Marching: constructive solid geometry

[w23]

With clever combinations of min, max and all this carp it's easy to add, subtract and intersect geometry. Also: repetition, mirroring, domain transforms.

Depends on #35

[rexim]

@w23 If I understand correctly you refer to https://en.wikipedia.org/wiki/Constructive_solid_geometry which sounds really interesting to implement on the stream. Thanks!

But why does it depend on #35 ?

[w23]

Because it's trivial to do for distance functions. I believe any other approach will require a lot of head scratching (never tried myself).

[rexim]

@w23 ok, let's resolve #35 first then. :)