#! /bin/perl
#
# -- makes BDF font italic
#     version 0.00.1
#     programmed by Yasuyuki Furukawa <furukawa@vinelinux.org>
#			* public domain *
#
# -- translated for Perl, hoping speed it up... (e-kagen)
#     2001/5/26 
#	by SHINYAMA Yusuke <euske@cl.cs.titech.ac.jp>  * public domain *
#    

$dy = 3;	# level of slant deep (2; Minimum and deepest)
$correct = 3;	# level of pixel correction
$debug = 0;
$verbose = 0;
$verbose_min = 100;

# The table for pixel correction
# format:
#                   before  <- | ->  after
#  "height  offset  pattern... | height  offset  pattern... "
# if the offset is zero, the pattern starts from last
# slant step immidiately.

# pattern of 'left down to up right'
$i = 0;
if ($correct >= 3) {
    $ptable[$i++] = "5 -2 ..@  .@   .@   @..  @.   1 -1 .\$";  # fixed
    $ptable[$i++] = "5 -4 ... @@@. ..@. .@. @. 2 -2 .\$, \$, ";
#     $ptable[$i++] = "5 -1 ...@. ...@. ..@. .@. @. 1 3 @\$";    # XXX
    $ptable[$i++] = "5 -2 .....@ ....@ ...@. ..@. @@. 1 0 ...@\$";
    $ptable[$i++] = "4 -3 ...@ ...@ ..@. @@..  1 -1 .\$@";
    $ptable[$i++] = "4 -3 ..@  ..@  .@.  @..   1  0 @\$";
    $ptable[$i++] = "4 -1 .@   .@   @..  @.    2 -1 \$, ,\$";
    $ptable[$i++] = "4 -2 ..@  ..@@ @@.. .@.   2 -1 .\$@ @@\$";
    $ptable[$i++] = "4 -2 .@   .@.  @..  @.    2 -1 \$, ,\$";
}
if ($correct >= 2) {
    $ptable[$i++] = "3 -2 ....@. ..@@.   @@... 1  0 @@\$...";
    $ptable[$i++] = "3 -1 ..@  .@  .@.        1  0 .,\$";
    $ptable[$i++] = "3 -2 .@   .@   @.@        1 -1 \$@";
    $ptable[$i++] = "3 -2 .@   .@.  @..        1 -1 \$.";
    $ptable[$i++] = "3 -2 .@   .@@  @..        1 -1 \$@";
    $ptable[$i++] = "3 -1 ..@  .@.  @@.        1  0 .,\$";
    $ptable[$i++] = "3 -2 @@.  .@.  @..        1 -1 \$,";
    $ptable[$i++] = "3 -1 @.@  .@.  ...        1  0 .@\$";
    $ptable[$i++] = "3 -1 ..@  .@.  .@@        1  0 .,\$";
#     $ptable[$i++] = "3 -2 ..@  .@@  @.@        1  0 @\$";  # XXX
}


# pattern of 'left up to down right'
if ($correct >= 3) {
    $ptable[$i++] = "6 -2 ..@. ...@. ...@. ...@. ..@. @@. 4 -1 ..\$, ...@ ..\$, .\$,";
    $ptable[$i++] = "4 -1 @..  @.@  .@.  .@.   1  1 \$@";
    $ptable[$i++] = "4 -3 @.   @@@  .@   .@    1 -1 \$.";
    $ptable[$i++] = "4 -3 ..   @@.  ..@. ..@.  2 -2 @, .\$,";
    $ptable[$i++] = "3 -2 @..  .@   .@         1 -1 \$.";
    $ptable[$i++] = "4 -1 .@. .@. ..@. ..@. 1 0 .,\$";
    $ptable[$i++] = "4 -1 .@. @@. ..@. ..@. 2 -1 @, @@\$"; # XXX
}
if ($correct >= 2) {
    $ptable[$i++] = "3 -1 @..  .@@  ..         1  0 .,@"; #
    $ptable[$i++] = "3 -2 @..  @@.  .@         1 -1 \$.";
    $ptable[$i++] = "3 -2 @.@  .@   .@         1 -1 \$@";
    $ptable[$i++] = "3 -1 .@.  .@.  ..@.       1  0 ..\$";
#     $ptable[$i++] = "4 -2 @.   @.   @.  .@@    1  0 \$."; # fixed , XXX
    $ptable[$i++] = "4 -1 @.   @.   .@@ ..     2  0 ,\$ .,\$";
    $ptable[$i++] = "3 -1 @.   @.   .@@        1  0 ,\$";
    $ptable[$i++] = "3 -2 ..   @@.  ..@        1 -1 @,.";
}

