From bda837fcd316a4f8ca90e631c620b8cc93c759a7 Mon Sep 17 00:00:00 2001
From: Mark Wooding <mdw@distorted.org.uk>
Date: Fri, 29 Apr 2022 17:50:33 +0100
Subject: [PATCH] mason/.perl-lib/TrivGal.pm: Handle EXIF `Orientation'.

Apparently Imlib2 doesn't do this for me. :-( OpenCamera hard-rotates
its images rather than using EXIF metadata, so I didn't notice before,
but my Nikon cameras don't do this.
---
 mason/.perl-lib/TrivGal.pm | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/mason/.perl-lib/TrivGal.pm b/mason/.perl-lib/TrivGal.pm
index 39c6913..4a41612 100644
--- a/mason/.perl-lib/TrivGal.pm
+++ b/mason/.perl-lib/TrivGal.pm
@@ -30,6 +30,7 @@ use autodie qw{:all};
 use Errno;
 use Exporter qw{import};
 use File::stat;
+use Image::ExifTool qw{};
 use Image::Imlib2;
 use User::pwent;
 use POSIX;
@@ -185,6 +186,16 @@ sub clean_temp_files () {
 ###--------------------------------------------------------------------------
 ### Scaled images.
 
+my %ORIENT =
+  (1 => [0, 0],
+   2 => [0, 1],
+   3 => [2, 0],
+   4 => [2, 1],
+   5 => [3, 1],
+   6 => [1, 0],
+   7 => [1, 1],
+   8 => [3, 0]);
+
 package TrivGal::Image {
   use File::Path qw{make_path};
   use File::stat;
@@ -216,7 +227,15 @@ package TrivGal::Image {
     my $img = $me->{img};
     unless (defined $img) {
       my $imgpath = "$IMGROOT/$path";
+      my $exif = new Image::ExifTool;
+      $exif->ExtractInfo($imgpath);
+      my $orient = $exif->GetValue("Orientation", "ValueConv");
       $img = $me->{img} = Image::Imlib2->load($imgpath);
+      if (defined $orient) {
+	my ($rot, $flip) = @{$ORIENT{$orient}};
+	if ($rot) { $img->image_orientate($rot); }
+	if ($flip) { $img->flip_horizontal($rot); }
+      }
     }
 
     my ($wd, $ht) = ($img->width, $img->height);
-- 
2.11.0