#!/opt/tools/bin/perl -w
use strict;
use Tk;
use Data::Dumper;
warn "Tk$Tk::VERSION\n";

my $ps = page_sizes();
my $psize = $ARGV[0];

unless (exists $ps->{$psize})
 {
  my @sizes = keys %$ps;
  die "@sizes\n";
 }
 
my $x = 0;
my $y = 0;

my $dx = $ARGV[1] || 297;
my $dy = $ARGV[2] || 210;

my $mw = MainWindow->new;
my $c  = $mw->Canvas(-width => 640, -height=>480);
$c->create('rectangle',$x,$y,$x+$dx,$y+$dy);
$c->create('line',$x,$y,$x+$dx,$y+$dy,-arrow => 'last');

#$c->create('rectangle',0,0,210,297);
#$c->create('line',0,0,210,297,-arrow => 'last');


my %opt = (
# -pageheight => $ps->{$psize}[1].'m',
#          -colormode  => $mode
          );
@opt{'-x','-y','-width','-height'} = $c->bbox('all');
$opt{'-width'}  -= $opt{'-x'};
$opt{'-height'} -= $opt{'-y'};

# PS origin is normally SW so avoid deltaX, deltaY
$opt{'-pageanchor'} = 'sw';
$opt{-pagey}  = 0;
$opt{'-rotate'} = ($opt{'-width'} > $opt{'-height'}) ? 1 : 0;
if ($opt{-rotate}) 
 {
  # x is bigger 
  $opt{-pagewidth} = $ps->{$psize}[1].'m';
  # and we have to shift it right to allow for rotate :-(
  $opt{-pagex} = $ps->{$psize}[0].'m';
 }
else
 {
  # y is bigger 
  $opt{-pageheight} = $ps->{$psize}[1].'m';
  $opt{-pagex} = 0;
 } 

warn Dumper(\%opt);
pseudo_code($c,%opt);

my $text = $c->postscript(%opt);
print $text;
pos($text) = 0;
while ($text =~ /\n((%%BoundingBox.*|\s*\d[\s\d\.-]*(translate|rotate|scale)))/g)
 {
  warn "$1\n";
 }

my %page_sizes;

sub page_sizes
{
 unless (keys %page_sizes)
  {
   my @list;
   my ($w,$h) = (297,420);
   for my $size (3..5)
    {
     $page_sizes{"A$size"} = [$w,$h];
     ($h,$w) = ($w,$h/2);
    }
  }
 return \%page_sizes;
}

sub Points
{
 my $s = shift;
 return undef unless defined $s;
 $s *= 72.0/25.4 if ($s =~ s/m$//);
 return $s;
}

sub pseudo_code
{
 my ($c,%opt) = @_;
 # PostScript transforms are:
 my $canvW = $opt{-width}  || $c->width;
 my $canvH = $opt{-height} || $c->height;
 my $canvX = $opt{-x}      || $c->canvasx(0);
 my $canvY = $opt{-y}      || $c->canvasy(0);
 my $pageX = exists $opt{-pagex} ? Points($opt{-pagex}) : (72*4.25); 
 my $pageY = exists $opt{-pagey} ? Points($opt{-pagey}) : (72*5.5); 
 my $scale = 1;
 if ($opt{-pagewidth}) 
  {
   $scale = Points($opt{-pagewidth})/$canvW; 
  } 
 elsif ($opt{-pageheight}) 
  {
   $scale = Points($opt{-pageheight})/$canvH; 
  } 
 else 
  {
   # $scale = (72/25.4)*ScreenMM/ScreenPixels; 
  }  
 my ($deltaX,$deltaY); 
 for ($opt{-pageanchor} || 'c')
  { 
   if (/w/)   { $deltaX = 0 } 
   elsif (/e/){ $deltaX = -$canvW }
   else       { $deltaX = -$canvW/2 } 
   if (/n/)   { $deltaY = -$canvH } 
   elsif (/s/){ $deltaY = 0 }
   else       { $deltaY = -$canvH/2 } 
  }
  
 warn "px=$pageX py=$pageY scale=$scale dx=$deltaX dy=$deltaY w=$canvW h=$canvH\n";  

 if (!$opt{-rotate})
  {
   warn '%%'.sprintf("BoundingBox: %d %d %d %d\n",
             $pageX + $scale*$deltaX,
	     $pageY + $scale*$deltaY,
	     $pageX + $scale*($deltaX + $canvW)+1,
	     $pageY + $scale*($deltaY + $canvH)+1);
  } 
 else 
  {
   warn '%%'.sprintf("BoundingBox: %d %d %d %d\n",
	     $pageX - $scale*($deltaY + $canvH)+1,
             $pageY + $scale*$deltaX,
	     $pageX - $scale*$deltaY+1,
	     $pageY + $scale*($deltaX + $canvW)+1);
  } 
               

 warn sprintf "translate(%g,%g)\n",$pageX,$pageY;
 warn "rotate(90)\n" if $opt{-rotate};
 warn sprintf "scale(%g,%g)\n",$scale,$scale;
 warn sprintf "translate(%g,%g)\n",$deltaX-$canvX,$deltaY;
}