Hi(gh)!

I tried to render a simple scene (no external files), but all I got is this:

povray +i20160826vorspann.pov +otest.png +fn +w640 +h480 +a.3 +k1 +p
Failed to parse command-line option

Obviously, the last two system upgrades during the last six weeks messed 
up my POV-Ray installation (earlier today, even the .povray folder in my 
/home/yadgar directory and, thus, povray.conf did not exist anymore!), 
so I purged povray and re-installed it - but it still doesn't work!

I run Debian Stable 8.3 on an amd64.

See you in Khyberspace!

Yadgar

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Am 21.09.2016 um 20:22 schrieb Jörg "Yadgar" Bleimann:
> Hi(gh)!
> 
> I tried to render a simple scene (no external files), but all I got is
> this:
> 
> povray +i20160826vorspann.pov +otest.png +fn +w640 +h480 +a.3 +k1 +p
> Failed to parse command-line option

Try `+a0.3` instead of `+a.3`.

I'm not sure if POV-Ray /should/ support dropping the leading zero in
command-line options (there's no clear statement about this in the
docs), but apparently it currently doesn't.

I'll have a look at POV-Ray's bowels to see if there are any hints about
the intended behaviour in this case.

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Am 21.09.2016 um 23:08 schrieb clipka:

> Try `+a0.3` instead of `+a.3`.
> 
> I'm not sure if POV-Ray /should/ support dropping the leading zero in
> command-line options (there's no clear statement about this in the
> docs), but apparently it currently doesn't.
> 
> I'll have a look at POV-Ray's bowels to see if there are any hints about
> the intended behaviour in this case.

The source code didn't give me much of a hint -- but running POV-Ray
3.62 did: That version was fine with `+a.3`. So there's a bug that needs
fixing.

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clipka <ano### [at] anonymousorg> wrote:
> Am 21.09.2016 um 23:08 schrieb clipka:
>
> > Try `+a0.3` instead of `+a.3`.
> >
> > I'm not sure if POV-Ray /should/ support dropping the leading zero in
> > command-line options (there's no clear statement about this in the
> > docs), but apparently it currently doesn't.
> >
> > I'll have a look at POV-Ray's bowels to see if there are any hints about
> > the intended behaviour in this case.
>
> The source code didn't give me much of a hint -- but running POV-Ray
> 3.62 did: That version was fine with `+a.3`. So there's a bug that needs
> fixing.

Wait: 3.6 and before had problems with that syntax because it can lead to cases
that cannot properly be decided when parsing the command line. You will have to
go back like 15 years to find the post about it ... and I am sorry, I do not
have that post at hand any more :-(

Thorsten

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Am 22.09.2016 um 06:01 schrieb Thorsten Froehlich:
> clipka <ano### [at] anonymousorg> wrote:
>> Am 21.09.2016 um 23:08 schrieb clipka:
>>
>>> Try `+a0.3` instead of `+a.3`.
>>>
>>> I'm not sure if POV-Ray /should/ support dropping the leading zero in
>>> command-line options (there's no clear statement about this in the
>>> docs), but apparently it currently doesn't.
>>>
>>> I'll have a look at POV-Ray's bowels to see if there are any hints about
>>> the intended behaviour in this case.
>>
>> The source code didn't give me much of a hint -- but running POV-Ray
>> 3.62 did: That version was fine with `+a.3`. So there's a bug that needs
>> fixing.
> 
> Wait: 3.6 and before had problems with that syntax because it can lead to cases
> that cannot properly be decided when parsing the command line. You will have to
> go back like 15 years to find the post about it ... and I am sorry, I do not
> have that post at hand any more :-(

Let me guess: You don't remember yourself what the problem was about,
and nobody deemed it worth documenting somewhere within the code, or any
other place easily accessible, right?

Fine then. If anybody ever stumbes across the problem again, I'll worry
about it.

From the fact that various other switches have been perfectly fine with
this notation all the time (`+j`, `+ec`, `+er`, `kf`, `+ki`, `+k`, `+sc`
and `+sr`, to name only those already present in 3.62, and to not
mention the `+mv` switch that wouldn't make much sense), my current
presumption is that it was just a historic artifact, that may have led
to conflicts due to the way command line switches had been processed
internally, and that there are no fundamental ambiguities that cannot be
overcome by a smarter implementation.


As a side note, it turns out that POV-Ray 3.62 for Windows didn't
support `+a.3` either; it just simply did not report any error if it
came across an unrecognized command line option.

But since POV-Ray supports dropping leading zeros in the SDL, and also
in many switches, I think it doesn't make sense to /specifically/ deny
this functionality in the `+a` switch.

(It also doesn't make sense to deny it in the `+ef` and `+sf` switches,
but that needs to be addressed separately as the internal handling is a
bit more complicated in these special cases.)

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clipka <ano### [at] anonymousorg> wrote:
> Let me guess: You don't remember yourself what the problem was about,
> and nobody deemed it worth documenting somewhere within the code, or any
> other place easily accessible, right?

I recall coming up with a quick fix for this, but that is about it, indeed :-(

Documentation is highly overrated ;-)

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Am 22.09.2016 um 20:22 schrieb Thorsten Froehlich:
> clipka <ano### [at] anonymousorg> wrote:
>> Let me guess: You don't remember yourself what the problem was about,
>> and nobody deemed it worth documenting somewhere within the code, or any
>> other place easily accessible, right?
> 
> I recall coming up with a quick fix for this, but that is about it, indeed :-(
> 
> Documentation is highly overrated ;-)

Could it have been that some portion of the code erroneously identified
`+am` as `+a` with a (nonsensical) parameter value `m`, and that the
quick fix was to internally change `+a` (in its incarnation with
parameter) to `+a0`?

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On 9/22/2016 7:22 PM, Thorsten Froehlich wrote:
> Documentation is highly overrated;-)


The sign of a true programmer. :-P

-- 

Regards
     Stephen

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On 9/22/2016 2:22 PM, Thorsten Froehlich wrote:
> Documentation is highly overrated ;-)

well isn't that just special! was i just thrown under the bus? gets up 
and dusts off tire marks ... feeling a bit like rodney dangerfield

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Am 23.09.2016 um 12:25 schrieb Jim Holsenback:
> On 9/22/2016 2:22 PM, Thorsten Froehlich wrote:
>> Documentation is highly overrated ;-)
> 
> well isn't that just special! was i just thrown under the bus? gets up
> and dusts off tire marks ... feeling a bit like rodney dangerfield

We're talking about code documentation here. Writing down why stuff was
implemented the way it is implemented, clarifying why the code actually
works even though it looks crooked - that sort of thing.

I don't think you want to hop onto /that/ bus ;)

http://l7.alamy.com/zooms/50d362a49add41a6a5f5ead67fc38777/old-overloaded-public-transport-with-goods-on-the-roof-of-the-bus-f0n46n.jpg

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