img: Don't generate new verison of image if it is scaled to be larger in either dimen...

Although imagemagick handles even really large sizes sanely, using a page
file, doing so would just waste time and disk space, since the browser
can be told to resize it larger.

diff --git a/IkiWiki/Plugin/img.pm b/IkiWiki/Plugin/img.pm
index 5f97e38108ad22cfb9cde8dd9500d298201752be..9ae85c4e682839d7a2179785e1c4e504d6ecc866 100644 (file)
--- a/IkiWiki/Plugin/img.pm
+++ b/IkiWiki/Plugin/img.pm
@@ -65,6 +65,8 @@ sub preprocess (@) {
        my $imglink;
        my $r;
 
+       my ($dwidth, $dheight);
+
        if ($params{size} ne 'full') {
                add_depends($params{page}, $image);
 
@@ -86,7 +88,15 @@ sub preprocess (@) {
                        $r = $im->Read($srcfile);
                        error sprintf(gettext("failed to read %s: %s"), $file, $r) if $r;
 
-                       $r = $im->Resize(geometry => "${w}x${h}");
+                       # don't resize any larger
+                       my ($rw, $rh) = ($w, $h);
+                       if ((length $rw && $rw > $im->Get("width")) ||
+                           (length $rh && $rh > $im->Get("height"))) {
+                               $rw=$im->Get("width");
+                               $rh=$im->Get("height");
+                       }
+
+                       $r = $im->Resize(geometry => "${rw}x${rh}");
                        error sprintf(gettext("failed to resize: %s"), $r) if $r;
 
                        # don't actually write file in preview mode
@@ -98,11 +108,34 @@ sub preprocess (@) {
                                $imglink = $file;
                        }
                }
+
+               # since we don't really resize larger, set the display
+               # size, so the browser can scale the image up if necessary
+               if (length $w && length $h) {
+                       ($dwidth, $dheight)=($w, $h);
+               }
+               # avoid division by zero on 0x0 image
+               elsif ($im->Get("width") == 0 || $im->Get("height") == 0) {
+                       ($dwidth, $dheight)=(0, 0);
+               }
+               # calculate unspecified size from the other one, preserving
+               # aspect ratio
+               elsif (length $w) {
+                       $dwidth=$w;
+                       $dheight=$w / $im->Get("width") * $im->Get("height");
+               }
+               elsif (length $h) {
+                       $dheight=$h;
+                       $dwidth=$h / $im->Get("height") * $im->Get("width");
+               }
+
        }
        else {
                $r = $im->Read($srcfile);
                error sprintf(gettext("failed to read %s: %s"), $file, $r) if $r;
                $imglink = $file;
+               $dwidth = $im->Get("width");
+               $dheight = $im->Get("height");
        }
 
        my ($fileurl, $imgurl);
@@ -120,8 +153,8 @@ sub preprocess (@) {
        }
 
        my $imgtag='<img src="'.$imgurl.
-               '" width="'.$im->Get("width").
-               '" height="'.$im->Get("height").'"'.
+               '" width="'.$dwidth.
+               '" height="'.$dheight.'"'.
                (exists $params{alt} ? ' alt="'.$params{alt}.'"' : '').
                (exists $params{title} ? ' title="'.$params{title}.'"' : '').
                (exists $params{align} ? ' align="'.$params{align}.'"' : '').

diff --git a/debian/changelog b/debian/changelog
index 870abfdd575125c8559fba415de27ab5eebb1248..9926925660349a0d1688e19441454a44988372c9 100644 (file)
--- a/debian/changelog
+++ b/debian/changelog
@@ -37,6 +37,8 @@ ikiwiki (3.1415926) UNRELEASED; urgency=low
   * po: fix interdiction to create pages of type po (intrigeri)
   * po: po: favor the type of linking page's masterpage on page creation
     (intrigeri)
+  * img: Don't generate new verison of image if it is scaled to be
+    larger in either dimension.
 
  -- Joey Hess <joeyh@debian.org>  Wed, 12 Aug 2009 12:25:30 -0400