my $progname = $0; $progname =~ s@.*/@@g;
-my $version = q{ $Revision: 1.15 $ }; $version =~ s/^[^0-9]+([0-9.]+).*$/$1/;
+my $version = q{ $Revision: 1.16 $ }; $version =~ s/^[^0-9]+([0-9.]+).*$/$1/;
my $verbose = 0;
#
my $good_file_re = '\.(gif|p?jpe?g|png|tiff?|xbm|xpm)$';
+# JPEG, GIF, and PNG files that are are smaller than this size in either
+# direction are rejected: this is so that you can use an image directory
+# that contains both big images and thumbnails, and have it only select
+# the big versions.
+#
+my $min_image_width = 255;
+my $min_image_height = 255;
+
# These are programs that can be used to put an image file on the root
# window (including virtual root windows.) The first one of these programs
# that exists on $PATH will be used (with the file name as the last arg.)
#
-# If you add other programs to this list, please let me know!
+# Generally this isn't used any more; when "xscreensaver-getimage" invokes
+# this program, it does so with the "-file" argument (meaning that we just
+# return the file name) and then xscreensaver-getimage loads that file
+# directly. However, if you invoke "xscreensaver-getimage-file" directly,
+# without "-file", this will be used to actually load the image.
#
my @programs = (
"chbg -once -xscreensaver -max_grow 4 -max_size 100",
}
-my @all_files = ();
-my %seen_inodes;
-my $skip_count = 0;
-my $dir_count = 1;
+my @all_files = (); # list of "good" files we've collected
+my %seen_inodes; # for breaking recursive symlink loops
+my $skip_count = 0; # number of files skipped, for diagnostic messages
+my $dir_count = 1; # number of directories seen, for diagnostic messages
sub find_all_files {
my ($dir) = @_;
exit 1;
}
- my $n = int (rand ($#all_files + 1));
- my $file = $all_files[$n];
+ my $max_tries = 50;
+ for (my $i = 0; $i < $max_tries; $i++) {
- print STDERR "$progname: chose file $n: $file\n" if ($verbose > 1);
- return $file;
-}
+ my $n = int (rand ($#all_files + 1));
+ my $file = $all_files[$n];
+ if (large_enough_p ($file)) {
+ return $file;
+ }
+ }
+ print STDERR "$progname: no suitable images in $dir " .
+ "(after $max_tries tries)\n";
+ exit 1;
+}
sub display_file {
}
+sub large_enough_p {
+ my ($file) = @_;
+
+ my ($w, $h) = image_file_size ($file);
+
+ if (!defined ($h)) {
+ print STDERR "$progname: $file: unable to determine image size\n"
+ if ($verbose);
+ # Assume that unknown files are of good sizes: this will happen if
+ # they matched $good_file_re, but we don't have code to parse them.
+ # (This will also happen if the file is junk...)
+ return 1;
+ }
+
+ if ($w < $min_image_width || $h < $min_image_height) {
+ print STDERR "$progname: $file: too small ($w x $h)\n" if ($verbose > 1);
+ return 0;
+ }
+
+ print STDERR "$progname: $file: $w x $h\n" if ($verbose > 1);
+ return 1;
+}
+
+
+
+# Given the raw body of a GIF document, returns the dimensions of the image.
+#
+sub gif_size {
+ my ($body) = @_;
+ my $type = substr($body, 0, 6);
+ my $s;
+ return () unless ($type =~ /GIF8[7,9]a/);
+ $s = substr ($body, 6, 10);
+ my ($a,$b,$c,$d) = unpack ("C"x4, $s);
+ return (($b<<8|$a), ($d<<8|$c));
+}
+
+# Given the raw body of a JPEG document, returns the dimensions of the image.
+#
+sub jpeg_size {
+ my ($body) = @_;
+ my $i = 0;
+ my $L = length($body);
+
+ my $c1 = substr($body, $i, 1); $i++;
+ my $c2 = substr($body, $i, 1); $i++;
+ return () unless (ord($c1) == 0xFF && ord($c2) == 0xD8);
+
+ my $ch = "0";
+ while (ord($ch) != 0xDA && $i < $L) {
+ # Find next marker, beginning with 0xFF.
+ while (ord($ch) != 0xFF) {
+ return () if (length($body) <= $i);
+ $ch = substr($body, $i, 1); $i++;
+ }
+ # markers can be padded with any number of 0xFF.
+ while (ord($ch) == 0xFF) {
+ return () if (length($body) <= $i);
+ $ch = substr($body, $i, 1); $i++;
+ }
+
+ # $ch contains the value of the marker.
+ my $marker = ord($ch);
+
+ if (($marker >= 0xC0) &&
+ ($marker <= 0xCF) &&
+ ($marker != 0xC4) &&
+ ($marker != 0xCC)) { # it's a SOFn marker
+ $i += 3;
+ return () if (length($body) <= $i);
+ my $s = substr($body, $i, 4); $i += 4;
+ my ($a,$b,$c,$d) = unpack("C"x4, $s);
+ return (($c<<8|$d), ($a<<8|$b));
+
+ } else {
+ # We must skip variables, since FFs in variable names aren't
+ # valid JPEG markers.
+ return () if (length($body) <= $i);
+ my $s = substr($body, $i, 2); $i += 2;
+ my ($c1, $c2) = unpack ("C"x2, $s);
+ my $length = ($c1 << 8) | $c2;
+ return () if ($length < 2);
+ $i += $length-2;
+ }
+ }
+ return ();
+}
+
+# Given the raw body of a PNG document, returns the dimensions of the image.
+#
+sub png_size {
+ my ($body) = @_;
+ return () unless ($body =~ m/^\211PNG\r/);
+ my ($bits) = ($body =~ m/^.{12}(.{12})/s);
+ return () unless defined ($bits);
+ return () unless ($bits =~ /^IHDR/);
+ my ($ign, $w, $h) = unpack("a4N2", $bits);
+ return ($w, $h);
+}
+
+
+# Given the raw body of a GIF, JPEG, or PNG document, returns the dimensions
+# of the image.
+#
+sub image_size {
+ my ($body) = @_;
+ my ($w, $h) = gif_size ($body);
+ if ($w && $h) { return ($w, $h); }
+ ($w, $h) = jpeg_size ($body);
+ if ($w && $h) { return ($w, $h); }
+ # #### TODO: need image parsers for TIFF, XPM, XBM.
+ return png_size ($body);
+}
+
+# Returns the dimensions of the image file.
+#
+sub image_file_size {
+ my ($file) = @_;
+ my $body = '';
+ local *IN;
+ if (! open (IN, "<$file")) {
+ print STDERR "$progname: $file: $!\n" if ($verbose);
+ return undef;
+ }
+ while (<IN>) {
+ $body .= $_;
+ last if (length($body) > 1024 * 100); # the first 100k should be enough
+ }
+ close IN;
+ return image_size ($body);
+}
+
+
sub usage {
print STDERR "usage: $progname [--verbose] [--name] file-or-directory\n\n" .
" Puts the given image file (or a randomly selected image from the\n" .
projects / xscreensaver / blobdiff