Sanity test: pixel-by-pixel comparison

11 years ago · 74865cb10f
5 changed files with 45 additions and 20 deletions
--- a/.gitignore
+++ b/.gitignore
@ -33,4 +33,5 @@ benchmarks/_output/*.pdf
 benchmarks/_output/
 samples/_output/*.svg
 *.sublime-workspace
-spec/samples/sanity.html
+spec/samples/sanity.html
+spec/samples/_diffs/*.png
--- a/spec/samples/_diffs/gitkeep.txt
+++ b/spec/samples/_diffs/gitkeep.txt
--- a/spec/samples/sanity.html.erb
+++ b/spec/samples/sanity.html.erb
@ -6,12 +6,7 @@
 		<title>Squib Sanity Test for v<%=Squib::VERSION%></title>
 		<style>
 			body{
-				background-color: #dedede;
-				font-color: white;
-			}
-			table, td, tr{
-				border: 1px solid black;
-				border-collapse: true;
+				background:url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAYAAACNMs+9AAAAHElEQVQYlWO4ePFiAzGY4eLFiw0MxIBRhVRRCADsljgKUbBKPgAAAABJRU5ErkJggg==) repeat;
 			}
 			img{
 				width: 30%;
@ -20,14 +15,14 @@
 	</head>
 <body>
 	<% count = 0 %>
-	<% images.each do |exp, actual| %>
+	<% images.each do |exp, actual, diff| %>
 		<img src="<%=exp %>">&nbsp;
 		<img src="<%=actual %>">&nbsp;
+		<img src="<%=diff %>">&nbsp;
 		<br>
 		<%=exp %>
 		<hr>
 		<% count += 1 %>
 	<% end %>
-	</table>
 <body>
 </html>
--- a/spec/samples/sanity.rb
+++ b/spec/samples/sanity.rb
@ -1,19 +1,31 @@
 require 'launchy'
 require 'erb'
+require 'cairo'
+require 'ruby-progressbar'

 # An pixel-by-pixel comparison of sample images for visual regression testing
 class Sanity

  @@EXPECTED_DIR = "#{File.expand_path(File.dirname(__FILE__))}/expected/"
  @@OUTPUT_DIR   = "#{File.expand_path(File.dirname(__FILE__))}/../../samples/_output/"
+  @@DIFF_DIR     = "#{File.expand_path(File.dirname(__FILE__))}/_diffs/"
  @@SANITY_ERB   = "#{File.expand_path(File.dirname(__FILE__))}/sanity.html.erb"
  @@SANITY_HTML  = "#{File.expand_path(File.dirname(__FILE__))}/sanity.html"

  def images
-    images = {}
-    Dir[@@EXPECTED_DIR + "/**/*.png"].each do |exp_png|
-      images["file:///" + exp_png] = "file:///" + @@OUTPUT_DIR + File.basename(exp_png)
+    images   = []
+    exp_pngs = Dir[@@EXPECTED_DIR + "/**/*.png"]
+    bar      = ProgressBar.create(title: 'Diffing images', total: exp_pngs.size)
+    exp_pngs.each do |exp_png|
+      row = []
+      actual_png = @@OUTPUT_DIR + File.basename(exp_png)
+      row << "file:///" + exp_png
+      row << "file:///" + actual_png #actual
+      row << "file:///" + diff_image(exp_png, actual_png)
+      images << row
+      bar.increment
    end
+    bar.finish
    return images
  end

@ -21,13 +33,33 @@ class Sanity
    puts "Building sanity test..."
    sanity_template = File.read(@@SANITY_ERB)
    process_erb(sanity_template)
-    # render_markdown(sanity_template)
    Launchy.open("file:///" + @@SANITY_HTML)
    puts "Done."
  end

  private

+  def diff_image(exp_file, actual_file)
+    exp         = Cairo::ImageSurface.from_png(exp_file)
+    exp_data    = exp.data.bytes
+    actual_data = Cairo::ImageSurface.from_png(actual_file).data.bytes
+    new_data    = Array.new(exp_data.size, 255)
+    unless exp_data == actual_data # this seems to be the fastest initial comparison
+      (0..exp_data.size).each do |i|
+        empty = (i % 4 == 3) ? 0 : 255 # alpha channel is empty, others are just black
+        new_data[i] = (exp_data[i] == actual_data[i]) ? empty : 128
+      end
+    end
+    out = Cairo::ImageSurface.new(new_data.pack('c*'), exp.format, exp.width, exp.height, exp.stride)
+    out_file = @@DIFF_DIR + exp_file[exp_file.rindex("/")..-1]
+    out.write_to_png(out_file)
+    out_file
+  end
+
+  def diff_pixel(exp, actual)
+    (exp == actual) ? [0, 0, 0, 0] : [255, 0, 0, 255]
+  end
+
  def process_erb(sanity_template)
    renderer = ERB.new(sanity_template)
    File.open(@@SANITY_HTML, 'w+') do |html|
@ -35,11 +67,4 @@ class Sanity
    end
  end

-  # def render_markdown(sanity_template)
-  #   md = Redcarpet::Markdown.new(Redcarpet::Render::HTML, autolink: true, tables: true)
-  #   File.open(@@SANITY_HTML, 'w+') do |html|
-  #     html.write(md.render(sanity_template))
-  #   end
-  # end
-
 end
--- a/squib.sublime-project
+++ b/squib.sublime-project
@ -12,6 +12,10 @@
 			"name": "rake",
 			"shell_cmd": "rake",
 		},
+		{
+			"name": "rake sanity",
+			"shell_cmd": "rake sanity",
+		},
 		{
 			"name": "rake run[text_options]",
 			"shell_cmd": "rake run[text_options]",