#! /usr/bin/perl -w
#
# Convert BDF files to incore MWCFONT structure 'C' source
# Copyright (c) 2002, 2003 by Greg Haerr <greg@censoft.com>
#
# modified 09/13/02 correct output when no DEFAULT_CHAR, allow numeric font name
# modified 09/12/02 added -limit <max_encode_hex_value> option
# modified on 09/10/02 by G Haerr
#	- fixed DWIDTH 0 parsing
#	- don't limit font size to 0x7e characters
#	- changed offset data to unsigned long for large fonts
#	- don't generate width table if fixed-width
#	- added defaultchar to output
#	- added bits_size member for loadable fonts
# modified on 3/26/00 by G Haerr added ascent field, fixed $IMAGE_BITS
# modified on 2/10/00 by K Harris to accept any size input character
# modified by G Haerr from bdftobogl for 16 bit MWIMAGEBITS
# originally from BOGL - Ben's Own Graphics Library <pfaffben@debian.org>.

use POSIX;

$name = (reverse split /\//, $0)[0];
$limit_char = 65535;

while (defined $ARGV[0]) {
    my $arg = shift;

    if (($arg eq "-limit") && scalar(@ARGV) > 0) {
	$limit_char = hex shift;
    } elsif ($arg =~ "-.+") {
	print "$name: unknown option '$arg'\n";
	exit 1;
    } else {
	unshift(@ARGV, $arg);
	last;
    }
}

if ($#ARGV < 0) {
    print "Usage: $name [-limit <max_encode_hex_value>] font.bdf > font.c\n";
    exit 1;
}

$IMAGE_BITS = 16;
$IMAGE_NIBBLES = $IMAGE_BITS/4;
$IMAGE_MASK = 0xffff;

$file = $ARGV[0];

$font = $file;
$font =~ s/\.bdf//;
$font =~ tr/a-zA-Z0-9_/_/cs;

print "/* Generated by $name on ", substr(`date`, 0, -1), ". */\n";
print "#include \"device.h\"\n\n";

open BDF, "<$file" || die;
while (<BDF>) {
    chop;
    $pixel_size = $1 if /^PIXEL_SIZE (\d+)$/;
    $font_ascent = $1 if /^FONT_ASCENT (\d+)$/;
    $font_descent = $1 if /^FONT_DESCENT (\d+)$/;
    $font_name = $1 if /^FONT (.*)$/;
    $default_char = $1 if /^DEFAULT_CHAR (\d+)$/;
    ($fbbw, $fbbh, $fbbx, $fbby) = ($1, $2, $3, $4) if /^FONTBOUNDINGBOX (-?\d+) (-?\d+) (-?\d+) (-?\d+)/;
    
    last if /^CHARS /;
}

$font_width = $fbbw - $fbbx;
undef $fbbw, undef $fbbh, undef $fbbx, undef $fbby;

print "/* Font information:\n\n";
print "   name: $font_name\n";
print "   pixel size: $pixel_size\n" if defined $pixel_size;
print "   ascent: $font_ascent\n";
print "   descent: $font_descent\n";
print "*/\n\n";

print "/* Font character bitmap data. */\n";
print "static MWIMAGEBITS _${font}_bits[] = {\n";

$ch_height = $font_ascent + $font_descent;
$ofs = 0;
$maxwidth = 0;
$firstchar = -1;
$lastchar = -1;
while (<BDF>) {
    chop;
    undef $encoding, undef $width, undef $bbx, undef $bby, undef $bbw, undef $bbh if /^STARTCHAR /;
    $encoding = $1 if /^ENCODING (\d+)/;
	last if defined $encoding && $encoding > $limit_char;
    $width = $1 if /^DWIDTH (-?\d+)/;
    	$width = $font_width if defined $width && $width <= 0;
    ($bbw, $bbh, $bbx, $bby) = ($1, $2, $3, $4) if /^BBX (-?\d+) (-?\d+) (-?\d+) (-?\d+)/;

   if (/^BITMAP$/) {
		next if !defined $encoding;
		$firstchar = $encoding if $firstchar < 0;
		$lastchar = $encoding if $lastchar < $encoding;
		$encoding_tab[$encoding] = $ofs;
		$width -= $bbx, $bbx = 0 if $bbx < 0;
		$width[$encoding] = $width;
		$maxwidth = $width if $width > $maxwidth;
		$ch_words  = int (($width+$IMAGE_BITS-1)/$IMAGE_BITS);
		$ch_bits   = $ch_words*$IMAGE_BITS;
		for (my $i = 0; $i < $ch_height; $i++) {
			for (my $k = 0; $k < $ch_words; $k++) {
	    		$bm[$i][$k] = 0;
			}
		}
		for (my $i = 0; ; $i++) {
	    	$_ = <BDF>;
	    	chop;
	    	last if /^ENDCHAR$/;
		
