Vit Zyka wrote:
> Mojca Miklavec wrote:
> > Thomas A. Schmitz wrote:
> >
> >>I am still at a loss how to achieve one thing in ConTeXt that was
> >>pretty easy in Keynote or (shudder) Powerpoint: When I wanted to
> >>highlight something on a map or a picture, I would just draw a red
> >>circle around it. What would be the proper way to do this in ConTeXt?
> >>Adding a layer with a red circle drawn in Metapost, then positioning
> >>it by trial and error? Or can anyone point to a better solution?
> >
...
> > In this case it would be fine to have a \framed[...foreground=...] command
> > :)
>
> Use
>
> \framed
> [background={foreground,BgFront}]
> {\externalfigure[Kochloewe_c][width=10cm]}}
>
> Define your picture as BgFront. 'foreground' is fixed word that
> identifies layer 0 (text). So you can stack bacground as follow:
> background={...,MyLayer-2,MyLayer-1,foreground,MyLayer1,MyLayer2,...}
Uau! Thanks a lot for a very nice hint. So you can make something like that:
\setupcolors[state=start]
\starttext
\setupMPvariables[CircleSomething][dimension={(100,100)},center={(50,50)},r=10]
\startuseMPgraphic{CircleSomething}
pair dimension, center;
% TODO: this also has to be passed as parameter!!!
% now it stands for: width=10cm
scale := 10cm/(xpart \MPvar{dimension});
picture bboxpicture;
dimension := \MPvar{dimension} scaled scale;
center := \MPvar{center} scaled scale;
r := \MPvar{r}*scale;
pickup pencircle scaled 2pt;
% proper bounding box
fill unitsquare xyscaled dimension;
bboxpicture := currentpicture;
currentpicture := nullpicture;
draw fullcircle scaled (2*r) shifted center withcolor red;
setbounds currentpicture to boundingbox bboxpicture;
\stopuseMPgraphic
\defineoverlay[CircleBlueTulip][\uniqueMPgraphic{CircleSomething}{dimension={(400,460)},center={(222,460-330)},r=25}]
\defineoverlay[CircleRedTulip][\useMPgraphic{CircleSomething}{dimension={(400,460)},center={(148,460-330)},r=25}]
\framed[background={foreground,CircleBlueTulip},offset=0pt,strut=no]{\externalfigure[Kochloewe_c][width=10cm]}
\framed[background={foreground,CircleRedTulip},offset=0pt,strut=no]{\externalfigure[Kochloewe_c][width=10cm]}
\stoptext
Mojca
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