commit 3ba147e702a5ae0af6e8b3b0296d256c3246a546
parent a2d146ec32a26ccca9ffa68d3c840ec5b08cca96
Author: Bjørn Erik Pedersen <bjorn.erik.pedersen@gmail.com>
Date: Wed, 16 Dec 2020 13:52:47 +0100
images: Add images.Overlay filter
This allows for constructs ala:
```
{{ $overlay := $img.Filter (images.Overlay $logo 50 50 )}}
```
Or:
```
{{ $logoFilter := (images.Overlay $logo 50 50 ) }}
{{ $overlay := $img | images.Filter $logoFilter }}
```
Which will overlay the logo in the top left corner (x=50, y=50) of `$img`.
Fixes #8057
Fixes #4595
Updates #6731
Diffstat:
12 files changed, 101 insertions(+), 2 deletions(-)
diff --git a/docs/content/en/functions/images/index.md b/docs/content/en/functions/images/index.md
@@ -17,6 +17,30 @@ toc: true
See [images.Filter](#filter) for how to apply these filters to an image.
+### Overlay
+
+{{< new-in "0.80.0" >}}
+
+{{% funcsig %}}
+images.Overlay SRC X Y
+{{% /funcsig %}}
+
+Overlay creates a filter that overlays the source image at position x y, e.g:
+
+
+```go-html-template
+{{ $logoFilter := (images.Overlay $logo 50 50 ) }}
+{{ $img := $img | images.Filter $logoFilter }}
+```
+
+A shorter version of the above, if you only need to apply the filter once:
+
+```go-html-template
+{{ $img := $img.Filter (images.Overlay $logo 50 50 )}}
+```
+
+The above will overlay `$logo` in the upper left corner of `$img` (at position `x=50, y=50`).
+
### Brightness
{{% funcsig %}}
diff --git a/resources/image.go b/resources/image.go
@@ -242,7 +242,7 @@ func (i *imageResource) doWithImageConfig(conf images.ImageConfig, f func(src im
errOp := conf.Action
errPath := i.getSourceFilename()
- src, err := i.decodeSource()
+ src, err := i.DecodeImage()
if err != nil {
return nil, nil, &os.PathError{Op: errOp, Path: errPath, Err: err}
}
@@ -324,7 +324,9 @@ func (i *imageResource) decodeImageConfig(action, spec string) (images.ImageConf
return conf, nil
}
-func (i *imageResource) decodeSource() (image.Image, error) {
+// DecodeImage decodes the image source into an Image.
+// This an internal method and may change.
+func (i *imageResource) DecodeImage() (image.Image, error) {
f, err := i.ReadSeekCloser()
if err != nil {
return nil, _errors.Wrap(err, "failed to open image for decode")
diff --git a/resources/image_test.go b/resources/image_test.go
@@ -533,6 +533,11 @@ func TestImageOperationsGolden(t *testing.T) {
fmt.Println(workDir)
}
+ gopher := fetchImageForSpec(spec, c, "gopher-hero8.png")
+ var err error
+ gopher, err = gopher.Resize("30x")
+ c.Assert(err, qt.IsNil)
+
// Test PNGs with alpha channel.
for _, img := range []string{"gopher-hero8.png", "gradient-circle.png"} {
orig := fetchImageForSpec(spec, c, img)
@@ -589,6 +594,7 @@ func TestImageOperationsGolden(t *testing.T) {
f.Invert(),
f.Hue(22),
f.Contrast(32.5),
+ f.Overlay(gopher.(images.ImageSource), 20, 30),
}
resized, err := orig.Fill("400x200 center")
diff --git a/resources/images/filters.go b/resources/images/filters.go
@@ -25,6 +25,14 @@ const filterAPIVersion = 0
type Filters struct {
}
+// Overlay creates a filter that overlays src at position x y.
+func (*Filters) Overlay(src ImageSource, x, y interface{}) gift.Filter {
+ return filter{
+ Options: newFilterOpts(src.Key(), x, y),
+ Filter: overlayFilter{src: src, x: cast.ToInt(x), y: cast.ToInt(y)},
+ }
+}
+
// Brightness creates a filter that changes the brightness of an image.
