[cairo] [RFC] Color space API (partial proposal)
cloos at jhcloos.com
Sun Feb 28 11:44:55 PST 2010
>>>>> "Adrian" == Adrian Johnson <ajohnson at redneon.com> writes:
>> The more general solution would be to specify the tint transform as a
>> And a type7 gradient can make for a reasonably convincing alternate for
>> things like metalic, opalescent, iridescent spots or glossy overcoats.
>> (Not exact, of course, but not unreasonable either.)
Adrian> How would the tint transform be derived from a type 7 gradient?
I must have forgotten that separation and devicen do not allow pattern
spaces as alternates. [SIGH]
A linear gradient will translate well to a linear type0 function or a
stitching of them. But cubic type0 and type2 (exponential) functions
are also useful.
I suppose were cairo to have support for cubic-interprolated shadings,
it could use them for specifying cubic type0 tint transform functions;
when they are used as shadings it should be possible to geneate a mesh
from them by making several of the control points co-incident.
As for type4 functions, an api to support them either would be
excessively verbose or likely would need to consume cairoscript syntax.
PDF Type1 shadings are a good match, though, so were cairo to support
type1 shadings that could be used for type4 tint transform functions.
>> Which begs the question of when the type6/7 gradient code will be added. ☺
Adrian> Good question. My last update to the API and implementation is at
Adrian> . The only feedback I got on the list was Behdad preferred some of
Adrian> the API functions to be renamed .
That renaming looks like a reasonable thing to do.
Ghostscript cannot render mesh-gradient-overlap-transp.pdf or
mesh-gradient.pdf (I tried 8.71 and the icc_work branch). It would be
interesting to see what it could do with level3 ps of those, presuming
that using level3 could avoid the fallback images.
(btrfs makes for *slow* git pulls and branch switching.)
in commit 0946988c580b059be9477f27616905a7db227a0e,
s/ie if not control points/ie if no control points/
Otherwise, the api and codebase look ready to me for master, after a
read through »git log -p --reverse 9b932d7cd.. « on that branch.
I also like the direction your cms branch is headed.
In that branch, the doc for cairo_render_intent_t repeats the
default line cap style rather than specifying the default render
James Cloos <cloos at jhcloos.com> OpenPGP: 1024D/ED7DAEA6
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