#!/usr/bin/env perl

use constant
Version => '1.02';

my $help = 
<<'DOC'
= mkpic - interface for making pictures with mfpic

= Synopsis
mkpic [options] [picfile]	

Options:
-c,--clean			remove all but the input file and die
-p,--pdfsample			create pdf file with sample images
-f,--font=<font command>	set default font for labels
   --[no]box			produce framed boxes
-V,--version			report version number and die
-h,--help			display help info and die
   --[no]debug			display debugging information
-l,--log=<logfile>		file for warning messages

Without an input file, the DATA section is used.

= Command overview
begin	 name xl yl xmin ymin xmax ymax xlabel ylabel
end	
stop	
var=value	
#	 comment
	
arccst	 xcenter ycenter xstart ystart theta
arcset	 xstart ystart xend yend theta
arccrtt	 xcenter ycenter radius theta1 theta2
arc3	 x1 y1 x2 y2 x3 y3
	
xmark	 [label1] x1 [label2] x2 ...
Xmark	 [label1] x1 [label2] x2 ...
ymark	 [label1] y1 [label2] y2 ...
Ymark	 [label1] y1 [label2] y2 ...
	
xdrop	 x y
ydrop	 x y
xydrop	 x y
	
arrow	 x1 y1 x2 y2 label
label	 YX x y label
xlabels	 YX x y dx label ...
ylabels	 YX x y dy label ...
	
point	 x1 y1 x2 y2 ...
dpoint	 x1 y1 dx1 dy1 ...
lines	 x1 y1 x2 y2 ...
dlines	 x1 y1 dx1 dy1 ...
curve	 x1 y1 x2 y2 ...
dcurve	 x1 y1 dx1 dy1 ...
	
rect	 x1 y1 x2 y2
drect	 x y dx dy
dcrect	 x y dx dy
crect	 x1 y1 x2 y2
arect	 xc yc width height theta
bar	 x xdev height
	
func	 xmin xmax step expression-in-x
	
grid	 dx dy xgap ygap
hatch	 
bhat	 
ehat	 

= Description
mkpic provides an easy interface for making small pictures with mfpic. To
this end you create an input file has to be created consisting of
commands, one per line, with space separated parameters (or you modify the
DATA section of the mkpic script, which is used if you run it without an
input file). For an extensive description see the file mkpicdoc.pdf, which
is part of the distribution.

mkpic produces two files. Assuming an input file named |picfile| defaulting
to |mkpic| these are:

picfile.mac	
	a macro file which will contain |TeX| commands for every picture
picfile.sty	
	a style file for latex, defining the same |TeX| commands for every picture.

With the |--pdfsample| option, two other files are produced:

picfile.pdf	
	a PDF file containing all pictures. 
	This lets you easily check the results of your designs.

picfile.tex	
	the |TeX| source used for creating this PDF file.

In |LaTeX|, you have to include |\usepackage{picfile}| and to include
commands like |\Fig|/name/ in your source, where /name/ is the
name you gave one of your pictures in an mkpic |begin| command.

In TeX and ConTeXt, you have to |\input picfile.mac| and to
include commands like |\Fig|/name/ in your source, where /name/ is
the name you gave one of your pictures in an mkpic |begin| command.

In TeX, you must use the |\bye| command (/not/ |\end| to finish your TeX source 

See the RUNNING section for how to run mkpic and TeX, LaTeX, or ConTeXt.

= Commands
The source is set up so that it is easy to add your own commands,
Currently the following commands have been implemented (the arguments
are not listed here; for those, refer to the SYNOPSIS section):

begin, end	
	Every picture begins with the |begin| command and ends with the |end|
	command.  The |begin| command defines a name for the picture and
	defines a tex command with that name, prefixed with 'Fig'. The
	resulting command is written to a |.mac| file. Thus the command
	
	    begin aa ...
	
	starts writing |\def\Figaa{...| to the |.mac| file, and the
	picture can be reproduced in a |TeX| document by importing the |.mac| file
	and using the |\Figaa| command. 
	
	xl and yl are the lengths of the x- and y-axes. xlabel and ylabel are
	the label that are placed at the ends of those axes. Use a space to
	suppress labeling, or "-" to suppress drawing the axes at all.
	
stop	
	stops further reading of the input. Useful if you have many pictures,
	but want to see only the first few for testing purposes.
	
var=value	
	sets the variable var to value. This variable, or an expression containing it,
	can be used instead of any numerical parameter. Variable names may contain 
	lower and uppercase letters, digits or underscores, with the restriction that 
	they must start with a letter and may not end in an underscore. 
	