// The percentage parameter must be in range (-100, 100).
func (*Filters) Brightness(percentage interface{}) gift.Filter {
diff --git a/resources/images/image.go b/resources/images/image.go
@@ -325,3 +325,9 @@ func IsOpaque(img image.Image) bool {
return false
}
+
+// ImageSource identifies and decodes an image.
+type ImageSource interface {
+ DecodeImage() (image.Image, error)
+ Key() string
+}
diff --git a/resources/images/overlay.go b/resources/images/overlay.go
@@ -0,0 +1,43 @@
+// Copyright 2020 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 (
+ "fmt"
+ "image"
+ "image/draw"
+
+ "github.com/disintegration/gift"
+)
+
+var _ gift.Filter = (*overlayFilter)(nil)
+
+type overlayFilter struct {
+ src ImageSource
+ x, y int
+}
+
+func (f overlayFilter) Draw(dst draw.Image, src image.Image, options *gift.Options) {
+ overlaySrc, err := f.src.DecodeImage()
+ if err != nil {
+ panic(fmt.Sprintf("failed to decode image: %s", err))
+ }
+
+ gift.New().Draw(dst, src)
+ gift.New().DrawAt(dst, overlaySrc, image.Pt(f.x, f.y), gift.OverOperator)
+}
+
+func (f overlayFilter) Bounds(srcBounds image.Rectangle) image.Rectangle {
+ return image.Rect(0, 0, srcBounds.Dx(), srcBounds.Dy())
+}
diff --git a/resources/resource/resourcetypes.go b/resources/resource/resourcetypes.go
@@ -14,6 +14,8 @@
package resource
import (
+ "image"
+
"github.com/gohugoio/hugo/common/maps"
"github.com/gohugoio/hugo/langs"
"github.com/gohugoio/hugo/media"
@@ -59,6 +61,9 @@ type ImageOps interface {
Resize(spec string) (Image, error)
Filter(filters ...interface{}) (Image, error)
Exif() *exif.Exif
+
+ // Internal
+ DecodeImage() (image.Image, error)
}
type ResourceTypeProvider interface {
diff --git a/resources/testdata/golden/gohugoio24_huc57dd738f4724f4b341121e66fd85555_267952_3ad578dd67cd055b4382e4062918d0a2.png b/resources/testdata/golden/gohugoio24_huc57dd738f4724f4b341121e66fd85555_267952_3ad578dd67cd055b4382e4062918d0a2.png
Binary files differ.
diff --git a/resources/testdata/golden/gohugoio8_hu7f72c00afdf7634587afaa5eff2a25b2_73538_b4afd8d32218a87ed1f7e351368501c3.png b/resources/testdata/golden/gohugoio8_hu7f72c00afdf7634587afaa5eff2a25b2_73538_b4afd8d32218a87ed1f7e351368501c3.png
Binary files differ.
diff --git a/resources/testdata/golden/gopher-hero8_huaa0cd7d2cfc14ff32a57f171896f2285_13327_30x0_resize_box_2.png b/resources/testdata/golden/gopher-hero8_huaa0cd7d2cfc14ff32a57f171896f2285_13327_30x0_resize_box_2.png
Binary files differ.
diff --git a/resources/testdata/golden/sunset_hu59e56ffff1bc1d8d122b1403d34e039f_90587_da536a2a5436e387d0d482675e08ad48.jpg b/resources/testdata/golden/sunset_hu59e56ffff1bc1d8d122b1403d34e039f_90587_da536a2a5436e387d0d482675e08ad48.jpg
Binary files differ.
diff --git a/resources/transform.go b/resources/transform.go
@@ -16,6 +16,7 @@ package resources
import (
"bytes"
"fmt"
+ "image"
"io"
"path"
"strings"
@@ -264,6 +265,10 @@ func (r *resourceAdapter) Width() int {
return r.getImageOps().Width()
}
+func (r *resourceAdapter) DecodeImage() (image.Image, error) {
+ return r.getImageOps().DecodeImage()
+}
+
func (r *resourceAdapter) getImageOps() resource.ImageOps {
img, ok := r.target.(resource.ImageOps)
if !ok {