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hugo/resources/images/auto_orient.go

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1.6 KiB
Go

// Copyright 2024 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"
"github.com/spf13/cast"
)
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 v, ok := exifInfo.Tags["Orientation"]; ok {
orientation := cast.ToInt(v)
if filter, ok := transformationFilters[orientation]; ok {
return filter
}
}
}
return nil
}