I worked a bit on Marzipan this week-end, and started playing with bitmap orbits. The idea is the same as for point orbits and line orbits: we look at the iterations of the escaping points, and we look at the distance on the plane between the complex numbers represented by these iterations and a given set on the same plane.
Since my creativity was apparently all used up by trying to make the algorithm work instead of trying to find a nice bitmap to play with, I simply have the name of my project somewhere on an image, as black&white. I pre-compute a distance map to that bitmap (in a very approximate and most probably buggy way right now – something’s not quite right there, but good enough for a first approximation) and I use that distance map to display the points I’m interested in when rendering the fractal.
The very annoying thing is that I do have a bug on the zooming algorithm – things tend to flip and/or to go to weird places. I haven’t been able to track it down yet: it must be said that I’m typically hopeless at handling 2D grids and scaling factors without breaking a neuron or two, and that on top of that, as mentioned previously, I’m probably making my own life miserable by using a non-standard window manager. I’ll probably need to go to KDE or something to debug this thing properly (sigh :/)
Still, in the meantime, I’m not unhappy with the results 🙂