images: Text filter that draws text with the given options (#9239)

Fixes #9238
This commit is contained in:
Paul van Brouwershaven 2021-12-07 11:29:55 +01:00 committed by GitHub
parent 5538507e90
commit 283394a4fd
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15 changed files with 160 additions and 2 deletions

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@ -40,6 +40,27 @@ A shorter version of the above, if you only need to apply the filter once:
The above will overlay `$logo` in the upper left corner of `$img` (at position `x=50, y=50`).
### Text
Using the `Text` filter, you can add text to an image.
{{% funcsig %}}
images.Text TEXT DICT)
{{% /funcsig %}}
The following example will add the text `Hugo rocks!` to the image with the specified color, size and position.
```
{{ $img := resources.Get "/images/background.png"}}
{{ $img = $img.Filter (images.Text "Hugo rocks!" (dict
"color" "#ffffff"
"size" 60
"linespacing" 2
"x" 10
"y" 20
))}}
```
### Brightness
{{% funcsig %}}

2
go.mod
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@ -60,7 +60,7 @@ require (
github.com/yuin/goldmark v1.4.4
github.com/yuin/goldmark-highlighting v0.0.0-20200307114337-60d527fdb691
gocloud.dev v0.20.0
golang.org/x/image v0.0.0-20210220032944-ac19c3e999fb
golang.org/x/image v0.0.0-20211028202545-6944b10bf410
golang.org/x/net v0.0.0-20210614182718-04defd469f4e
golang.org/x/sync v0.0.0-20210220032951-036812b2e83c
golang.org/x/text v0.3.7

3
go.sum
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@ -577,8 +577,9 @@ golang.org/x/exp v0.0.0-20200207192155-f17229e696bd/go.mod h1:J/WKrq2StrnmMY6+EH
golang.org/x/exp v0.0.0-20200224162631-6cc2880d07d6/go.mod h1:3jZMyOhIsHpP37uCMkUooju7aAi5cS1Q23tOzKc+0MU=
golang.org/x/image v0.0.0-20190227222117-0694c2d4d067/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=
golang.org/x/image v0.0.0-20190802002840-cff245a6509b/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
golang.org/x/image v0.0.0-20210220032944-ac19c3e999fb h1:fqpd0EBDzlHRCjiphRR5Zo/RSWWQlWv34418dnEixWk=
golang.org/x/image v0.0.0-20210220032944-ac19c3e999fb/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
golang.org/x/image v0.0.0-20211028202545-6944b10bf410 h1:hTftEOvwiOq2+O8k2D5/Q7COC7k5Qcrgc2TFURJYnvQ=
golang.org/x/image v0.0.0-20211028202545-6944b10bf410/go.mod h1:023OzeP/+EPmXeapQh35lcL3II3LrY8Ic+EFFKVhULM=
golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
golang.org/x/lint v0.0.0-20190227174305-5b3e6a55c961/go.mod h1:wehouNa3lNwaWXcvxsM5YxQ5yQlVC4a0KAMCusXpPoU=
golang.org/x/lint v0.0.0-20190301231843-5614ed5bae6f/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=

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@ -674,6 +674,9 @@ func TestImageOperationsGolden(t *testing.T) {
f.Hue(22),
f.Contrast(32.5),
f.Overlay(gopher.(images.ImageSource), 20, 30),
f.Text("No options"),
f.Text("This long text is to test line breaks. Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat."),
f.Text("Hugo rocks!", map[string]interface{}{"x": 30, "y": 30, "size": 15, "color": "#ff0000"}),
}
resized, err := orig.Fill("400x200 center")

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@ -15,6 +15,8 @@
package images
import (
"github.com/gohugoio/hugo/common/maps"
"github.com/disintegration/gift"
"github.com/spf13/cast"
)
@ -33,6 +35,43 @@ func (*Filters) Overlay(src ImageSource, x, y interface{}) gift.Filter {
}
}
// Text creates a filter that draws text with the given options.
func (*Filters) Text(text string, options ...interface{}) gift.Filter {
tf := textFilter{
text: text,
color: "#ffffff",
size: 20,
x: 10,
y: 10,
linespacing: 2,
}
var opt map[string]interface{}
if len(options) > 0 {
opt := maps.MustToParamsAndPrepare(options[0])
for option, v := range opt {
switch option {
case "color":
tf.color = cast.ToString(v)
case "size":
tf.size = cast.ToFloat64(v)
case "x":
tf.x = cast.ToInt(v)
case "y":
tf.y = cast.ToInt(v)
case "linespacing":
tf.linespacing = cast.ToInt(v)
}
}
}
return filter{
Options: newFilterOpts(text, opt),
Filter: tf,
}
}
// 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 {

94
resources/images/text.go Normal file
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@ -0,0 +1,94 @@
// Copyright 2021 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"
"strings"
"github.com/disintegration/gift"
"golang.org/x/image/font"
"golang.org/x/image/font/gofont/goregular"
"golang.org/x/image/font/opentype"
"golang.org/x/image/math/fixed"
)
var _ gift.Filter = (*textFilter)(nil)
type textFilter struct {
text, color string
x, y int
size float64
linespacing int
}
func (f textFilter) Draw(dst draw.Image, src image.Image, options *gift.Options) {
color, err := hexStringToColor(f.color)
if err != nil {
panic(err)
}
// Load and parse font
ttf := goregular.TTF
otf, err := opentype.Parse(ttf)
if err != nil {
panic(err)
}
// Set font options
face, err := opentype.NewFace(otf, &opentype.FaceOptions{
Size: f.size,
DPI: 72,
Hinting: font.HintingNone,
})
if err != nil {
panic(err)
}
d := font.Drawer{
Dst: dst,
Src: image.NewUniform(color),
Face: face,
}
gift.New().Draw(dst, src)
// Draw text, consider and include linebreaks
maxWidth := dst.Bounds().Dx() - 20
fontHeight := face.Metrics().Ascent.Ceil()
// Correct y position based on font and size
f.y = f.y + fontHeight
// Start position
y := f.y
d.Dot = fixed.P(f.x, f.y)
// Draw text and break line at max width
parts := strings.Fields(f.text)
for _, str := range parts {
strWith := font.MeasureString(face, str)
if (d.Dot.X.Ceil() + strWith.Ceil()) >= maxWidth {
y = y + fontHeight + f.linespacing
d.Dot = fixed.P(f.x, y)
}
d.DrawString(str + " ")
}
}
func (f textFilter) Bounds(srcBounds image.Rectangle) image.Rectangle {
return image.Rect(0, 0, srcBounds.Dx(), srcBounds.Dy())
}

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