feat: support create Rgb color from Hsl value, issue#40

Author: inhere

README.md

@@ -417,6 +417,16 @@ rgb.Println("rgb color")
 rgb.C256().Println("256 color")
 ```
 
+**More converts functions**:
+
+convert to rgb:
+
+- `func RGBFromSlice(rgb []uint8, isBg ...bool) RGBColor`
+- `func RGBFromString(rgb string, isBg ...bool) RGBColor`
+- `func HEX(hex string, isBg ...bool) RGBColor`
+- `func HSL(h, s, l float32, isBg ...bool) RGBColor`
+- `func HSLInt(h, s, l int, isBg ...bool) RGBColor`
+
 ## Func refer
 
 There are some useful functions reference

color_rgb.go

@@ -71,10 +71,10 @@ const (
 // 	RGBColor{30,144,255, 0}
 // 	RGBColor{30,144,255, 1}
 //
-// NOTICE: now support RGB color on windows CMD, PowerShell
+// NOTICE: now support RGB color on Windows CMD, PowerShell
 type RGBColor [4]uint8
 
-// create a empty RGBColor
+// create an empty RGBColor
 var emptyRGBColor = RGBColor{3: 99}
 
 // RGB color create.
@@ -97,6 +97,16 @@ func Rgb(r, g, b uint8, isBg ...bool) RGBColor { return RGB(r, g, b, isBg...) }
 // Bit24 alias of the RGB()
 func Bit24(r, g, b uint8, isBg ...bool) RGBColor { return RGB(r, g, b, isBg...) }
 
+// RgbFromInt create instance from int r,g,b value
+func RgbFromInt(r, g, b int, isBg ...bool) RGBColor {
+	return RGB(uint8(r), uint8(g), uint8(b), isBg...)
+}
+
+// RgbFromInts create instance from []int r,g,b value
+func RgbFromInts(rgb []int, isBg ...bool) RGBColor {
+	return RGB(uint8(rgb[0]), uint8(rgb[1]), uint8(rgb[2]), isBg...)
+}
+
 // HEX create RGB color from a HEX color string.
 //
 // Usage:
@@ -118,7 +128,8 @@ func HEX(hex string, isBg ...bool) RGBColor {
 func Hex(hex string, isBg ...bool) RGBColor { return HEX(hex, isBg...) }
 
 // HSL create RGB color from a hsl value.
-func HSL(h, s, l float32, isBg ...bool) RGBColor {
+// more see HslToRgb()
+func HSL(h, s, l float64, isBg ...bool) RGBColor {
 	if rgb := HslToRgb(h, s, l); len(rgb) > 0 {
 		return RGB(rgb[0], rgb[1], rgb[2], isBg...)
 	}
@@ -128,15 +139,29 @@ func HSL(h, s, l float32, isBg ...bool) RGBColor {
 }
 
 // Hsl alias of the HSL()
-func Hsl(h, s, l float32, isBg ...bool) RGBColor { return HSL(h, s, l, isBg...) }
+func Hsl(h, s, l float64, isBg ...bool) RGBColor { return HSL(h, s, l, isBg...) }
+
+// HSLInt create RGB color from a hsl int value.
+// more see HslIntToRgb()
+func HSLInt(h, s, l int, isBg ...bool) RGBColor {
+	if rgb := HslIntToRgb(h, s, l); len(rgb) > 0 {
+		return RGB(rgb[0], rgb[1], rgb[2], isBg...)
+	}
+
+	// mark is empty
+	return emptyRGBColor
+}
+
+// HslInt alias of the HSLInt()
+func HslInt(h, s, l int, isBg ...bool) RGBColor { return HSLInt(h, s, l, isBg...) }
 
 // RGBFromSlice quick RGBColor from slice
 func RGBFromSlice(rgb []uint8, isBg ...bool) RGBColor {
 	return RGB(rgb[0], rgb[1], rgb[2], isBg...)
 }
 
 // RGBFromString create RGB color from a string.
