Since the tubes are symmetrical, instead of using an extra vertex to flip the winding order, I just mirror all horizontal coordinates so that the triangles flip inside out.
This adds a front-facing primitive towards the back side of every travel line, causing those lines to be visible from both sides regardless of backface culling. This doubles the number of vertices for travel moves, but due to backface culling it comes down to approximately the same performance as the original.
in the Feedrate color scheme. Due to the travel speed is normally very
high compared with the other speeds in the model, the gradient is now
gradual instead of linear in order to show more changes in the low
values and less changes in the high values.
Adapt also the button styles and themes' colors.
Set the play/pause button to the left and reduce the size.
