grokify/mogo

package colors

import (
    "image/color"

    "github.com/grokify/mogo/math/mathutil"
)

// GoogleChartColorsHex is the color palette for Google Charts as collected by
// Craig Davis here: https://gist.github.com/there4/2579834
var GoogleChartColorsHex = [...]string{
    "#3366CC",
    "#DC3912",
    "#FF9900",
    "#109618",
    "#990099",
    "#3B3EAC",
    "#0099C6",
    "#DD4477",
    "#66AA00",
    "#B82E2E",
    "#316395",
    "#994499",
    "#22AA99",
    "#AAAA11",
    "#6633CC",
    "#E67300",
    "#8B0707",
    "#329262",
    "#5574A6",
    "#3B3EAC",
}

func GetGoogleChartColors() []color.RGBA {
    rgbas := []color.RGBA{}
    for _, hex := range GoogleChartColorsHex {
        rgb, err := ParseHex(hex)
        if err != nil {
            panic(err)
        }
        rgbas = append(rgbas, rgb)
    }
    return rgbas
}

var GoogleChartColors = GetGoogleChartColors()

func GoogleChartColorX(index uint64) color.RGBA {
    _, remainder := mathutil.DivideInt64(int64(index),
        int64(len(GoogleChartColorsHex)))
    return GoogleChartColors[remainder]
}