Problem: Round brush

Round brush large of 70 pixels on a square 1000x1000pixel is very, too much slow

Requirement:

Main requirement is fast painting with default brush. Other paintops are not very important and it is just nice to have them fast.

Krita problem

mask generation
tile caching when bitBlting (both when applying the stroke and when doing the recomposition)
updating the display

Solution

Possible solution is to check how mypaint uses the tile engine and what is slow in tile engine with valgrind. Mask generation can be implemented with more clever algorithm? I would need to find out. OpenGL can be used to render the stroke and composite the result to KisPaintDevice in the end. OpenCL has been released. Maybe some stuff can be paralized with OpenCL.

Problem: Select brush

Select brush / size / custom brush is cumbersome

Requirement

Less clicks to get the job done for changing the parameters for paintops.

Krita problem

Paintop presets saving is not done yet, sliders should be used more in the UI. For opacity , you need to click on the label with the opacity percent ; and after a slider appear , and at end you can click to raise or lower opacity.... Why not just a slider ? [David]

Solution

KDE4.3.x has exp slider which would be cool to have. KOffice does not want to depend on KDE4.3 but KDE4.2, so #ifdefs needs to be used. The bugs from bugs.kde.org shows that tablet user does not like spinboxes that much.

Vera is working on preset ui, so maybe help her to implement the stuff she designs faster as I have more experiences with Qt probably.

Problem: openexr layers

Performence

Requirement

Painting on openexr with layers and 10000x4000 images with 500x500 brushes (so performance again)

Krita problem

It is slow

Solution

It is unknown.

{{{ ASCI notes:

OpenGL based paint device?
caching the horizontal and vertical iterators

}}}