%D \module
%D   [      file=s-pre-16,
%D        version=1999.09.01, 
%D          title=\CONTEXT\ Style File,
%D       subtitle=Presentation Environment 16,
%D         author=Hans Hagen,
%D           date=\currentdate,
%D      copyright={PRAGMA / Hans Hagen \& Ton Otten}]
%C
%C This module is part of the \CONTEXT\ macro||package and is
%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
%C details.

%D The first version of this style was made late summer 1999,
%D but its first usage was during a course I gave in BRNO.
%D It's a rather simple style with a dominating background. 

\setuppapersize
  [S6][S6]

\setupbodyfont
  [pos,14.4pt]

\setuplayout
  [topspace=100pt,
   backspace=120pt,
   header=0pt,
   footer=0pt,
   width=middle,
   height=middle]

\setupbackgrounds
  [text]
  [backgroundoffset=80pt,
   background=GoOn]

\setupbackgrounds
  [page]
  [background={FuzzyCircle,Again}]

\setupcolors
  [state=start]

\definecolor[gray] [s=.4]
\definecolor[white][s=.8] 

\definecolor[red]  [r=.8] \definecolor[cyan]   [g=.8,b=.8] 
\definecolor[green][g=.8] \definecolor[magenta][r=.8,b=.8] 
\definecolor[blue] [b=.8] \definecolor[yellow] [r=.8,g=.8] 

\definecolor[PageColor][gray]
\definecolor[TextColor][yellow]
\definecolor[LineColor][blue]

\setupinteraction
  [state=start,
   color=LineColor,
   contrastcolor=LineColor]

\setupinteractionscreen
  [option=max]

\setupitemize
  [each]
  [color=blue,
   symbol=FuzzyDot]

\startuseMPgraphic{FuzzyCircle}
  path p ; numeric w, h, l ; 
  w := OverlayWidth ; h := OverlayHeight ; 
  def dd = (1 randomized (1/5)) enddef ; 
  pickup pencircle xscaled 10pt yscaled 2pt rotated 30;
  for i:=1 upto 50 : 
    p := (-dd,-dd)..(dd,-dd)..(dd,dd)..(-dd,dd)..cycle ; 
    p := p rotatedaround (center p, uniformdeviate 360) ;   
    p := p xscaled (w/2) yscaled (h/2) ; 
    l := length(p)/2 ; 
    p := p cutbefore point   (uniformdeviate l) of p ;   
    p := p cutafter  point (l+uniformdeviate l) of p ;   
    draw p withcolor \MPcolor{LineColor} randomized (.4,1) ;
  endfor ; 
  picture s ; s := currentpicture xysized (w-15,h-15) ;
  currentpicture := nullpicture ;
  fill boundingbox s enlarged 60pt withcolor \MPcolor{PageColor} ; 
  addto currentpicture also s ; 
\stopuseMPgraphic

\startuseMPgraphic{FuzzyDot}
  path p ; numeric w ; 
  w := BodyFontSize/2 ; 
  def dd = (w randomized (w/2)) enddef ; 
  pickup pencircle xscaled (w/2) yscaled (w/3) rotated 30 ;
  for i=0 step 45 until 135 : 
    p := (-dd,0)--(dd,0) ;
    p := p rotatedaround (origin,i-w+uniformdeviate w) ;
    draw p withcolor \MPcolor{LineColor} randomized (.3,.8) ;
  endfor ; 
\stopuseMPgraphic

\defineoverlay [FuzzyCircle] [\useMPgraphic{FuzzyCircle}]
\defineoverlay [GoOn]        [{\setupinteraction[click=no]\overlaybutton{forward}}]
\defineoverlay [Again]       [\overlaybutton{firstpage}]

\definesymbol 
  [FuzzyDot] 
  [\lower\dp\strutbox\hbox{\useMPgraphic{FuzzyDot}}]

\def\Item%
  {\par\noindent\symbol[FuzzyDot]\hskip.5em\nobreak}

\setupitemize 
  [all]
  [packed]
  [symbol=FuzzyDot]

\def\NextIdea%
  {\blank[back,medium]
   \midaligned{\symbol[FuzzyDot]}
   \blank[medium]
   \blank[disable]}

\definehead [Topic] [chapter]
\definehead [Nopic] [title]

\setuphead
  [Topic, Nopic]
  [alternative=middle,
   before=,
   number=no,
   style=\bfb]

\setuplist
  [Topic]
  [alternative=g,
   interaction=all]

%D Since we want a colored text, and since color directive 
%D can spoil the spacing, we use a foregroundcolor. 

\setupbackgrounds
  [text]
  [foregroundcolor=TextColor]

%D Unfortunately this does not work when on the page colors 
%D are set, so we play safe and say: 

\setupmakeup
  [standard]
  [color=TextColor]

\def\StartIdea%
  {\startstandardmakeup
   \setupwhitespace[medium]
   \setupblank[medium]
   \setupalign[broad,middle]}

\def\StopIdea%
  {\stopstandardmakeup}

\def\Topics#1%
  {\Nopic{#1}
   \startcolumns
     \setupinteraction[color=TextColor,contrastcolor=TextColor]
     \placelist[Topic]
   \stopcolumns
   \page}

%D Some fakes. 

\def\Subject  {\Topic}
\def\Subjects {}

%D A bonus (copied from \type {s-pre-02} but with a different 
%D vertical alignment. 

\def\StartTitlePage%
  {\startstandardmakeup
   \bfd\setupinterlinespace
   \setupalign[middle]
   \vfil
   \let\\=\vfil}

\def\StopTitlePage%
  {\vfil
   \stopstandardmakeup}

\def\TitlePage#1%
  {\StartTitlePage#1\StopTitlePage}

\doifnotmode{demo}{\endinput}

\starttext 

\Topics{...}

\StartIdea 
  \Topic{...}
  ... 
  \NextIdea 
  ...
\StopIdea

\stoptext 
