Re: t-tikz: problem with colorspace pgfprgb

[Aditya Mahajan <adityam@umich.edu>]

On Mon, 3 Mar 2008, Mojca Miklavec wrote:

> On Mon, Mar 3, 2008 at 6:15 AM, Aditya Mahajan wrote:
>> On Sun, 2 Mar 2008, Finn Martensen wrote:
>>> 2008/3/2, Aditya Mahajan <adityam@umich.edu>:
>> >
>> >>> I have the following problem with TikZ: When I use the "patterns"
>> >>> library in a tikzpicture environment, the file is compiled without
>> >>> problems and creates a PDF file. However, Acrobat displays an error
>> >>> message "Could not find the ColorSpace named 'pgfprgb'". [...]
>> >>
>> >> Can you please post a minimal example? I have compiled a few examples
>> >>  from the tikz manual by using all tikz librarries, but never had this
>> >>  problem.
>> >
>> > It just discovered that it depends, e.g., on whether there is only one
>> > page with a tikzpicture or more pages with tikzpictures. To give code
>> > examples: the first works, but not the second
>> >
>> > **************************************
>> > Code with no problems:
>> > **************************************
>> > \usemodule[tikz]
>> > \usetikzlibrary[patterns]
>> > \starttext
>> > \starttikzpicture
>> > \fill[pattern=dots] (0,0) -- (0,1) -- (1,1) -- (1,0);
>> > \stoptikzpicture
>> > \stoptext
>> >
>> > **************************************
>> > Code with problems:
>> > **************************************
>> > \usemodule[tikz]
>> > \usetikzlibrary[patterns]
>> > \starttext
>> > \starttikzpicture
>> > \draw (0,0) -- (1,0);
>> > \stoptikzpicture
>> > \page
>> > \starttikzpicture
>> > \fill[pattern=dots] (0,0) -- (0,1) -- (1,1) -- (1,0);
>> > \stoptikzpicture
>> > \stoptext
>>
>>  I can reproduce this problem. On linux, with evince pdf viewer (2.21.91) I
>>  get "Error: Bad color space 'pgfprgb'", with Adobe reader (8.1.2) "Wrong
>>  operand type".
>>
>>  The example does work fine with plain TeX and LaTeX. Something
>>  wrong in the way patterns are handled by tikz for context. I do not think
>>  that anyone on this list understands the internals of TikZ. Your best bet
>>  is to report this to the tikz-mailing list.
>
> Till Tantau has already replied (privately):
>
>>  I tracked down this problem. It turns out that ConTeXt does, well,
>>  radical things with the page resources (it simply resets them after
>>  each page, which is why a pattern cannot be used on any page other
>>  than the page on which it is defined). I'll try to fix this later,
>>  although ConTeXt could be a bit less aggressive, here...
>
> --------
>
>>  I fixed this in the CVS. You will have to check it out to use the patch.
>>
>>  The main problem is that pgf and context both fight over who can set
>>  page resources. As there is no clean way to do this, both pgf and
>>  context have their own systems.
>>
>>  Actually, context's system is a bit cleaner, but we also have to
>>  support latex and plain tex.
>>
>>  Anyway, I put in some patches that should solve the problem under
>>  normal circumstances. If you use ConTeXt commands that also mess
>>  around with extended graphic states, some further changes would
>>  presumably be necessary, but I'm not sure.

Works well the minimal example that Finn posted.

> So ... feel free to test it (should I set up automatic updates of tikz
> from cvs for the minimals?).

That will be nice. Actually, what do you mirror at the minimals, the 
current context stable or the current beta?

Aditya
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