build: add matplotplusplus as git submodule

.gitmodules

@@ -13,3 +13,6 @@
 [submodule "third_party/glob"]
 	path = third_party/glob
 	url = https://github.com/p-ranav/glob.git
+[submodule "third_party/matplotplusplus"]
+	path = third_party/matplotplusplus
+	url = https://github.com/alandefreitas/matplotplusplus.git

CMakeLists.txt

@@ -31,6 +31,7 @@ include(${oops_3rd_cmake_dir}/argparse.cmake)
 include(${oops_3rd_cmake_dir}/fmt.cmake)
 include(${oops_3rd_cmake_dir}/scnlib.cmake)
 include(${oops_3rd_cmake_dir}/glob.cmake)
+include(${oops_3rd_cmake_dir}/matplotplusplus.cmake)
 if(ENABLE_TEST)
     include(${oops_3rd_cmake_dir}/googletest.cmake)
 endif()

third_party/cmake/matplotplusplus.cmake

@@ -0,0 +1,13 @@
+# matplotplusplus-1.2.2 (fe308e13)
+set(lib_dir ${oops_3rd_dir}/matplotplusplus)
+if(NOT EXISTS "${lib_dir}/CMakeLists.txt")
+    execute_process(COMMAND git submodule update --init --recursive ${lib_dir})
+endif()
+
+add_subdirectory(${lib_dir})
+if(TARGET nodesoup)
+    target_compile_options(nodesoup PRIVATE -w)
+endif()
+if(TARGET matplot)
+    target_compile_options(matplot PRIVATE -w)
+endif()