text: import {
      parseParamNumber,
      pixel
  } from '../functions'
  
  /*
   * @param {Number} amount  -100..100  ,  value < 0  is darken, value > 0 is brighten 
   */
  export default function brightness (amount = 1) {
      amount = parseParamNumber(amount)    
      const $C = Math.floor(255 * (amount / 100));
  
      return pixel(() => {
          $r += $C 
          $g += $C 
          $b += $C 
      },{ $C })
  }