From 647ec149ca935a56a00653ad5111494fac50fd80 Mon Sep 17 00:00:00 2001
From: Paulo <hi@paulo.is>
Date: Fri, 8 May 2015 23:18:11 +0200
Subject: [PATCH] Add retina files support on automatic_image_sizes

---
 .../lib/middleman-more/extensions/automatic_image_sizes.rb | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/middleman-core/lib/middleman-more/extensions/automatic_image_sizes.rb b/middleman-core/lib/middleman-more/extensions/automatic_image_sizes.rb
index 56cb6ebf..f95a0d70 100644
--- a/middleman-core/lib/middleman-more/extensions/automatic_image_sizes.rb
+++ b/middleman-core/lib/middleman-more/extensions/automatic_image_sizes.rb
@@ -23,6 +23,13 @@ class Middleman::Extensions::AutomaticImageSizes < ::Middleman::Extension
         if File.exist?(full_path)
           begin
             width, height = ::FastImage.size(full_path, raise_on_failure: true)
+            # Check for @2x and @3x image
+            retina = full_path.match/(@(\d)x\.[a-zA-Z]{3,4}$/)
+            if retina
+              factor  = retina[1].to_i
+              width   = width / factor
+              height  = height / factor
+            end
             params[:width]  = width
             params[:height] = height
           rescue FastImage::UnknownImageType