gz-physics8: new formula for ionic (#2473)

Signed-off-by: Ian Chen <ichen@openrobotics.org>
Signed-off-by: Addisu Z. Taddese <addisu@openrobotics.org>
Co-authored-by: Steve Peters <scpeters@openrobotics.org>
Co-authored-by: Addisu Z. Taddese <addisu@openrobotics.org>

Formula/gz-physics8.rb

@@ -0,0 +1,104 @@
+class GzPhysics8 < Formula
+  desc "Physics library for robotics applications"
+  homepage "https://github.com/gazebosim/gz-physics"
+  url "https://github.com/gazebosim/gz-physics.git", branch: "main"
+  version "7.999.999-0-20231016"
+  license "Apache-2.0"
+
+  head "https://github.com/gazebosim/gz-physics.git", branch: "main"
+
+  depends_on "cmake" => [:build, :test]
+
+  depends_on "bullet"
+  depends_on "dartsim"
+  depends_on "google-benchmark"
+  depends_on "gz-cmake4"
+  depends_on "gz-common6"
+  depends_on "gz-math8"
+  depends_on "gz-plugin3"
+  depends_on "gz-utils3"
+  depends_on macos: :mojave # c++17
+  depends_on "pkg-config"
+  depends_on "sdformat15"
+
+  def install
+    rpaths = [
+      rpath,
+      rpath(source: lib/"gz-physics-8/engine-plugins", target: lib),
+    ]
+    cmake_args = std_cmake_args
+    cmake_args << "-DBUILD_TESTING=OFF"
+    cmake_args << "-DCMAKE_INSTALL_RPATH=#{rpaths.join(";")}"
+
+    mkdir "build" do
+      system "cmake", "..", *cmake_args
+      system "make", "install"
+    end
+  end
+
+  test do
+    # test plugins in subfolders
+    %w[bullet-featherstone bullet dartsim tpe].each do |engine|
+      p = lib/"gz-physics-8/engine-plugins/libgz-physics-#{engine}-plugin.dylib"
+      # Use gz-plugin --info command to check plugin linking
+      cmd = Formula["gz-plugin3"].opt_libexec/"gz/plugin3/gz-plugin"
+      args = ["--info", "--plugin"] << p
+      # print command and check return code
+      system cmd, *args
+      # check that library was loaded properly
+      _, stderr = system_command(cmd, args: args)
+      error_string = "Error while loading the library"
+      assert stderr.exclude?(error_string), error_string
+    end
+    # build against API
+    (testpath/"test.cpp").write <<-EOS
+      #include "gz/plugin/Loader.hh"
+      #include "gz/physics/ConstructEmpty.hh"
+      #include "gz/physics/RequestEngine.hh"
+      int main()
+      {
+        gz::plugin::Loader loader;
+        loader.LoadLib("#{opt_lib}/libgz-physics8-dartsim-plugin.dylib");
+        gz::plugin::PluginPtr dartsim =
+            loader.Instantiate("gz::physics::dartsim::Plugin");
+        using featureList = gz::physics::FeatureList<
+            gz::physics::ConstructEmptyWorldFeature>;
+        auto engine =
+            gz::physics::RequestEngine3d<featureList>::From(dartsim);
+        return engine == nullptr;
+      }
+    EOS
+    (testpath/"CMakeLists.txt").write <<-EOS
+      cmake_minimum_required(VERSION 3.10.2 FATAL_ERROR)
+      find_package(gz-physics8 REQUIRED)
+      find_package(gz-plugin3 REQUIRED COMPONENTS all)
+      add_executable(test_cmake test.cpp)
+      target_link_libraries(test_cmake
+          gz-physics8::gz-physics8
+          gz-plugin3::loader)
+    EOS
+    system "pkg-config", "gz-physics8"
+    cflags   = `pkg-config --cflags gz-physics8`.split
+    ldflags  = `pkg-config --libs gz-physics8`.split
+    system "pkg-config", "gz-plugin3-loader"
+    loader_cflags   = `pkg-config --cflags gz-plugin3-loader`.split
+    loader_ldflags  = `pkg-config --libs gz-plugin3-loader`.split
+    system ENV.cc, "test.cpp",
+                   *cflags,
+                   *ldflags,
+                   *loader_cflags,
+                   *loader_ldflags,
+                   "-lc++",
+                   "-o", "test"
+    system "./test"
+    # test building with cmake
+    mkdir "build" do
+      system "cmake", ".."
+      system "make"
+      system "./test_cmake"
+    end
+    # check for Xcode frameworks in bottle
+    cmd_not_grep_xcode = "! grep -rnI 'Applications[/]Xcode' #{prefix}"
+    system cmd_not_grep_xcode
+  end
+end