1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
|
// 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/color"
"image/draw"
"github.com/disintegration/gift"
)
var _ gift.Filter = (*paddingFilter)(nil)
type paddingFilter struct {
top, right, bottom, left int
ccolor color.Color // canvas color
}
func (f paddingFilter) Draw(dst draw.Image, src image.Image, options *gift.Options) {
w := src.Bounds().Dx() + f.left + f.right
h := src.Bounds().Dy() + f.top + f.bottom
if w < 1 {
panic("final image width will be less than 1 pixel: check padding values")
}
if h < 1 {
panic("final image height will be less than 1 pixel: check padding values")
}
i := image.NewRGBA(image.Rect(0, 0, w, h))
draw.Draw(i, i.Bounds(), image.NewUniform(f.ccolor), image.Point{}, draw.Src)
gift.New().Draw(dst, i)
gift.New().DrawAt(dst, src, image.Pt(f.left, f.top), gift.OverOperator)
}
func (f paddingFilter) Bounds(srcBounds image.Rectangle) image.Rectangle {
return image.Rect(0, 0, srcBounds.Dx()+f.left+f.right, srcBounds.Dy()+f.top+f.bottom)
}
|
