I was having headache fiddling with some fragment programs when Helder (of SpeedCrunch fame) asked me an innocent question that eventually triggered me to write the Graphics Dojo example for this week: rendering the well-known HSV cylinder in 3-D. At first, I thought using a fragment program is the perfect solution, but considering that we are Trolls, let us write a pure Qt solution that works everywhere. So check out the code!
Unfortunately, in its current state, the code is not really optimized for (near) real-time rendering. If it would have been fast enough (which I guess not really feasible with a non-OpenGL solution), we could have used it for a fancy color picker. Why use a 2-D color picker/dialog when you can have a 3-D one? I'm sure once the 3-D version is introduced, the 2-D version quickly becomes confusing for any creature on this planet.
The question now: shall I do the HSL sphere?