colorgrad

package module
v0.10.0 Latest Latest
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 Go to latest Published: Aug 15, 2024 License: Apache-2.0, MIT Imports: 8 Imported by: 39

README

colorgrad

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Go (Golang) color scales library for data visualization, charts, games, maps, generative art and others.

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Index

import "github.com/mazznoer/colorgrad"

Custom Gradient

Basic
grad, err := colorgrad.NewGradient().Build()

img

Custom Colors
grad, err := colorgrad.NewGradient().
    Colors(
        colorgrad.Rgb8(0, 206, 209, 255),
        colorgrad.Rgb8(255, 105, 180, 255),
        colorgrad.Rgb(0.274, 0.5, 0.7, 1),
        colorgrad.Hsv(50, 1, 1, 1),
        colorgrad.Hsv(348, 0.9, 0.8, 1),
    ).
    Build()

img

Using Web Color Format

HtmlColors() method accepts named colors, hexadecimal (#rgb, #rgba, #rrggbb, #rrggbbaa), rgb(), rgba(), hsl(), hsla(), hwb(), and hsv().

grad, err := colorgrad.NewGradient().
    HtmlColors("#C41189", "#00BFFF", "#FFD700").
    Build()

img

grad, err := colorgrad.NewGradient().
    HtmlColors("gold", "hotpink", "darkturquoise").
    Build()

img

grad, err := colorgrad.NewGradient().
    HtmlColors(
        "rgb(125,110,221)",
        "rgb(90%,45%,97%)",
        "hsl(229,79%,85%)",
    ).
    Build()

img

Domain & Color Position

Default domain is [0..1].

grad, err := colorgrad.NewGradient().
    HtmlColors("deeppink", "gold", "seagreen").
    Build()

img

Set the domain to [0..100].

grad, err := colorgrad.NewGradient().
    HtmlColors("deeppink", "gold", "seagreen").
    Domain(0, 100).
    Build()

img

Set the domain to [-1..1].

grad, err := colorgrad.NewGradient().
    HtmlColors("deeppink", "gold", "seagreen").
    Domain(-1, 1).
    Build()

img

Set exact position for each color. The domain is [0..1].

grad, err := colorgrad.NewGradient().
    HtmlColors("deeppink", "gold", "seagreen").
    Domain(0, 0.7, 1).
    Build()

img

Set exact position for each color. The domain is [15..80].

grad, err := colorgrad.NewGradient().
    HtmlColors("deeppink", "gold", "seagreen").
    Domain(15, 30, 80).
    Build()

img

Blending Mode
grad, err := colorgrad.NewGradient().
    HtmlColors("#FFF", "#00F").
    Mode(colorgrad.BlendRgb).
    Build()

blend-modes

Interpolation Mode
grad, err := colorgrad.NewGradient().
    HtmlColors("#C41189", "#00BFFF", "#FFD700").
    Interpolation(colorgrad.InterpolationLinear).
    Build()

InterpolationLinear interpolation-linear

InterpolationCatmullRom interpolation-catmull-rom

InterpolationBasis interpolation-basis

Preset Gradients

See PRESET.md

Parsing GIMP Gradient

import "os"

foreground := colorgrad.Rgb(0, 0, 0, 1)
background := colorgrad.Rgb(1, 1, 1, 1)
file, err := os.Open("Abstract_1.ggr")

if err != nil {
	panic(err)
}

defer file.Close()
grad, name, err2 := colorgrad.ParseGgr(file, foreground, background)
fmt.Println(name) // Abstract 1

gimp-gradient

Using the Gradient

Get the domain
grad := colorgrad.Rainbow()

fmt.Println(grad.Domain()) // 0 1
Get single color at certain position
grad := colorgrad.Rainbow()

fmt.Println(grad.At(0.0).HexString()) // #6e40aa
fmt.Println(grad.At(0.5).HexString()) // #aff05b
fmt.Println(grad.At(1.0).HexString()) // #6e40aa
Get n colors evenly spaced across gradient
grad := colorgrad.Rainbow()

for _, c := range grad.Colors(10) {
    fmt.Println(c.HexString())
}

Output:

#6e40aa
#c83dac
#ff5375
#ff8c38
#c9d33a
#7cf659
#5dea8d
#48b8d0
#4775de
#6e40aa
Hard-Edged Gradient

