mirror of
https://github.com/gohugoio/hugo.git
synced 2024-12-24 00:51:04 +00:00
84 lines
1.9 KiB
Go
84 lines
1.9 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
|
|
|
|
import (
|
|
"encoding/hex"
|
|
"image/color"
|
|
"strings"
|
|
|
|
"github.com/pkg/errors"
|
|
)
|
|
|
|
// AddColorToPalette adds c as the first color in p if not already there.
|
|
// Note that it does no additional checks, so callers must make sure
|
|
// that the palette is valid for the relevant format.
|
|
func AddColorToPalette(c color.Color, p color.Palette) color.Palette {
|
|
var found bool
|
|
for _, cc := range p {
|
|
if c == cc {
|
|
found = true
|
|
break
|
|
}
|
|
}
|
|
|
|
if !found {
|
|
p = append(color.Palette{c}, p...)
|
|
}
|
|
|
|
return p
|
|
}
|
|
|
|
// ReplaceColorInPalette will replace the color in palette p closest to c in Euclidean
|
|
// R,G,B,A space with c.
|
|
func ReplaceColorInPalette(c color.Color, p color.Palette) {
|
|
p[p.Index(c)] = c
|
|
}
|
|
|
|
func hexStringToColor(s string) (color.Color, error) {
|
|
s = strings.TrimPrefix(s, "#")
|
|
|
|
if len(s) != 3 && len(s) != 6 {
|
|
return nil, errors.Errorf("invalid color code: %q", s)
|
|
}
|
|
|
|
s = strings.ToLower(s)
|
|
|
|
if len(s) == 3 {
|
|
var v string
|
|
for _, r := range s {
|
|
v += string(r) + string(r)
|
|
}
|
|
s = v
|
|
}
|
|
|
|
// Standard colors.
|
|
if s == "ffffff" {
|
|
return color.White, nil
|
|
}
|
|
|
|
if s == "000000" {
|
|
return color.Black, nil
|
|
}
|
|
|
|
// Set Alfa to white.
|
|
s += "ff"
|
|
|
|
b, err := hex.DecodeString(s)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return color.RGBA{b[0], b[1], b[2], b[3]}, nil
|
|
}
|