Remove current web backend

Preparing for WebAssembly

README.md

@@ -39,7 +39,7 @@ rake test:int testcard
 # Build `test/audio.rb` natively using MRuby and run
 rake test:native audio
 
-# Build `test/mouse.rb` for the web using Opal and run in the default browser
+# Build `test/mouse.rb` for the web using WebAssembly and run in the default browser
 rake test:web mouse
 ```
 
@@ -67,7 +67,7 @@ Whether adding a feature or fixing a bug, try to do the following to ensure your
 
 - **Check if there is an existing issue, and if not, open a new one to start a discussion.** Before dedicating time and energy to an idea or fix, let's make sure it's consistent with the principles and goals of the project, and that we have a solid strategy in place to implement and test.
 
-- **Use a subset of Ruby that works everywhere.** Ruby 2D applications are, of course, written in Ruby. Some users may choose to harness the full power of the language, standard library, and ecosystem of gems by writing interpreted apps targeting the standard implementation, [MRI](https://en.wikipedia.org/wiki/Ruby_MRI). Others may want to target the web via [Opal](http://opalrb.org), so their app can be run in any browser. And others still may want to compile their app to native code via [MRuby](http://mruby.org), so they can embed it on platforms like the [Raspberry Pi](https://www.raspberrypi.org), or run it on mobile platforms like iOS and Android, or on the big screen with Apple TV or Amazon Fire TV. Or even further, some may want to do all three! Ruby 2D aims to support all of these use cases, even with the same app codebase. Your code contribution to this gem has to support a subset of Ruby that is compatible and behaves similarly across MRI, MRuby, and Opal. Beyond reading the documentation for each Ruby implementation, you can also try out code snippets on the command line using their respective REPLs: `irb` (MRI), `mirb` (MRuby), and `opal-repl` (Opal).
+- **Use a subset of Ruby that works everywhere.** Ruby 2D applications are, of course, written in Ruby. Some users may choose to harness the full power of the language, standard library, and ecosystem of gems by writing interpreted apps targeting the standard implementation, [MRI](https://en.wikipedia.org/wiki/Ruby_MRI). Others may want to target the web via [WebAssembly](https://webassembly.org), mobile devices, or build native desktop applications, all which make use of a different Ruby implementation called [MRuby](http://mruby.org). Ruby 2D aims to support all of these use cases, even with the same app codebase. Your contribution must support a subset of Ruby that is compatible with and behaves similarly across MRI and MRuby. Beyond reading the documentation for each Ruby implementation, you can also try out code snippets on the command line using their respective REPLs: `irb` for MRI, and `mirb` for MRuby.
 
 - **Comprehensively test your change.** Unlike other Ruby libraries, not everything here can be easily covered with unit tests alone. We also need to make sure things look and sound right, inputs work as expected, and behavior is consistent across all [platforms Ruby 2D supports](http://www.ruby2d.com/platforms).
 

bin/ruby2d

@@ -115,38 +115,6 @@ end
 # Build a web-based version of the provided Ruby application
 def build_web(rb_file)
   puts "Warning: ".warn + "This feature is currently disabled while it's being upgraded."
-  return
-
-  check_build_src_file(rb_file)
-
-  # Assemble the Ruby 2D library in one `.rb` file and compile to JS
-  make_lib
-  `opal --compile --no-opal build/lib.rb > build/lib.js`
-
-  # Read the provided Ruby source file, copy to build dir, and compile to JS
-  File.open('build/src.rb', 'w') { |file| file << strip_require(rb_file) }
-  `opal --compile --no-opal build/src.rb > build/src.js`
-  FileUtils.cp "#{@gem_dir}/ext/ruby2d/ruby2d-opal.rb", "build/"
-  `opal --compile --no-opal build/ruby2d-opal.rb > build/ruby2d-opal.js`
-
-  # Combine contents of JS source files and compiled JS into one file
-  open('build/app.js', 'w') do |f|
-    f << File.read("#{@gem_dir}/assets/simple2d.js") << "\n\n"
-    f << File.read("#{@gem_dir}/assets/opal.js") << "\n\n"
-    f << File.read("build/lib.js") << "\n\n"
-    f << File.read("build/ruby2d-opal.js") << "\n\n"
-    f << File.read("build/src.js") << "\n\n"
-  end
-
-  # Copy over HTML template
-  FileUtils.cp "#{@gem_dir}/assets/template.html", "build/app.html"
-
-  # Clean up
-  clean_up unless @debug
-
-  # Success!
-  puts "Web app created at `build/app.js`",
-       "  Run by opening `build/app.html`"
 end
 
 
@@ -204,7 +172,6 @@ end
 def clean_up(cmd = nil)
   FileUtils.rm(
     Dir.glob('build/{src,lib}.{rb,c,js}') +
-    Dir.glob('build/ruby2d-opal.{rb,js}') +
     Dir.glob('build/app.c')
   )
   if cmd == :all

lib/ruby2d/image.rb

@@ -8,22 +8,17 @@ class Image
     attr_accessor :x, :y, :width, :height, :rotate, :data
 
     def initialize(path, opts = {})
-      @path = path
-
-      unless RUBY_ENGINE == 'opal'
-        unless File.exist? @path
-          raise Error, "Cannot find image file `#{@path}`"
-        end
+      unless File.exist? path
+        raise Error, "Cannot find image file `#{path}`"
       end
-
+      @path = path
       @x = opts[:x] || 0
       @y = opts[:y] || 0
       @z = opts[:z] || 0
       @width = opts[:width] || nil
       @height = opts[:height] || nil
       @rotate = opts[:rotate] || 0
       self.color = opts[:color] || 'white'
-
       ext_init(@path)
       add
     end

lib/ruby2d/music.rb

@@ -7,13 +7,9 @@ class Music
     attr_accessor :loop, :data
 
     def initialize(path)
-
-      unless RUBY_ENGINE == 'opal'
-        unless File.exist? path
-          raise Error, "Cannot find audio file `#{path}`"
-        end
+      unless File.exist? path
+        raise Error, "Cannot find audio file `#{path}`"
       end
-
       @path = path
       @loop = false
       ext_init(path)