zigbee-shepherd-converters/converters/utils.js

Collection of device converters to be used with zigbee-shepherd

'use strict';
/**
 * From: https://github.com/usolved/cie-rgb-converter/blob/master/cie_rgb_converter.js
 * Converts RGB color space to CIE color space
 * @param {Number} red
 * @param {Number} green
 * @param {Number} blue
 * @return {Array} Array that contains the CIE color values for x and y
 */
function rgbToXY(red, green, blue) {
    // The RGB values should be between 0 and 1. So convert them.
    // The RGB color (255, 0, 100) becomes (1.0, 0.0, 0.39)
    red /= 255; green /= 255; blue /= 255;

    // Apply a gamma correction to the RGB values, which makes the color
    // more vivid and more the like the color displayed on the screen of your device
    red = (red > 0.04045) ? Math.pow((red + 0.055) / (1.0 + 0.055), 2.4) : (red / 12.92);
    green = (green > 0.04045) ? Math.pow((green + 0.055) / (1.0 + 0.055), 2.4) : (green / 12.92);
    blue = (blue > 0.04045) ? Math.pow((blue + 0.055) / (1.0 + 0.055), 2.4) : (blue / 12.92);

    // RGB values to XYZ using the Wide RGB D65 conversion formula
    const X = red * 0.664511 + green * 0.154324 + blue * 0.162028;
    const Y = red * 0.283881 + green * 0.668433 + blue * 0.047685;
    const Z = red * 0.000088 + green * 0.072310 + blue * 0.986039;

    // Calculate the xy values from the XYZ values
    let x = (X / (X + Y + Z)).toFixed(4);
    let y = (Y / (X + Y + Z)).toFixed(4);

    if (isNaN(x)) {
        x = 0;
    }

    if (isNaN(y)) {
        y = 0;
    }

    return {x: Number.parseFloat(x), y: Number.parseFloat(y)};
}

function hexToXY(hex) {
    const rgb = hexToRgb(hex);
    return rgbToXY(rgb.r, rgb.g, rgb.b);
}

function hexToRgb(hex) {
    hex = hex.replace('#', '');
    const bigint = parseInt(hex, 16);
    const r = (bigint >> 16) & 255;
    const g = (bigint >> 8) & 255;
    const b = bigint & 255;

    return {r: r, g: g, b: b};
}

function getKeyByValue(object, value, fallback) {
    const key = Object.keys(object).find((k) => object[k] === value);
    return key != null ? Number(key) : (fallback || 0);
}

module.exports = {
    rgbToXY: rgbToXY,
    hexToXY: hexToXY,
    hexToRgb: hexToRgb,
    getKeyByValue: getKeyByValue,
};