vips_driver.rb in capybara-screenshot-diff-1.9.0

- old
+ new

@@ -13,10 +13,12 @@
   module Screenshot
     module Diff
       # Compare two images and determine if they are equal, different, or within some comparison
       # range considering color values and difference area size.
       module Drivers
+        DEFAULT_HIGHLIGHT_COLOR = [255, 0, 0, 255].freeze
+
         class VipsDriver < BaseDriver
           def find_difference_region(comparison)
             new_image, base_image, options = comparison.new_image, comparison.base_image, comparison.options
 
             diff_mask = VipsUtil.difference_mask(base_image, new_image, options[:color_distance_limit])
@@ -24,13 +26,12 @@
             region = nil if region && same_as?(region, base_image)
 
             result = Difference.new(region, {}, comparison)
 
             unless result.blank?
-              meta = {}
-              meta[:difference_level] = difference_level(diff_mask, base_image) if comparison.options[:tolerance]
-              result.meta = meta
+              result.meta[:difference_level] = difference_level(diff_mask, base_image) if comparison.options[:tolerance]
+              result.meta[:diff_mask] = diff_mask
             end
 
             result
           end
 
@@ -47,10 +48,12 @@
           def filter_image_with_median(image, median_filter_window_size)
             image.median(median_filter_window_size)
           end
 
           def add_black_box(memo, region)
+            return memo unless region
+
             memo.draw_rect([0, 0, 0, 0], *region.to_top_left_corner_coordinates, fill: true)
           end
 
           def difference_level(diff_mask, old_img, _region = nil)
             VipsUtil.difference_area_size_by(diff_mask).to_f / image_area_size(old_img)
@@ -96,9 +99,17 @@
             end
           end
 
           def same_pixels?(comparison)
             (comparison.new_image == comparison.base_image).min == 255
+          end
+
+          def merge(new_image, base_image)
+            base_image.composite2(new_image, :over)
+          end
+
+          def highlight_mask(diff_mask, merged_image, color: DEFAULT_HIGHLIGHT_COLOR)
+            diff_mask.ifthenelse(color, merged_image * 0.75)
           end
 
           private
 
           def same_as?(region, base_image)