Add formula for libangle

Formula/libangle.rb

@@ -0,0 +1,40 @@
+class Libangle < Formula
+  desc "Conformant OpenGL ES implementation for Windows, Mac, Linux, iOS and Android"
+  homepage "https://github.com/google/angle"
+  url "https://github.com/google/angle.git", using: :git, revision: "29b222a3c07c541cafa459ae6886134da3493a4b"
+  version "4844.29b222a"
+  license "BSD-3-Clause"
+
+  depends_on "meson" => :build
+  depends_on "ninja" => :build
+  depends_on "libangle-deps@4844" => :build
+
+  def install
+    libangleDeps = "#{Formula["libangle-deps@4844"].opt_prefix}/deps"
+    Dir.each_child(libangleDeps) do |dep|
+      rm_rf "#{dep}"
+      ln_s "#{libangleDeps}/#{dep}", "#{dep}"
+    end
+
+    path = PATH.new(ENV["PATH"], "#{Dir.pwd}/third_party/depot_tools")
+    with_env(PATH: path) do
+      if Hardware::CPU.arm?
+        system "gn", "gen", "--args=is_debug=false target_cpu=arm64 use_custom_libcxx=false treat_warnings_as_errors=false", "./angle_build"
+      else
+        system "gn", "gen", "--args=is_debug=false use_custom_libcxx=false treat_warnings_as_errors=false", "./angle_build"
+      end
+
+      system "ninja", "-v", "-C", "angle_build"
+
+      lib.install "angle_build/libEGL.dylib"
+      lib.install "angle_build/libGLESv2.dylib"
+      lib.install "angle_build/libGLESv1_CM.dylib"
+
+      include.install Pathname.glob("include/*")
+    end
+  end
+
+  test do
+    system "true"
+  end
+end