#! /usr/local/bin/perl

## move.cgi v0.1a (MOVE IMAGE) 2001.04.22 by techan

# Image File Folder
$imgdir = './';

# Image1 to be moved
$image1 = 'fs1';

# Image2 to be moved (The size (width and height) of Image2
# must be the same as that of Image1.)
$image2 = 'fs2';

# Window Size (Width, Height)
@w_h = (300, 68);

# mime type for MNG in your server
$mime = 'video/x-mng';

# Ticks per second
$tps = 1000;

# The number of repeats for reciprocating motion (integer >=1)
$repeat = 50;

# Moving Pitch (pixels) (integer >=1)
$interval = 1;

# Framing Mode (1 - 4)
$fr_mode = 4;

# Direction of reciprocating motion (horizontal: 0, vertical: 1)
$direction = 0;

## Main

if ($ARGV[0] =~ s/([\d]+)//) { $interval = $1; }
if ($ARGV[0] eq 'horizontal') { $direction = 0; }
elsif ($ARGV[0] eq 'vertical') { $direction = 1; }

&InitCrcTable;

$r = "NG\r\n\x1a\n";
$sig_p = "\x89P".$r;
$sig_m = "\x8aM".$r;
# $sig_j = "\x8bJ".$r;

# Check File

$file = $imgdir.$image1.'.png';
$size = -s $file;
open(IN, "< $file") || &Error(1);
binmode(IN);
read(IN, $sig, 8);
if ($sig ne $sig_p) { close(IN); &Error(2); }
read(IN, $img1, $size-8);
close(IN);

$file = $imgdir.$image2.'.png';
$size = -s $file;
open(IN, "< $file") || &Error(1);
binmode(IN);
read(IN, $sig, 8);
if ($sig ne $sig_p) { close(IN); &Error(2); }
read(IN, $img2, $size-8);
close(IN);

$interval = int($interval);
if ($interval < 1) { $interval = 1; }

if ($direction == 0) {
	$x_c = unpack("N", substr($img1, 8, 4));
	$loop = int(($w_h[0] - $x_c) / $interval);
	$x_move = $interval;
	$y_move = 0;
} else {
	$y_c = unpack("N", substr($img1, 12, 4));
	$loop = int(($w_h[1] - $y_c) / $interval);
	$x_move = 0;
	$y_move = $interval;
}

$|=1;
print "Content-type: $mime\n\n";
binmode(STDOUT);

# Signature
print $sig_m;

# MHDR
$data = 'MHDR'.pack("N7",
	$w_h[0],	# Width
	$w_h[1],	# Height
	$tps,	# Ticks per second
	0,	# Layers (unspecified)
	0,	# Frames (unspecified)
	0,	# Time (unspecified)
	767);	# Simplicity
&OutputData;

# BACK
$data = 'BACK'.pack("n3",
	50000,	# Red_background: 2 bytes
	50000,	# Green_background: 2 bytes
	50000);	# Blue_background: 2 bytes
&OutputData;

# DEFI1
$data = 'DEFI'.pack("nC",
	1,	# Object_id: 2 bytes
	1);	# Do_not_show: 1 byte
&OutputData;
print $img1;
undef($img1);

# DEFI2
$data = 'DEFI'.pack("nC",
	2,	# Object_id: 2 bytes
	1);	# Do_not_show: 1 byte
&OutputData;
print $img2;
undef($img2);

# FRAM1
$data = 'FRAM'.pack("C6N",
	$fr_mode,	# Framing_mode: 1 byte
	0,	# Null_Separator: 1 byte
	1,	# Change_interframe_delay: 1 byte
	0,	# Change_timeout_and_termination: 1 byte
	0,	# Change_layer_clipping_boundaries: 1 byte
	0,	# Change_sync_id_list: 1 byte
	1);	# Interframe_delay: 4 byte
&OutputData;

