tools/util/image/color.go

package image

import (
	"fmt"
	"gopkg.in/gographics/imagick.v3/imagick"
	"icloudapp.cn/tools/util"
	"strconv"
	"strings"
)

type Color struct {
	Red   uint32
	Green uint32
	Blue  uint32
	Alpha uint32

	R uint8
	G uint8
	B uint8
	A uint8
}

func NewColor(color string) *Color {
	return &Color{}
}

// PaddingColorTo8 将color补充到8位，最后两位位Alpha
func PaddingColorTo8(color string) string {
	hexColor := strings.Replace(color, "#", "", 1)
	strRune := []rune(hexColor)
	var strBuild strings.Builder
	if len(hexColor) == 3 {
		for i := 0; i < 3; i++ {
			strBuild.WriteString(string(strRune[i]))
			strBuild.WriteString(string(strRune[i]))
		}
		strBuild.WriteString("FF")
		hexColor = strBuild.String()
	}
	if len(hexColor) > 8 {
		hexColor = util.CutString(hexColor, 0, 8)
	}
	strBuild.WriteString(hexColor)
	if len(hexColor) < 8 {
		padding := 8 - len(hexColor)
		for i := 0; i < padding; i++ {
			strBuild.WriteString("F")
		}
	}
	return strBuild.String()
}

// Alpha rgb alpha  0 透明 -> 1 不透明
func Alpha(color string) (string, Color, float64) {
	// 0 透明 -> 1 不透明
	opacity := 1.0
	hexColor := PaddingColorTo8(color)

	color = util.CutString(hexColor, 0, 6)

	hexAlpha, _ := strconv.ParseInt(util.CutString(hexColor, 6, 8), 16, 10)
	opacity = float64(int((float64(hexAlpha)/255)*100)) / 100
	color = fmt.Sprintf("#%s", color)

	var rgb Color
	rgbRune := []rune(hexColor)

	red := string(rgbRune[0:2])
	r, _ := strconv.ParseInt(red, 16, 10)
	rgb.Red = uint32(r)
	rgb.R = uint8(r)

	green := string(rgbRune[2:4])
	g, _ := strconv.ParseInt(green, 16, 10)
	rgb.Green = uint32(g)
	rgb.G = uint8(g)

	blue := string(rgbRune[4:6])
	b, _ := strconv.ParseInt(blue, 16, 10)
	rgb.Blue = uint32(b)
	rgb.B = uint8(b)

	alpha := string(rgbRune[6:8])
	a, _ := strconv.ParseInt(alpha, 16, 10)
	rgb.Alpha = uint32(a / 255)
	rgb.A = uint8(a)

	return color, rgb, opacity
}

// Pixel PixelWand
func Pixel(color string) *imagick.PixelWand {
	destColor, _, alpha := Alpha(color)
	g := imagick.NewPixelWand()
	g.SetColor(destColor)
	g.SetAlpha(alpha)
	return g
}

func OpacityPixel() *imagick.PixelWand {
	pw := imagick.NewPixelWand()
	pw.SetColor("none")
	return pw
}