# Noire [![GoDoc](https://godoc.org/github.com/teacat/noire?status.svg)](https://godoc.org/github.com/teacat/noire) [![Coverage Status](https://coveralls.io/repos/github/teacat/noire/badge.svg?branch=master#1)](https://coveralls.io/github/teacat/noire?branch=master) [![Build Status](https://travis-ci.com/teacat/noire.svg?branch=master#1)](https://travis-ci.com/teacat/noire) [![Go Report Card](https://goreportcard.com/badge/github.com/teacat/noire#1)](https://goreportcard.com/report/github.com/teacat/noire) A color library which supports converting between the RGB, HSL, HSV, CMYK, Hex, HTML and some additional functions (tint, saturation). Requires atleast **Go 1.10** version due to the `math.Round`(https://golang.org/pkg/math/#Round) function call. ## Supported colors Noire is able to convert the colors between: - RGB - CMYK - HSL - HSV - Hex - HTML ## Benchmark ``` Specification: 4.2 GHz Intel Core i7 (8750H) 32 GB 2666 MHz DDR4 goos: windows goarch: amd64 pkg: github.com/teacat/noire BenchmarkCMYKToRGB-12 100000000 22.5 ns/op 0 B/op 0 allocs/op BenchmarkRGBToCMYK-12 50000000 26.9 ns/op 0 B/op 0 allocs/op BenchmarkRGBToHSL-12 50000000 26.6 ns/op 0 B/op 0 allocs/op BenchmarkHSLToRGB-12 100000000 17.2 ns/op 0 B/op 0 allocs/op BenchmarkHSVToRGB-12 100000000 15.3 ns/op 0 B/op 0 allocs/op BenchmarkRGBToHSV-12 50000000 29.3 ns/op 0 B/op 0 allocs/op BenchmarkRGBToHex-12 20000000 85.4 ns/op 32 B/op 4 allocs/op BenchmarkHexToRGB-12 50000000 36.1 ns/op 8 B/op 1 allocs/op BenchmarkHTMLToRGBName-12 20000000 118 ns/op 40 B/op 3 allocs/op BenchmarkHTMLToRGBHex-12 30000000 41.0 ns/op 8 B/op 1 allocs/op BenchmarkRGBToHTML-12 20000000 103 ns/op 32 B/op 4 allocs/op BenchmarkMix-12 5000000 292 ns/op 112 B/op 5 allocs/op BenchmarkHue-12 50000000 33.5 ns/op 0 B/op 0 allocs/op BenchmarkSaturation-12 50000000 33.7 ns/op 0 B/op 0 allocs/op BenchmarkLightness-12 50000000 33.7 ns/op 0 B/op 0 allocs/op BenchmarkAdjustHue-12 20000000 79.0 ns/op 32 B/op 1 allocs/op BenchmarkLighten-12 20000000 78.2 ns/op 32 B/op 1 allocs/op BenchmarkDarken-12 20000000 77.8 ns/op 32 B/op 1 allocs/op BenchmarkSaturate-12 20000000 74.1 ns/op 32 B/op 1 allocs/op BenchmarkDesaturate-12 20000000 79.0 ns/op 32 B/op 1 allocs/op BenchmarkGrayscale-12 20000000 71.8 ns/op 32 B/op 1 allocs/op BenchmarkComplement-12 20000000 79.9 ns/op 32 B/op 1 allocs/op BenchmarkTint-12 30000000 40.8 ns/op 32 B/op 1 allocs/op BenchmarkShade-12 30000000 40.9 ns/op 32 B/op 1 allocs/op BenchmarkInvert-12 50000000 24.9 ns/op 32 B/op 1 allocs/op BenchmarkLuminanaceWCAG-12 10000000 224 ns/op 0 B/op 0 allocs/op BenchmarkLuminanace-12 300000000 6.00 ns/op 0 B/op 0 allocs/op BenchmarkContrast-12 5000000 257 ns/op 0 B/op 0 allocs/op BenchmarkIsLight-12 2000000000 0.26 ns/op 0 B/op 0 allocs/op BenchmarkIsDark-12 2000000000 0.26 ns/op 0 B/op 0 allocs/op BenchmarkHSV-12 50000000 34.2 ns/op 0 B/op 0 allocs/op BenchmarkHSVA-12 50000000 35.0 ns/op 0 B/op 0 allocs/op BenchmarkHSL-12 50000000 31.9 ns/op 0 B/op 0 allocs/op BenchmarkHSLA-12 50000000 32.0 ns/op 0 B/op 0 allocs/op BenchmarkRGB-12 2000000000 0.52 ns/op 0 B/op 0 allocs/op BenchmarkRGBA-12 2000000000 0.26 ns/op 0 B/op 0 