############################################################
# ConvertTiffsToPS
#
#	Convert a list of tiff files to PS files 
#
# RETURNS:
#	A list of the paths of the postscript files
############################################################
use threads;
use threads::shared;
sub ConvertTiffsToPS {
	my (@tiffpaths) = @_;

	my @pspaths;		# to be filled in.	
	my @threads;
	foreach my $tiffpath (@tiffpaths){
		(my $pspath = $tiffpath) =~ s/\.tiff?$/\.PS/i;
		push @pspaths, $pspath;
		
		print "Converting $tiffpath to $pspath\n";
		my $thread = async { Tiff2PS($tiffpath, $pspath) };
		push @threads,$thread;
	}

	print("Waiting for child processes...");
	print join(",\n",map {$_->join()} @threads);
	print("child processes complete...");

	confess "Somethings wrong".Dumper(\@tiffpaths,\@pspaths)
		unless (scalar(@tiffpaths) == scalar(@pspaths));
	
	# return the list of PS files
	return @pspaths;
}


# Take a tifffile, and produce a PS file next to it.
sub Tiff2PS {
	my ($tiffpath,$pspath) = @_;

	#local $| = 1;  # has no visible effect either way... 

	print qq("$TIFF2PS_COMMAND" "$tiffpath" |\n);
	open TIFF2PS, qq("$TIFF2PS_COMMAND" "$tiffpath"|) 
		or confess "Can't run $TIFF2PS_COMMAND";
	open PSOUT, ">$pspath" 
		or confess "Can't open $pspath for writing!\n";

	my $flag = 0;
	foreach my $line (<TIFF2PS>) {	
		print PSOUT $line;

		# Add the following line only once...
		if (!$flag && $line =~ /^%%BoundingBox: (\d+) (\d+) (\d+) (\d+)/o) {
			my ($w,$h) = ($3-$1, $4-$2);
			# Fix the pagesize, since GS wants everything to be 8.5x11" portrait
			print PSOUT "<< /PageSize [$w $h] >> setpagedevice\n";
			# Short-circuit prevents expensive regexp match afterwards
			$flag = 1;
		}
	}

	close TIFF2PS;
	close PSOUT;

	if (! -e $pspath) {
		warn("**TIFF2PS Problem: $!");
		confess "Tiff2PS Error: $!";
	} else {
		print "$pspath created...\n";
	}
	
	return $pspath;
}