%  shadbox.sty
%
%    17 Mar 1996
%    Glazkov D.A.
%    e-mail: glazkov@sci.lpi.msk.su
%
%    117924 Moscow, Leninsky Prosp. 53
%    P.N.Lebedev Physical Institute of
%    Russian Academy of Sciences
%             RUSSIA
%
%
%
%     The goal of this command is to darken the background of any box -
%     text, figure, table etc. In the contrast to PostScript drivers,
%     DVIWIN etc. there is not used any driver-specific properties, but
%     standard Plain(La) TeX. Small black squares is places in the area
%     of the box. The dimension of black square (length \deltablack) may be
%     set by any means (\setlength). But it's reasonable to choose 
%     this dimension little greater than dimension of point of the
%     output printer. By default it is equal to 0.3pt, that is suitable
%     for the printer of 300 dpi.
%
%     The degree of darkness is regulated by means of change the distance
%     between small black squares. In this style squares are placed in the
%     rectangular order - it's simpler, but result is not always very good.
%     - See the style "shadbox1.sty".
%
%     The retribution for driver-independence is: the less squares and
%     nearer to each other, the greater the size of output DVI-file (and
%     grows quickly). One must experiment to find balance between quality
%     of shadow and size of output file.
%
%
%
%       You may change this code freely. But please inform me if you use
%       or improve these commands.
%
%
%
%     Usage:
%
%	\shadbox{x}{abc}
%
%            x   - ratio showing how many times the distance between squares
%                  greater than their size (may be only >1). 1 corresponds
%                  to black darkness, 2 corresponds to 50% darkness.
%
%            abc - the box, which must be darken
%

\newdimen\deltablack
\newdimen\delt
\deltablack=0.3pt
\def\shadbox#1#2{%
  \delt=#1\deltablack
  \setbox2=\hbox{#2}%
%
  \setbox3=\hbox{\vrule width\deltablack height\deltablack depth0pt}%
  \wd3=\delt
  \ht3=\delt
  \setbox4=\vbox to\ht2{%
    \leaders\copy3\vfil\hrule width 0pt height-\dp2 depth\dp2}%
  \setbox5=\hbox to\wd2{\leaders\copy4\hfil}%
  \wd5=0pt\relax
  \ht5=0pt\relax
  \dp5=0pt\relax
  \leavevmode\box5\box2%
}


\def\shadboxalt#1#2{%
  \delt=#1\deltablack
  \setbox2=\hbox{#2}%
%
  \setbox3=\hbox{\vrule width\deltablack height\deltablack depth0pt}%
  \wd3=\delt
  \ht3=2\delt
  \setbox4=\vbox to\ht2{%
    \leaders\copy3\vfil\hrule width 0pt height-\dp2 depth\dp2}%
  \setbox3=\hbox{\hbox{}\raise\delt\hbox{\vrule width\deltablack
	      height\deltablack depth0pt}}%
  \wd3=\delt
  \ht3=2\delt
  \dp3=0pt\relax
  \setbox6=\vbox to\ht2{\leaders\copy3\vfil\hrule width 0pt height-\dp2 depth\dp2}%
  \setbox7=\hbox{\box4\box6}%
  \setbox5=\hbox to\wd2{\leaders\copy7\hfil}%
  \wd5=0pt\relax
  \ht5=0pt\relax
  \dp5=0pt\relax
  \leavevmode\box5\box2%
}