# least pattern
$ptable[$i++] = "4 -2 ..@ .@  @@@ ..      2 -1 \$@ @,@";
$ptable[$i++] = "3 -1 .@.. @.@. .@@.  1 0 \$";   # fixed
$ptable[$i++] = "2 -1 .@  @.          1 -1 \$";

$flag = 0;		# reading status
if ($ARGV[0] eq "-h") {
    &usage();
    exit(0);
}
if ($ARGV[0] eq "-V") {
    $verbose = 1;
    shift @ARGV;
}
if ($ARGV[0] eq "-d") {
    $debug = 1;
    shift @ARGV;
}
if ($ARGV[0] eq "-D") {
    $debug = 2;
    shift @ARGV;
}
if (@ARGV[0] eq "-p") {
    &print_ptable();
    exit(1);
}

@vmeter = ( "|", "\\", "-", "/" );

@x=split(/\s/, `stty size 2>/dev/null`);
$col = $x[1];
$col = 0 if ($col !~ /^[1-9]/ || $col < 30);

sub usage() {
    print "usage: mkitalic [-V|-d|-p] {input BDF} > {output BDF}\n";
    print "      -V   verbose\n";
    print "      -p   output pettern table for pixel correction\n";
    print "      -d   debug level 1\n";
    print "      -D   debug level 2\n";
}


#
# correct_pixel(width, height)
#
# Correct the pixels to make pettern
# more clear after the slanting.
# Reference the ptable at the BEGIN
# routine.
#
sub correct_pixel {
    my $x, $y, $xx, $n, $nn, $d, $dd, $i, $j, $t;
    return if ($correct == 0);

    # add padding pixels from both side
    $line[$height] = "." x $width;
    for ($y = 0; $y <= $height; $y++) {
	$line[$y] = ".$line[$y].";
    }
    
    # pattern matching with ptable
    for ($y = $dy; $y < $height ; $y += $dy) {
	foreach $i (@ptable) {
	    @p = split(" ", $i);
	    $n = $p[1]; $d = $p[0];
	    next if ($y+$n < 0 || $y+$n+$d > $height + 1);
	    for ($x = 0; $x < $width-1; $x++) {
		$x = index($line[$y+$n], $p[2], $x);
		last if ($x == -1);
		for ($j = 1; $j < $d; $j++) {
		    $xx = index($line[$y+$n+$j], $p[$j+2], $x);
		    last if ($x != $xx);
		}
		if ($x == $xx) { # matched !
		    print "==== MATCH with \"$i\" ==== ($x,$y)\n" if ($debug > 1);
		    $nn = $p[$d+3]; $dd = $p[$d+2];
		    for ($j = 0; $j < $dd; $j++) {
			$t = $p[$j+$d+4];
			substr($line[$y+$nn+$j], $x, length($t)) = $t;
		    }
		    last;
		}
	    }
	}
    }

    # delete padding pixels from both side
    for ($y = 0; $y < $height; $y++) {
      	$line[$y] =~ s/^\.//;
      	$line[$y] =~ s/\.$//;
    }
}


#
# make_slant(width, height)
#
# Just slant the pattern of font.
#
sub make_slant {
    my $y, $i, $dcount=$dx, $ncount=0, $tp= '#' x $pad, $ts, $te;

    for ($y = 0; $y < $height; $y++) {
	if ($y % $dy == 0) {
	    $ts = '#' x ($dcount-- - 1);
	    $te = ('#' x $ncount++) . $tp;
	}
        $line[$y] = $ts . substr($line[$y], 0, $width) . $te;
    }
}


#
# print_ptable()
#
# Visualize ptable.
#
sub print_ptable {
    my $i, $j, $n, $d, $nn, $dd, $p, $pp, $t;
    
    print "\t==== PATTERN TABLE ====\n";
    print "\nFollowing patterns is for pixel correction in slant.\n";
    print "Priority between patterns depends on pattern ID.\n";

    foreach $i (@ptable) {
	@p = split(" ", $i);
	$n = $p[2]; $d = $p[1];
	for ($j = 0; $j < $d; $j++) { $pp[$j] = $p[$j+2]; }

