I'm working on Diffusion Curves (for master thesis) and will try to get them in Inkscape in the foreseeable future (this calender year hopefully). As I'm slowly getting more grip on the technical side of things (which is what my thesis will be about) I'd love some input (and help) on UI issues.
For those who haven't heard about them yet, they're basically a new and very(!) flexible way of specifying color transitions. You just assign colors to curves and let the program fill in the intermediate space using diffusion. This tends to create visually pleasing, smooth, transitions while allowing for a very complex geometry with minimal effort. More information (especially see the references at the bottom for examples): http://wiki.inkscape.org/wiki/index.php/Diffusion_Curves
My current thinking is that it would probably be best to treat diffusion curves as a paint server, allowing people to assign color to nodes (that either coincide with existing nodes or are positioned somewhere on the path). The colors would be linearly interpolated along the path. A scheme like this would fit in well with the idea of expanding the functionality of the gradient tool and having a general color picker.
Unfortunately this would sort of limit the ability to blur boundaries to the point that it might not make any sense. But then again, maybe it's a mistake to try and integrate two separate concepts (blur and color transitions), even in the original paper these are treated quite separately (the blur values are diffused separately and then a spatially varying blur is applied).
Any thoughts or suggestions would be helpful.
Also, would it make sense to apply diffusion curves to strokes? If so, how would that work?