-// support use color name in the {namedRgbColor}
+// support use color name in the {namedRgbMap}
 //
 // Usage:
 // 	c := RGBFromString("170,187,204")
@@ -145,8 +170,8 @@ func RGBFromSlice(rgb []uint8, isBg ...bool) RGBColor {
 // 	c := RGBFromString("brown")
 // 	c.Print("message with color brown")
 func RGBFromString(rgb string, isBg ...bool) RGBColor {
-	// use color name in the {namedRgbColor}
-	if rgbVal, ok := namedRgbColor[rgb]; ok {
+	// use color name in the {namedRgbMap}
+	if rgbVal, ok := namedRgbMap[rgb]; ok {
 		rgb = rgbVal
 	}
 
@@ -219,6 +244,11 @@ func (c RGBColor) Hex() string {
 	return fmt.Sprintf("%02x%02x%02x", c[0], c[1], c[2])
 }
 
+// RgbString to color code string without prefix. eg: "204,123,56"
+func (c RGBColor) RgbString() string {
+	return fmt.Sprintf("%d,%d,%d", c[0], c[1], c[2])
+}
+
 // FullCode to color code string with prefix
 func (c RGBColor) FullCode() string {
 	return c.String()

color_rgb_test.go

@@ -206,6 +206,14 @@ func TestPrintRGBColor(t *testing.T) {
 	HEXStyle("eee", "D50000").Println("deep-purple color")
 }
 
+func TestRGBStyle_SetOpts(t *testing.T) {
+	s := NewRGBStyle(RGB(234, 78, 23), RGB(20, 144, 234))
+	s.Println("rgb style message")
+
+	s.SetOpts(Opts{OpItalic, OpBold, OpUnderscore})
+	s.Println("RGB style message with options")
+}
+
 func testRgbToC256Color(t *testing.T, name string, c RGBColor, expected uint8) {
 	t.Log("RGB Color:", c.Sprint(name))
 	t.Log("256 Color:", c.C256().Sprint(name))
@@ -215,21 +223,13 @@ func testRgbToC256Color(t *testing.T, name string, c RGBColor, expected uint8) {
 	}
 }
 
-func TestRGBStyle_SetOpts(t *testing.T) {
-	s := NewRGBStyle(RGB(234, 78, 23), RGB(20, 144, 234))
-	s.Println("rgb style message")
-
-	s.SetOpts(Opts{OpItalic, OpBold, OpUnderscore})
-	s.Println("RGB style message with options")
-}
-
 func TestRgbToC256(t *testing.T) {
 	testRgbToC256Color(t, "white", RGB(255, 255, 255), 15)
 	testRgbToC256Color(t, "red", RGB(255, 0, 0), 9)
 	testRgbToC256Color(t, "yellow", RGB(255, 255, 0), 11)
-	testRgbToC256Color(t, "greenBg", RGB(0, 255, 0, true), 10)
+	testRgbToC256Color(t, "greenBg", RgbFromInt(0, 255, 0, true), 10)
 	testRgbToC256Color(t, "blueBg", RGB(0, 0, 255, true), 12)
-	testRgbToC256Color(t, "light blue", RGB(57, 187, 226), 74)
+	testRgbToC256Color(t, "light blue", RgbFromInts([]int{57, 187, 226}), 74)
 }
 
 func TestRgbToC256Background(t *testing.T) {
@@ -259,7 +259,21 @@ func TestRGBColor_C16(t *testing.T) {
 }
 
 func TestHSL(t *testing.T) {
-	hsl := HSL(0.33, 1, 0.5)
+	// red #ff0000	255, 0, 0
+	rgb := HSL(0, 1, 0.5)
+	rgb.Println("rgb color create by HSL; hex:", rgb.Hex(), "rgb:", rgb.RgbString())
+
+	rgb = Hsl(0, 1, 0.5)
+	rgb.Println("rgb color create by HSL; hex:", rgb.Hex(), "rgb:", rgb.RgbString())
+
+	rgb = HslInt(0, 100, 50)
+	rgb.Println("rgb color create by HSL int; hex:", rgb.Hex(), "rgb:", rgb.RgbString())
 
-	hsl.Println("rgb color create by HSL")
-}
+	// maroon #800000  128,0,0  0,100%,25%
+	rgb = HslInt(0, 100, 25)
+	rgb.Println("rgb color create by HSL int; hex:", rgb.Hex(), "rgb:", rgb.RgbString())
+
+	// darkgray	 #a9a9a9 169,169,169 0,0%,66%
+	rgb = HslInt(0, 0, 66)
+	rgb.Println("rgb color create by HSL int; hex:", rgb.Hex(), "rgb:", rgb.RgbString())
+}

convert.go

@@ -3,6 +3,7 @@ package color
 import (
 	"fmt"
 	"math"
+	"sort"
 	"strconv"
 	"strings"
 )
@@ -628,15 +629,17 @@ func C256ToRgbV1(val uint8) (rgb []uint8) {
  *  color: hsl(120, 75%, 75%)  // pastel green, and so on
  */
 
-// HslToRgbByInt Converts an HSL color value to RGB
+// HslIntToRgb Converts an HSL color value to RGB
 // Assumes h: 0-360, s: 0-100, l: 0-100
 // returns r, g, and b in the set [0, 255].
