website/assets/sass/bourbon/functions/_modular-scale.scss

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2015-08-30 12:34:43 -04:00
// Scaling Variables
$golden: 1.618;
$minor-second: 1.067;
$major-second: 1.125;
$minor-third: 1.2;
$major-third: 1.25;
$perfect-fourth: 1.333;
$augmented-fourth: 1.414;
$perfect-fifth: 1.5;
$minor-sixth: 1.6;
$major-sixth: 1.667;
$minor-seventh: 1.778;
$major-seventh: 1.875;
$octave: 2;
$major-tenth: 2.5;
$major-eleventh: 2.667;
$major-twelfth: 3;
$double-octave: 4;
$modular-scale-ratio: $perfect-fourth !default;
$modular-scale-base: em($em-base) !default;
@function modular-scale($increment, $value: $modular-scale-base, $ratio: $modular-scale-ratio) {
$v1: nth($value, 1);
$v2: nth($value, length($value));
$value: $v1;
// scale $v2 to just above $v1
@while $v2 > $v1 {
$v2: ($v2 / $ratio); // will be off-by-1
}
@while $v2 < $v1 {
$v2: ($v2 * $ratio); // will fix off-by-1
}
// check AFTER scaling $v2 to prevent double-counting corner-case
$double-stranded: $v2 > $v1;
@if $increment > 0 {
@for $i from 1 through $increment {
@if $double-stranded and ($v1 * $ratio) > $v2 {
$value: $v2;
$v2: ($v2 * $ratio);
} @else {
$v1: ($v1 * $ratio);
$value: $v1;
}
}
}
@if $increment < 0 {
// adjust $v2 to just below $v1
@if $double-stranded {
$v2: ($v2 / $ratio);
}
@for $i from $increment through -1 {
@if $double-stranded and ($v1 / $ratio) < $v2 {
$value: $v2;
$v2: ($v2 / $ratio);
} @else {
$v1: ($v1 / $ratio);
$value: $v1;
}
}
}
@return $value;
}