#! /usr/bin/perl -w
#
# Convert BDF files to nano-X font files
# modified by G Haerr from bdftobogl for 16 bit MWIMAGEBITS
# modified on 2/10/00 by K Harris to accept any size input character
# modified on 3/26/00 by G Haerr added ascent field, fixed $IMAGE_BITS
# modified on 2/15/06 by <bernie@codewiz.org> for DevLib.
# originally from BOGL - Ben's Own Graphics Library <pfaffben@debian.org>.
#

use POSIX;

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

$LAST_CHAR = 0xff;
$IMAGE_BITS = 8;
$IMAGE_NIBBLES = $IMAGE_BITS/4;
$IMAGE_MASK = 0xff;
$IMAGE_VERTICAL = 1;

$file = $ARGV[0];

$font = $file;
$font =~ s#.*/##; # remove path name
$font =~ s/\.bdf//;
$font =~ tr/a-zA-Z0-9_/_/cs;

print "/* Generated by convbdf on ", substr(`date`, 0, -1), ". */\n";
print "#include <gfx/font.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 = $1 if /^DEFAULT_CHAR (\d+)$/;

	last if /^CHARS /;
}

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

print "/* Font character bitmap data. */\n";
print "static const PROGMEM uint8_t font_${font}_glyphs[] = {\n";

$ch_height = $font_ascent + $font_descent;
$ofs = 0;
$maxwidth = 0;
$proportional = 0;
$firstchar = -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 > $LAST_CHAR;
	$width = $1 if /^DWIDTH (-?\d+)/;
	($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;
		$encoding_tab[$encoding] = $ofs;
		$width -= $bbx, $bbx = 0 if $bbx < 0;
		$width[$encoding] = $width;
		$maxwidth != 0 and $width != $maxwidth and $proportional = 1;
		$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;
				# if bbx pushes bits into next word
				# and no more bits from bdf file
				last if $padnibbles <= 0;
				$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;	
				}
			}
		}

		# GLYPH PREVIEW
###		printf "\n/* Character %c (0x%02x): ", $encoding, $encoding;
		printf "\n/* Character (0x%02x): ", $encoding;
		print "bbw=$bbw, bbh=$bbh, bbx=$bbx, bby=$bby, width=$width */\n";
	
		# GLYPH DATA
		if ($IMAGE_VERTICAL) {
			my $bitstring = "";
			for (my $k = 0; $k < int(($ch_height + $IMAGE_BITS - 1) / $IMAGE_BITS); $k++) {
				for (my $x = 0; $x < $width; $x++) {
					my $v = 0;
					for (my $y = 0; $y < $IMAGE_BITS && ($y + $k * $IMAGE_BITS < $ch_height); ++$y) {
						my $bit = ($bm[$k * $IMAGE_BITS + $y][int($x / $IMAGE_BITS)] & (1 << ($IMAGE_BITS - ($x % $IMAGE_BITS) - 1))) ? 1 : 0;
						$bitstring .= $bit ? '*' : ' ';
						$v |= $bit << $y;
					}
					$ofs++;
					printf "0x%02x, ", $v;
				}
				# Preview
				printf "/* $bitstring */\n";
			}
			
		}
		else { # IMAGE_HORIZONTAL

			# Preview
			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 (my $k=0; $k<$ch_words; $k++) {
					$ofs++;
					printf "0x%02x, ", $bm[$i][$k];
				}
				printf "\n";
			}
		}
   }
}

print "};\n\n";

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

if ($proportional) {
	print "/* Character->glyph data. */\n";
	print "static const PROGMEM uint16_t ${font}_offset[] = {\n";
	for (my $i = $firstchar; $i <= $LAST_CHAR; $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";

	print "/* Character width data. */\n";
	print "static const PROGMEM uint8_t ${font}_width[] = {\n";
	for (my $i = $firstchar; $i <= $LAST_CHAR; $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";

	$font_offset = "${font}_offset";
	$font_width = "${font}_width";
} else {
	$font_offset = "NULL";
	$font_width = "NULL";
}

$lastchar = $LAST_CHAR;
#$size = $lastchar - $firstchar + 1;

print <<EOF
/* Font structure definition. */
EXTERN_CONST Font font_${font} =
{
	/* .glyph  = */ font_${font}_glyphs,
	/* .name   =    "$font", */
	/* .width  = */ $maxwidth,
	/* .height = */ $ch_height,
	/* .ascent =    $font_ascent, */
	/* .first  = */ $firstchar,
	/* .last   = */ $lastchar,
	/* .offset = */ $font_offset,
	/* .width  = */ $font_width,
};
EOF