	$nn = $p[$d+4]; $dd = $p[$d+3];
	for ($j = 0; $j < $dd; $j++) {
	    $t = $p[$j+$d+4];
	    substr($p[-$n+$nn+2+$j], 0, length($t)) = $t;
	}

	print "\n\t--- pattern \"$i\" ---\n\n";
	for ($j = 0; $j < $d; $j++) {
	    print " " , $pp[$j] , " " x (7 - length($pp[$j]));
	    if ($j == int($d/2)) {
		print " ==>    ";
	    } else {
		print "        ";
	    }

	    print " " if ($j +$n < $dy);
	    print " " if ($j +$n < 0);
	    print $pp[$j];

	    print " " x (7 - length($pp[$j]));
	    if ($j == int($d/2)) {
		print " ==>    ";
	    } else {
		print "        ";
	    }
	    
	    print $p[$j+2] , "\n";
	}
    }
}


#
# MAIN LOOP
#
# All of the follows is the main
# loop routine.
#

sub main {
    my $x, $y, $tmp, $width, $height, $flag, $count, $max_chars, @F;
    my $ch_count, $m, $n, $l;
    while(<>) {
	chop;
	@F = split(/\s+/);
	# Change the font property
	if ($F[0] eq 'FONT') {
	    die("error: the input font is already italic.\n") if (/-I-/);
	    $F[1] =~ s/-[Rr]-/-I-/;
	    print join(" ", @F), "\n";
	
	# Change the font property
	} elsif ($F[0] eq 'SLANT') {
	    $F[1] =~ s/\042[Rr]\042/\042I\042/;
	    print join(" ", @F), "\n";
	
	# Get the metric information from the bounding box.
	} elsif ($F[0] eq 'BBX' || $F[0] eq 'FONTBOUNDINGBOX') {
	    $width  = $F[1];
	    $height = $F[2];
	    $dx = int(($height + $dy - 1)/$dy);
	    if (0< $height && 0 < $width) {
		$F[1] = $F[1] + $dx - 1;
		$F[3] = $F[3] - int(($dx -1)/2);
		$pad = (8 - ($F[1] % 8)) % 8;
	    } else {
		$pad = 0;
	    }
	    print join(" ", @F), "\n";
	
	# Get the number of characters.
	} elsif ($F[0] eq 'CHARS') {
	    $max_chars = $F[1];
	    print $_, "\n";
	    
	# Change inner state.
	} elsif ($F[0] eq 'BITMAP') {
	    $flag = 1;
	    $count = 0;
	    print $_, "\n";
	
	# Modify the every font pattern.
	} elsif ($F[0] eq 'ENDCHAR') {
	    # var @line is shared:
	    $tmp = $_;
	    
	    # correct pixel as pre-processing
	    &correct_pixel;
	    
	    # make simple slant font
	    &make_slant;
	    
	    # output font image
	    for ($y = 0; $y < $height; $y++) {
		if (!$debug) {
		    $_ = $line[$y];
		    s/\#/\./g;
		    s/\,/\./g;
		    s/\$/\@/g;
		    s/([.@][.@][.@][.@])/\1_/g;
		    s/\.\.\.\._/0/g;
		    s/\.\.\.\@_/1/g;
		    s/\.\.\@\._/2/g;
		    s/\.\.\@\@_/3/g;
		    s/\.\@\.\._/4/g;
		    s/\.\@\.\@_/5/g;
		    s/\.\@\@\._/6/g;
		    s/\.\@\@\@_/7/g;
		    s/\@\.\.\._/8/g;
		    s/\@\.\.\@_/9/g;
		    s/\@\.\@\._/A/g;
		    s/\@\.\@\@_/B/g;
		    s/\@\@\.\._/C/g;
		    s/\@\@\.\@_/D/g;
		    s/\@\@\@\._/E/g;
		    s/\@\@\@\@_/F/g;
		    $line[$y] = $_;
		}
		print $line[$y], "\n";
	    }
	    print $tmp, "\n";
	    
	    # Display progress bar in verbose mode
	    if (($ch_count++ % 20) == 0 && 
		$verbose && $max_chars > $verbose_min) {
		$n = int($ch_count * 100 / $max_chars);
		$m = int($n * ($col - 21) / 100);
		$l = $col - 20 - $m;
		print STDERR "\rprogress|" , "=" x $m , " " x $l , $n , "%" , $vmeter[$ch_count2++ % 4];
	    }
	    
	    $flag = 0;

	# Default
	} else {
	    if (0 < $flag) {
		s/0/\.\.\.\./g;
		s/1/\.\.\.\@/g;
		s/2/\.\.\@\./g;
		s/3/\.\.\@\@/g;
		s/4/\.\@\.\./g;
		s/5/\.\@\.\@/g;
		s/6/\.\@\@\./g;
		s/7/\.\@\@\@/g;
		s/8/\@\.\.\./g;
		s/9/\@\.\.\@/g;
		s/a/\@\.\@\./ig;
		s/b/\@\.\@\@/ig;
		s/c/\@\@\.\./ig;
		s/d/\@\@\.\@/ig;
		s/e/\@\@\@\./ig;
		s/f/\@\@\@\@/ig;
		$line[$count++] = $_;
	    } else {
		print $_, "\n";
	    }
	}
    }
}

&main;

print STDERR "\r" , " " x ($col - 3) , "\r" if ($verbose != 0 && $max_chars > $verbose_min);
exit(0);