#!/usr/local/bin/perl

$Version = "0.03 (18 December 2001)" ;

use Getopt::Std ;

# Find out the font differences between two dvi files. 
#
# What does it mean for 2 TeX fonts to be "different"? There are 
# four characteristics of a TeX font called from a .dvi file: 
#
#     1. name (e.g., cmr10 or ptmb)
#     2. font number
#     3. scaling (e.g., 1000 or 1200)
#     4. checksum
#
#  
# Options: 
#
# -c : ignore checksum when finding font differences
# -C : do NOT ignore checksum when finding font differences (default)
# -n : ignore font number when finding font differences (default)
# -N : do NOT ignore font number when finding font differences
# -s : ignore font scaling when finding font differences
# -S : do NOT ignore font scaling when finding font differences (default)
# -l : also list fonts in both files
# -O[#|F] : order by font number or name (later)
#
# Note: if -c is chosen, the checksum difference table will not appear.

$usage_string = 
"fontdiff.pl $Version
USAGE: fontdiff [options] dvi_file1 dvi_file2

OPTIONS
-c : ignore checksum when finding font differences
-C : do NOT ignore checksum when finding font differences (DEFAULT)
-n : ignore font number when finding font differences (DEFAULT)
-N : do NOT ignore font number when finding font differences
-s : ignore font scaling when finding font differences
-S : do NOT ignore font scaling when finding font differences (DEFAULT)
-l : list fonts for each file

Note: if -c is chosen, the checksum difference table will not appear.
Thus, 'fontdiff' (with no options) is equivalent to 'fontdff -C -n -S'
\n" ;
 

# Set the default flags here:

$ignore_FONTNUMBER   = 1 ;
$ignore_FONTSCALE    = 0 ;
$ignore_FONTCHECKSUM = 0 ;
$show_ALLFONTS = 0 ;

$number_of_args = $#ARGV ; 

getopts('cCsSnNl') ;

if ($opt_c)
{
  $ignore_FONTCHECKSUM = 1 ;
}

if ($opt_N)
{
  $ignore_FONTNUMBER = 0 ;
}

if ($opt_S)
{
  $ignore_FONTSCALE = 0 ;
}

if ($opt_s)
{
  $ignore_FONTSCALE = 1 ;
}

if ($opt_l)
{
  $show_ALLFONTS = 1 ;
}


# Check that there are at least three arguments. 
if ($number_of_args < 1) 
{
  print STDOUT "Not enough arguments.\n\n" ;
  print STDOUT $usage_string ; 
  exit 0 ; 
}

# Get the 2 filenames
$dvifile1 = $ARGV[0] ; 
$dvifile2 = $ARGV[1] ; 

# ERROR CHECKING.
# Check that these two files exist.
 
if (!(-f $dvifile1))
{
  # Maybe we need to append a .dvi
  if (-f "$dvifile1.dvi")
  {
    $dvifile1 = "$ARGV[0]" . ".dvi" ; 
  }
  else
  {
    print "ERROR. Cannot find file $dvifile1 or $dvifile1.dvi. Exiting.\n" ;
    exit 1 ;
  }
}

if (!(-f $dvifile2))
{
  # Maybe we need to append a .dvi
  if (-f "$dvifile2.dvi")
  {
    $dvifile2 = "$ARGV[1]" . ".dvi" ; 
  }
  else
  {
    print "ERROR. Cannot find file $dvifile2 or $dvifile2.dvi. Exiting.\n" ;
    exit 1 ;
  }
}

# Check that these two files are in fact dvi files. 
$ret_value = `dvii -C $dvifile1` ;
if (!($ret_value =~ /passed/))
{
  print "ERROR. $dvifile1 is not a valid .dvi file. Exiting.\n" ;
  exit 1 ;
}

$ret_value = `dvii -C $dvifile2` ;
if (!($ret_value =~ /passed/))
{
  print "ERROR. $dvifile2 is not a valid .dvi file. Exiting.\n" ;
  exit 1 ;
}

$separator =  "------------------------------" ;

# At this point we have two valid .dvi files. Get their fonts.
$fontlist1 = `dvii -f $dvifile1` ;
$fontlist2 = `dvii -f $dvifile2` ;