# SHOW1
$data = 'SHOW'.pack("n", 1);
&OutputData;

# LOOP0
$data = 'LOOP'.pack("CN",
	0,	# Nest_level: 1 byte
	$repeat);	# Iteration_count: 4 bytes
&OutputData;

# LOOP1
$data = 'LOOP'.pack("CN",
	1,	# Nest_level: 1 byte
	$loop);	# Iteration_count: 4 bytes
&OutputData;

# MOVE1
$data = 'MOVE'.pack("nnCNN",
	1,	# First_object: 2 bytes
	2,	# Last_object: 2 bytes
	1,	# Location_delta_type: 1 byte
	$x_move,	# X_location or delta_X_location: 4 bytes (signed integer)
	$y_move);	# Y_location or delta_Y_location: 4 bytes (signed integer)
&OutputData;

# FRAM2
$data = 'FRAM';
&OutputData;

# SHOW2
$data = 'SHOW'.pack("n", 1);
&OutputData;

# ENDL1
$data = "ENDL\x01";
&OutputData;

# LOOP2
$data = 'LOOP'.pack("CN",
	2,	# Nest_level: 1 byte
	$loop);	# Iteration_count: 4 bytes
		# Termination_condition: 1 byte
&OutputData;

# MOVE2
$data = 'MOVE'.pack("nnCNN",
	1,	# First_object: 2 bytes
	2,	# Last_object: 2 bytes
	1,	# Location_delta_type: 1 byte
	-$x_move,	# X_location or delta_X_location: 4 bytes (signed integer)
	-$y_move);	# Y_location or delta_Y_location: 4 bytes (signed integer)
&OutputData;

# FRAM3
$data = 'FRAM';
&OutputData;

# SHOW3
$data = 'SHOW'.pack("n", 2);
&OutputData;

# ENDL2
$data = "ENDL\x02";
&OutputData;

# ENDL0
$data = "ENDL\0";
&OutputData;

# MEND
print "\0\0\0\0MEND! \xf7\xd5";

exit(0);

sub Error
{
my $e = $_[0];

$black = "\0\0\0";
$red = "\xff\0\0";
$white = "\xff\xff\xff";

if ($e == 1) { $plte = $white.$black; }
elsif ($e == 2) { $plte = $white.$red; }
else { $plte = $red.$white; }

$plte = "PLTE".$plte;

$p = $sig_p;
$p.="\0\0\0\rIHDR";
$p.="\0\0\0\x1e\0\0\0\x0c\x01\x03\0\0\0";
$p.="\x4f\xe0\x9f\x71";
$p.="\0\0\0\x06".$plte.&CalcCrc($plte);
$p.="\0\0\0\x2eIDAT";
$p.="\x78\x9c\x63\x60\x40\x05\xbf\xcf\xcb\x7c\x60\x68\xd2\x58\xd4\x01";
$p.="\x21\x3e\x81\x88\xe6\xf3\x4a\x40\xb1\x2e\xa5\x05\x0c\x4d\x9e\x4a";
$p.="\x13\x18\x7e\x69\xcc\xe9\0\xab\x05\0\xb0\x88\x10\xb8";
$p.="\x57\x3a\0\xa1";
$p.="\0\0\0\0IEND\xaeB`\x82";

$|=1;
print "Content-type: $mime\n";
print "Content-length: 121\n\n";
binmode(STDOUT);
print $p;
exit(1);
}

sub InitCrcTable
{
my $d;
@crc_table = ();
for (0 .. 255) {
	$d = $_;
	for (0 .. 7) {
		if ($d & 1) { $d = 0xedb88320 ^ (($d >> 1) & 0x7fffffff); }
		else { $d = ($d >> 1) & 0x7fffffff; }
	}
	$crc_table[$_] = $d;
}
}

sub CalcCrc
{
my $data = $_[0];
my $c = 0xffffffff;
foreach (unpack("C*", $data)) {
	$c = $crc_table[($c ^ $_) & 0xff] ^ (($c >> 8) & 0xffffff);
}
return(pack("N", ~$c));
}

sub OutputData
{
print pack("N", length($data)-4).$data.&CalcCrc($data);
undef($data);
}
__END__