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- package Display::Image;
-
- use base qw(Exporter);
- our @EXPORT_OK = qw(image_size image_markup);
-
-
- =item image_size
-
- Returns (width, height) of a variety of image files. Called by icon_markup and
- line_parse. Uses Image::Size if available, otherwise uses a couple of built-in
- routines munged together from pngsize and jpegsize in wwwis, by Alex Knowles
- and Andrew Tong.
-
- =cut
-
- # needs to call wwwis routine below if we don't have Image::Size...
- my $has_imgsize = eval 'use Image::Size;';
-
- sub image_size {
- my ($image_file) = shift;
-
- my ($x, $y, $type);
-
- if ($has_imgsize) {
- ($x, $y, $type) = imgsize($image_file);
- }
- else {
- ($x, $y) = wwwis($image_file);
- }
-
- return ($x, $y);
- }
-
-
- sub wwwis {
- my ($image_file) = shift;
-
- my ($head, $if);
-
- if ( ! open $if, '<', $image_file ) {
- print STDERR "can't open IMG $image_file";
- return (0, 0);
- } else {
- binmode $if;
- if ($image_file =~ m/\.png$/) { # it's a PNG
- my ($a, $b, $c, $d, $e, $f, $g, $h) = 0;
-
- if (defined($image_file)
- && read($if, $head, 8) == 8
- && ($head eq "\x8a\x4d\x4e\x47\x0d\x0a\x1a\x0a" ||
- $head eq "\x89\x50\x4e\x47\x0d\x0a\x1a\x0a")
- && read($if, $head, 4) == 4
- && read($if, $head, 4) == 4
- && ($head eq "MHDR" || $head eq "IHDR")
- && read($if, $head, 8) == 8) {
- # ($x, $y) = unpack("I"x2, $head);
- # doesn't work on little-endian machines
- # return ($x,$y);
- ($a,$b,$c,$d,$e,$f,$g,$h) = unpack ("C"x8, $head);
- return ($a<<24|$b<<16|$c<<8|$d, $e<<24|$f<<16|$g<<8|$h);
- }
- } elsif ($image_file =~ m/\.jpe?g$/) { # it's a JPEG
- my($done) = 0;
- my($c1,$c2,$ch,$s,$length, $dummy) = (0,0,0,0,0,0);
- my($a,$b,$c,$d);
-
- if (defined($image_file)
- && read($if, $c1, 1)
- && read($if, $c2, 1)
- && ord($c1) == 0xFF
- && ord($c2) == 0xD8) {
- while (ord($ch) != 0xDA && !$done) {
- # Find next marker (JPEG markers begin with 0xFF)
- # This can hang the program!!
- while (ord($ch) != 0xFF) {
- return(0,0) unless read($if, $ch, 1);
- }
-
- # JPEG markers can be padded with unlimited 0xFF's
- while (ord($ch) == 0xFF) {
- return(0,0) unless read($if, $ch, 1);
- }
-
- # Now, $ch contains the value of the marker.
- if ((ord($ch) >= 0xC0) && (ord($ch) <= 0xC3)) {
- return(0,0) unless read ($if, $dummy, 3);
- return(0,0) unless read($if, $s, 4);
- ($a,$b,$c,$d)=unpack("C"x4,$s);
- return ($c<<8|$d, $a<<8|$b );
- } else {
- # We **MUST** skip variables, since FF's within
- # variable names are NOT valid JPEG markers
- return(0,0) unless read ($if, $s, 2);
- ($c1, $c2) = unpack("C"x2,$s);
- $length = $c1<<8|$c2;
- last if (!defined($length) || $length < 2);
- read($if, $dummy, $length-2);
- }
- }
- }
- }
-
- return (0,0);
- }
- }
-
- 1;
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