Optimize images

Gemfile

@@ -47,6 +47,7 @@ gem "commonmarker", require: false
 gem "invisible_captcha" # Unobtrusive and flexible spam protection for Rails apps [https://github.com/markets/invisible_captcha]
 gem "color_conversion" # A ruby gem to perform color conversions [https://github.com/devrieda/color_conversion]
 gem "meta-tags" # Search Engine Optimization (SEO) for Ruby on Rails applications. [https://github.com/kpumuk/meta-tags]
+gem "fastimage", require: false # FastImage finds the size or type of an image given its uri by fetching as little as needed [https://github.com/sdsykes/fastimage]
 
 gem "bootsnap", require: false # Reduces boot times through caching; required in config/boot.rb [https://github.com/Shopify/bootsnap]
 

Gemfile.lock

@@ -223,6 +223,7 @@ GEM
       multipart-post (~> 2)
     faraday-net_http (3.4.0)
       net-http (>= 0.5.0)
+    fastimage (2.3.1)
     ferrum (0.15)
       addressable (~> 2.5)
       concurrent-ruby (~> 1.1)
@@ -640,6 +641,7 @@ DEPENDENCIES
   erb_lint
   factory_bot_rails
   faker
+  fastimage
   flipper
   flipper-active_record
   flipper-ui

app/content/pages/articles/add-your-rails-app-to-the-home-screen.html.mdrb

@@ -68,8 +68,7 @@ You can also view installation instructions for various browsers below:
 
 <%= turbo_frame_tag "pwa_installation_instructions", src: pwa_installation_instructions_path %>
 
-If it worked, you should be able to open Joy of Rails as a standalone application. Voilà!
-![Screenshot of Joy of Rails in its standalone form](articles/add-your-rails-app-to-the-home-screen/standalone.jpg)
+If it worked, you should be able to open Joy of Rails as a standalone application. Voilà! ![Screenshot of Joy of Rails in its standalone form](articles/add-your-rails-app-to-the-home-screen/standalone.jpg)
 
 ## What does it mean for a web app to be installable?
 
@@ -246,7 +245,7 @@ end
 As mentioned previously, you should have, at minimum, two square images to represent your app icon on install screens: `192x192` and `512x512`. If you started from a new Rails 7.2+ app, you‘ll want to remove the generated app icon from the Rails app generator and make your own.
 
 Here are the app icons for Joy of Rails:
-![Joy of Rails app icon 192x192](app-icons/icon-192.png 'Joy of Rails app icon 192x192') ![Joy of Rails app icon 512x512](app-icons/icon-512.png 'Joy of Rails app icon 512x512')
+![Joy of Rails app icon 192x192](articles/add-your-rails-app-to-the-home-screen/icon-192.png 'Joy of Rails app icon 192x192') ![Joy of Rails app icon 512x512](articles/add-your-rails-app-to-the-home-screen/icon-512.png 'Joy of Rails app icon 512x512')
 
 I used ImageMagick 7 to convert these icons from the original with a command like:
 
@@ -270,7 +269,7 @@ Some browsers will present the icon in a circular window that will crop a signif
 ![A masked icon](articles/add-your-rails-app-to-the-home-screen/masked-icon-bad.jpg 'A not-so-nice masked icon')
 
 My approach is to use a separate set of icons with more room to breathe. Compare the two variation:
-![Primary app icon](app-icons/icon-192.png 'Primary app icon') ![Maskable app icon](app-icons/icon-192-maskable.png 'Maskable app icon')
+![Primary app icon](articles/add-your-rails-app-to-the-home-screen/icon-192.png 'Primary app icon') ![Maskable app icon](articles/add-your-rails-app-to-the-home-screen/icon-192-maskable.png 'Maskable app icon')
 
 The new icon a lot better when masked:
 ![A masked icon](articles/add-your-rails-app-to-the-home-screen/masked-icon-good.jpg 'A nice masked icon')

app/views/components/content/image.rb

@@ -0,0 +1,53 @@
+module Content
+  class Image < ApplicationComponent
+    attr_reader :src, :alt, :title, :attributes
+
+    def initialize(src, alt: "", title: "", **attributes)
+      @src = src
+      @alt = alt.presence || File.basename(src, ".*").humanize
+      @title = title
+      @attributes = attributes
+    end
+
+    def view_template
+      figure do
+        img(alt:, loading: "lazy", **image_attributes, **attributes)
+        figcaption { title } if title.present?
+      end
+    end
+
+    private
+
+    def asset_path(*) = helpers.asset_path(*)
+
+    def image_attributes
+      if webp_src?
+        {
+          src: asset_path(webp_src)
+        }
+      elsif optimized_src?
+        {
+          src: asset_path(optimized_src)
+        }
+      else
+        {
+          src: asset_path(src)
+        }
+      end
+    end
+
+    def webp_src? = File.exist? Rails.root.join("app", "assets", "images", webp_src)
+
+    def webp_src = "#{dirname}/#{basename}.webp"
+
+    def optimized_src? = File.exist? Rails.root.join("app", "assets", "images", optimized_src)
+
+    def optimized_src = "#{dirname}/#{basename}-opt.#{ext}"
+
+    def ext = File.extname(src)
+
+    def basename = File.basename(src, ".*")
+
+    def dirname = File.dirname(src)
+  end
+end

app/views/components/markdown/article.rb

@@ -21,10 +21,8 @@ def code_block(source, metadata = "", **attributes)
 
   def image(src, alt: "", title: "")
     title, json_attributes = parse_text_and_metadata(title, separator: "|")
-    figure(**json_attributes) do
-      image_tag(src, alt: alt, title: title, loading: "lazy")
-      figcaption { title }
-    end
+
+    render ::Content::Image.new(src, alt: alt, title: title, **json_attributes)
   end
 
