remove CPP11 option in CMakeLists.txt and add some comments

Author: Nathan Ho

01a-BoringMixer/CMakeLists.txt

@@ -12,7 +12,13 @@ if(APPLE OR WIN32)
 set(CMAKE_SHARED_MODULE_SUFFIX ".scx")
 endif()
 
-option(CPP11 "Build with c++11." ON)
+# The below monstrosity sets compiler flags for SSE (Streaming SIMD Extensions). Among many other things, SSE protects
+# against denormal numbers, which are known to cause glitchy audio in some cases.
+
+# Some processors do not support SSE and will produce errors if you try to add SSE flags, so we also have to introduce
+# conditional logic to guard against those errors.
+
+# It's a real mess, and generally there's no need to touch it :)
 
 if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_COMPILER_IS_CLANG)
     add_definitions(-fvisibility=hidden)
@@ -54,11 +60,10 @@ if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_COMPILER_IS_CLANG)
         add_definitions(-march=native)
     endif()
 
-    if(CPP11)
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
-        if(CMAKE_COMPILER_IS_CLANG)
-            set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libc++")
-        endif()
+    # Plugin headers require C++11, which must be explicitly enabled for gcc and clang.
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
+    if(CMAKE_COMPILER_IS_CLANG)
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -stdlib=libc++")
     endif()
 endif()
 if(MINGW)