In article <3a07cfe7@news.povray.org>, "Wlodzimierz ABX Skiba" 
<abx### [at] abxartpl> wrote:

> my english may be poor sometimes :-(
> 
> Chris Huff wrote in message ...
> >> but you put sign "=" between meaning of "all" and "gray"
> >> is it true in other color spaces ?
> >
> >The "=" operator isn't used in this patch...I don't know what you mean.
> 
> I mean that in your first post you don't know what is better
> name - "all" or "gray" - but you don't precise what "all" should
> represent - if the same as gray than what should be used for
> all curves in other color spaces ?

Oh, I see what you mean, "all" will mean something different in other 
color spaces...I will probably change it to use "rgb" instead of "all".

> > > >Your syntax will cause confusion("I can modify red and green at 
> > > >the same time, but not blue and saturation?").
> > > it depends of implementation in your planned patch :-)
> > No, it doesn't. For example, you can't manipulate red and hue 
> > simultaneously... yes I know this

But your syntax would allow something like:
red SPLINE hue SPLINE
which doesn't make sense.


(interesting stuff about color syntax)

I have been thinking about new ways of specifying colors(which I still 
think is a separate issue from the curves filter), but I would use a 
slightly different syntax:
color           (tells POV a color is coming)
rgb|hsl|cmy|    (color space name)
< c1, c2, c3>   (A 3 component vector specifying the color values)

Keywords red, green, and blue wouldn't be used any more, at least not 
for specifying colors. You wouldn't need hue, saturation, magenta, 
yellow, etc. either. This would be less backwards compatible, but 
simpler and better for future syntax. It would be easier for new users 
to learn, and doesn't have the problem of someone specifying something 
like "red Something hue SomethingElse".
Filter and transmit wouldn't be specified as part of the color, they 
would be part of a separate "transparency" block in the pigment. Layered 
textures would also have a way to specify different transparency effects 
that would only affect the texture layering.

Splines would be able to directly replace color maps:
pigment {
    PATTERN
    color_spline rgb|hsl|cmy spline {...}
    color_spline rgb|hsl|cmy spline {...}, spline {...}, spline {...}
}
This is something that should be easy to add while keeping the current 
syntax.
Or maybe just use one spline that interpolates between colors...that 
would be very easy to do, since splines can already interpolate between 
5-dimensional vectors. However, it would make modifying one color a bit 
more difficult.

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

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