#!/usr/bin/env perl
use strict;
use warnings;
use v5.10;

my ($fname, $array_name) = @ARGV;

die "Usage: $0 <file>\n" unless $fname;

my $fh;
open $fh, '<', $fname or die "$0: $!\n";

my $header = <$fh>;
die "$0: $fname: unknown file format\n" unless $header eq "P4\n";

my $len;
{
    my $line = <$fh>;
    chomp $line;
    last if ($len) = $line =~ /^8 (\d+)$/;
    redo if $line =~ /^#/;
    die "$0: $fname: couldn't parse header\n";
}

local $/;
# read rest of file and return a list of the ascii value for each byte
my @bin = map { ord($_) } split //, <$fh>;

die "$0: $fname should have $len bytes image data, got: " . scalar(@bin) . "\n"
    unless scalar(@bin) == $len;

say "/* autogenerated by util/mkfont */";
say "const unsigned char $array_name\[$len] = {";

# break up in max. 8 bytes per line
while (my @line = splice @bin, 0, 8) {
    # seperated by commata, depending on how many bytes we have
    my $hexify = join ', ', ('0x%02x') x scalar(@line);
    printf "  $hexify" , @line;
    # if there's more bytes left, seperate next block by a comma
    print scalar(@bin) > 0 ? ",\n" : "\n";
}

say "};"