On 05/21/2018 04:35 PM, clipka wrote:
> Am 21.05.2018 um 16:39 schrieb William F Pokorny:
> 
> POV-Ray has never used single-precision floats. 

Taking you to mean never in the 'solvers'.

> I doubt even DKBTrace
> ever did: At least as of version 2.01, even on the Atari it already used
> double-precision floats.
> 
> As a matter of fact, the IBM-PC configuration for DKBTrace 2.01 (*)
> actually defined DBL as `long double` when a coprocessor was present.
> DKBTrace 2.12 (**) additionally set EPSILON to 1.0e-15 instead of 1.0e-5
> in that case (provided the compiler used wasn't Turbo-C, presumably
> because it would define `long double` as 64-bit). This was carried on at
> least until POV-Ray v2.2, but must have been gotten lost between v2.2
> for DOS and v3.6 for Windows. (My guess would be that the Windows
> version never had it.)
> 
> (* See here:
> https://groups.google.com/forum/#!topic/comp.sources.amiga/icNQTp_txHE)
> 
> (** See here: http://cd.textfiles.com/somuch/smsharew/CPROG/)
> 

Thanks. I've never dug as far back. True too I was speculating about how 
many might have actually been running early POV-Ray. Me taking the early 
as v1.0 "#define DBL double to be a mechanism those without FPUs and 
early small bus sizes were running with "define DBL float" instead. Not 
that I was running POV-RAY or even aware of POV-Ray that early.

Don't remember exactly, but I didn't have a personal machine with an 
actual FPU until the late 90s. First 64 bit machine early 2000s I guess. 
My very first personally owned machine was an 8bit z80 based custom 
built thing...

Bill P.

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