Tablet SupportKrita has relied on Qt's graphics tablet support since Krita 2.0. We consciously dropped our own X11-level code in favour of the cross-platform API that Qt offered. And apart from the lack of support for non-Wacom tablets, this was mostly enough on X11. On Windows, the story was different, and we were confronted by problems with offsets, bad performance, no support for tablets with built-in digitizers like the Lenovo Helix.
So, with leaden shoes, we decided to dive in, and do our own tablet support. This was mostly done by Dmitry Kazakov during a week-long visit to Deventer, sponsored by the Krita Foundation. We now have our own code on X11 and Windows. Drawing is much, much smoother because we can process much more information and issues with offsets are gone.
OpenGL and ShadersKrita was one of the first painting applications to support OpenGL to render the image. And while OpenGL gave us awesome performance when rotating, panning or zooming, rendering quality was lacking a bit.
That's because by default, OpenGL scales using some fast, but inaccurate algorithms. Basically, the user had the choice between grainy and blurry rendering.
Again, as part of his sponsored work by the Krita Foundation, Dmitry took the lead and implemented a high-quality scaling algorithm on top of the modern, shader-based architecture Boudewijn had originally implemented.
The result? Even at small zoom levels, the high-quality scaling option gives beautiful and fast results!
http://krita.org - Corel Painter / Adobe Photoshop alternative.