   private

app/views/components/pages/card.rb

@@ -13,12 +13,12 @@ def initialize(title:, description:, image:, request_path:)
     def view_template
       article(class: "") do
         a(href: request_path, class: "block") do
-          figure(class: "page-card--image w-full") do
-            image_tag @image || "https://placehold.co/640x360?text=#{title}",
-              alt: "#{File.basename(@image, ".*").humanize} illustration",
-              class: "w-full rounded-2xl object-cover aspect-[16/9]",
-              loading: "lazy"
-          end
+          render Content::Image.new \
+            image || "https://placehold.co/640x360?text=#{title}",
+            alt: "#{File.basename(image, ".*").humanize} illustration",
+            title: nil,
+            loading: "lazy",
+            class: "w-full rounded-2xl object-cover aspect-[16/9]"
         end
         div(class: "max-w-xl") do
           h3(

app/views/components/pages/summary.rb

@@ -55,11 +55,11 @@ def content(**)
 
     def figure_image(**)
       div(**) do
-        figure(class: "page-summary--image") do
-          image_tag image,
-            alt: "#{File.basename(image, ".*").humanize} illustration",
-            class: "w-full object-cover aspect-[2/1] lg:aspect-[3/2]"
-        end
+        render Content::Image.new(image,
+          alt: "#{File.basename(image, ".*").humanize} illustration",
+          title: nil,
+          loading: nil,
+          class: "w-full object-cover aspect-[2/1] lg:aspect-[3/2]")
       rescue
         ActionView::Template::Error
       end

script/convert-webp

@@ -1,13 +1,127 @@
 #!/usr/bin/env ruby
 
+# ENV["BUNDLE_GEMFILE"] ||= File.expand_path("../Gemfile", __dir__)
+
+# bundle_binstub = File.expand_path("bundle", __dir__)
+
+# if File.file?(bundle_binstub)
+#   if File.read(bundle_binstub, 300).include?("This file was generated by Bundler")
+#     load(bundle_binstub)
+#   else
+#     abort("Your `bin/bundle` was not generated by Bundler, so this binstub cannot run.
+# Replace `bin/bundle` by running `bundle binstubs bundler --force`, then run this command again.")
+#   end
+# end
+
+# require "rubygems"
+# require "bundler/setup"
+
+require "fastimage"
+
+force = false
+
+class ImageFile
+  def exists?
+    File.exist?(file)
+  end
+
+  attr_reader :file
+  def initialize(file)
+    @file = file
+  end
+
+  def to_s = file
+
+  def to_str = file
+
+  def as(*suffixes)
+    ext = suffixes.pop
+    ImageFile.new("#{dirname}/#{([basename] + suffixes).join("-")}.#{ext}")
+  end
+
+  def as_webp = as("webp")
+
+  def as_opt_jpg = as("opt", "jpg")
+
+  def ext = File.extname(file)
+
+  def basename = File.basename(file, ".*")
+
+  def dirname = File.dirname(file)
+end
+
+module Cmd
+  def self.run(cmd)
+    puts cmd
+    system cmd
+  end
+
+  def self.webp(img, force: false, quality: 90, tries: 0)
+    dest = img.as_webp.to_s
+
+    if force || !File.exist?(dest)
+      cmd = "magick #{img}"
+
+      opts = ["-define webp:method=6", "-quality #{quality}"]
+
+      # Resize if width is specified and image is larger
+      opts << "-resize 1200x" if FastImage.size(img.to_s)[0] > 1200
+
+      # Lossless compression for images < 96kB
+      if File.size?(img) && File.size(img) < 98_304 # 96kB
+        opts << "-define webp:lossless=true"
+      end
+
+      opts << dest
+
+      run "#{cmd} #{opts.join(" ")}"
+
+      if File.size(dest) > 131_072 && # 128kB
+          tries < 8
+        webp(img, force: true, quality: quality - 5, tries: tries + 1)
+      end
+    end
+  end
+
+  def self.jpg(img, force: false, quality: 90, tries: 0)
+    dest = img.as_opt_jpg.to_s
+    if force || !File.exist?(dest)
+      run "magick #{img} -strip -interlace Plane -quality #{quality}% #{dest}"
+
+      if File.size(dest) > 131_072 && # 128kB
+          tries < 8
+        jpg(img, force: true, quality: quality - 5, tries: tries + 1)
+      end
+    end
+  end
+end
+
 ARGV.each do |file|
-  basename = File.basename(file, ".*")
-  dir = File.dirname(file)
+  Dir.glob(file).each do |file|
+    img = ImageFile.new(file)
+    next unless %w[.jpg .jpeg .png].include?(img.ext)
+    next if img.to_s.include?("-opt.jpg")
+    Cmd.webp img, force: force
+  end
+
+  Dir.glob(file).each do |file|
+    img = ImageFile.new(file)
+    next unless %w[.jpg .jpeg].include?(img.ext)
+    next if img.to_s.include?("-opt.jpg")
+    next if File.size(img) < 32_768 # 32kB
+    Cmd.jpg img, force: force
+  end
 
-  webp = "#{dir}/#{basename}.webp"
+  Dir.glob(file).each do |file|
+    img = ImageFile.new(file)
 
-  cmd = "magick #{file} -quality 50 -define webp:lossless=true -resize 960x480 #{webp}"
+    files = [img.as_webp.to_s, img.as_opt_jpg.to_s].filter { |f| File.exist?(f) }
 
-  puts cmd
-  system cmd
+    smallest = files.min { |a, b| File.size(a) <=> File.size(b) }
+    files.each do |f|
+      if f != smallest || File.size(f) > File.size(img.to_s)
+        File.delete(f)
+      end
+    end
+  end
 end