Describir: Lighting calculations

  _  _     _____    _    _     _____      _____    _____                ___    
 | \| ||  |  ___|| | || | ||  |  ___||   / ___//  |  ___||   ____      / _ \\  
 |  ' ||  | ||__   | || | ||  | ||__     \___ \\  | ||__    |    \\   | / \ || 
 | .  ||  | ||__   | \\_/ ||  | ||__     /    //  | ||__    | [] ||   | \_/ || 
 |_|\_||  |_____||  \____//   |_____||  /____//   |_____||  |  __//    \___//  
 `-` -`   `-----`    `---`    `-----`  `-----`    `-----`   |_|`-`     `---`   
                                                            `-`