Convert Darker to Lighter or Vice versa

Advertisement

Function Code: Function Code:

/* Helper function */
var pad = function(num, totalChars) {
    var pad = '0';
    num = num + '';
    while (num.length < totalChars) {
        num = pad + num;
    }
    return num;
};

// Ratio is between 0 and 1
var changeColor = function(color, ratio, darker) {
    // Trim trailing/leading whitespace
    color = color.replace(/^s*|s*$/, '');

    // Expand three-digit hex
    color = color.replace(
        /^#?([a-f0-9])([a-f0-9])([a-f0-9])$/i,
        '#$1$1$2$2$3$3'
    );

    // Calculate ratio
    var difference = Math.round(ratio * 256) * (darker ? -1 : 1),
        // Determine if input is RGB(A)
        rgb = color.match(new RegExp('^rgba?\(\s*' +
            '(\d|[1-9]\d|1\d{2}|2[0-4][0-9]|25[0-5])' +
            '\s*,\s*' +
            '(\d|[1-9]\d|1\d{2}|2[0-4][0-9]|25[0-5])' +
            '\s*,\s*' +
            '(\d|[1-9]\d|1\d{2}|2[0-4][0-9]|25[0-5])' +
            '(?:\s*,\s*' +
            '(0|1|0?\.\d+))?' +
            '\s*\)



Top ↑

How to use? How to use?

/*--------------------------------------------------------*/
var hex     = '#ffa039';
var rgb     = 'rgb(255, 153, 0)';
var rgba    = 'rgba(255, 153, 0, 0.3)';


//  Convert colors
//      Here .2 is ratio
var hex_light   = lighterColor( hex , .2);
var hex_dark    = darkerColor( hex , .2);

var rgb_light   = lighterColor( rgb , .2);
var rgb_dark    = darkerColor( rgb , .2);

var rgba_light  = lighterColor( rgba , .2);
var rgba_dark   = darkerColor( rgba , .2);

How to use?

Refer: http://jsfiddle.net/maheshwaghmare/25tsu1r5/3/

How ratio works?

Refer: http://jsfiddle.net/maheshwaghmare/85bqkwep/

, 'i')),
alpha = !!rgb && rgb[4] != null ? rgb[4] : null,

// Convert hex to decimal
decimal = !!rgb? [rgb[1], rgb[2], rgb[3]] : color.replace(
/^#?([a-f0-9][a-f0-9])([a-f0-9][a-f0-9])([a-f0-9][a-f0-9])/i,
function() {
return parseInt(arguments[1], 16) + ',' +
parseInt(arguments[2], 16) + ',' +
parseInt(arguments[3], 16);
}
).split(/,/),
returnValue;

// Return RGB(A)
return !!rgb ?
'rgb' + (alpha !== null ? 'a' : '') + '(' +
Math[darker ? 'max' : 'min'](
parseInt(decimal[0], 10) + difference, darker ? 0 : 255
) + ', ' +
Math[darker ? 'max' : 'min'](
parseInt(decimal[1], 10) + difference, darker ? 0 : 255
) + ', ' +
Math[darker ? 'max' : 'min'](
parseInt(decimal[2], 10) + difference, darker ? 0 : 255
) +
(alpha !== null ? ', ' + alpha : '') +
')' :
// Return hex
[
'#',
pad(Math[darker ? 'max' : 'min'](
parseInt(decimal[0], 10) + difference, darker ? 0 : 255
).toString(16), 2),
pad(Math[darker ? 'max' : 'min'](
parseInt(decimal[1], 10) + difference, darker ? 0 : 255
).toString(16), 2),
pad(Math[darker ? 'max' : 'min'](
parseInt(decimal[2], 10) + difference, darker ? 0 : 255
).toString(16), 2)
].join('');
};
var lighterColor = function(color, ratio) {
return changeColor(color, ratio, false);
};
var darkerColor = function(color, ratio) {
return changeColor(color, ratio, true);
};

Top ↑

How to use? How to use?


How to use?

Refer: http://jsfiddle.net/maheshwaghmare/25tsu1r5/3/

How ratio works?

Refer: http://jsfiddle.net/maheshwaghmare/85bqkwep/