 //
 // Usage:
-//	HslToRgbByInt(120, 100, 50)
-//	HslToRgbByInt(120, 100, 25)
-func HslToRgbByInt(h, s, l int) (rgb []uint8) {
-	return HslToRgb(float32(h)/360, float32(s)/100, float32(l)/100)
+//	HslIntToRgb(0, 100, 50) // red
+//	HslIntToRgb(120, 100, 50) // lime
+//	HslIntToRgb(120, 100, 25) // dark green
+//	HslIntToRgb(120, 100, 75) // light green
+func HslIntToRgb(h, s, l int) (rgb []uint8) {
+	return HslToRgb(float64(h)/360, float64(s)/100, float64(l)/100)
 }
 
 // HslToRgb Converts an HSL color value to RGB. Conversion formula
@@ -645,50 +648,110 @@ func HslToRgbByInt(h, s, l int) (rgb []uint8) {
 // returns r, g, and b in the set [0, 255].
 //
 // Usage:
-//	rgbVals := HslToRgb(0.33, 1, 0.5)
-func HslToRgb(h, s, l float32) (rgb []uint8) {
-	var r, g, b float32
+//	rgbVals := HslToRgb(0, 1, 0.5) // red
+func HslToRgb(h, s, l float64) (rgb []uint8) {
+	var r, g, b float64
 
 	if s == 0 { // achromatic
 		r, g, b = l, l, l
 	} else {
-		var hue2rgb = func(p, q, t float32) float32 {
-			if t < 0 {
+		var hue2rgb = func(p, q, t float64) float64 {
+			if t < 0.0 {
 				t += 1
 			}
-			if t > 1 {
+			if t > 1.0 {
 				t -= 1
 			}
-			if t < 1/6 {
-				return p + (q-p)*6*t
+
+			if t < 1.0/6.0 {
+				return p + (q-p)*6.0*t
 			}
 
-			if t < 1/2 {
+			if t < 1.0/2.0 {
 				return q
 			}
-			if t < 2/3 {
-				return p + (q-p)*(2/3-t)*6
+
+			if t < 2.0/3.0 {
+				return p + (q-p)*(2.0/3.0-t)*6.0
 			}
 			return p
 		}
 
 		// q = l < 0.5 ? l * (1 + s) : l + s - l*s
-		var q float32
+		var q float64
 		if l < 0.5 {
-			q = l * (1 + s)
+			q = l * (1.0 + s)
 		} else {
 			q = l + s - l*s
 		}
 
-		var p = 2*l - q
+		var p = 2.0*l - q
 
-		r = hue2rgb(p, q, h+1/3)
+		r = hue2rgb(p, q, h+1.0/3.0)
 		g = hue2rgb(p, q, h)
-		b = hue2rgb(p, q, h-1/3)
+		b = hue2rgb(p, q, h-1.0/3.0)
+	}
+
+	// return []uint8{uint8(r * 255), uint8(g * 255), uint8(b * 255)}
+	return []uint8{
+		uint8(math.Round(r * 255)),
+		uint8(math.Round(g * 255)),
+		uint8(math.Round(b * 255)),
+	}
+}
+
+// RgbToHslInt Converts an RGB color value to HSL. Conversion formula
+// Assumes r, g, and b are contained in the set [0, 255] and
+// returns [h,s,l] h: 0-360, s: 0-100, l: 0-100.
+func RgbToHslInt(r, g, b uint8) []int {
+	f64s := RgbToHsl(r, g, b)
+
+	return []int{int(f64s[0] * 360), int(f64s[1] * 100), int(f64s[2] * 100)}
+}
+
+// RgbToHsl Converts an RGB color value to HSL. Conversion formula
+// adapted from http://en.wikipedia.org/wiki/HSL_color_space.
