word edit: -area option crops thumbnails with relative offsets

Preferred viewport configuration replacing unmaintainable combinations of
-crop, -chop, -shave, &al.

diff --git a/writer.plp b/writer.plp
index 76c00b1fecf0e38daf9edeba50ead06f09c675fd..7280142226a1c30dd19ddeb734e9825b02636f0e 100644 (file)
--- a/writer.plp
+++ b/writer.plp
@@ -209,6 +209,19 @@ elsif ($ENV{REQUEST_METHOD} eq 'POST') {{
                if (-e $imgpath) {
                        my $xyres = $row->{cover} ? '600x400' : '300x200';
                        my @cmds = @{ $row->{thumb} // [] };
+                       if (my ($cmdarg) = grep { $cmds[$_] eq '-area' } 0 .. $#cmds) {
+                               # replace option by permillage crop
+                               my @dim = map { $_ / 1000 } split /\D/, $cmds[$cmdarg + 1];
+                               splice @cmds, $cmdarg, 2, (
+                                       -set => 'option:distort:viewport' => sprintf(
+                                               '%%[fx:w*%s]x%%[fx:h*%s]+%%[fx:w*%s]+%%[fx:h*%s]',
+                                               ($dim[2] || 1) - $dim[0], # width  = x2 - x1
+                                               ($dim[3] || 1) - $dim[1], # height = y2 - y1
+                                               @dim[0, 1]                # offset = x1,y1
+                                       ),
+                                       -distort => SRT => 0, # noop transform to apply viewport
+                               );
+                       }
                        @cmds = (
                                'convert',
                                -delete => '1--1', -background => 'white',