Pencil tool stylus pressure inverts on part of the pressure curve. (Windows nightly build, Huion Q620M)

Summary:

Using pencil tool, applying lightest to heaviest pressure, resulting thickness is at first fixed/non-responsive, then becomes thinner(!) with increasing pressure, then reverses course and becomes thicker with pressure as expected.

NB: the calligraphy tool appears to respond to pressure correctly with no problem. Windows Ink is enabled in Huion driver.

Steps to reproduce:

  • open Inkscape with empty profile dir
  • select Pencil tool
  • turn on pressure sensitivity
  • try to draw simple straight line with lightest possible pressure
  • underneath that line, draw the same line again, but gradually increase pressure to maximum

What happened?

Picture attached. Lines were drawn from upper right to lower left. foo

What should have happened?

The perfectly uniform width of the lightest-possible-pressure line bugs me, but I suppose it's possible that's correct. Given my hand is not that steady, I would have expected at least some tiny width variation, but OK mabye.

The second line should start at the same width but get progressively thicker. The narrow part of the second line is closer to the width I would have expected to get with minimum pressure, but maybe that's irrelevant.

The red outline shown during drawing correctly shows what is going to happen; that is, it gets narrower with increasing pressure at the same spot.

Version info


Inkscape 1.2-dev (236a794e, 2022-01-13)

    GLib version:     2.70.2
    GTK version:      3.24.31
    glibmm version:   2.66.2
    gtkmm version:    3.24.5
    libxml2 version:  2.9.12
    libxslt version:  1.1.34
    Cairo version:    1.17.4
    Pango version:    1.50.3
    HarfBuzz version: 3.2.0

    OS version:       Windows 10 21H1