spritegen.pl: Add pngcrush/slow options + force png32 + atomic replace

A recent version of imagemagick creates 16 bit depth PNG images by
default for some reason. This results in an unnecessarily large file
size increase and pngcrush doesn't do much to counter it (and its
-bit_depth option has been deprecated, too).

The atomic replace is quite handy to avoid people seeing any wierd
intermediate images while the slow+pngcrush options are being used.

3 files changed, 24 insertions, 6 deletions

diff --git a/data/config_example.pl b/data/config_example.pl
index 9c255bb2..b1e405ce 100644
--- a/data/config_example.pl
+++ b/data/config_example.pl
@@ -40,3 +40,7 @@ package VNDB;
 # Uncomment the compression method to use for the generated Javascript (or just leave as-is to disable compression)
 #$JSGEN{compress} = 'JavaScript::Minifier::XS';
 #$JSGEN{compress} = "|/usr/bin/uglifyjs --compress --mangle";
+
+# Uncomment to generate an extra small icons.png (note: setting both pngcrush and slow options really is slow)
+#$SPRITEGEN{pngcrush} = '/usr/bin/pngcrush';
+#$SPRITEGEN{slow} = 1;
diff --git a/data/global.pl b/data/global.pl
index 5cefa5ff..de810926 100644
--- a/data/global.pl
+++ b/data/global.pl
@@ -140,6 +140,13 @@ our %JSGEN = (
 );
 
 
+# Options for spritegen.pl
+our %SPRITEGEN = (
+  slow => 0,
+  pngcrush => undef,
+);
+
+
 # allow the settings to be overwritten in config.pl
 require $ROOT.'/data/config.pl' if -f $ROOT.'/data/config.pl';
 
diff --git a/util/spritegen.pl b/util/spritegen.pl
index c6f830f7..3b3c88c3 100755
--- a/util/spritegen.pl
+++ b/util/spritegen.pl
@@ -1,5 +1,7 @@
 #!/usr/bin/perl
 
+package VNDB;
+
 use strict;
 use warnings;
 use Image::Magick;
@@ -7,9 +9,11 @@ use Cwd 'abs_path';
 
 our $ROOT;
 BEGIN { ($ROOT = abs_path $0) =~ s{/util/spritegen\.pl$}{}; }
+require $ROOT.'/data/global.pl';
 
 my $path = "$ROOT/data/icons";
 my $icons = "$ROOT/static/f/icons.png";
+my $ticons = "$ROOT/static/f/icons~.png";
 my $css = "$ROOT/data/icons/icons.css";
 
 my @img = map {
@@ -78,8 +82,8 @@ sub minstrip {
   my $optsize = 1e10;
   for my $w ($minwidth..$maxwidth) {
     my $size = genstrip($w)*$w;
-    # To optimize for file size, uncommment below line. It's slow, but saves about 150 bytes (while using pngcrush).
-    #$size = img();
+    # Optimize for file size rather than pixel count if slow is set
+    $size = img() if $VNDB::SPRITEGEN{slow};
     if($size < $optsize) {
       $optw = $w;
       $optsize = $size;
@@ -108,12 +112,15 @@ sub img {
   for my $i (@img) {
     print $img->Composite(image => $i->{i}, x => $i->{x}, y => $i->{y});
   }
-  print $img->Write($icons);
+  print $img->Write("png32:$ticons");
   undef $img;
 
-  `pngcrush -q "$icons" "$icons~" 2>/dev/null && mv "$icons~" "$icons"`;
+  if($VNDB::SPRITEGEN{pngcrush}) {
+    `$VNDB::SPRITEGEN{pngcrush} -q "$ticons" "$ticons~"`;
+    rename "$ticons~", $ticons or die $!;
+  }
 
-  my $size = -s $icons;
+  my $size = -s $ticons;
   #printf "Dim: %dx%d, size: %d, pixels wasted: %d\n", $w, $h, $size, $w*$h-$minpixels;
   $size;
 }
@@ -137,7 +144,7 @@ sub css {
 }
 
 
-#genstrip 80;
 minstrip;
 img;
 css;
+rename $ticons, $icons or die $!;