hugo/tpl/images/images.go
Bjørn Erik Pedersen 823f53c861
Add a set of image filters
With this you can do variants of this:

```
{{ $img := resources.Get "images/misc/3-jenny.jpg" }}
{{ $img := $img.Resize "300x" }}
{{ $g1 := $img.Filter images.Grayscale }}
{{ $g2 := $img | images.Filter (images.Saturate 30) (images.GaussianBlur 3) }}
```

Fixes #6255
2019-08-28 15:59:54 +02:00

110 lines
2.6 KiB
Go

// Copyright 2019 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 provides template functions for manipulating images.
package images
import (
"image"
"sync"
"github.com/disintegration/gift"
"github.com/pkg/errors"
"github.com/gohugoio/hugo/resources/images"
"github.com/gohugoio/hugo/resources/resource"
// Importing image codecs for image.DecodeConfig
_ "image/gif"
_ "image/jpeg"
_ "image/png"
// Import webp codec
_ "golang.org/x/image/webp"
"github.com/gohugoio/hugo/deps"
"github.com/spf13/cast"
)
// New returns a new instance of the images-namespaced template functions.
func New(deps *deps.Deps) *Namespace {
return &Namespace{
Filters: &images.Filters{},
cache: map[string]image.Config{},
deps: deps,
}
}
// Namespace provides template functions for the "images" namespace.
type Namespace struct {
*images.Filters
cacheMu sync.RWMutex
cache map[string]image.Config
deps *deps.Deps
}
// Config returns the image.Config for the specified path relative to the
// working directory.
func (ns *Namespace) Config(path interface{}) (image.Config, error) {
filename, err := cast.ToStringE(path)
if err != nil {
return image.Config{}, err
}
if filename == "" {
return image.Config{}, errors.New("config needs a filename")
}
// Check cache for image config.
ns.cacheMu.RLock()
config, ok := ns.cache[filename]
ns.cacheMu.RUnlock()
if ok {
return config, nil
}
f, err := ns.deps.Fs.WorkingDir.Open(filename)
if err != nil {
return image.Config{}, err
}
defer f.Close()
config, _, err = image.DecodeConfig(f)
if err != nil {
return config, err
}
ns.cacheMu.Lock()
ns.cache[filename] = config
ns.cacheMu.Unlock()
return config, nil
}
func (ns *Namespace) Filter(args ...interface{}) (resource.Image, error) {
if len(args) < 2 {
return nil, errors.New("must provide an image and one or more filters")
}
img := args[len(args)-1].(resource.Image)
filtersv := args[:len(args)-1]
filters := make([]gift.Filter, len(filtersv))
for i, f := range filtersv {
filters[i] = f.(gift.Filter)
}
return img.Filter(filters...)
}