g2o 20201223 (new formula)

Closes #86410.

Signed-off-by: Carlo Cabrera <30379873+carlocab@users.noreply.github.com>
Signed-off-by: rui <rui@chenrui.dev>
Signed-off-by: BrewTestBot <1589480+BrewTestBot@users.noreply.github.com>

Formula/g2o.rb

@@ -0,0 +1,58 @@
+class G2o < Formula
+  desc "General framework for graph optimization"
+  homepage "https://openslam-org.github.io/g2o.html"
+  url "https://github.com/RainerKuemmerle/g2o/archive/refs/tags/20201223_git.tar.gz"
+  version "20201223"
+  sha256 "20af80edf8fd237e29bd21859b8fc734e615680e8838824e8b3f120c5f4c1672"
+  license "BSD-2-Clause"
+
+  depends_on "cmake" => :build
+  depends_on "eigen"
+
+  resource "testdata" do
+    url "https://raw.githubusercontent.com/OpenSLAM-org/openslam_g2o/2362b9e1e9dab318625cd0af9ba314c47ba8de48/data/2d/intel/intel.g2o"
+    sha256 "4d87aaf96e1e04e47c723c371386b15358c71e98c05dad16b786d585f9fd70ff"
+  end
+
+  def install
+    cmake_args = std_cmake_args + %w[-DG2O_BUILD_EXAMPLES=OFF]
+    # For Intel: manually set desired SSE features to enable support for older machines.
+    # See https://gcc.gnu.org/onlinedocs/gcc/x86-Options.html for supported CPU features
+    if Hardware::CPU.intel?
+      cmake_args << "-DDO_SSE_AUTODETECT=OFF"
+      case Hardware.oldest_cpu
+      when :nehalem
+        cmake_args += %w[-DDISABLE_SSE4_A=ON]
+      when :core2
+        cmake_args += %w[-DDISABLE_SSE4_1=ON -DDISABLE_SSE4_2=ON -DDISABLE_SSE4_A=ON]
+      else
+        odie "Unexpected oldest supported CPU \"#{Hardware.oldest_cpu}\""
+      end
+    end
+
+    system "cmake", "-S", ".", "-B", "build", *cmake_args
+
+    # Avoid references to Homebrew shims
+    inreplace "build/g2o/config.h", Superenv.shims_path/ENV.cxx, ENV.cxx
+
+    system "cmake", "--build", "build"
+    system "cmake", "--install", "build"
+
+    (pkgshare/"examples").install "g2o/examples/simple_optimize"
+  end
+
+  test do
+    cp_r pkgshare/"examples/simple_optimize", testpath/"src"
+    libs = %w[-lg2o_core -lg2o_solver_eigen -lg2o_stuff -lg2o_types_slam2d -lg2o_types_slam3d]
+    cd "src" do
+      system ENV.cxx, "simple_optimize.cpp",
+             "-I#{opt_include}", "-I#{Formula["eigen"].opt_include}/eigen3",
+             "-L#{opt_lib}", *libs, "-std=c++11", "-o", testpath/"simple_optimize"
+    end
+
+    resource("testdata").stage do
+      last_output = shell_output(testpath/"simple_optimize intel.g2o 2>&1").lines.last
+      assert_match("edges= 1837", last_output)
+    end
+  end
+end