		   @hexnibbles = split //,$_;
			for (my $k=0; $k<$ch_words; $k++) {
			   $ndx = $k*$IMAGE_NIBBLES;
				$padnibbles = @hexnibbles - $ndx;
				last if $padnibbles <= 0; # if bbx pushes bits into next word
												 # and no more bits from bdf file
				$padnibbles = 0 if $padnibbles >= $IMAGE_NIBBLES;
			   $value = hex join '',@hexnibbles[$ndx..($ndx+$IMAGE_NIBBLES-1-$padnibbles)];
	   		$value = $value << ($padnibbles*$IMAGE_NIBBLES);	
	   		$bm[$ch_height - $font_descent - $bby - $bbh + $i][$k] |= 
						$value >> ($bbx);	
				if ($bbx) {	# handle overflow into next image_word
	   			$bm[$ch_height - $font_descent - $bby - $bbh + $i][$k+1] =
						($value << ($IMAGE_BITS - $bbx)) & $IMAGE_MASK;	
				}
			}
		}
	
###		printf "\n/* Character %c (0x%02x):\n", $encoding, $encoding;
		printf "\n/* Character (0x%02x):\n", $encoding;
		print "   bbw=$bbw, bbh=$bbh, bbx=$bbx, bby=$bby, width=$width\n";
		print "   +", ("-" x $ch_bits), "+\n";
		for (my $i = 0; $i < $ch_height; $i++) {
			print "   |";
			for (my $k = 0; $k < $ch_words; $k++) {
	   		for (my $j = $IMAGE_BITS - 1; $j >= 0; $j--) {
					print $bm[$i][$k] & (1 << $j) ? "*" : " ";
	   		}
			}
	   	print "|\n";
		}
		print "   +", ("-" x $ch_bits), "+ */\n";
	
		for (my $i = 0; $i < $ch_height; $i++) {
			for ($k=0; $k<$ch_words; $k++) {
   			$ofs++;
	   		printf "0x%04x, ", $bm[$i][$k];
			}
	   	printf "\n";
		}
   }
}

print "};\n\n";

##print STDERR "Maximum character width=$maxwidth\n";

$default_char = $firstchar if !defined $default_char;

print "/* Character->glyph mapping. */\n";
print "static unsigned long _${font}_offset[] = {\n";
for (my $i = $firstchar; $i <= $lastchar; $i++) {
    my $char = $i;
    my $ofs = $encoding_tab[$i];
    $ofs = $encoding_tab[$default_char], $char = $default_char if !defined $ofs;
### printf "  $ofs,\t/* %c (0x%02x) */\n", $char, $i;
    printf "  $ofs,\t/* (0x%02x) */\n", $i;
}
print "};\n\n";

$gen_width_table = 0;
for (my $i = $firstchar; $i <= $lastchar; $i++) {
    my $char = $i;
    my $width = $width[$i];
    $width = $width[$default_char] if !defined $encoding_tab[$i];
    $gen_width_table = 1 if $width != $maxwidth
}

if ($gen_width_table) {
	print "/* Character width data. */\n";
	print "static unsigned char _${font}_width[] = {\n";
	for (my $i = $firstchar; $i <= $lastchar; $i++) {
	    my $char = $i;
	    my $width = $width[$i];
	    $width = $width[$default_char], $char = $default_char if !defined $encoding_tab[$i];
	### printf "  $width,\t/* %c (0x%02x) */\n", $char, $i;
	    printf "  $width,\t/* (0x%02x) */\n", $i;
	}
	print "};\n\n";
}

$size = $lastchar - $firstchar + 1;

print "/* Exported structure definition. */\n";
print "MWCFONT font_${font} = {\n";
print "  \"$font\",\n";
print "  $maxwidth,\n";
print "  $ch_height,\n";
print "  $font_ascent,\n";
print "  $firstchar,\n";
print "  $size,\n";
print "  _${font}_bits,\n";
print "  _${font}_offset,\n";
if ($gen_width_table) {
	print "  _${font}_width,\n";
} else { print "  0,  /* fixed width*/\n"; }
print "  $default_char,\n";
print "  sizeof(_${font}_bits)/sizeof(MWIMAGEBITS),\n";
print "};\n";