src/_core/_mixins/_image.scss
// Image Mixins
// - Responsive image
// - Retina image
// Responsive image
//
// Keep images from scaling beyond the width of their parents.
@mixin img-responsive($display: block) {
display: $display;
max-width: 100%; // Part 1: Set a maximum relative to the parent
height: auto; // Part 2: Scale the height according to the width, otherwise you get stretching
}
// Retina image
//
// Short retina mixin for setting background-image and -size. Note that the
// spelling of `min--moz-device-pixel-ratio` is intentional.
@mixin img-retina($file-1x, $file-2x, $width-1x, $height-1x) {
background-image: url(if($bootstrap-sass-asset-helper, twbs-image-path("#{$file-1x}"), "#{$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(if($bootstrap-sass-asset-helper, twbs-image-path("#{$file-2x}"), "#{$file-2x}"));
background-size: $width-1x $height-1x;
}
}