added sass functions to allow getting the unit value demensions of a sprite image

lib/compass/sprite_importer.rb

@@ -105,7 +105,7 @@ module Compass
 
     # Generates the Sass for this sprite file
     def self.content_for_images(uri, name, skip_overrides = false)
-      binder = Compass::Sprites::Binding.new(:name => name, :uri => uri, :skip_overrides => skip_overrides, :sprite_names => sprite_names(uri))
+      binder = Compass::Sprites::Binding.new(:name => name, :uri => uri, :skip_overrides => skip_overrides, :sprite_names => sprite_names(uri), :files => files(uri))
       CONTENT_TEMPLATE.result(binder.get_binding)
     end
   end

lib/compass/sprite_importer/content.erb

@@ -23,7 +23,7 @@ $<%= name %>-layout:vertical !default;
  <% end %>
 
  $<%= name %>-sprites: sprite-map("<%= uri %>",
- <% sprite_names.map do |sprite_name| %>
+ <% sprite_names.each do |sprite_name| %>
    $<%= name %>-<%= sprite_name %>-position: $<%= name %>-<%= sprite_name %>-position, 
    $<%= name %>-<%= sprite_name %>-spacing:  $<%= name %>-<%= sprite_name %>-spacing, 
    $<%= name %>-<%= sprite_name %>-repeat:   $<%= name %>-<%= sprite_name %>-repeat,
@@ -39,6 +39,14 @@ $<%= name %>-layout:vertical !default;
   background: $<%= name %>-sprites no-repeat;
 }
 
+//sass functions to return the demensions of a sprite image as units
+<% [:width, :height].each do |demension| %>
+  @function <%= name %>-sprite-<%= demension %>($name) {
+    $file: sprite_file($<%= name %>-sprites, $name);
+    @return image-<%= demension %>($file);
+  }
+<% end %>
+
 // Use this to set the dimensions of an element
 // based on the size of the original image.
 @mixin <%= name %>-sprite-dimensions($name) {

test/integrations/sprites_test.rb

@@ -718,4 +718,27 @@ class SpritesTest < Test::Unit::TestCase
     assert_correct css.gsub("\n", '').gsub(' ', ''), other_css.gsub("\n", '').gsub(' ', '')
   end
 
+  it "should allow use of demension functions" do
+    css = render <<-SCSS
+      @import "squares/*.png";
+      $h: squares-sprite-height(twenty-by-twenty);
+      $w: squares-sprite-width(twenty-by-twenty);
+      .div {
+        height:$h + 1px;
+        width:$w + 2px;
+      }
+    SCSS
+    other_css = <<-CSS
+      .squares-sprite {
+        background: url('/squares-sbbc18e2129.png') no-repeat;
+      }
+      .div {
+        height:21px;
+        width:22px;
+      }
+    CSS
+    assert_correct css.gsub("\n", '').gsub(' ', ''), other_css.gsub("\n", '').gsub(' ', '')
+  end
+
+
 end