Interest in supporting Tangent Colorgrading Panels? LiftGammaGain Widget reset bug

[Michael Hirczy]

Greetings!

I have been using kdenlive for quite some time now, and it's a fantastic
NLE, thx a lot for that!

While trying to learn the craft of filmmaking (as a hobbyist), I also
stumbled upon the topic of color correction.
Since I'm a full-stack-nerd/geek *gg*, I like nice hardware with knobs and
displays :D

So I managed to find a used Tangent CP200 color control surface and
contacted Tangent about support for Linux.
I got the full development package and I'm actually in the process of
learning c++ and qt to make support for the Tangent hardware inside of
KDEenlive.
(I've been coding for about 30 years, worked fulltime as Java-Dev and
although technology has quite evolved through the years, it's still easy for
me to read someone's code and refactor it to my needs)

Is there interest to put Tangent-support into the official repository?
since they released their Ripple, color grading software is not so expensive
anymore...

I will program it anyways, so maybe it can be some help to others...

When researching the code for color grading, I found a interesting behaviour
of the LiftGammaGain-Widget:
On every color correction panel you have 2 buttons to reset color and
brightness independently.
During my first steps I found, that resetting the color wheel in the LGGW
works as intended (just reset the color wheel), but resetting the brightness
bar will reset the color wheel, too!

I don't know if this is intended or a bug - but I decided to change it to my
needs (only reset the brightness/value bar):
In colorwheel.cpp I just changed line 178:
            // old code: c =
NegQColor::fromRgbF(m_defaultValue/m_sizeFactor,
m_defaultValue/m_sizeFactor, m_defaultValue/m_sizeFactor);
            c = NegQColor::fromHsvF(m_color.hueF(), m_color.saturationF(),
m_defaultValue/m_sizeFactor);

ATM I'm not very good at git, so I don't like to submit such a small change
to the official repository.
(aaand I'm actually using the 18.08 branch for my dev-testing)

If there's need to implement this into the repo, could someone of the devs
do this? 
Otherwise, if the actual reset-algorithm is planned to work like this, just
keep it this way :)

thx and greetings
michi