#!/afs/athena/contrib/perl/perl

#catch control c's

$SIG{'INT'} = 'sigint_grabber';

sub sigint_grabber {
	&clean($just_name);
	exit(0);
	}


#set up so we can get the appropriate graphics binaries

$host_type = $ENV{"HOSTTYPE"} || $ENV {"hosttype"};
$bin_dir = "$host_type" . "bin";
if (system("/bin/athena/attach -q graphics")) {
	die "Can't attach graphics utilities\n";} 

# variables

  $in = $ARGV[0];

  #where to put the file
  $destdir = ".";  #default to pwd
  $destdir = $ARGV[2] if $ARGV[1] =~ /\-dest/;
  $destdir = $ARGV[4] if $ARGV[3] =~ /\-dest/;
  $destdir =~ s/\/\s*$//;

  #how to size it
  $scale_factor = 1; #default to incoming size

  $scale_factor = $ARGV[2] if $ARGV[1] =~ /\-scale/;
  $scale_factor = $ARGV[4] if $ARGV[3] =~ /\-scale/;

  if (!-d $destdir) {die "Error: Can't find $destdir!\n";}
  if ($scale_factor !~ /\d+|auto/) {die "Error: scale has to be a number or the string 'auto'!\n";}

#check for right kind of filename and do the thing

if ($in =~ /\-all/) {
	open(ALLOFEM,"ls -1 *.tif |");
	while(<ALLOFEM>) {
		chop;
		@all[$i] = $_;
		++$i;
	}
FILE:
	foreach $in(@all) {
		&doit;
		next FILE;
		}
	exit(0);
	}

elsif ($in !~ /.\.tif$/i) {
        print "Gotta start with a tif (ending in \'.tif\' or \'.TIF\') file,\n or \'-all\' to convert all appropriate files in the current directory!\n"; 
&usage;
        }
else {
   &doit;
   exit(0);	
}

sub doit {

if (-e "$in") {
	# do the thing
	print "Working on: $in\n";
	$scale_factor =~ /\s*auto\s*/ && do 
		{&autoscale($in); &tif2gif; &clean($just_name);};
	&tif2gif;
	&clean($just_name);
	}
else {
	die "Aborting cause I can't open the file \'$in\'\n";
	}
}

sub autoscale {

local($infile) = @_;

#calculate an appropriate 'full screen' size for the thing
#assume 760 pixels for a 'normal' screen width - may want to change this

open(TIFFINFO,"/mit/graphics/$bin_dir/tiffinfo $infile |");
        while(<TIFFINFO>) {
                /\s*Image Width:\s*(\d+)/ && do {$width = $1;};
		$scale_factor = 760 / (1 + $width);
		}
		print "Incoming image is $width pixels wide. Auto scaling to 760 pixels..\n";

}


#Here's the real stuff, such as it is

sub tif2gif {

 $file = substr($in,0,(length($in)-4));

&get_just_filename($file);

 # a reminder for our user..
 print "Destination directory: $destdir\nScale factor: $scale_factor\nOutput file name: $file.gif\n\n";

  #Three steps for graphic conversion:

  #1. convert tiff to pnm file 

  if(system("/mit/graphics/$bin_dir/tifftopnm $in > /tmp/$just_name.temp")) {
	&clean($file);
	die "Sorry, I can't deal with this file. Bailing..\n";
	}


  #2. reduce pnm to manageable size for screen display 

  # pnmscale produces reasonably good quality. pnmdepth then reduces the 
  # grayscale bits and makes file smaller without too much loss of quality. 
  # Depth of 4 bits (5 'colors') seems to be deep enough.

   if (system("/mit/graphics/$bin_dir/pnmscale $scale_factor /tmp/$just_name.temp > /tmp/$just_name.temp.reduced")) {
	&clean($file);
        die "Sorry, I can't deal with this file. Bailing..\n";
        }

   if (system("/mit/graphics/$bin_dir/pnmdepth 4 /tmp/$just_name.temp.reduced > /tmp/$just_name.temp.reduced.depth4")) {
 	&clean($file);
        die "Sorry, I can't deal with this file. Bailing..\n";
        }

  #3. convert reduced ppm to gif, give it the gif extension, and dump it in
  #   the destination directory

  system("/mit/graphics/$bin_dir/ppmtogif /tmp/$just_name.temp.reduced.depth4  > $destdir/$just_name.gif");

}

sub clean {

# zap work files
  local($just_name) = @_;

    system("/bin/rm /tmp/$just_name.temp");
    system("/bin/rm /tmp/$just_name.temp.reduced");
    system("/bin/rm /tmp/$just_name.temp.reduced.depth4");

}

sub usage {

die "usage: giffit ['filename' '-all'] -scale [scaling factor] [auto] -dest [destination directory]\n";       

}

sub get_just_filename {
 
  #extracts a filename from the end of a full path;
 
  local($path) = @_;
  @split_filename_path = split(/\//,$path);
  $just_name = $split_filename_path[$#split_filename_path];
#  chop $just_name;
  return($just_name);
}