Krita/Hacking
Krita Development Overview
Building KDE Software
Krita is a great place to start even if you are brand new to KDE development. We'd love to have you join!
KDE has undergone big changes since a major 2014 reorganization. As a result, working with KDE software has never been easier. Unfortunately, since the changes were so widespread, the documentation has not caught up at all. If you are embarking on the journey, please remember that all of these wiki pages are open to editing. (Select the OpenID / Identity Login option with your KDE Identity account.)
The KDE Techbase Wiki has instructions for new developers. On top of basic tools of C++, git, and general notions of building and packaging large code bases, some special tools that are particular to Krita are Qt, CMake, and KDE Frameworks. It can be very helpful for you to get started to find and read some of the articles discussing these tools.
https://techbase.kde.org/Development http://flossmanuals.net/kde-guide/ https://techbase.kde.org/Contribute
Getting in touch
https://forum.kde.org/viewtopic.php?f=288&t=125955
Building Krita
There are guides to building Krita on the Krita main page. There are two types of builds: using software from a package manager, only possible on Linux, and building everything from source.
Development Philosophy
Krita is nearly ten years old, consists of around 1.1 million lines of code, and has had many individual contributors throughout the years. If you run into something in the code that doesn't make sense to you, you may very well be the only person who knows what's going on.