Re: metaobj and transparent colors with \MPcolor

["Eckhart Guthöhrlein" <eckhart.guthoehrlein@uni-bielefeld.de>]

On Fri, Jul 23, 2004 at 11:38:28AM -0700, Hans Hagen Outside wrote:
> >>If I use the fillcolor as an argument to the object
> >>
> >>    newBox.test(btex Transparent? etex) "filled(true)"
> >>        "fillcolor(\MPcolor{Durchsichtig})";
> >
> can you try
>                 fillcolor \MPcolor{...}
> 
> or maybe
> 
> color xxxx ; xxxx := \MPcolor{...} ; fillcolor(xxxx) ;

Here is my current file, which just gives a white background in the box.

\setupcolors[state=start]
\setupbackgrounds[page][background=color,backgroundcolor=red]
\definecolor[Transparent][r=0,g=1,b=1,t=0,a=normal]
\startreusableMPgraphic{test}
	input metaobj;
	color t; t:=\MPcolor{Transparent};
	setObjectDefaultOption("Box")("fillcolor")(t);
	newBox.test(btex Transparent? etex) "filled(true)";
	Obj(test).c=origin;
	drawObj(test);
\stopreusableMPgraphic
\starttext
	\reuseMPgraphic{test}
\stoptext

Experimenting with default degrees of transparency, e.g. t=0.5, I have
noticed that the object is indeed filled using the Transparent color.
The problem seems to be that all objects in metaobj are filled using a
non-transparent white by default. Subsequent filling with a completely
transparent color then of course gives just white.
Well, I just want to see my normal page background through the object.
Can I achieve this?

-- 
Eckhart