s_wall_thickness is not setting values as per description

[Tau512]

What happened?

I'm not sure if this is a problem with some overextrusion i'm seeing recently (not sure if slicer or print - still trying to figure it out!!) but i've noticed the following along with various nightly fixes with flow/extrusion related issues:

in the case of a 0.4mm nozzle (as defined with nozzle_diameter[0]) and as per the description of wall thickness, it states it must be between nozzle size and 2*nozzle size; so 0.4-0.8mm.

Trying some random values, it appears it also allows it substantially over 2x nozzle, but also seems to be doing something wrong with calculations as 1.299999 results in a 0.91 for 1 wall, or 1.78mm for 2 walls :

Project file & How to reproduce

set 0.4mm nozzle.

adjust wall thickness values inside description limits.
adjust wall thickness values outside of description limits

Version

GTK3 ubu64 nightly 14441cf AppImage

Operating system

No response

Printer model

No response

[legend069]

this is likely a floating point calculation error
can reproduce on 2.4.58.5 - windows
typing "1.3" into s_wall_thickness pressing enter and it auto corrects itself to 1.2999999x

[Tau512]

it wasnt so much the rounding error, but the fact the description shows it can only be UPTO 2x nozzle (so 0.8 max wall thickness).

same 0.4mm nozzle with 1.1mm thickness = 1.14mm for 1 perimeter which isnt that far off 3x nozzle size:

[supermerill]

There was an error.
The external perimeter half-spacing was used as a full spacing (so it was a bit bigger than expected).
fixed for next version.