Convert gradient to hard-edged gradient with 11 segments and 0 smoothness.

grad := colorgrad.Rainbow().Sharp(11, 0)

img

This is the effect of different smoothness.

img

Examples

Gradient Image
package main

import (
    "image"
    "image/png"
    "os"

    "github.com/mazznoer/colorgrad"
)

func main() {
    grad, _ := colorgrad.NewGradient().
        HtmlColors("#C41189", "#00BFFF", "#FFD700").
        Build()

    w := 1500
    h := 70
    fw := float64(w)

    img := image.NewRGBA(image.Rect(0, 0, w, h))

    for x := 0; x < w; x++ {
        col := grad.At(float64(x) / fw)
        for y := 0; y < h; y++ {
            img.Set(x, y, col)
        }
    }

    file, err := os.Create("gradient.png")
    if err != nil {
        panic(err.Error())
    }
    defer file.Close()
    png.Encode(file, img)
}

Example output:

img

Colored Noise
package main

import (
    "image"
    "image/png"
    "os"

    "github.com/mazznoer/colorgrad"
    "github.com/ojrac/opensimplex-go"
)

func main() {
    w := 600
    h := 350
    scale := 0.02

    grad := colorgrad.Rainbow().Sharp(7, 0.2)
    noise := opensimplex.NewNormalized(996)
    img := image.NewRGBA(image.Rect(0, 0, w, h))

    for y := 0; y < h; y++ {
        for x := 0; x < w; x++ {
            t := noise.Eval2(float64(x)*scale, float64(y)*scale)
            img.Set(x, y, grad.At(t))
        }
    }

    file, err := os.Create("noise.png")
    if err != nil {
        panic(err.Error())
    }
    defer file.Close()
    png.Encode(file, img)
}

Example output:

noise

Playground

Dependencies

Inspirations

Documentation

Overview

Example (CustomGradient) 
package main

import (
	"fmt"

	"github.com/mazznoer/colorgrad"
)

func main() {
	grad, err := colorgrad.NewGradient().
		HtmlColors("red", "#FFD700", "lime").
		Domain(0, 0.35, 1).
		Mode(colorgrad.BlendOklab).
		Build()

	if err != nil {
		panic(err)
	}

	fmt.Println(grad.At(0).HexString())
	fmt.Println(grad.At(1).HexString())
}

Output:

#ff0000
#00ff00
Example (PresetGradient) 
package main

import (
	"fmt"

	"github.com/mazznoer/colorgrad"
)

func main() {
	grad := colorgrad.Rainbow()
	dmin, dmax := grad.Domain()

	fmt.Println(dmin, dmax)
	fmt.Println(grad.At(0).HexString())
}

Output:

0 1
#6e40aa

Index

Examples

Constants

This section is empty.

Variables

View Source 
var Hsl = csscolorparser.FromHsl
View Source 
var Hsv = csscolorparser.FromHsv
View Source 
var Hwb = csscolorparser.FromHwb
View Source 
var LinearRgb = csscolorparser.FromLinearRGB
View Source 
var Oklab = csscolorparser.FromOklab
View Source 
var Oklch = csscolorparser.FromOklch

Functions

This section is empty.

Types

type BlendMode 

type BlendMode int
const (
	BlendRgb BlendMode = iota
	BlendLinearRgb
	BlendOklab
)

func (BlendMode) String added in v0.9.1 

func (b BlendMode) String() string

type Color added in v0.10.0 

type Color = csscolorparser.Color

func GoColor added in v0.10.0 

func GoColor(col color.Color) Color

func Rgb added in v0.10.0 

func Rgb(r, g, b, a float64) Color

func Rgb8 added in v0.10.0 

func Rgb8(r, g, b, a uint8) Color

type Gradient 

type Gradient struct {
	// contains filtered or unexported fields
}

func Blues 

func Blues() Gradient

func BrBG added in v0.3.0 

func BrBG() Gradient

func BuGn added in v0.7.0 

func BuGn() Gradient

func BuPu added in v0.7.0 

func BuPu() Gradient

func Cividis 

func Cividis() Gradient

func Cool 

func Cool() Gradient

func CubehelixDefault added in v0.2.0 

func CubehelixDefault() Gradient

func GnBu added in v0.7.0 

func GnBu() Gradient

func Greens 

func Greens() Gradient

func Greys 

func Greys() Gradient

func Inferno 

func Inferno() Gradient

func Magma 

func Magma() Gradient

func OrRd added in v0.7.0 

func OrRd() Gradient

func Oranges 

func Oranges() Gradient

func PRGn added in v0.3.0 

func PRGn() Gradient

func ParseGgr added in v0.9.0 

func ParseGgr(r io.Reader, fg, bg Color) (Gradient, string, error)

