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/*
Copyright (C) 2019 Leo Tenenbaum
This file is part of AutoArt.
AutoArt is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
AutoArt is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with AutoArt. If not, see <https://www.gnu.org/licenses/>.
*/
package autoutils
import (
"math"
)
func HSVToRGB(h uint8, s uint8, v uint8) (uint8, uint8, uint8) {
// https://en.wikipedia.org/wiki/HSL_and_HSV#HSV_to_RGB
V := float64(v) / 256
S := float64(s) / 256
C := V * S
H := float64(h) / (256/6)
X := float64(C) * (1 - math.Abs(math.Mod(H, 2) - 1))
var r, g, b float64
switch true {
case s == 0:
r, g, b = 0, 0, 0
case H <= 1:
r, g, b = C, X, 0
case H <= 2:
r, g, b = X, C, 0
case H <= 3:
r, g, b = 0, C, X
case H <= 4:
r, g, b = 0, X, C
case H <= 5:
r, g, b = X, 0, C
default:
r, g, b = C, 0, X
}
m := V - C
r += m
g += m
b += m
r *= 255
g *= 255
b *= 255
return uint8(r), uint8(g), uint8(b)
}
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