. A choice under the table of the lines sets either for the double-track lines of the station, kept in the record of the station, and by itself a line takes the mixed block where a warning disc stands for its wrong-track trains and no N signal does. Set the line signals places the N signals or the warning disc and takes the other away, a block boundary drawn places the N signals of a line both ways, and sbl_odstep.inc switches both block signals of a section with its 7th parameter. The name shown at the mouse while drawing takes the letter the block signal will get where its number stands already.
The station schematic shows the lines out to the next stations straightened: their block sections in the colours of their names with their lengths, the joints, the block signals and the warning discs with their km on the outside of the line, the axis in km; Lines fits them in, a section under the mouse tells its name, length and km, and a click on it flies there in the 3d view.
The track mode Kilometrage (X, under More) puts a point of the km where a track is clicked: the line, the km and, at a jump,
the km on from it. The axis of a line follows the main paths of the switches through the tracks of its points; on a
double-track line it runs between the tracks, and where they part on formations of their own and come together again it
runs along the longer one, the shorter one going by its own length with its last hectometre before they meet taking up
the difference (PKP GK-1 6.1.12). The km between the points are stretched to the length of the scenery evenly; the panel
lists the points with the stretch, the 3D view shows the axis, a tick at each hectometre, the points with their km and
the km of the lines by the mouse. Read the km from the posts turns the hectometre posts along the line into the points
of its km, a jump where two runs of numbers meet, and warns of a jump on a curve or at a station (Id-1 § 19). Each change
is a step of undo.
The station keeps its km and the direction of its numbering in its record. The block signals are named after their km, odd on track 1 and even on track 2, the sections after the signals at their ends, and each signal gets the control of its section.