# Make the lists into arrays
@fontarray1 = split /\n/, $fontlist1 ; 
@fontarray2 = split /\n/, $fontlist2 ; 

# Remove the font numbering, but only if we are ignoring font number.
if ($ignore_FONTNUMBER)
{
  foreach $element (@fontarray1) 
  {
    $element =~ s/f:\[([0-9]+)/f:[NN/ ;
  }
  foreach $element (@fontarray2) 
  {
    $element =~ s/f:\[([0-9]+)/f:[NN/ ;
  }
}

# Remove the font scaling, but only if we are ignoring scaling.
if ($ignore_FONTSCALE)
{
  foreach $element (@fontarray1) 
  {
    $element =~ s?([0-9]+)\]::?SSSS]::? ;
  }
  foreach $element (@fontarray2) 
  {
    $element =~ s?([0-9]+)\]::?SSSS]::? ;
  }
}

# Remove duplicate entries in the two lists. 
undef %saw;
@compressed1 = grep(!$saw{$_}++, @fontarray1);

undef %saw;
@compressed2 = grep(!$saw{$_}++, @fontarray2);


# From the PERL FAQ...
#@union = @intersection = @difference = ();
#%count = ();
#foreach $element (@fontarray1, @fontarray2) { $count{$element}++ }
#foreach $element (keys %count) {
#    push @union, $element;
#    push @{ $count{$element} > 1 ? \@intersection : \@difference }, $element;
#}

# Make hashes...
foreach $element (@compressed1) 
{
  $hash1{$element} = 1 ;

  if (!($ignore_FONTCHECKSUM))
  {
    # Get checksum
    if ($element =~ m/::([0123456789abcdef]{8})$/i)
    {
      $checksum = $1 ;
    }
    $checksum1{$element} = $checksum ;
  }

}

foreach $element (@compressed2) 
{
  $hash2{$element} = 1 ;

  if (!($ignore_FONTCHECKSUM))
  {
    # Get checksum
    if ($element =~ m/::([0123456789abcdef]{8})$/i)
    {
      $checksum = $1 ;
    }
    $checksum2{$element} = $checksum ;
  }
}

print "Fonts in $dvifile1 NOT in $dvifile2:\n" ; 
if ($show_ALLFONTS)
{
  print "NOTE: fonts marked with * are in BOTH files\n" ; 
}
print "$separator\n" ;
foreach $element (@compressed1)
{
  if ($hash2{$element} != 1)
  {
    print "  $element\n" ; 
  }
  else
  {
    if ($show_ALLFONTS)
    {
      print "* $element\n" ; 
    }
  }

}
print "$separator\n" ;

print "\n" ; 

print "Fonts in $dvifile2 NOT in $dvifile1:\n" ; 
if ($show_ALLFONTS)
{
  print "NOTE: fonts marked with * are in BOTH files\n" ; 
}
print "$separator\n" ;
foreach $element (@compressed2)
{
  if ($hash1{$element} != 1)
  {
    print "  $element\n" ; 
  }
  else
  {
    if ($show_ALLFONTS)
    {
      print "* $element\n" ; 
    }
  }

}
print "$separator\n" ;


# CHECKSUM DIFFERENCES
# Find fonts in common that have different checksums.
if (!($ignore_FONTCHECKSUM))
{
  print "\nFonts in common that have DIFFERENT checksums:\n" ; 
  print "$separator\n" ;
  foreach $element (@compressed1)
  {
    if ($hash2{$element} == 1)
    {
      # Find the checksums of each. 
      $cs1 = $checksum1{$element} ;
      $cs2 = $checksum2{$element} ;

      # If they differ, print it out. 
      if (!($cs1 eq $cs2))
      {
        print "$element:\n" ;
        print "in $dvifile1 has checksum $cs1\n" ;
        print "in $dvifile2 has checksum $cs2\n" ;
      }
    }
  }
  print "$separator\n" ;
}



## HISTORY

# "0.02 (23 September 2001)" - initial version
# "0.03 (18 December 2001)" - fixed scale ignore code