Re: CMYK colours

[David Kastrup]

address@hidden writes:

> Hi all,
>
> I just came across the issue of printing coloured scores and wondered
> if it's possible to use CMYK colours in LilyPond. From what the NR
> says this seems impossible but I wanted to ask anyway.
>
> If it is *not* possible, what would be - theoretically - the
> complexity of adding support for that?
> It might be rather straightforward to provide a conversion function in
> Scheme (ignoring the issue of colour profiles), but I'm talking of
> native support.

LilyPond does not actually track colors in any manner if I remember
correctly.  It just passes them through.  So take a look at how RGB
support is done, and CMYK support should be straightforward to add.
Instead of adding new user-level commands, you could just permit the
color commands to accept lists with 4 members as well as three and then
just let the backends emit different commands.

That's minimally invasive but would not allow us to use RGBA in a
similar manner.  But maybe partial transparency is better dealt with
using separate primitives anyway.

-- 
David Kastrup