Hummer12007
Support fractional values
Supersedes #51 Fixes #50
first one adds parsing fractional percentages, unconditionally, and alters the calculations to account for it
second one adds --frac to print percentages as floats. I'm not sure if it warrants a short option (-f and -F may be useful for other stuff).
I'll sit on it for some time and think about it.
If anyone is interested @bbarenblat @Atemu, please test it (there might be some regressions in calculations).
Percentage changes are floating point for a reason.
Can you elaborate, @Hummer12007?
#118 is not fixed by this.
I don't mean to come off as dismissive here, but are fractional percentages actually useful? It feels like more trouble than it's worth. At least on my system, a +/-1% change is already almost imperceptible.
With such a low max brightness, setting a fractional brightness isn't accurate anyway. If precision is truly what a user needs, setting the brightness in device units is always going to be as precise and accurate as possible.
$ ./brightnessctl -m --frac s 50%
amdgpu_bl1,backlight,128,50.2%,255
$ ./brightnessctl -m --frac s 10%+
amdgpu_bl1,backlight,154,60.39%,255
$ ./brightnessctl -m --frac s 10%-
amdgpu_bl1,backlight,129,50.59%,255
$ ./brightnessctl -m --frac s 10%+
amdgpu_bl1,backlight,155,60.78%,255
$ ./brightnessctl -m --frac s 10%-
amdgpu_bl1,backlight,130,50.98%,255
$ ./brightnessctl -m --frac s 10%+
amdgpu_bl1,backlight,156,61.18%,255
$ ./brightnessctl -m --frac s 10%-
amdgpu_bl1,backlight,131,51.37%,255
$ ./brightnessctl -m --frac s 10%+
amdgpu_bl1,backlight,157,61.57%,255
$ ./brightnessctl -m --frac s 10%-
amdgpu_bl1,backlight,132,51.76%,255
$ ./brightnessctl -m --frac s 10%+
amdgpu_bl1,backlight,158,61.96%,255
$ ./brightnessctl -m --frac s 10%-
amdgpu_bl1,backlight,133,52.16%,255
$ ./brightnessctl -m --frac s 10%+
amdgpu_bl1,backlight,159,62.35%,255
$ ./brightnessctl -m --frac s 10%-
amdgpu_bl1,backlight,134,52.55%,255
$ ./brightnessctl -m --frac s 10%+
amdgpu_bl1,backlight,160,62.75%,255
$ ./brightnessctl -m --frac s 10%-
amdgpu_bl1,backlight,135,52.94%,255
I don't really remember tbh, but https://github.com/Hummer12007/brightnessctl/commit/7b607b35ee4d1f0f660626ff6a9c95ed7d4da778 fixed a bug, and was more correct than the previous behavior. Most likely in the case with an exponent set. I'll try to play around a bit more with the code later. 0-255 is a really nice pathological case though.
Something along the following lines may fix your use case: if the delta is a percentage, and the current value corresponds to the result of trying to set an integer percentage, then round down the percentage; which would obviously break if the exponent gets changed but w/e.
@Hummer12007 a5a9a95788e43510043e903c8bd012df57e88a9f didn't work. Does #128 work for you?