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

[Ross McFarland]

Jost Boekemeier said:
>  --- Kai-Uwe Behrmann <ku.b at gmx.de> schrieb:
>
>> But I'm
>> definitely uninterested
>> > in new top-level API that only works for some
>> subset of the backends.
>
> Wasn't that exactly what Ross proposed?
>
> I may be slightly confused by the whole discussion;
> but why not simply pass the color with a token that
> describes how to interpret the color values the
> backend receives.  Some backends may reject the token,
> but I don't see that as a problem; cairo depends on
> the backend and its resolution anyway.

that is exactly what i'm proposing. with the added note that i don't think any
of the current backends would support anything more than rgb and that we
should place the extended color api to set non-rgb color in a seperate header
that apps won't normally use. i just see it as a good step to take to 'future
proof' the color pathway, or at least allow for it to grow.

-rm