Re: [Lib2geom-devel] some todos and wishes

[njh <nj...@nj...>]

On Fri, 13 Apr 2007, mgsloan wrote:

> As far as the plotters, cairo_md_sb can handle D2<Piecewise<SBasis> >.
> Actually, Piecewise<D2<SBasis> > would be loads easier to implement - will
> do next time.

I think JF has swayed me to only using pw<d2 for the bulk of operations 
and use sectionize to convert d2<pw to pw<d2.  I can't think of any 
compelling d2<pw cases really, other than perhaps avoiding excessing 
segmentation.  That suggests better joining algorithms.

> The thing is, either way there's going to be a check.  I suppose the good
> thing about disallowing it is that it doesn't matter what the function
> actually does.  The current convention is that it is indeed constant zero,
> but i suppose concat does need a bit of work in that respect.  Yes, that's
> the main way to reasonably represent 0.

My biggest dislike of empty = 0 is that there is no analogous constant 
vale version.

>> - define some standard functions for pw<sb>: sqrt, cos, sin...

- general purpose bezier to sbasis (essentially a sparse matrix multiply)
- pow of various forms (pow(sb, double), pow(double, sb) etc)
- solve boundary value ODE (which is essentially what exp and sin do
     already)
- compose with periodic function
- geometric conversion to beziers (raph's algorithm perhaps?)

There is also a fair amount of old code which can be removed or simplified 
with Path2

njh