coverage/pill.go

package main

import (
	"fmt"
	"math"
	"strconv"
)

const svgTemplate string = `<?xml version="1.0" encoding="UTF-8"?>
<svg xmlns="http://www.w3.org/2000/svg" width="108" height="20" version="1.1">
    <linearGradient x2="0" y2="100%">
        <stop offset="0" stop-color="#bbb" stop-opacity=".1"/>
        <stop offset="1" stop-opacity=".1"/>
    </linearGradient>
    <mask id="a">
        <rect width="108" height="20" rx="12" fill="#fff"/>
    </mask>
    <g mask="url(#a)">
        <path d="M0 0h66v20H0z" fill="{{.BaseColour}}"/>
        <path d="M66 0h44v20H66z" fill="{{.FillColour}}"/>
    </g>
    <g fill="#fff" text-anchor="middle" font-family="DejaVu Sans,Verdana,Geneva,sans-serif" font-size="11">
        <text x="34" y="14" fill="#010101" fill-opacity="0.5">coverage</text>
        <text x="34" y="13">coverage</text>
        <text x="87" y="15" fill="#010101" fill-opacity=".5">{{.Percentage}}%</text>
        <text x="87" y="14">{{.Percentage}}%</text>
    </g>
</svg>`

const (
	baseColour         = "#555"
	modifier   float64 = 0.2
	maxValue           = 220
	blue               = 55
)

type CoveragePill struct {
	Percentage string
	BaseColour string
	FillColour string
}

func percentageToRGB(percentage float64) string {
	red := modifier + clamp(2-2*math.Pow(percentage, 2), 0, 1)*(1-modifier)
	green := modifier + clamp(2*math.Pow(percentage, 2), 0, 1)*(1-modifier)

	redValue := strconv.Itoa(int(red * maxValue))
	greenValue := strconv.Itoa(int(green * maxValue))
	blueValue := strconv.Itoa(blue)

	return "rgb(" + redValue + ", " + greenValue + ", " + blueValue + ")"
}

func clamp(operation float64, min float64, max float64) float64 {
	if operation < min {
		return min
	}
	if operation > max {
		return max
	}
	return operation
}

func round(num float64) int {
	return int(num + math.Copysign(0.5, num))
}

func toOneDecimal(num float64) string {
	output := math.Pow(10, float64(5))
	return fmt.Sprintf("%.1f", float64(round(num*output))/output)
}