In article <3d4989dc@news.povray.org>, Warp <war### [at] tagpovrayorg> 
wrote:

>   It's not out of question. It's just difficult to make it so that it will
> work without problems in any system where POV-Ray has been ported. The
> biggest problem is endianess, and a minor problem is different floating
> point formats (which is actually a major problem in the case that the
> format is different; but I consider it minor here because virtually all
> practical computers use the same floating point format).

You could just standardize on one floating point format for the POV data 
files, and write platform indpendant code that reads it byte by byte and 
converts it to a float or takes a float and writes it in the correct 
format, but the format might have different precision from what is 
native on some platforms. I don't think this would cause any serious 
problems...it's a pain, but not an insurmountable obstacle.


>   After this is done, it should be easy to just make a raw dump of the
> bytecode to a file. This file will then be the binary format. Reading
> this file will then be extremely easy: Just read the entire file to memory
> and start interpreting. This saves the parsing stage, which can be really
> slow.

Actually, the compilation stage isn't necessarily that slow...you could 
get a huge speedup over the present parser by just compiling to 
bytecodes and running on the VM every time. Combine this with a compact 
mesh format (maybe a custom binary format compressed with gzip 
compression), and you have taken care of most of the reasons for a 
binary scene format.

Another possibility: instead of saving the compiled bytecode program or 
the internal data structures of the raytracer, save the commands the 
program makes to the tracer. These commands could be used to rebuild the 
scene without compiling/loading and interpreting the scene file, but 
would be easier to serialize to a file than the complex internal data 
structures: they would already be pretty serial in nature. I don't see 
much reason to go through the effort though...whatever you do, you end 
up with a non-human-readable file that is smaller than the text file 
(but not significantly smaller than a compressed version of the text 
file would be) and another input file format to worry about with 
transferring between unofficial versions and updating the official 
version.

-- 
Christopher James Huff <chr### [at] maccom>
POV-Ray TAG e-mail: chr### [at] tagpovrayorg
TAG web site: http://tag.povray.org/

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