#	 
	denotes a comment
	
xmark, ymark, Xmark, Ymark	
	These commands place one or more labels along the x- or y-axes, either
	below (|xmark| and |ymark|) or above (|Xmark| and |Ymark|) the axis.
	
	For the |[xXyY]mark| commands a parameter containing any character
	other than [-.0-9] is interpreted as the label (this implies that you
	cannot use expressions here!) to be placed and its position is expected
	in the next parameter. If a parameter is just a number, it is placed at
	that x-position. If you want a number to be interpreted as a label, put
	it in braces: |{1950}|.
	
arccst	
	(Mnemonic: |c|enter |s|tart |t|heta.)
	Draws an arc with its center in |xcenter,ycenter|, starting in |xstart,ystart|
	and with an arc length of |theta| degrees.
	
arcset	
	(Mnemonic: |s|tart |e|nd |t|heta.)
	Draws an arc starting in |xstart,ystart|end ending in |xend,yend|
	and with an arc length of |theta| degrees.
	
arccrtt	
	(Mnemonic: |c|enter |r|adius |t|heta1 |t|heta2.)
	Draws an arc with its center in |xcenter,ycenter|, a radius |radius|
	starting at |theta1| degrees and ending at |theta2| degrees.
	
arc3	
	(Mnemonic: |3| points.)
	Draws an arc starting at |(x1,y1)|, through |(x2,y2)| and ending in |(x3,y3)|.
	
xdrop, ydrop, xydrop	
	These commands draw dotted arrows perpendicularly to the x-axis, the
	y-axis and both axes, respectively, ending on the axes with the
	arrow head.
	
arrow	
	draws an arrow from |(x1,y1)| to |(x2,y2)| labeled on its tail with
	|label|
	
label	
	draws a label at |(x,y)|. |YX| tells how it will be adjusted: for
	Y=t,b,c |(x,y)| will be, in the y-direction, on top, bottom or center
	of the label respectively, for X=l,r,c it will be, in the x-direction,
	left, right or center adjusted on |(x,y)|. Thus
	
	    label tl 0 0 Hello World!
	
	will draw the string "Hello World"  with its lower left corner at (0,0)
	
xlabels	
	draws many labels, starting at |(x,y)|, and incrementing |x| with |dx|
	after every label. |YX|: see |label|. Labels may not contain spaces;
	if you need spaces, use - instead.
	
ylabels	
	Same as |xlabels|, but incrementing |y| with |dy| instead.
	
point	
	draws points (dots) at |(x1,y1)|, |(x2,y2)| et cetera.
	
dpoint	
	draws points (dots) starting at |(x1,y1)| and then moving by 
	|(dx1,dy1)|, |(dx2,dy2)| et cetera.
	
lines	 
	draws line segments from |(x1,y1)| to |(x2,y2)|, |(x3,y3)| et cetera.
	
dlines	
	draws line segments starting at |(x1,y1)| and then moving by 
	|(dx1,dy1)|, |(dx2,dy2)| et cetera.
	
curve	
	draws a bezier curve from |(x1,y1)| to |(x2,y2)|, |(x3,y3)| et cetera.
	
dcurve	
	draws a bezier curve starting at |(x1,y1)| and then moving by 
	|(dx1,dy1)|, |(dx2,dy2)| et cetera.
	
rect	
	draws a rectangle with diagonal points at |(x1,y1)| and |(x2,y2)|.
	
drect	
	draws a rectangle with diagonal points at |(x,y)| and |(x+dx,y+dy)|.
	
