A mixin used to generate heading sizes. You provide min and max heading sizes and it calculates all the sizes in between. The sizes can be calculated proportionally or augmented by a ratio. Note that calculating based on a ratio requires the modular-scale extension.

_heading-sizes.sass

// Requires modular-scale

=heading-sizes($max-size: 30px, $min-size: 16px, $max-heading: 1, $min-heading: 6, $ratio: 1, $debug: false)

  $number-of-headings: $min-heading - $max-heading + 1
  $scaled-size-of-max-heading: modular-scale($number-of-headings - 1, $min-size, $ratio)
  $coefficient: 0

  @if $ratio != 1
    @if modular-scale(1, 1, octave()) != 2
      @warn "Using heading-sizes with a ratio other than 1 requires modular-scale."
    $coefficient: ($scaled-size-of-max-heading - $min-size) / ($max-size - $min-size)


  @for $i from 1 through $number-of-headings

    $heading: $number-of-headings - $i + $max-heading

    h#{$heading}

      $size: foo

      @if $ratio == 1
        $size-without-min: $max-size - $min-size
        $increment: $size-without-min / ($number-of-headings - 1)
        $current-increment: $increment * ($i - 1)
        $size: $min-size + $current-increment

      @else
        $scaled-size: modular-scale($i - 1, $min-size, $ratio)
        $difference: $scaled-size - $min-size
        $shrinked-difference: $difference / $coefficient
        $size: $min-size + $shrinked-difference

      font-size: $size

      @if $debug
        &:after
          content: "#{$size}"