resources/images: Create AutoOrient image filter

Closes #11717

resources/images/auto_orient.go

@@ -0,0 +1,60 @@
+// Copyright 2023 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package images
+
+import (
+	"image"
+	"image/draw"
+
+	"github.com/disintegration/gift"
+	"github.com/gohugoio/hugo/resources/images/exif"
+)
+
+var _ gift.Filter = (*autoOrientFilter)(nil)
+
+var transformationFilters = map[int]gift.Filter{
+	2: gift.FlipHorizontal(),
+	3: gift.Rotate180(),
+	4: gift.FlipVertical(),
+	5: gift.Transpose(),
+	6: gift.Rotate270(),
+	7: gift.Transverse(),
+	8: gift.Rotate90(),
+}
+
+type autoOrientFilter struct{}
+
+type ImageFilterFromOrientationProvider interface {
+	AutoOrient(exifInfo *exif.ExifInfo) gift.Filter
+}
+
+func (f autoOrientFilter) Draw(dst draw.Image, src image.Image, options *gift.Options) {
+	panic("not supported")
+}
+
+func (f autoOrientFilter) Bounds(srcBounds image.Rectangle) image.Rectangle {
+	panic("not supported")
+}
+
+func (f autoOrientFilter) AutoOrient(exifInfo *exif.ExifInfo) gift.Filter {
+	if exifInfo != nil {
+		if orientation, ok := exifInfo.Tags["Orientation"].(int); ok {
+			if filter, ok := transformationFilters[orientation]; ok {
+				return filter
+			}
+		}
+	}
+
+	return nil
+}