Sass convert length units

_convert-units.scss

/*
# Convert Units (function)

TODO: Description

*/
// ---------------------------------------

@function convert-units ( $length, $as: rem, $root: 16, $ppi: 96 ) {
  $unit: unit($length);
  $value: strip-units($length);
  $ratio: $value;
  $result: $length;
  
  // convert length in
  @if $unit == "px" {
    // $value: $value;
    $ratio: $value / $root;
  }
  @else if $unit == "em"
    or $unit == "rem"
    or $unit == "" {
    // $ratio: $ratio;
    $value: $ratio * $root;
  }
  @else if $unit == "%" {
    $ratio: $ratio / 10;
    $value: $ratio * $root;
  }
  @else if $unit == "pt" {
    $value: ($value * $ppi) / 72;
    $ratio: $value / $root;
  }
  @else if $unit == "pc" {
    $value: (($value * 12) * $ppi) / 72;
    $ratio: $value / $root;
  
  // convert length out
  @if $as == "%" {
    $result: percentage($ratio);
  }
  @else if $as == "/" {
    $result: $ratio;
  }
  @else if $as == "px" {
    $result: $value * 1px;
  }
  @else if $as == "em" {
    $result: $ratio * 1em;
  }
  @else if $as == "rem" {
    $result: $ratio * 1rem;
  }
  @else if $as == "pt" {
    $result: ($value * 72) / $ppi;
  }
  @else if $as == "pc" {
    $result: (($value * 72) / $ppi) / 12;
  }
  
  @return $result;
}

// ---------------------------------------