Re: How to get randomly coloured text in metapost?

[Marco <netuse@lavabit.com>]

> > Is it possible to get the metapost construct »withcolor« to work
> > with text or do I have to take a different approach?
>
> I understood from a much earlier discussion with Hans that "withcolor"
> will not be made to work with text, whose color therefore has to be
> set with ConTeXt constructs.
Thanks for the information. But how to do this? How can I set up the
randomness in ConTeXt? I browsed a bit through the sources and found a
lua snipped producing random integers. So here's my first attempt.

% only Integers, so not much variation in color :-(
\def\r{\ctxlua{commands.getrandomcounta(0,1)}}

% Defining the colour at this point makes it kind of static again
\definecolor[my][r=\r,g=\r,b=\r]
\starttext
\startuseMPgraphic {1}

% The colour is all the same, but different in each run
for i=0 upto 5:
  label(textext("\color[my]{Test}"), (i*1cm,-2cm));
endfor;

% Does not work, results in compile error
% for i=0 upto 5:
%   label(textext("\definecolor[my][r=\r,g=\r,b=\r]\color[my]{Test}"),
%       (i*1cm,-3cm));
% endfor;

\stopuseMPgraphic
\useMPgraphic {1}
\stoptext

Maybe this code is an improvable step in the right direction, maybe it's
rubbish. Necessary improvements need to be:

    i) need of floating point random numbers
   ii) random colours per call and not per ConTeXt run
  iii) the use is quite verbose, so need to put it in a macro

Any hints appreciated.

Marco


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