wireguard-reverse-proxy/reveal.js-master/js/utils/color.js

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JavaScript

/**
* Converts various color input formats to an {r:0,g:0,b:0} object.
*
* @param {string} color The string representation of a color
* @example
* colorToRgb('#000');
* @example
* colorToRgb('#000000');
* @example
* colorToRgb('rgb(0,0,0)');
* @example
* colorToRgb('rgba(0,0,0)');
*
* @return {{r: number, g: number, b: number, [a]: number}|null}
*/
export const colorToRgb = ( color ) => {
let hex3 = color.match( /^#([0-9a-f]{3})$/i );
if( hex3 && hex3[1] ) {
hex3 = hex3[1];
return {
r: parseInt( hex3.charAt( 0 ), 16 ) * 0x11,
g: parseInt( hex3.charAt( 1 ), 16 ) * 0x11,
b: parseInt( hex3.charAt( 2 ), 16 ) * 0x11
};
}
let hex6 = color.match( /^#([0-9a-f]{6})$/i );
if( hex6 && hex6[1] ) {
hex6 = hex6[1];
return {
r: parseInt( hex6.slice( 0, 2 ), 16 ),
g: parseInt( hex6.slice( 2, 4 ), 16 ),
b: parseInt( hex6.slice( 4, 6 ), 16 )
};
}
let rgb = color.match( /^rgb\s*\(\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)\s*\)$/i );
if( rgb ) {
return {
r: parseInt( rgb[1], 10 ),
g: parseInt( rgb[2], 10 ),
b: parseInt( rgb[3], 10 )
};
}
let rgba = color.match( /^rgba\s*\(\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)\s*\,\s*([\d]+|[\d]*.[\d]+)\s*\)$/i );
if( rgba ) {
return {
r: parseInt( rgba[1], 10 ),
g: parseInt( rgba[2], 10 ),
b: parseInt( rgba[3], 10 ),
a: parseFloat( rgba[4] )
};
}
return null;
}
/**
* Calculates brightness on a scale of 0-255.
*
* @param {string} color See colorToRgb for supported formats.
* @see {@link colorToRgb}
*/
export const colorBrightness = ( color ) => {
if( typeof color === 'string' ) color = colorToRgb( color );
if( color ) {
return ( color.r * 299 + color.g * 587 + color.b * 114 ) / 1000;
}
return null;
}