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| import { rgb2value, rgb2whiteness, rgb2hue } from './util';
|
| /* Convert between RGB and HSV
| /* ========================================================================== */
|
| export function rgb2hsv(rgbR, rgbG, rgbB, fallbackhue) {
| const hsvV = rgb2value(rgbR, rgbG, rgbB);
| const hsvW = rgb2whiteness(rgbR, rgbG, rgbB);
| const hsvH = rgb2hue(rgbR, rgbG, rgbB, fallbackhue);
|
| // calculate saturation
| const hsvS = hsvV === hsvW ? 0 : (hsvV - hsvW) / hsvV * 100;
|
| return [ hsvH, hsvS, hsvV ];
| }
|
| export function hsv2rgb(hsvH, hsvS, hsvV) {
| const rgbI = Math.floor(hsvH / 60);
|
| // calculate rgb parts
| const rgbF = hsvH / 60 - rgbI & 1 ? hsvH / 60 - rgbI : 1 - hsvH / 60 - rgbI;
| const rgbM = hsvV * (100 - hsvS) / 100;
| const rgbN = hsvV * (100 - hsvS * rgbF) / 100;
|
| const [ rgbR, rgbG, rgbB ] = rgbI === 5
| ? [ hsvV, rgbM, rgbN ]
| : rgbI === 4
| ? [ rgbN, rgbM, hsvV ]
| : rgbI === 3
| ? [ rgbM, rgbN, hsvV ]
| : rgbI === 2
| ? [ rgbM, hsvV, rgbN ]
| : rgbI === 1
| ? [ rgbN, hsvV, rgbM ]
| : [ hsvV, rgbN, rgbM ];
|
| return [ rgbR, rgbG, rgbB ];
| }
|
| /*
|
| References
| ----------
|
| - http://alvyray.com/Papers/CG/hsv2rgb.htm
|
| /* ========================================================================== */
|
|