+// Assumes r, g, and b are contained in the set [0, 255] and
+// returns h, s, and l in the set [0, 1].
+func RgbToHsl(r, g, b uint8) []float64 {
+	// to float64
+	fr, fg, fb := float64(r), float64(g), float64(b)
+	// percentage
+	pr, pg, pb := float64(r)/255.0, float64(g)/255.0, float64(b)/255.0
+
+	ps := []float64{pr, pg, pb}
+	sort.Float64s(ps)
+
+	min, max := ps[0], ps[2]
+	// max := math.Max(math.Max(pr, pg), pb)
+	// min := math.Min(math.Min(pr, pg), pb)
+
+	mid := (max + min) / 2
+
+	h, s, l := mid, mid, mid
+
+	if max == min {
+		h, s = 0, 0 // achromatic
+	} else {
+		var d = max - min
+		// s = l > 0.5 ? d / (2 - max - min) : d / (max + min)
+		s = compareF64Val(l > 0.5, d/(2-max-min), d/(max+min))
+
+		switch max {
+		case fr:
+			// h = (g - b) / d + (g < b ? 6 : 0)
+			h = (fg - fb) / d
+			h += compareF64Val(g < b, 6, 0)
+		case fg:
+			h = (fb-fr)/d + 2
+		case fb:
+			h = (fr-fg)/d + 4
+		}
+
+		h /= 6
 	}
 
-	// return [math.round(r * 255), Math.round(g * 255), Math.round(b * 255)];
-	return []uint8{uint8(r * 255 / 100), uint8(g * 255 / 100), uint8(b * 255 / 100)}
+	return []float64{h, s, l}
 }
 
 /**************************************************************
@@ -707,12 +770,13 @@ func HslToRgb(h, s, l float32) (rgb []uint8) {
 // Assumes h: 0-360, s: 0-100, l: 0-100
 // returns r, g, and b in the set [0, 255].
 func HsvToRgb(h, s, v int) (rgb []uint8) {
+	// TODO ...
 	return
 }
 
 // Named rgb colors
 // https://www.w3.org/TR/css-color-3/#svg-color
-var namedRgbColor = map[string]string{
+var namedRgbMap = map[string]string{
 	"aliceblue":            "240,248,255", // #F0F8FF
 	"antiquewhite":         "250,235,215", // #FAEBD7
 	"aqua":                 "0,255,255",   // #00FFFF

convert_test.go

@@ -0,0 +1,45 @@
+package color
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRgb2basic(t *testing.T) {
+	assert.Equal(t, uint8(31), Rgb2basic(134, 56, 56, false))
+	assert.Equal(t, uint8(41), Rgb2basic(134, 56, 56, true))
+	assert.Equal(t, uint8(46), Rgb2basic(57, 187, 226, true))
+}
+
+func TestHslToRgb(t *testing.T) {
+	// red #ff0000	255,0,0  0,100%,50%
+	rgbVal := HslToRgb(0, 1, 0.5)
+	// fmt.Println(rgbVal)
+	assert.Equal(t, []uint8{255, 0, 0}, rgbVal)
+
+	rgbVal = HslIntToRgb(0, 100, 50)
+	// fmt.Println(rgbVal)
+	assert.Equal(t, []uint8{255, 0, 0}, rgbVal)
+
+	rgbVal = HslIntToRgb(0, 100, 25)
+	// fmt.Println(rgbVal)
+	assert.Equal(t, []uint8{128, 0, 0}, rgbVal)
+
+	// darkgray	 #a9a9a9 169,169,169 0,0%,66%
+	rgbVal = HslIntToRgb(0, 0, 66)
+	fmt.Println(rgbVal)
+	assert.Equal(t, []uint8{168, 168, 168}, rgbVal)
+
+	rgbVal = HslToRgb(0, 0, 0.6627)
+	fmt.Println(rgbVal)
+	assert.Equal(t, []uint8{169, 169, 169}, rgbVal)
+
+	hslVal := RgbToHslInt(rgbVal[0], rgbVal[1], rgbVal[2])
+	fmt.Println(hslVal)
+	assert.Equal(t, []int{0, 0, 66}, hslVal)
+
+	hslFVal := RgbToHsl(rgbVal[0], rgbVal[1], rgbVal[2])
+	fmt.Println(hslFVal)
+}