Turns out it was much easier than I feared. I'm now generating Spot
colors under the PDF renderer in version 0.95. This only works with fo
-- I don't need SVG support, so I haven't even looked at adding it
there.

 

I'm a bit unhappy with the underlying code - the biggest issue was that
the "colorSpace" member of PDFPathPaint is a PDFDeviceColorSpace and the
PDFResources "addColorSpace" method expects a PDFICCBasedColorSpace.
Changing the methods to expect a PDFColorSpace interface argument is a
bit unsatisfying as well. I spent some time trying to find a way to use
polymorphism here, but it was still rather ugly. 

 

Tomorrow I'm moving on to the bitmap-based renderers.

 

I haven't diff'd the code with HEAD, so I'm not certain how compatible
my hacks are beyond .95.

 

Anyone interested in helping me clean it up or providing some thoughts
as to an approach?

 

-Patrick

 

From: Patrick Jaromin [mailto:patr...@jgsullivan.com] 
Sent: Wednesday, January 27, 2010 2:37 PM
To: fop-dev@xmlgraphics.apache.org
Subject: Understanding the PDFRenderer

 

I've been charged with implementing spot colors in FOP.  I've followed
some earlier threads, but the discussion appears to have ended without
any final contribution from the poster.

 

First - just in case I've missed it - is there any work that's been done
on this that I'm not seeing?

 

Second - I've begun the process and have discovered that parsing the
function is rather easy (I chose to extend rgb-icc after following some
prior threads). I've also reviewed the PDF specification and have a
decent understanding of how to make this work in PDF format...and can
manually insert the appropriate code into the file. So, the my next step
is to work out the code to emit the appropriate PDF commands from FOP.
I've created a "PDFSeparationColorSpace" class and extended "ColorExt." 

 

My issue now is that I'm having trouble following the flow of the PDF
document generation - and consequently haven't yet worked out where I
can and should add my resources (the ColorSpace and tint function) to
the document resources. 

 

I'm still working through the code and believe I can ultimately suss
this out by myself if I have to, but I would be very grateful if someone
with some experience with this renderer could provide some time-saving
hints/guidance.

 

BTW, I'm working with the 0.95 code base (I can't move to trunk right
now) and will gladly contribute the results if they're usable/wanted.

 

Thanks!

 

-Patrick

 

________________________________

Patrick K. Jaromin

VP Technology

312.943.1600 * fax 312.640.8100

 

JGSullivan Interactive, Inc.

 

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