[cairo] [RFC] Color space API (partial proposal)

Andrea Canciani ranma42 at gmail.com
Mon Feb 22 09:31:52 PST 2010

On Mon, Feb 22, 2010 at 2:06 PM, ecir hana <ecir.hana at gmail.com> wrote:
> On Mon, Feb 22, 2010 at 2:29 AM, Andrea Canciani <ranma42 at gmail.com> wrote:
> Thank you very much, as well!
> It might take a while while a digest the diff but one thing is already
> not very clear to me: to create any "cairo_color_t" you seem to
> require "cairo_color_space_t". But in practice (printing) you simply
> sometimes don't have a profile and you still want to define another
> color than RGB. Am I misreading your proposal or it is really not
> possible to create a spot color (or spot colors, as in DeviceN)
> without having a profile? (I also assume that PDF's "tintTransform" is
> going to be filled by underlying CMS, right? Should there be a way to
> define it explicitly?)

Well, the current proposal doesn't even allow creating DeviceGray
and DeviceCMYK spaces (but I will probably add those later).
If I understood the PDF spec correctly, to be able to use DeviceN
you would have to specify how to convert your n components to
a known color space anyway... why not take one step further and build
a real color profile? (i.e. use a PCS as your alternateSpace)
I know that adding color space constructor taking a color space and a tint
transform we would remove the profile creation burden from the user...
it might happen, but right now I don't see it as a priority (and I'm not even
sure it's a good idea, as I'd like everybody to use device-independent
color spaces in most cases, while this might allow DeviceRGB-based DeviceN).

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