@mixin resize-sprite

@mixin resize-sprite($map, $sprite, $percent) {
  $spritePath: 'generated/' + sprite-path($map);
  $spriteWidth: image-width($spritePath);
  $spriteHeight: image-height($spritePath);
  $width: image-width(sprite-file($map, $sprite));
  $height: image-height(sprite-file($map, $sprite));

  @include background-size(ceil($spriteWidth * ($percent/100)) ceil($spriteHeight * ($percent/100)));
  background-image: image_url($spritePath);
  width: ceil($width*($percent/100));
  height: ceil($height*($percent/100));
  background-position: 0 floor(nth(sprite-position($map, $sprite), 2)  * ($percent/100));
}