Switch build system to CMake

This unifies the build system across platforms, including doing
development inside Visual Studio. No change to other code.

CMakeLists.txt

@@ -43,6 +43,7 @@ target_include_directories(gl PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}")
 # ---------------
 add_executable(sm)
 add_subdirectory(src)
+<<<<<<< HEAD
 
 # Math library
 find_library(MATHLIB m)
@@ -63,6 +64,23 @@ target_compile_definitions(sm PRIVATE
 
 # Nintendo Switch extra setup
 if (NINTENDO_SWITCH)
+=======
+target_link_libraries(sm PRIVATE SDL2::SDL2 gl)
+set_target_properties(sm PROPERTIES C_STANDARD 11)
+
+if (MSVC)
+    target_compile_options(sm PRIVATE ${msvc_warnings})
+else()
+    target_link_libraries(sm PRIVATE m)
+    target_compile_definitions(sm PRIVATE SYSTEM_VOLUME_MIXER_AVAILABLE=0)
+    target_compile_options(sm PRIVATE ${c_warnings})
+endif()
+
+# Nintendo Switch extra setup
+if (NINTENDO_SWITCH)
+    target_compile_definitions(sm PUBLIC __SWITCH__)
+
+>>>>>>> 6d96c49 (Switch build system to CMake)
     # needs to be linked with g++ for C++ stdlib
     enable_language(CXX)
     set_target_properties(sm PROPERTIES