crect	
	clears a rectangle with diagonal points at |(x1,y1)| and |(x2,y2)|.
	
dcrect	
	clears a rectangle with diagonal points at |(x,y)| and |(x+dx,y+dy)|.
	
arect	
	draws a rectangle with a widdh |width| and a height |height|;
	the middle of the bottom is at |(xc,yc)| and the centerline through 
	|(xc,yc)| makes an angle |theta| with the x-axis.
	
bar	
	draws a equivalent with |rect x-xdev 0 x+xdev height|
	
func	
	draws the function given by |expression-in-x| between |xmin| and
	|xmax|, stepping with |step| units in the x-direction.
	Note that the |expression-in-x| will be evaluated by |Metafont|, so 
	you will have to use metafont syntax.
	
grid	
	draw dotted grid lines at distances dx and dy in the x- and y
	directions; the gaps between the dots are set to |xgap| an |ygap|
	respectively. For an esthetic appearance, be sure to use integer
	|dx/xgap| and |dy/ygap| ratios.
	
hatch	
	hatch the closed curve that follows.
	
bhat	
	starts a path that will eventually be closed, and then hatched.
	
ehat	
	ends a path started with |bhat|, closes it and then hatches it.
	
anything else	
	will be inserted as is in the macro file, and therefore should be a
	valid |mfpic| statement. You use this when you need such a statement
	only once, or a few times and therefore see no need to define a proper
	command for it.

= Running mkpic/TeX
The effect of running 
	mkpic picfile
is the creation of |picfile.mac|, which you can |\input| into a TeX or
ConTeXt source, and |picfile.sty| which can be input into a LaTeX
source using the |\usepackage| command.

After running TeX (or LaTeX or ConTeXt), you will find a file
|picfile.mf| and you will have to run Metafont on it, which
(assuming you configured TeX for 600 dpi) produces picfile.600gf. This
file will have to be converted to a pk file with gftopk. Finally, you
need to run TeX, normally at least twice, again. So for pdfLaTeX the sequence is:

	mkpic picfile
	pdflatex file.tex
	mf picfile
	gftopk picfile.600gf
	pdflatex file
	pdflatex file

= Bug
Currently only up to 256 pictures can be generated. In the future this
problem will probably be solved by introducing more than one font and
generating tex-command names that have the font name in front.

= Changes
Changes with respect to version 0.1:
- added mkpicdoc.tex to the distribution

= Author and copyright
Author	Wybo Dekker
Email	U{Wybo@dekkerdocumenten.nl}{wybo@dekkerdocumenten.nl}
License	Released under the U{www.gnu.org/copyleft/gpl.html}{GNU General Public License}
DOC
;

use vars
  qw/$xgap $ygap $dx $dy $xl $yl $x3 $y3 $height $Z $d $F $r $theta1 $theta2/;

sub evaluate {
   defined or die "Missing parameter at line $.\n";
   if ( !m|^[0-9.]+$| ) {
      my $x = '';  # we build up the expression with $-ized variable names in $x
      while ($_) {
         unless (/[A-Za-z0-9]+/) { $x .= $_; last }
         my ( $left, $middle, $right ) = ( $`, $&, $' );
         $x .= $left
           . ( ( $middle =~ m|^[0-9.]+$| || $fun{$middle} ) ? "" : '$' )
           . $middle;
         $_ = $right;
      }
      $_ = $x;
      eval "\$_=$_" while m|[^0-9.-]|;
   }
   $_;
}

sub parse {
   my @x;
   ( $command_name, @x ) =
     split ( /\s+/, $_, scalar @_ + 1 );    # input values/expressions in @x
   print LOG "command: $command_name\n" if $debug;
   for ( my $i = 0 ; $i < @_ ; $i++ ) {     # each variable to be set
      $_ = $x[$i];                          # take the expression
      if ( $_[$i] !~ /^[A-Z]/ )
      {    # if name of receiving var not capitalized: await numerical
         evaluate;
      }
      my $varname = "$_[$i]";
      $$varname = $_;
      print LOG "$varname=$_\n" if $debug;
   }
}