allocs/op BenchmarkCMYK-12 50000000 32.9 ns/op 0 B/op 0 allocs/op BenchmarkHex-12 20000000 90.1 ns/op 32 B/op 4 allocs/op BenchmarkHTMLHex-12 10000000 146 ns/op 40 B/op 5 allocs/op BenchmarkHTMLName-12 20000000 107 ns/op 32 B/op 4 allocs/op BenchmarkHTMLRGBA-12 2000000 839 ns/op 96 B/op 5 allocs/op PASS ok github.com/teacat/noire 67.640s Success: Benchmarks passed. ``` ## Installation To install Noire by simply typing `go get` in the terminal. ```bash $ go get github.com/teacat/noire ``` ## Usage Initialize a new color with `noire.NewRGB` (or `NewHex`) to modify the color with `Lighten` or `Tint`, etc. ```go package main import ( "fmt" "github.com/teacat/noire" ) func main() { c := noire.NewRGB(255, 255, 255) fmt.Println(c.Invert().Hex()) // Output: 000000 fmt.Println(c.Invert().HTML()) // Output: Black fmt.Println(c.Lighten(1).RGB()) // Output: 255, 255, 255 } ``` ## Description There are few functions results cannot be visualized, so make sure to check the [GoDoc](https://godoc.org/github.com/teacat/noire) to see how they work. - `Hue`: Get the Hue angle of the current color based on the HSL algorithm. - `Saturation`: Get the Saturation of the current color based on the HSL algorithm. - `Lightness`： Get the Lightness of the current color based on the HSL algorithm. - `LuminanaceWCAG`：Get the Luminance of the current color based on the WCAG 2.0 algorithm. - `Luminanace`: Get the Luminance of the current color. - `Contrast`: Get the Contrast of the current color based on the WCAG Luminance algorithm. - `IsLight`: Returns true if the color is a light scheme, it might not be the same as what human eyes can see. - `IsDark`: Returns true if the color is a dark scheme, it might not be the same as what human eyes can see. ### Lighten ![Result preview](./assets/lighten.png) Lighten a color based on HSL mode, it might makes the color a bit way too bright or washed out. ```go func main() { c := NewRGB(219, 112, 148) fmt.Println(c.Lighten(0.15).Hex()) // Output: EAADC2 } ``` ### Brighten ![Result preview](./assets/brighten.png) Increases the brightness of the color based on RGB mode. ```go func main() { c := NewRGB(0, 0, 0) fmt.Println(c.Brighten(0.1).Hex()) // Output: 1A1A1A } ``` ### Tint ![Result preview](./assets/tint.png) Mixing with a white color as base to get the best balance to increase the brightness of a color. ```go func main() { c := NewRGB(0, 0, 0) fmt.Println(c.Tint(0.1).Hex()) // Output: 1A1A1A } ``` ### Darken ![Result preview](./assets/darken.png) Darken a color based on HSL mode, it might makes the color a bit way too dark or dimmed. ```go func main() { c := NewRGB(219, 112, 148) fmt.Println(c.Darken(0.15).Hex()) // Output: CB3366 } ``` ### Shade ![Result preview](./assets/shade.png) Mixing with a black color as base to get the best balance to increase the brightness of a color. ```go func main() { c := NewRGB(219, 112, 148) fmt.Println(c.Shade(0.15).Hex()) // Output: BA5F7E } ``` ### Saturate ![Result preview](./assets/saturate.png) Increases the saturation of the color based on HSL mode. ```go func main() { c := NewRGB(219, 112, 148) fmt.Println(c.Saturate(0.5).Hex()) // Output: FF4C88 } ``` ### Desaturate ![Result preview](./assets/desaturate.png) Decreases the saturation of the color based on HSL mode. ```go func main() { c := NewRGB(219, 112, 148) fmt.Println(c.Desaturate(0.15).Hex()) // Output: AE9DA3 } ``` ### AdjustHue ![Result preview](./assets/adjust-hue.png) Rotates the Hue angle of the color based on HSL mode, it still goes clockwise if the value was set over than 360 degree. ```go func main() { c := NewRGB(219, 112, 148) fmt.Println(c.AdjustHue(30).Hex()) // Output: DB8270 } ``` ### Mix ![Result preview](./assets/mix.png) Mixing two colors with a value that specified the weight of the second color. ```go func main() { c1 := NewHex("F00") c2 := NewHex("00F") fmt.Println(c1.Mix(c2, 0.5).HTML()) // Output: Purple } ``` ### Invert ![Result preview](./assets/invert.png) Get the opposite color that based on the RGB color map (it's not a complementary color). ```go func main() { c := NewRGB(219, 112, 148) fmt.Println(c.Invert().Hex()) // Output: 248F6B } ``` ### Complement ![Result preview](./assets/complement.png) Get the complementary color of the current color, same as `AdjustHue(180)`. ```go func main() { c := NewRGB(219, 112, 148) fmt.Println(c.Complement().Hex()) // Output: 70DBB7 } ``` ### Grayscale ![Result preview](./assets/grayscale.png) Converts the color to grayscale, same as `Desaturate(1)`. ```go func main() { c := NewRGB(219, 112, 148) fmt.Println(c.Grayscale().Hex()) // Output: A5A5A5 } ``` ### Foreground ![Result preview](./assets/foreground.png) Get the suggested foreground color by calculating the color luminance, it returns a white color when the color is dark, vise versa. ```go func main() { c := NewHTML("Green") fmt.Println(c.Foreground().HTML()) // Output: White c = NewHTML("Red") fmt.Println(c.Foreground().HTML()) // Output: White c = NewHTML("Yellow") fmt.Println(c.Foreground().HTML()) // Output: Black } ``` ## References [RGB 轉 HSV, HSL (線上色碼轉換 HSL, HSV, RGB, HEX)](https://www.ginifab.com.tw/tools/colors/rgb_to_hsv_hsl.html) [ozdemirburak/iris: PHP library for color manipulation and conversion.](https://github.com/ozdemirburak/iris) [G17: Ensuring that a contrast ratio of at least 7:1 exists between text (and images of text) and background behind the text | Techniques for WCAG 2.0](https://www.w3.org/TR/WCAG20-TECHS/G17.html#G17-tests) [Using Sass to automatically pick text colors](https://medium.com/dev-channel/using-sass-to-automatically-pick-text-colors-4ba7645d2796) [Relative luminance - Wikipedia](https://en.wikipedia.org/wiki/Relative_luminance) [user interface - Given a background color, how to get a foreground color that makes it readable on that background color? - Stack Overflow](https://stackoverflow.com/questions/3116260/given-a-background-color-how-to-get-a-foreground-color-that-makes-it-readable-o) [image - Formula to determine brightness of RGB color - Stack Overflow](https://stackoverflow.com/questions/596216/formula-to-determine-brightness-of-rgb-color) [Ant Design 色板生成算法演进之路 - 知乎](https://zhuanlan.zhihu.com/p/32422584) [Sass 基础——颜色函数\_Preprocessor, Sass, SCSS 教程\_w3cplus](https://www.w3cplus.com/preprocessor/sass-color-function.html)