func PiYG added in v0.3.0 

func PiYG() Gradient

func Plasma 

func Plasma() Gradient

func PuBu added in v0.7.0 

func PuBu() Gradient

func PuBuGn added in v0.7.0 

func PuBuGn() Gradient

func PuOr added in v0.3.0 

func PuOr() Gradient

func PuRd added in v0.7.0 

func PuRd() Gradient

func Purples 

func Purples() Gradient

func Rainbow 

func Rainbow() Gradient

func RdBu added in v0.3.0 

func RdBu() Gradient

func RdGy added in v0.3.0 

func RdGy() Gradient

func RdPu added in v0.7.0 

func RdPu() Gradient

func RdYlBu added in v0.3.0 

func RdYlBu() Gradient

func RdYlGn added in v0.3.0 

func RdYlGn() Gradient

func Reds 

func Reds() Gradient

func Sinebow 

func Sinebow() Gradient

func Spectral 

func Spectral() Gradient

func Turbo 

func Turbo() Gradient

func Viridis 

func Viridis() Gradient

func Warm 

func Warm() Gradient

func YlGn added in v0.7.0 

func YlGn() Gradient

func YlGnBu added in v0.7.0 

func YlGnBu() Gradient

func YlOrBr added in v0.7.0 

func YlOrBr() Gradient

func YlOrRd added in v0.7.0 

func YlOrRd() Gradient

func (Gradient) At 

func (g Gradient) At(t float64) Color

Get color at certain position

func (Gradient) Colors 

func (g Gradient) Colors(count uint) []Color

Get n colors evenly spaced across gradient

func (Gradient) Domain added in v0.5.0 

func (g Gradient) Domain() (float64, float64)

Get the gradient domain min and max

func (Gradient) ReflectAt added in v0.9.0 

func (g Gradient) ReflectAt(t float64) Color

Get color at certain position

func (Gradient) RepeatAt added in v0.9.0 

func (g Gradient) RepeatAt(t float64) Color

Get color at certain position

func (Gradient) Sharp added in v0.5.0 

func (g Gradient) Sharp(segment uint, smoothness float64) Gradient

Return a new hard-edge gradient

type GradientBuilder 

type GradientBuilder struct {
	// contains filtered or unexported fields
}

func NewGradient 

func NewGradient() *GradientBuilder

func (*GradientBuilder) Build 

func (gb *GradientBuilder) Build() (Gradient, error)

func (*GradientBuilder) Colors 

func (gb *GradientBuilder) Colors(colors ...Color) *GradientBuilder

func (*GradientBuilder) Domain 

func (gb *GradientBuilder) Domain(positions ...float64) *GradientBuilder

func (*GradientBuilder) GetColors added in v0.10.0 

func (gb *GradientBuilder) GetColors() *[]Color

For testing purposes

func (*GradientBuilder) GetPositions added in v0.10.0 

func (gb *GradientBuilder) GetPositions() *[]float64

For testing purposes

func (*GradientBuilder) HtmlColors added in v0.4.0 

func (gb *GradientBuilder) HtmlColors(htmlColors ...string) *GradientBuilder

func (*GradientBuilder) Interpolation added in v0.9.0 

func (gb *GradientBuilder) Interpolation(mode Interpolation) *GradientBuilder

func (*GradientBuilder) Mode 

func (gb *GradientBuilder) Mode(mode BlendMode) *GradientBuilder

type Interpolation added in v0.9.0 

type Interpolation int
const (
	InterpolationLinear Interpolation = iota
	InterpolationCatmullRom
	InterpolationBasis
)

func (Interpolation) String added in v0.9.1 

func (i Interpolation) String() string

Source Files

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