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.
In place of a line bent every ten metres to keep within 0.1 m of every bump,
the grades and the vertical curves are fitted to the ground the way the
profile fits them. Where the formation is made in the terrain model the line
keeps to the radius of the norms and cuts and fills; over the ground left as
it is it bends as sharply as it has to. The joints keep the height and the
grade of the track joined, no grade is capped and no piece is under 5 m.