sub parse_array {
   my @x;
   ( $command_name, @x ) = split ( /\s+/, $_[0] );
   print LOG "command: $command_name\n" if $debug;
   unless ( $command_name =~ /mark/ ) {
      for (@x) {
         evaluate;
      }
   }
   print LOG "parse_array returns: @x\n" if $debug;
   @x;
}

sub open_macrofile {
   my $rerun = 0;
   # we need to rerun if:
   # - one of the needed files is missing or else
   # - the input file is newer than the .mac file or else 
   # - the present options differ from/keep the previous ones

   # check the presence of needed files:
   chomp( $_ = -f $tex ? $tex : `which mkpic` );
   my $inputtime = ( stat($_) )[9];
   for ( "mac", "sty" ) {
      -f "$tex.$_" or $rerun = 1, last;
   }
   # if all are there, test if the input is older than the .mac file:
   !$rerun && ( stat("$tex.mac") )[9] > $inputtime or $rerun = 1;

   # if that's true too, check that the previous option were the same:
   unless ($rerun) {
      open( MAC, "$tex.mac" );
      $_ = <MAC>;
      $_ eq $options or $rerun = 1;
      close MAC;
   }
   $rerun or return (0);
   open( MAC, ">$tex.mac" );
   select MAC;
   $_ = <<'EOF'
      % vim: syntax=tex
      \input mfpic
      \let\circle\undefinedcs
      \mfpicunit.01mm
      \opengraphsfile{TX}
      \def\ifundefined#1{\expandafter\ifx\csname#1\endcsname\relax}
      \def\doatend{\closegraphsfile}
      \ifundefined{typefile}\else\appendtoks\doatend\to\everystoptext\fi % for context
      \ifundefined{documentclass}\else\AtEndDocument{\doatend}\fi % for latex
      \def\bye{\doatend\par\vfill\supereject\end} % plain
      \def\ruledhbox#1{\vbox{\hrule\hbox{\vrule\kern3pt
         \vbox{\kern3pt#1\kern3pt}\kern3pt\vrule}\hrule}}

EOF
   ;
   s/^\s+//gm;
   s/TX/$tex/gm;
   print MAC $options,$_;

   open( STY, ">$tex.sty" ) or die "Could not open $tex.sty: $!\n";
   $_ = <<'EOF'
      \ProvidesPackage{TX}
      \input TX.mac
      \endinput
EOF
   ;
   s/^\s+//gm;
   s/TX/$tex/gm;
   print STY;
   1;
}

sub sys {
   system("@_") and die "@_: $?\n";
}

sub parse_input {
   while (<$input>) {
      chomp;
      s/\s*#.*//;    # remove comment
      next unless $_;    # skip empty lines
      /^begin/ and do {
         parse qw(Name xl yl xmin ymin xmax ymax Xlabel Ylabel);
         $names{$Name} and die "multiple occurrences of picture named $Name\n";
         $names{$Name} = 1;

         $Xlabel = "" if $Xlabel eq '-';
         $Ylabel = "" if $Ylabel eq '-';
         $xscale = int( 100 * $xl / ( $xmax - $xmin ) + .5 );
         $yscale = int( 100 * $yl / ( $ymax - $ymin ) + .5 );
         $sx = sprintf( "%.2f", 100 / $xscale );
         $sy = sprintf( "%.2f", 100 / $yscale );
         $yx = $ymin > 0 ? $ymin : 0;    # y-position of the x-axis
         $xy = $xmin > 0 ? $xmin : 0;    # x-position of the y-axis
         $xlo = $xy - $sx;               # x-pos of right side of y-markers
         $ylo = $yx - $sy;               # y-pos of top side of x-markers
         $xhi = $xmax + 3 * $sx;         # x-pos of left side of x-labels
         $yhi = $ymax + 3 * $sy;         # y-pos of bottom side of y-labels
         print "%\n%====$Name====\n"
           . "\\def\\Fig$Name\{\\$box\{\\mftitle{$Name}%\n"
           . "\\def\\xlo{$xlo}\\def\\xhi{$xhi}%\n"
           . "\\def\\ylo{$ylo}\\def\\yhi{$yhi}%\n"
           . "\\def\\xy{$xy}\\def\\yx{$yx}%\n"
           . "\\mfpic[$xscale][$yscale]{$xmin}{$xmax}{$ymin}{$ymax}%\n"
           . "\\hatchwd{2}%\n"
           . ( $Xlabel ? "\\tlabel[bc]($xy,$yhi){$font $Ylabel}%\n" : '' )
           . ( $Ylabel ? "\\tlabel[cl]($xhi,$yx){$font $Xlabel}%\n" : '' );
         print TEX "\\Fig$Name\\par{\\bf $Name}\\eject\n" if $pdfsample;
      }, next;

