#!/usr/bin/perl -w

# convert a VM bitmap from a pbm ascii file into assembler source for aslc68k
# prints source to stdout
# image size 48 x 32 pixel, colordepth 24bpp, only 2 colors used
# written by Soeren Gust, sgust@ithh.informationstheater.de
# not very good commented, sorry.

use strict;

open(FILE, $ARGV[0]) or die "Can't open file";

my ($filetype, $size, $color) = ("#", "#", "#");

while($filetype =~ /^#/) { chomp($filetype = <FILE>); }
if ($filetype ne "P3") { die "Wrong filetype"; }

while($size =~ /^#/) { chomp($size = <FILE>); }
if ($size ne "48 32") { die "Wrong size"; }

while($color =~ /^#/) { chomp($color = <FILE>); }
if ($color ne "255") { die "Wrong colordepth"; }

my ($red, $green, $blue, $vmscolor, $indexcolor, @palette, @bitmap);
my $maxcolor = 0;

for my $y (0..31) {
	for my $x (0..47) {
		chomp($red = <FILE>);
		chomp($green = <FILE>);
		chomp($blue = <FILE>);
		$red = $red >> 4;
		$green = $green >> 4;
		$blue = $blue >> 4;
		$vmscolor = 0xf000 + 256 * $red + 16 * $green + $blue;
		$indexcolor = -1;
		for my $i (0..$maxcolor-1) {
			if ($palette[$i] == $vmscolor) {
				$indexcolor = $i;
				last;
			}
		}
		if ($indexcolor == -1) {
			$indexcolor = $maxcolor;
			$palette[$maxcolor++] = $vmscolor;
			if ($maxcolor > 2) { die "Too many colors"; }
		}
		$bitmap[$y*48+$x] = $indexcolor;
	}
}

# fill up palette with white
for my $i ($maxcolor..1) {
	$palette[$i] = 0xffff;
}

# invert if necessary, check could be much better
if ($palette[0] < $palette[1]) {
	for my $i (0..32*48-1) {
		$bitmap[$i] = 1 - $bitmap[$i];
	}
}

# print icon bitmap
print "; bitmap generated by ppmtovmbitmap.pl\n";
my $p = 0;
for my $y (0..31) {
	print "\011.byte ";
	for my $x (0..5) {
		printf "\$%02x", ($bitmap[$p] << 7) +
				 ($bitmap[$p+1] << 6) +
				 ($bitmap[$p+2] << 5) +
				 ($bitmap[$p+3] << 4) +
				 ($bitmap[$p+4] << 3) +
				 ($bitmap[$p+5] << 2) +
				 ($bitmap[$p+6] << 1) +
				  $bitmap[$p+7];
		$p += 8;
		print ',' unless ($x == 5);
	}
	print "\n";
}