POV-Ray : Newsgroups : povray.unofficial.patches : Initial povr branch keywords id_type() and id_types_match() : Re: Initial povr branch keywords id_type() and id_types_match() Server Time
21 Apr 2024 07:32:22 EDT (-0400)
  Re: Initial povr branch keywords id_type() and id_types_match()  
From: William F Pokorny
Date: 24 May 2021 23:22:40
Message: <60ac6d80$1@news.povray.org>
On 5/24/21 2:17 PM, Tor Olav Kristensen wrote:
> William F Pokorny <ano### [at] anonymousorg> wrote:
>> In povray.general we recently discussed implementing some limited type
>> checking. Attached is an include files showing testing for two new
>> keywords in the povr branch called id_type() and id_types_match().
>>
>> Note. Though the id values often change from release to release I found
>> an id_type() works in a switch statement making the id_type() worthwhile
>> too, I thought.
> 
...
> Can it also be used with different functions types, splines, matrices,
> transforms, materials, file descriptors, light sources, cameras, color maps, and
> other maps ?
> 

Played with these more tonight and I'm now leaning toward dropping 
id_types_match(). As with most things the more I played the more the 
hidden gotchas popped out, and the more complex the code got.

Answers to your category/type questions are mostly yes. Functions come 
in two types depending on whether they return doubles or vectors. Light 
sources I've not tested as yet, but I think those have always been 
considered objects and so will likely get lumped with spheres et al(1).

In some oddness, there is a MACRO_ID_TOKEN, but it's impossible to 
evaluate macro names because once they exist the parser attempts to run 
them. I don't see a way to work around it - excepting maybe via some 
very messy methods.

Bill P.

(1) - It's only code, as an old friend used to say to my enhancement 
requests. :-) Likely some way to tell the object is really a light and 
we could then set some bogus, large value maybe - or negative values. 
There are, I know, some object type 'flags' that get set when objects 
are created. We'll see.


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