      /^arccst/ and do {                 # arc center start theta
         parse qw(xc yc x1 y1 theta);
         print "\\arc[c]{($xc,$yc),($x1,$y1),$theta}\n";
      }, next;

      /^arcset/ and do {                 # arc start end theta
         parse qw(x1 y1 x2 y2 theta);
         print "\\arc[s]{($x1,$y1),($x2,$y2),$theta}\n";
      }, next;

      /^arccrtt/ and do {                # arc center radius theta1 theta2
         parse qw(xc yc r theta1 theta2);
         print "\\arc[p]{($xc,$yc),$theta1,$theta2,$r}\n";
      }, next;

      /^arc3/ and do {                   # arc three points
         parse qw(x1 y1 x2 y2 x3 y3);
         print "\\arc[t]{($x1,$y1),($x2,$y2),($x3,$y3)}\n";
      }, next;

      /^arrow/ and do {
         parse qw(x1 y1 x2 y2 Label);
         my $yd = $y1 > $y2 ? -3 : 3;
         print "\\tlabel[bc]($x1,$y1){$font $Label}%\n"
           . "\\arrow\\lines{($x1,"
           . ( $y1 + $yd * $sy )
           . "),($x2,$y2)}%\n";
      }, next;

      /^[xyXY]mark/ and do {
         @z = parse_array($_);
         for ( $i = 0 ; $i < @z ; $i++ ) {
            $label = $z[$i];
            if ( $label =~ /^[-.\d]+$/ ) {
               $label = "\$$label\$";
            } else {
               $i++;
            }
            $x =
              $command_name =~ /x/i ? $z[$i]
              : $command_name =~ /y/ ? $xlo
              : -$xlo;
            $y =
              $command_name =~ /y/i ? $z[$i]
              : $command_name =~ /x/ ? $ylo
              : -$ylo;
            print "\\tlabel[$pos{$command_name}]($x,$y)"
              . "{\\rm \\strut $label}%\n";
         }
      }, next;

      /^grid/ and do {
         parse qw(xdist ydist xgap ygap);
         $topmaxy = ( int( $ymax / $ydist ) * $ydist );
         $lftmaxx = ( int( $xmin / $xdist ) * $xdist );
         $botmaxy = ( int( $ymin / $ydist ) * $ydist );
         $rtmaxx  = ( int( $xmax / $xdist ) * $xdist );
         for ( $t = $lftmaxx ; $t <= $rtmaxx ; $t += $xdist ) {
            print
              "\\dotted[.5pt,$xgap mm]\\lines{($t,$botmaxy),($t,$topmaxy)}%\n";
         }
         for ( $t = $botmaxy ; $t <= $topmaxy ; $t += $ydist ) {
            print
              "\\dotted[.5pt,$ygap mm]\\lines{($lftmaxx,$t),($rtmaxx,$t)}%\n";
         }
      }, next;

      /^bar/ and do {
         parse qw(x xdev height);
         $x1 = $x - $xdev;
         $x2 = $x + $xdev;
         $y1 = 0;
         $y2 = $height;
         print "\\rect{($x1,$y1),($x2,$y2)}%\n";
      }, next;

