[color] Added method 'Term2RGB'

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## Changelog
 
+### 12.92.0
+
+* `[color]` Added method `Term2RGB`
+
 ### 12.91.0
 
 * `[terminal/tty]` Added method `IsTMUX`

color/color.go

@@ -438,12 +438,12 @@ func Hex2RGBA(h Hex) RGBA {
 	return RGBA{uint8(h.v>>16) & 0xFF, uint8(h.v>>8) & 0xFF, uint8(h.v) & 0xFF, 0}
 }
 
-// RGB2Term convert rgb color to terminal color code
+// RGB2Term converts RGB color to terminal color code
 // https://misc.flogisoft.com/bash/tip_colors_and_formatting#colors1
 func RGB2Term(c RGB) int {
 	R, G, B := int(c.R), int(c.G), int(c.B)
 
-	// grayscale
+	// Grayscale
 	if R == G && G == B {
 		if R == 175 {
 			return 145
@@ -455,6 +455,72 @@ func RGB2Term(c RGB) int {
 	return 36*(R/51) + 6*(G/51) + (B / 51) + 16
 }
 
+// Term2RGB converts terminal color code (0-255) to RGB color
+// https://misc.flogisoft.com/bash/tip_colors_and_formatting#colors1
+func Term2RGB(c uint8) RGB {
+	// Grayscale
+	if c > 231 {
+		c = ((c - 232) * 10) + 8
+		return RGB{c, c, c}
+	}
+
+	// Default colors (not standardized, average values)
+	switch c {
+	case 0:
+		return RGB{}
+	case 1:
+		return RGB{255, 0, 0}
+	case 2:
+		return RGB{0, 255, 0}
+	case 3:
+		return RGB{255, 255, 0}
+	case 4:
+		return RGB{0, 0, 255}
+	case 5:
+		return RGB{255, 0, 255}
+	case 6:
+		return RGB{0, 255, 255}
+	case 7:
+		return RGB{191, 191, 191}
+	case 8:
+		return RGB{64, 64, 64}
+	case 9:
+		return RGB{255, 127, 127}
+	case 10:
+		return RGB{127, 255, 127}
+	case 11:
+		return RGB{255, 255, 127}
+	case 12:
+		return RGB{127, 127, 255}
+	case 13:
+		return RGB{255, 127, 255}
+	case 14:
+		return RGB{127, 255, 255}
+	case 15:
+		return RGB{127, 127, 127}
+	}
+
+	var r, g, b, ir, ig, ib uint8
+
+	ir = (c - 16) / 36
+	ig = ((c - 16) % 36) / 6
+	ib = (c - 16) % 6
+
+	if ir > 0 {
+		r = (ir * 40) + 55
+	}
+
+	if ig > 0 {
+		g = (ig * 40) + 55
+	}
+
+	if ib > 0 {
+		b = (ib * 40) + 55
+	}
+
+	return RGB{r, g, b}
+}
+
 // RGB2CMYK converts RGB color to CMYK
 func RGB2CMYK(c RGB) CMYK {
 	R, G, B := float64(c.R)/255.0, float64(c.G)/255.0, float64(c.B)/255.0

color/color_test.go

@@ -176,11 +176,31 @@ func (s *ColorSuite) TestTerm(c *C) {
 	c.Assert(RGB{0, 175, 175}.ToTerm(), Equals, 37)
 	c.Assert(RGB{255, 255, 0}.ToTerm(), Equals, 226)
 	c.Assert(RGB{135, 175, 215}.ToTerm(), Equals, 110)
-	// grayscale
 	c.Assert(RGB{175, 175, 175}.ToTerm(), Equals, 145)
 	c.Assert(RGB{18, 18, 18}.ToTerm(), Equals, 233)
 	c.Assert(RGB{48, 48, 48}.ToTerm(), Equals, 236)
 	c.Assert(RGB{238, 238, 238}.ToTerm(), Equals, 255)
+
+	c.Assert(Term2RGB(0), DeepEquals, RGB{0, 0, 0})
+	c.Assert(Term2RGB(1), DeepEquals, RGB{255, 0, 0})
+	c.Assert(Term2RGB(2), DeepEquals, RGB{0, 255, 0})
+	c.Assert(Term2RGB(3), DeepEquals, RGB{255, 255, 0})
+	c.Assert(Term2RGB(4), DeepEquals, RGB{0, 0, 255})
+	c.Assert(Term2RGB(5), DeepEquals, RGB{255, 0, 255})
+	c.Assert(Term2RGB(6), DeepEquals, RGB{0, 255, 255})
+	c.Assert(Term2RGB(7), DeepEquals, RGB{191, 191, 191})
+	c.Assert(Term2RGB(8), DeepEquals, RGB{64, 64, 64})
+	c.Assert(Term2RGB(9), DeepEquals, RGB{255, 127, 127})
+	c.Assert(Term2RGB(10), DeepEquals, RGB{127, 255, 127})
+	c.Assert(Term2RGB(11), DeepEquals, RGB{255, 255, 127})
+	c.Assert(Term2RGB(12), DeepEquals, RGB{127, 127, 255})
+	c.Assert(Term2RGB(13), DeepEquals, RGB{255, 127, 255})
+	c.Assert(Term2RGB(14), DeepEquals, RGB{127, 255, 255})
+	c.Assert(Term2RGB(15), DeepEquals, RGB{127, 127, 127})
+
+	c.Assert(Term2RGB(238), DeepEquals, RGB{68, 68, 68})
+	c.Assert(Term2RGB(153), DeepEquals, RGB{175, 215, 255})
+
 }
 
 func (s *ColorSuite) TestLuminance(c *C) {

color/examples_test.go

@@ -60,6 +60,14 @@ func ExampleRGB2Term() {
 	// Output: RGB{R:255 G:0 B:0} → \e[38;5;196m
 }
 
+func ExampleTerm2RGB() {
+	c := uint8(162)
+
+	fmt.Printf("%d → %s\n", c, Term2RGB(c))
+
+	// Output: 162 → RGB{R:215 G:0 B:135}
+}
+
 func ExampleRGB2CMYK() {
 	fmt.Printf("%s\n", RGB2CMYK(RGB{127, 25, 75}))
 

ek.go

@@ -20,7 +20,7 @@ import (
 // ////////////////////////////////////////////////////////////////////////////////// //
 
 // VERSION is current ek package version
-const VERSION = "12.91.0"
+const VERSION = "12.92.0"
 
 // ////////////////////////////////////////////////////////////////////////////////// //