[XeTeX] colour \specials not working with xdvipdfmx driver?

[Paul Howson]

On 10/09/2007, at 9:04 PM, Jonathan Kew wrote:

> I said a few days ago that these were supported in xdvipdfmx, but I
> was mis-remembering. Apologies for the confusion!
>
> The dvips-style "color" special should work (e.g., \special{color rgb
> R G B} where R G B are decimal values in the range 0.0 - 1.0).

Yes, I eventually discovered that through trial and error.

Some other discoveries:


DISCOVERY 1

These dvipdfm specials (examples straight from the dvipdfm manual) do  
not work:

\special{ pdf: bc [ 1 0 0 ] }
\special{ pdf: ec }

They are meant to be BeginColor and EndColor -- changing colours and  
pushing and popping a colour stack. They don't work in xdvipdfmx,  
producing this error report:

** WARNING ** Invalid color specification?
** WARNING ** Interpreting special command bc (pdf:) failed.
** WARNING ** >> at page="1" position="(72, 769.82)" (in PDF)
** WARNING ** >> xxx " pdf: bc [ 1 0 0 ] "
** WARNING ** End color with no corresponding begin color.



DISCOVERY 2

As you say, \special{color rgb R G B} DOES work. HOWEVER, these  
specials don't work:

\special{color push}
\special{color pop}

They have no effect -- i.e. if you do a push, change the colour to  
red for example, typeset something and then do a pop, the colour does  
NOT revert to black, it stays as red.


DISCOVERY 3

There is a very strange bug with \special{color rgb R G B}. On a long  
document, using this command inside macros to switch colours, we kept  
getting this error from xdvipdfmx:

	  ** ERROR ** Only RGB/CMYK/Gray currently supported

Paring the document back step by step eventually stopped the error.  
It appears that this error is generated after a certain number of  
colour change operations (i.e. \special{color rgb ...} commands).

The only way to prevent it is to insert a color push before each  
colour change, like this:

\special{color push}\special{color rgb R G B}

Then it works for the long document. Crazy.

The saga of getting xetex/xdvipdfmx working on Linux to process a  
file that works perfectly with xetex/xdv2pdf on the Mac continues ...

I will post a separate note about font issues.

Paul Howson

----------------------------------------------------------------
Paul Howson
The Design Group Qld, Warwick Qld Australia (www.tdgq.com.au)
email: paul at tdgq.com.au    blog: www.tdgq.com.au/blog
GRAPHIC DESIGN    WEB SITE DESIGN