blame: source/misc/embedded_libs/fmt-8.1.1/doc/bootstrap/mixins/image.less

// Image Mixins

// - Responsive image

// - Retina image

// Responsive image

//

// Keep images from scaling beyond the width of their parents.

.img-responsive(@display: block) {

  display: @display;

  max-width: 100%; // Part 1: Set a maximum relative to the parent

  height: auto; // Part 2: Scale the height according to the width, otherwise you get stretching

}

// Retina image

//

// Short retina mixin for setting background-image and -size. Note that the

// spelling of `min--moz-device-pixel-ratio` is intentional.

.img-retina(@file-1x; @file-2x; @width-1x; @height-1x) {

  background-image: url("@{file-1x}");

  @media

  only screen and (-webkit-min-device-pixel-ratio: 2),

  only screen and (   min--moz-device-pixel-ratio: 2),

  only screen and (     -o-min-device-pixel-ratio: 2/1),

  only screen and (        min-device-pixel-ratio: 2),

  only screen and (                min-resolution: 192dpi),

  only screen and (                min-resolution: 2dppx) {

    background-image: url("@{file-2x}");

    background-size: @width-1x @height-1x;

  }

}