hsv.go

package coco

import "math"

func Hsv2Rgb(h float64, s float64, v float64) [3]float64 {
	h = h / 60
	s = s / 100
	v = v / 100
	hi := math.Mod(math.Floor(h), 6)
	f := h - math.Floor(h)
	p := 255 * v * (1 - s)
	q := 255 * v * (1 - (s * f))
	t := 255 * v * (1 - (s * (1 - f)))
	v *= 255

	var result [3]float64

	switch hi {
	case 0:
		result[0] = math.Round(v)
		result[1] = math.Round(t)
		result[2] = math.Round(p)
	case 1:
		result[0] = math.Round(q)
		result[1] = math.Round(v)
		result[2] = math.Round(p)
	case 2:
		result[0] = math.Round(p)
		result[1] = math.Round(v)
		result[2] = math.Round(t)
	case 3:
		result[0] = math.Round(p)
		result[1] = math.Round(q)
		result[2] = math.Round(v)
	case 4:
		result[0] = math.Round(t)
		result[1] = math.Round(p)
		result[2] = math.Round(v)
	case 5:
		result[0] = math.Round(v)
		result[1] = math.Round(p)
		result[2] = math.Round(q)
	}
	return result
}

func Hsv2Hsl(h float64, s float64, v float64) [3]float64 {
	s = s / 100
	v = v / 100
	vmin := math.Max(v, 0.01)
	var sl float64
	var l float64

	l = (2 - s) * v
	lmin := (2 - s) * vmin
	sl = s * vmin

	if lmin <= 1 {
		sl /= lmin
	} else {
		sl /= 2 - lmin
	}

	// sl = sl

	if math.IsNaN(sl) {
		sl = 0
	}

	l /= 2

	var result [3]float64
	result[0] = math.Round(h)
	result[1] = math.Round(sl * 100)
	result[2] = math.Round(l * 100)

	return result
}

func Hsv2Hcg(h float64, s float64, v float64) [3]float64 {
	s = s / 100
	v = v / 100

	c := s * v
	var g float64 = 0

	if c < 1.0 {
		g = (v - c) / (1 - c)
	}

	var result [3]float64
	result[0] = math.Round(h)
	result[1] = math.Round(c * 100)
	result[2] = math.Round(g * 100)

	return result
}