[cairo] RFC the idea of n-plane color support

[Alexander Larsson]

On Sat, 2004-10-30 at 18:53 -0400, Ross McFarland wrote:
> On Sat, 2004-10-30 at 17:54, Carl Worth wrote:
> > 
> > An opaque color type would only make sense for one specific
> > backend. That breaks the design of cairo, and would also break the
> > implementation as almost all the backends end up using the image backend
> > as a fallback for certain operations.
> 
> nothing would be broken b/c the standard backends wouldn't support
> anything but using sRGB (programming assertions.) the normal interfaces
> would still talk in sRGB and backends would still interpret it as sRGB.
> it would just internally be represented by something that could hold
> other types. so that if special tied apps and backends (printer/press
> RIP's) could be developed with cairo.
> 
> what i'm proposing would cause no visible changes to apps. and only
> (possibly) slight changes to backends (array indexes rather than struct
> members. changes it took me a couple of mins to make in my local copy of
> the backends.)
> 
> 	clr.red
> becomes
> 	clr.planes[PLANE_RED] 

What about spot color support in Cairo? Spot colors don't mix well with
blending and transparency, but they are used a lot in printing.

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 Alexander Larsson                                            Red Hat, Inc 
                   alexl at redhat.com    alla at lysator.liu.se 
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