hi,

William F Pokorny <ano### [at] anonymousorg> wrote:
> On 10/13/19 11:19 AM, jr wrote:
> > William F Pokorny <ano### [at] anonymousorg> wrote:
> >> On 10/7/19 1:07 PM, jr wrote:
> >>> William F Pokorny <ano### [at] anonymousorg> wrote:
> >>>> Perhaps, finally, a good test case for isosurface artefacts I've worked
> >>>> around for years! Confirmation Windows / OSX showing similar artefacts
> >>>> would be useful. Linux users not on Ubuntu 18.04 too.
> >>>> ...
> >>>
> >>> same artefacts (identical looking) on a Slackware box, using
> >>> 3.8.0-alpha.10013324.unofficial.
> >>>
> >> Thanks jr.
> >
> > pleasure.
> >
> > (am dismayed -- riled, actually -- that no Windows/Mac users found the few
> > minutes it took, apparently)
> >
>
> :-) Ah, everyone is busy and focused upon what they're focused upon. I'm
> bad at even minor task switching/juggling. Plus! Could be they see the
> man off wandering in the weeds - as a man off wandering in the weeds.

quite the image..  </grin>


> ...
> The code involved makes use of abs/fabs, min, max and the like.
> Behaviors of which - especially when you don't get the expected C++
> standard library version(1) - can be different.
>
> (1) - As happened with vector.h abs() use when linux users initially
> tried the v3.8 user defined camera. The immediate fix was to use fabs(),
> but on my to-do, someday, list to look at vector.h more closely. I
> suspect it still the case we are getting the c99 math functions in
> vector.h and not the standard library versions due cyclic includes, but
> maybe not, and maybe I should stop looking for weeds to whack.
>
> Related to (1): Had the thought to perhaps enforce std::abs, std::min,
> std::max use over bare abs/fabs ?/..., min, max names enabled with
> 'using...' statements in coretypes.h & types.h. These in particular are
> known to have MS VS to other compiler implementation differences.

in a way I'm surprised that POV-Ray does not contain its own low-level maths
library, I'd have thought that an advantage.  so, I wonder (not knowing the code
base + off the top of my head) whether collecting various low-level routines
into a "convenience" library included with POV-Ray would not help with platform
independence/"implementation differences".  libraries like the GSL (see
attached) are highly optimised and easily wrapped/"plundered".


regards ,jr.

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