      /^d?(point|lines|curve|rect|crect)/ and do {
         @z = parse_array($_);
         $command_name =~ /^d/ and do {    # relative points
            for ( $i = 3 ; $i < @z ; $i += 2 ) {
               $z[$i] += $z[ $i - 2 ];
               $z[ $i - 1 ] += $z[ $i - 3 ];
            }
            $command_name =~ s/^d//;
         };
         $_ = "$command_name @z";
         # for example: crect 5 20 20 5
         s/^/\\/;      # \crect 5 20 20 5
         s/\s+/{(/;    # \crect{(5 20 20 5
         while (/ +/) {
            s/ +([-.\d]+)(\s+)?/,$1),\n(/;
         }               # \crect{(5,20),(20,5)
         s/,\n\($/}/;    # \crect{(5,20),(20,5)}
         s/crect/gclear\\rect/;
         # \gclear\rect{(5,20),(20,5)}
         print "$_\n";
      }, next;

      /^func/ and do {
         parse qw(x y d F);
         print "\\function{$x,$y,$d}{$F}%\n";
      }, next;

      /^hatch/ and do {
         print '\rhatch\draw\lclosed';
      }, next;

      /^bhat/ and do {
         print '\rhatch\lclosed\connect', "\n";
      }, next;

      /^ehat/ and do {
         print '\endconnect', "\n";
      }, next;

      /^xdrop/ and do {
         parse qw(x y);
         print "\\dotted\\arrow" . "\\lines{($x,$y),($xy,$y)}%\n";
      }, next;

      /^ydrop/ and do {
         parse qw(x y);
         print "\\dotted\\arrow" . "\\lines{($x,$y),($x,$yx)}%\n";
      }, next;

      /^xydrop/ and do {
         parse qw(x y);
         print "\\dashed\\arrow" . "\\lines{($x,$y),($xy,$y)}%\n";
         print "\\dashed\\arrow" . "\\lines{($x,$y),($x,$yx)}%\n";
      }, next;

      /^xlabels/ and do {
         parse qw(M x y dx Z);
         @z = split ( /\s+/, $Z );
         for (@z) {
            print "\\tlabel[$M]($x,$y){$font $_}%\n";
            $x += $dx;
         }
      }, next;

      /^ylabels/ and do {
         parse qw(M x y dy Z);
         @z = split ( /\s+/, $Z );
         for (@z) {
            print "\\tlabel[$M]($x,$y){$font $_}%\n";
            $y += $dy;
         }
      }, next;

      /^label/ and do {
         parse qw(M x y Label);
         $M =~ /^[bct][lcr]$/ or die "illegal label in $_\n";
         print "\\tlabel[$M]($x,$y){$font $Label}%\n";
      }, next;

      /^end/ and do {
         # axes drawn last for easier rect clears:
         print "\\arrow[\\axisheadlen]\\lines" . "{($xmin,$yx),($xmax,$yx)}%\n"
           if $Xlabel;
         print "\\arrow[\\axisheadlen]\\lines" . "{($xy,$ymin),($xy,$ymax)}%\n"
           if $Ylabel;
         print "\\endmfpic}}%\n";
      }, next;

      /^arect/ and do {
         parse qw/xc yc w h theta/;
         $theta *= 3.141592 / 180;
         $ws = $w / 2 * sin($theta);
         $wc = $w / 2 * cos($theta);
         $hs = $h * sin($theta);
         $hc = $h * cos($theta);
         print "\\lines{($xc-$ws,$yc+$wc),($xc-$ws+$hc,$yc+$wc+$hs),($xc+$ws+$hc,$yc-$wc+$hs),($xc+$ws,$yc-$wc),($xc-$ws,$yc+$wc)}\n";
      }, next;

      /^(\w+)\s*=/ and do {
         $var = $1;
         evaluate;
         print LOG "$var=$$var\n" if $debug;
      }, next;

