django-compass-mixins/lib/compass/utilities/sprites/_base.scss

// Determines those states for which you want to enable magic sprite selectors
$sprite-selectors: hover, target, active !default;

// Set the width and height of an element to the original
// dimensions of an image before it was included in the sprite.
@mixin sprite-dimensions($map, $sprite) {
  height: image-height(sprite-file($map, $sprite));
  width: image-width(sprite-file($map, $sprite));
}

// Set the background position of the given sprite `$map` to display the
// sprite of the given `$sprite` name. You can move the image relative to its
// natural position by passing `$offset-x` and `$offset-y`.
@mixin sprite-background-position($map, $sprite, $offset-x: 0, $offset-y: 0) {
  background-position: sprite-position($map, $sprite, $offset-x, $offset-y);  
}


// Determines if you want to include magic selectors in your sprites
$disable-magic-sprite-selectors:false !default;

// Include the position and (optionally) dimensions of this `$sprite`
// in the given sprite `$map`. The sprite url should come from either a base
// class or you can specify the `sprite-url` explicitly like this:
//
//     background: $map no-repeat;
@mixin sprite($map, $sprite, $dimensions: false, $offset-x: 0, $offset-y: 0) {
  @include sprite-background-position($map, $sprite, $offset-x, $offset-y);
  @if $dimensions {
    @include sprite-dimensions($map, $sprite);
  }
  @if not $disable-magic-sprite-selectors {
    @include sprite-selectors($map, $sprite, $sprite, $offset-x, $offset-y);
  }
}

// Include the selectors for the `$sprite` given the `$map` and the 
// `$full-sprite-name`
// @private
@mixin sprite-selectors($map, $sprite-name, $full-sprite-name, $offset-x: 0, $offset-y: 0) {
  @each $selector in $sprite-selectors {
    @if sprite_has_selector($map, $sprite-name, $selector) {
      &:#{$selector}, &.#{$full-sprite-name}_#{$selector}, &.#{$full-sprite-name}-#{$selector} {
          @include sprite-background-position($map, "#{$sprite-name}_#{$selector}", $offset-x, $offset-y);
      }
    }
  }
}

// Generates a class for each space separated name in `$sprite-names`.
// The class will be of the form .<map-name>-<sprite-name>.
//
// If a base class is provided, then each class will extend it.
//
// If `$dimensions` is `true`, the sprite dimensions will specified.
@mixin sprites($map, $sprite-names, $base-class: false, $dimensions: false, $prefix: sprite-map-name($map), $offset-x: 0, $offset-y: 0) {
  @each $sprite-name in $sprite-names {
    @if sprite_does_not_have_parent($map, $sprite-name) {
      $full-sprite-name: "#{$prefix}-#{$sprite-name}";
      .#{$full-sprite-name} {
        @if $base-class { @extend #{$base-class}; }
        @include sprite($map, $sprite-name, $dimensions, $offset-x, $offset-y);
      }
    }
  }
}