/usr/share/gocode/src/github.com/alecthomas/chroma/colour.go is in golang-github-alecthomas-chroma-dev 0.4.0+git20180402.51d250f-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 | package chroma
import (
"fmt"
"math"
"strconv"
"strings"
)
// ANSI2RGB maps ANSI colour names, as supported by Chroma, to hex RGB values.
var ANSI2RGB = map[string]string{
"#ansiblack": "000000",
"#ansidarkred": "7f0000",
"#ansidarkgreen": "007f00",
"#ansibrown": "7f7fe0",
"#ansidarkblue": "00007f",
"#ansipurple": "7f007f",
"#ansiteal": "007f7f",
"#ansilightgray": "e5e5e5",
// Normal
"#ansidarkgray": "555555",
"#ansired": "ff0000",
"#ansigreen": "00ff00",
"#ansiyellow": "ffff00",
"#ansiblue": "0000ff",
"#ansifuchsia": "ff00ff",
"#ansiturquoise": "00ffff",
"#ansiwhite": "ffffff",
// Aliases without the "ansi" prefix, because...why?
"#black": "000000",
"#darkred": "7f0000",
"#darkgreen": "007f00",
"#brown": "7f7fe0",
"#darkblue": "00007f",
"#purple": "7f007f",
"#teal": "007f7f",
"#lightgray": "e5e5e5",
// Normal
"#darkgray": "555555",
"#red": "ff0000",
"#green": "00ff00",
"#yellow": "ffff00",
"#blue": "0000ff",
"#fuchsia": "ff00ff",
"#turquoise": "00ffff",
"#white": "ffffff",
}
// Colour represents an RGB colour.
type Colour int32
// NewColour creates a Colour directly from RGB values.
func NewColour(r, g, b uint8) Colour {
return ParseColour(fmt.Sprintf("%02x%02x%02x", r, g, b))
}
// Distance between this colour and another.
//
// This uses the approach described here (https://www.compuphase.com/cmetric.htm).
// This is not as accurate as LAB, et. al. but is *vastly* simpler and sufficient for our needs.
func (c Colour) Distance(e2 Colour) float64 {
rmean := int(c.Red()+e2.Red()) / 2
r := int(c.Red() - e2.Red())
g := int(c.Green() - e2.Green())
b := int(c.Blue() - e2.Blue())
return math.Sqrt(float64((((512 + rmean) * r * r) >> 8) + 4*g*g + (((767 - rmean) * b * b) >> 8)))
}
// Brighten returns a copy of this colour with its brightness adjusted.
//
// If factor is negative, the colour is darkened.
//
// Uses approach described here (http://www.pvladov.com/2012/09/make-color-lighter-or-darker.html).
func (c Colour) Brighten(factor float64) Colour {
r := float64(c.Red())
g := float64(c.Green())
b := float64(c.Blue())
if factor < 0 {
factor++
r *= factor
g *= factor
b *= factor
} else {
r = (255-r)*factor + r
g = (255-g)*factor + g
b = (255-b)*factor + b
}
return NewColour(uint8(r), uint8(g), uint8(b))
}
// Brightness of the colour (roughly) in the range 0.0 to 1.0
func (c Colour) Brightness() float64 {
return (float64(c.Red()) + float64(c.Green()) + float64(c.Blue())) / 255.0 / 3.0
}
// ParseColour in the forms #rgb, #rrggbb, #ansi<colour>, or #<colour>.
// Will return an "unset" colour if invalid.
func ParseColour(colour string) Colour {
colour = normaliseColour(colour)
n, err := strconv.ParseUint(colour, 16, 32)
if err != nil {
return 0
}
return Colour(n + 1)
}
// MustParseColour is like ParseColour except it panics if the colour is invalid.
//
// Will panic if colour is in an invalid format.
func MustParseColour(colour string) Colour {
parsed := ParseColour(colour)
if !parsed.IsSet() {
panic(fmt.Errorf("invalid colour %q", colour))
}
return parsed
}
func (c Colour) IsSet() bool { return c != 0 }
func (c Colour) String() string { return fmt.Sprintf("#%06x", int(c-1)) }
func (c Colour) GoString() string { return fmt.Sprintf("Colour(0x%06x)", int(c-1)) }
// Red component of colour.
func (c Colour) Red() uint8 { return uint8(((c - 1) >> 16) & 0xff) }
// Green component of colour.
func (c Colour) Green() uint8 { return uint8(((c - 1) >> 8) & 0xff) }
// Blue component of colour.
func (c Colour) Blue() uint8 { return uint8((c - 1) & 0xff) }
// Colours is an orderable set of colours.
type Colours []Colour
func (c Colours) Len() int { return len(c) }
func (c Colours) Swap(i, j int) { c[i], c[j] = c[j], c[i] }
func (c Colours) Less(i, j int) bool { return c[i] < c[j] }
// Convert colours to #rrggbb.
func normaliseColour(colour string) string {
if ansi, ok := ANSI2RGB[colour]; ok {
return ansi
}
if strings.HasPrefix(colour, "#") {
colour = colour[1:]
if len(colour) == 3 {
return colour[0:1] + colour[0:1] + colour[1:2] + colour[1:2] + colour[2:3] + colour[2:3]
}
}
return colour
}
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