      /^stop/ and do { last };    # stop reading the input

      print "$_\n" if $_;         # anything else printed literally

   }
   print MAC "\\endinput\n";
   close(MAC);
   if ($pdfsample) {
      print TEX "\\bye\n";
      close(TEX);
      sys("pdftex --interaction batchmode $tex 2>/dev/null");
      sys("mf $tex; gftopk $tex.${dpi}gf");
      sys("pdftex --interaction batchmode $tex 2>/dev/null");
      for ( ( "log", "mf", "tfm", "${dpi}pk", "${dpi}gf", ) ) {
         unlink "$tex.$_";
      }
   }
}

sub help { undef $/; open(FH,$0); print "Usage:".[split(/= .*\n/,<FH>)]->[3]; exit 1 }
sub install { system('instscript --extras=mkpicdoc.tex,mkpicdoc.pdf -zp mkpic'); exit 0; }

use Getopt::Long;
Getopt::Long::Configure("bundling_override");

GetOptions(
   'c|clean'     => \$clean,        # remove all but input file and don't run
   'p|pdfsample' => \$pdfsample,    # create pdf file with sample images
   'b|box!'      => \$box,          # produce framed boxes
   'f|font=s'    => \$font,         # default font instead of rm
   'V|version'   => \$version,      # report version number and die
   'h|help'      => \&help,         # display help info and die
   'd|debug!'    => \$debug,        # print debug information
   'l|log=s'     => \$log,          # file for warning messages
   'I'           => \&install	    # not for general use
);

if ($version) { print Version."\n"; exit; };
$font = $font || '\rm';
$box ||= '';
$pdfsample ||= 0;
if ($log) {
   open( LOG, ">>$log" ) or die "Could not open $log for output: $!\n";
} else {
   *LOG = *STDERR;
}

# find printer density
if ( open( IN, `kpsewhich --format="web2c files" mktex.cnf` ) ) {
   while (<IN>) {
      /BDPI=(\d+)/ and $dpi = $1, last;
   }
} else {
   print LOG "could not find mktex.cnf; forcing 600dpi\n";
   $dpi = 600;
}

# we'll place the options in the .mac file so that, in the next run,
# we can see if the previous run had the same options; if so and if 
# the input file is older than the .mac file, we won't rerun mkpic:
$options = "% font:$font box:$box dpi=$dpi pdfsample:$pdfsample\n";

$tex = shift;
if ($tex) {
   open( IN, $tex ) or die "Could not open $tex\n";
   $input = *IN;
} else {
   $input = *DATA;
   $tex   = 'mkpic';
}

$clean and do {
   for ( eval "qw(mf ${dpi}gf ${dpi}pk log dvi pdf mac tex tfm sty)" ) {
      unlink "$tex.$_";
   }
   exit 0;
};

open_macrofile() or die "mkpic: no new run needed\n";
print LOG "Mkpic Warning: Rerun (La)TeX\n" if $log;

$box = $box ? 'ruledhbox' : 'hbox';
if ($pdfsample) {
   open( TEX, ">$tex.tex" );
   ($_ = <<EOF ) =~ s/^\s+//gm;
     \\input $tex.mac
     \\parindent0pt\\parskip2ex
     \\nopagenumbers\\vsize=260mm
EOF
   print TEX;
}

%pos = (
   'xmark' => 'tc',    # positions for [xyXY]marks
   'ymark' => 'cr',
   'Xmark' => 'bc',
   'Ymark' => 'cl'
);
%fun = (
   sin   => 1,
   cos   => 1,
   sqrt  => 1,
   atan2 => 1,
   abs   => 1,
   exp   => 1,
   int   => 1,
   log   => 1,
   not   => 1
);

%names = ();

parse_input;

