[Fluxus] commits

[Dave Griffiths]

>> * fixed bug in save-primitive for indexed polys as .obj
>> * added tools for evaluating polygons - these should eventually work on
>> any type of polygon primitive, they do on most of them now:
>>   - poly-for-each-face
>>   - poly-for-each-triangle
>>   - poly-for-each-tri-sample (random sampling)
>> * added examples/poly-eval.scm which show how to use these things
>> * added (rndhemi) and (hrndhemi) for generating points on hemispheres
>> (solid or hollow)
>> * added examples/occlusion-bake.scm - should work ok, runs in a thread
>> for previewing the raytracing
> thanks! compiles and runs fine.

Cool - thanks for the fast feedback...

> although i found some mix-up with the
> documentation of the tricks.ss functions and line-intersect.

Yep - I've got to go through the documentation for all this next. I'm not
sure what to do with tricks.ss, the code in there is halfway between
examples and useful but optional things people might want to use.

> did you remove poly-type? i haven't used it yet, and these new
> evaluators look very handy. i'm just curious.

I had some problems with returning a symbol from C++ - eg, if I return:

scheme_make_symbol("triangle-list");

from poly-type in fluxus-engine.so, then in scheme:

(eq? (poly-type) 'triangle-list)

always evaluates to #f.

Maybe one for the plt list, but I temporarily got round it by returning
the enum value in C++ with (poly-type-enum) and adding a (poly-type) in
scheme which maps the numbers to symbols, which works.

cheers,

dave