Re: Different colors in LaTeX and ConTeXt

[Henri Menke <henrimenke@gmail.com>]

On 07/12/2016 10:03 PM, Hans Hagen wrote:
> On 7/12/2016 9:39 PM, Henri Menke wrote:
>> Dear Aditya and Hans,
>>
>> I'm not so sure about it being a bug in pgfplots.  I played a little and
>> encountered the following.
> 
> As Aditya pointed out, these (probably used for tracing) colors are
> defined in such a way that they don't go via the context resolver. As
> these (few) colors are basically x windows colors, you can start your
> document with:
> 
> \usecolors[xwi]
> 
> which will set the context colors differently.

Adding \usecolors[xwi] to the example does not change anything.  Looking
at base/colo-imp-xwi.mkiv revealed, that it does not alter the way
colors are defined, but just defines a huge bunch of additional ones.

> 
>>> \usemodule[tikz]
>>> \starttext
>>>
>>> % Original gray
>>> \blackrule[color=gray,width=1cm,height=1pt]
>>>
>>> \starttikzpicture
>>>   \draw[gray,line width=1pt] (0,0) -- (1,0);
>>> \stoptikzpicture
>>>
>>> % New colors
>>> \definecolor[gray][s=0.5]
>>> \unprotect
>>> \pgfutil@definecolor{tikzgray}{gray}{0.5}
>>> \protect
>>>
>>> % Now ConTeXt's gray = tikzgray
>>> \blackrule[color=gray,width=1cm,height=1pt]
> 
> How is that supposed to work? Context will not inherit colors from tikz,
> the most you can expect is the reverse: tikz using context color
> definitions.

I'm very sorry for the confusion.  What I did was to adjust ConTeXt's
gray to have the same grayscale value as the tikzgray.  As is shown
below, the redefinition of gray does not propagate to TikZ.

> 
>>> \starttikzpicture
>>>   \draw[tikzgray,line width=1pt] (0,0) -- (1,0);
>>> \stoptikzpicture
>>>
>>> % Inside TikZ gray is still off
>>> \starttikzpicture
>>>   \draw[gray,line width=1pt] (0,0) -- (1,0);
>>> \stoptikzpicture
>>>
>>> \stoptext

In pgfutil-context.def there is though

\let\pgfutil@registergray \pgf@context@registergray

So it seems as if gray *should* be propagated from ConTeXt to TikZ,
which apparently takes place when loading TikZ.  Moving
\definecolor[gray][s=0.5] before \usemodule[tikz] shows this behavior.

The question is how to keep colors from ConTeXt and TikZ in sync.

Cheers,
Henri

> 
>> Cheers,
>> Henri
>>
>> On 07/12/2016 08:23 PM, Aditya Mahajan wrote:
>>> On Tue, 12 Jul 2016, Hans Hagen wrote:
>>>
>>>> On 7/12/2016 5:07 PM, Aditya Mahajan wrote:
>>>>> On Tue, 12 Jul 2016, Hans Hagen wrote:
>>>>>
>>>>>> On 7/12/2016 3:44 PM, Henri Menke wrote:
>>>>>>> Dear Hans,
>>>>>>>
>>>>>>> thanks for your reply.  Indeed there are color definitions in
>>>>>>> `pgfutil-context.def`.  However, they are commented out with the
>>>> message
>>>>>>>
>>>>>>>> % no need for x colors (users can load it if needed)
>>>>>>>> ...
>>>>>>>> %\pgfutil@definecolor{gray}{gray}{0.5}
>>>>>>>
>>>>>>> If I add
>>>>>>>
>>>>>>>> \csname pgfutil@definecolor\endcsname{gray}{gray}{0.5}
>>>>>>>
>>>>>>> to my document the gray shows up fine.  So that's for sure a
>>>>>>> feasible
>>>>>>> workaround.
>>>>>>>
>>>>>>> Can you comment on the phrase »no need for x colors (users can
>>>>>>> load it
>>>>>>> if needed)«?  I'm not quite sure what it means and it suggests that
>>>>>>> there exists a proper solution to my color problem.
>>>>>>
>>>>>> normally you want the same colors in tikz images as in context so
>>>>>> then
>>>>>> defining them in tikz is creating incompatibilities (your case is the
>>>>>> reverse and a-typical)
>>>>>
>>>>> However, without such redefinitions, tikz does not understand ConTeXt
>>>>> colors. I use a similar workaround in my documents as well.
>>>>
>>>> I have no clue what you mean.
>>>>
>>>> \definecolor[red][g=1]
>>>>
>>>> \startTEXpage
>>>>     \starttikzpicture
>>>>        \fill[red] (0,0) circle (1cm);
>>>>     \stoptikzpicture
>>>> \stopTEXpage
>>>>
>>>> works ok here and gives green. So, one can collect a list of colors
>>>> defined in tikz in a colo-imp-tikz.mkiv and load that one if needed.
>>>
>>> I guess it is a bug with pgfplots rather than tikz (which also means
>>> that it may be easier to pursuade pgfplot maintainers to use low level
>>> tikz interface, since tikz is already playing nice with context).
>>>
>>> \usemodule[tikz,pgfplots]
>>> \definecolor[red][g=1]
>>>
>>> \startmode[bug]
>>> \unprotect
>>> \pgfutil@definecolor{red}   {rgb} {0,1,0}
>>> \protect
>>> \stopmode
>>>
>>> \starttext
>>> \startTEXpage
>>>      \starttikzpicture
>>>        \startaxis
>>>          \addplot[color=red] coordinates { (0,0) (1,1) };
>>>        \stopaxis
>>>      \stoptikzpicture
>>> \stopTEXpage
>>> \stoptext
>>>
>>> Aditya
>>>
>>>
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>>
>> ___________________________________________________________________________________
>>
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>>
>>
> 
> 

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