__DATA__
l=20
begin steps l l 0 0 l l - -
\pen{2pt}
dlines 10 10 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1
end

begin rectangle 64 64 0 0 10 10  $x$ $y$
arect 5 5 3 2 60
lines 0 0 10 10 0 10 10 0
end

begin parabola 64 64 0 -6 4 5 $x$ $y$
xmark 2
Xmark 3
ymark -5 0 4
bhat
lines 0 0 0 4
func 0 3 .05 4-x*x
lines 3 -5 3 0
ehat
func 0 3.2 .05 4-x*x
xydrop 3 -5
arrow 3 4 1.7 1.1 $f(x)=4-x^2$
arrow 2 5 1 2 Area $O_1$
arrow 4 2 2.8 -2 Area $O_2$
end

begin droparrows 64 64 0 3 12 8 $x$ $y$
xmark $a$ 2 $x_1$ 4 $x_2$ 8 $b$ 10
ydrop 2 4.414
ydrop 4 5
ydrop 8 5.828
ydrop 10 6.162
label cc 4 4 $f(x_1)$
label cc 8 4 $f(x_2)$
label cc 7 8 $f(x)$ increasing on $[a,b]$
label cc 7 7.5 $x_1<x_2\Rightarrow f(x_1)<F(x_2)$
func 1 11 .1 x**(.5)+3
end

begin asymptotes 64 64 0 0 10 10 $x$ $y$
curve 1 1 2 3 4 5.7 7 8.1 9 9
point 2 3 4 5.7 7 8.1
\shift{(-.05,.05)}
func 1.4 2.6 .1 1.65*x-.3
func 3.2 4.8 .1 1.025*x+1.6
func 6.1 7.9 .1 .62*x+3.76
label cl 9.5 9 $f(x)$
label tl 5 5 $f^\prime(x)>0$
label tl 5 4 $f^\prime(x)$ decreasing
end

# the previous diagram was made when expression were not yet available
# with them, it's easier to use a defined curve and its calculated slopes
# and positions:
begin droppers 64 64 0 0 10 10 $x$ $y$
func 0 10 .1 3*(sqrt(x))
point 2 3*sqrt(2) 4 3*sqrt(4) 7 3*sqrt(7)
\shift{(-.05,.05)}
func 1.5 2.5 .1 3/2*(x/sqrt(2)+sqrt(2))
func 3.5 4.5 .1 3/2*(x/sqrt(4)+sqrt(4))
func 6.5 7.5 .1 3/2*(x/sqrt(7)+sqrt(7))
label cl 9.5 9 $f(x)$
label tl 5 5 $f^\prime(x)>0$
label tl 5 4 $f^\prime(x)$ decreasing
end

begin inflections 64 64 -.85 -1.5 1.5 5 $x$ $y$
func -.6 1.5 .05 6*(x**4)-8*(x**3)+1
lines -.2 1 .2 1
label cr -.25 1 horizontal
arrow .5 2 0 1 inflection point
arrow .8 1 .65 0 inflection point
arrow 1 5 1.5 4.375 $f(x)=6x^4-8x^3+1$
Xmark 1
ymark \raise-8pt\hbox{0} 0 -1
xydrop 1 -1
end

begin paraboloid 64 64 -4 -4 4 4 - -
\dashed
lines -4 0 0 0 0 0 0 -4  # neg z and neg y
\dashed
lines 0 0 3 1.73         # neg x
\arrow
lines 0 0 0 4            # pos z
\arrow
lines 0 0 4 0            # pos y
\arrow
lines 0 0 -3 -1.73       # pos x
\dotted
lines -1 4 -1 0 -4 -1.73 # intersections y=-1 plane
\dotted
lines -1 -.577 -4 -.577  # intersection x=2 plane with xy-plane
% extra helplines
\dotted
lines -2 .423 -2 -.577 0 0 0 1 -2 .423
Ymark 3
% end of extras
\dotted
lines 0 3 -1 3 -4 1.27
\dashed\sclosed
curve -3 2.42 -1.5 2.711 -1 2.42 -2.5 2.134
label bc 0 yhi $z$
label cl xhi 0 $y$
label tr -3.1 -1.8 $x$
label cl -.85 -.577 2
label tc 0 5.5 $f(x,y)=x^2-4x+2y^2+4y+7$
xmark -1
Ymark 1
\shift{(-2,.42)}
\dashed
func 0 .5 .1 9*x*x
func -.5 0 .1 7*x*x
\dashed
func -1 0 .1 2*x*x
func 0 1 .1 2*x*x
end