libinput-soften_delta-gnuplot-graph

#!/usr/bin/gnuplot
# soften_delta function from libinput/src/filter.c. 
# 
# static double
# soften_delta(double last_delta, double delta)
# {
#     if (delta < -1.0 || delta > 1.0) {
#         if (delta > last_delta)
#             return delta - 0.5;
#         else if (delta < last_delta)
#             return delta + 0.5;
#     }
#     return delta;
# }

sd(dx, dx_old) = (abs(dx) < 1.0) ? dx : \
                        (dx > dx_old) ? dx - 0.5 : \
                                (dx < dx_old) ? dx + 0.5 : \
                                    dx

set xrange [-3:3]
set yrange [-3:3]
set isosamples 20
splot sd(x, y) with points
pause -1