Dogcows Code - chaz/yoink/blob - scripts/textureattr.pl

   1 #!/usr/bin/env perl
   2
   3 #
   4 # A wrapper around pngcrush to read and write the texture attributes of a
   5 # Yoink texture in PNG format.
   6 #
   7
   8 my $infile      = shift or die "Missing argument";
   9 my $outfile     = shift;
  10
  11 if ($infile eq "-h" or $infile eq "--help") {
  12         print <<END
  13 Edit the texture attributes of a Yoink texture file.
  14 Usage: texture_edit.pl infile.png [outfile.png]
  15 If outfile.png is not specified, infile.png will be written
  16 back onto itself.
  17 END
  18 ;
  19         exit 0;
  20 }
  21
  22 my $key = "X-Yoink-Texture";
  23
  24 use File::Copy;
  25 use File::Temp;
  26
  27 # Handle file contents as a whole, not line-by-line.
  28 local $/;
  29
  30 # Read in the image file for the first time.
  31 open FILE, $infile or die $!;
  32 my $bytes = <FILE>;
  33 close(FILE);
  34
  35 # See if we can't determine what the text currently is.
  36 my $text = "";
  37 if ($bytes =~ m/(.{4})tEXt$key(\0)/g)
  38 {
  39         my $offset = pos($bytes);
  40         my $size = unpack("N", $1) - (length($key) + 1);
  41         $text = substr($bytes, $offset, $size);
  42 }
  43
  44 # Write that text to a temporary file.
  45 $tmpfile = new File::Temp(UNLINK => 1);
  46 print $tmpfile $text;
  47
  48 # Allow the user a chance to edit the text.
  49 system("\${EDITOR:-vi} $tmpfile");
  50 (0 == $? >> 8) or die "Editor exited with an error";
  51
  52 # Reread the text from the temporary file.
  53 seek $tmpfile, 0, 0;
  54 $text = <$tmpfile>;
  55
  56 # Use pngcrush to rewrite the image file with the new text.
  57 system("pngcrush", "-fix", "-oldtimestamp", "-rem", "text", "-text", "b",
  58         $key, $text, $infile, $tmpfile);
  59 if (0 == $? >> 8) {
  60         not $outfile and $outfile = $infile;
  61         seek $tmpfile, 0, 0;
  62         copy($tmpfile, $outfile) or die $!;
  63 } else {
  64         die "pngcrush exited with an error";
  65 }
  66