[pgf-tikz] RGB colour model for plain TeX users

[Henri Menke]

Dear Jim,

Thanks for the suggestion.  I've opened a new issue on GitHub for it
and added it to the roadmap for the next release.

    https://github.com/pgf-tikz/pgf/issues/772

Kind regards,
Henri

On 11/9/19 8:35 AM, Jim wrote:
> Hi,
> 
> In Section 15.2 of the manual it says (under the "For plain TeX users"
> paragraph)
>         Only the two color models gray and rgb are supported.
> 
> In .../texmf-dist/tex/generic/pgf/utilities/pgfutil-plain.def it
> defines the macros
>         \pgfutil at emu@rgb#1#2,#3,#4\@nil
> and
>         \pgfutil at emu@gray#1#2,#3,#4\@nil
> 
> I have used the following to implement the RGB model:
> 
> \def\pgfutil at emu@RGB#1#2,#3,#4\@nil
> {
>     \pgfmathsetmacro{\@red@}{#2/255}%
>     \pgfmathsetmacro{\@green@}{#3/255}%
>     \pgfmathsetmacro{\@blue@}{#4/255}%
>     \expandafter\edef\csname\string\color@#1\endcsname
>         {\noexpand\xcolor@ {}{}{rgb}{\@red@,\@green@,\@blue@}}
> }
> 
> and it works in all the cases I have tried.
> 
> Is there any chance of having this code (or better, but equivalent code)
> added to pgfutil-plain.def, and the note in Section 15.2 of the manual
> updated?
> 
> Thanks.
> 
>                                 Jim