SCSS: Angled Mask

mixin-angled-mask.scss

/*********************
ANGLED MASKS
*********************/

@mixin angled-mask($pseudo, $flip: false, $angle: 1.5deg) {
  // Possible values for $pseudo are: before, after, both
  @if $pseudo == 'before' or $pseudo == 'after' or $pseudo == 'both' {
    position: relative;
    z-index: 1;
    $selector: if($pseudo == 'both', '&:before,&:after', '&:#{$pseudo}');

    #{$selector} {
      background: inherit;
      content: '';
      display: block;
      height: 50%;
      left: 0;
      position: absolute;
      right: 0;
      z-index: -1;
      -webkit-backface-visibility: hidden; // for Chrome Windows
    }

    @if $pseudo == 'before' {
      #{$selector} {
        top: 0;

        @if $flip {
          transform: skewY($angle * -1);
          transform-origin: 0 0;
        } @else {
          transform: skewY($angle);
          transform-origin: 100% 0;
        }
      }
    }

    @if $pseudo == 'after' {
      #{$selector} {
        bottom: 0;

        @if $flip {
          transform: skewY($angle);
          transform-origin: 0 100%;
        } @else {
          transform: skewY($angle * -1);
          transform-origin: 100%;
        }
      }
    }

    @if $pseudo == 'both' {
      &:before {
        top: 0;

        @if $flip {
          transform: skewY($angle * -1);
          transform-origin: 0 0;
        } @else {
          transform: skewY($angle);
          transform-origin: 100% 0;
        }
      }

      &:after {
        bottom: 0;

        @if $flip {
          transform: skewY($angle);
          transform-origin: 0 0;
        } @else {
          transform: skewY($angle * -1);
          transform-origin: 100%;
        }
      }
    }
  }
}

// Styles
.edge--bottom {
  @include angle(after);
}

.edge--bottom--reverse {
  @include angle(after, true);
}

.edge--top {
  @include angle(before);
}

.edge--top--reverse {
  @include angle(before, true);
}

.edge--both {
  @include angle(both);
}

.edge--both--reverse {
  @include angle(both, true);
}