The brush settings editor could use some nice symbolic icons for the various inputs to the MyPaint brush engine, to be displayed alongside text or even on their own. They would be primarily for informational purposes, and helping users identify what buttons or sections do.
We need icons for:
Pressure
How hard you press with the stylus nib
Concepts: weights, force vector arrows, bowling balls on a pin
Fine speed
How fast you’re moving, averaged over a very short distance. Changes fast
Concepts: cheetah, sprinter, gymnast, motorcycle, speed arrows or lines
Almost but not quite the length of time spent drawing a stroke with pressure.
Concepts: stopwatch, clock
Direction
The angle in which the stroke is going (0 through 180 degrees)
Just the angle matters, not which direction you’re going. If you stop and then reverse over your line, it stays the same.
Concepts: protractor, double-ended compass pointer or double-ended arrow at an angle
Declination
This is part of tilt. It’s 0° when the stylus is perpendicular to the tablet/screen, and 90° when it’s lying flat.
Concepts: astronomer’s telescope, hemisphere with a dot, angle between vertical and an angled pen
Ascension
The other part of tilt. This is “right ascension”, or the rotation of the pen nib in the plane of the tablet/screen.
It’s 0° when the stylus nib is pointing at you +90° when the nib points to your left, -90° when it points directly right.
Concepts: geometry, signposts showing North, spin the bottle, compass
Custom
This is an input made up of other inputs. It’s kind of a convenience variable for
Concepts: An algebraic italic “x”. Feedback loop (it doesn’t really).
Wheel
MyPaint doesn’t support this yet, but it’s the angle on a tablet touchring associated with a pen, or the angle of the flow rate wheel on a digital “airbrush” stylus
MyPaint doesn’t support this yet, but it’s a very fancy tilt feature. It’s the amount of turn you put along the axis of the pen itself
Concepts: quill pen nib used backwards, the very edge of a flat or Filbert brush.
Toy
This is for libmypaint developers, when they’re developing a new input feature. Make it playful and funny!
Please design these icons in a single colour in Inkscape on a 16x16 pixel grid, and if possible, use 2px wide strokes and rounded corners. The icon may be scaled up to ~256 px at times, so it needs to look good at larger sizes. We have several examples in the desktop/icons folder of the MyPaint repository, and there is a template file in the svg folder.
It’s also worth noting that MyPaint is designed for white-on-black as well as black-on-white. Your icon may appear as either foreground colour.
Everyone should feel free suggest better concepts than mine. Sketches are welcome too of course, provided they’ll look good when traced by an Inkscape-ist and rendered at the 16 pixel size.
