CMakeLists: reorganise how system deps are handled.

Allowing each dependency to be system-wide or not is gonna be an
improvement, especially when it comes to IDE memory usage.

CMakeLists.txt

@@ -23,23 +23,21 @@ set(ZLIB_USE_STATIC_LIBS ON CACHE BOOL "" FORCE) # Required on setups where zlib
 
 option(SAVETOOL_USE_SYSTEM_LIBS "Use system-wide versions of the dependencies instead of the versions provided by submodules." OFF)
 
+include(CMakeDependentOption)
+cmake_dependent_option(SAVETOOL_USE_SYSTEM_CORRADE_MAGNUM "Use system-wide versions of Corrade and Magnum." ON "SAVETOOL_USE_SYSTEM_LIBS" OFF)
+cmake_dependent_option(SAVETOOL_USE_SYSTEM_SDL2 "Use a system-wide version of SDL2." ON "SAVETOOL_USE_SYSTEM_LIBS" OFF)
+cmake_dependent_option(SAVETOOL_USE_SYSTEM_LIBZIP "Use a system-wide version of libzip." ON "SAVETOOL_USE_SYSTEM_LIBS" OFF)
+cmake_dependent_option(SAVETOOL_USE_SYSTEM_EFSW "Use a system-wide version of EFSW." ON "SAVETOOL_USE_SYSTEM_LIBS" OFF)
+cmake_dependent_option(SAVETOOL_USE_SYSTEM_LIBCURL "Use a system-wide version of libcurl." ON "SAVETOOL_USE_SYSTEM_LIBS" OFF)
+
 if(NOT SAVETOOL_USE_SYSTEM_LIBS)
     # Generic variables shared by multiple libs that don't provide their own.
     set(BUILD_SHARED_LIBS OFF CACHE BOOL "" FORCE)
     set(BUILD_STATIC_LIBS ON CACHE BOOL "" FORCE)
     set(BUILD_TESTING OFF CACHE BOOL "" FORCE)
+endif(NOT SAVETOOL_USE_SYSTEM_LIBS)
 
-    set(CORRADE_BUILD_DEPRECATED OFF CACHE BOOL "" FORCE)
+if(NOT SAVETOOL_USE_SYSTEM_SDL2)
-    set(CORRADE_BUILD_STATIC ON CACHE BOOL "" FORCE)
-    set(CORRADE_BUILD_STATIC_PIC ON CACHE BOOL "" FORCE)
-    set(CORRADE_BUILD_STATIC_UNIQUE_GLOBALS OFF CACHE BOOL "" FORCE)
-    set(CORRADE_BUILD_TESTS OFF CACHE BOOL "" FORCE)
-    set(CORRADE_WITH_INTERCONNECT OFF CACHE BOOL "" FORCE)
-    set(CORRADE_WITH_PLUGINMANAGER OFF CACHE BOOL "" FORCE)
-    set(CORRADE_WITH_TESTSUITE OFF CACHE BOOL "" FORCE)
-    set(CORRADE_WITH_MAIN ON CACHE BOOL "" FORCE)
-    add_subdirectory(third-party/corrade EXCLUDE_FROM_ALL)
-
     set(DIRECTX OFF CACHE BOOL "" FORCE) # We use OpenGL.
     set(SDL_ATOMIC OFF CACHE BOOL "" FORCE)
     set(SDL_CPUINFO OFF CACHE BOOL "" FORCE)
@@ -55,6 +53,19 @@ if(NOT SAVETOOL_USE_SYSTEM_LIBS)
     set(SDL_TIMERS ON CACHE BOOL "" FORCE)
     set(SDL_SHARED OFF CACHE BOOL "" FORCE)
     add_subdirectory(third-party/SDL EXCLUDE_FROM_ALL)
+endif(NOT SAVETOOL_USE_SYSTEM_SDL2)
+
+if(NOT SAVETOOL_USE_SYSTEM_CORRADE_MAGNUM)
+    set(CORRADE_BUILD_DEPRECATED OFF CACHE BOOL "" FORCE)
+    set(CORRADE_BUILD_STATIC ON CACHE BOOL "" FORCE)
+    set(CORRADE_BUILD_STATIC_PIC ON CACHE BOOL "" FORCE)
+    set(CORRADE_BUILD_STATIC_UNIQUE_GLOBALS OFF CACHE BOOL "" FORCE)
+    set(CORRADE_BUILD_TESTS OFF CACHE BOOL "" FORCE)
+    set(CORRADE_WITH_INTERCONNECT OFF CACHE BOOL "" FORCE)
+    set(CORRADE_WITH_PLUGINMANAGER OFF CACHE BOOL "" FORCE)
+    set(CORRADE_WITH_TESTSUITE OFF CACHE BOOL "" FORCE)
+    set(CORRADE_WITH_MAIN ON CACHE BOOL "" FORCE)
+    add_subdirectory(third-party/corrade EXCLUDE_FROM_ALL)
 
     set(MAGNUM_BUILD_STATIC ON CACHE BOOL "" FORCE)
     set(MAGNUM_BUILD_STATIC_PIC ON CACHE BOOL "" FORCE)
@@ -85,7 +96,9 @@ if(NOT SAVETOOL_USE_SYSTEM_LIBS)
     set(IMGUI_DIR ${CMAKE_CURRENT_SOURCE_DIR}/third-party/imgui)
     set(MAGNUM_WITH_IMGUI ON CACHE BOOL "" FORCE)
     add_subdirectory(third-party/magnum-integration EXCLUDE_FROM_ALL)
+endif(NOT SAVETOOL_USE_SYSTEM_CORRADE_MAGNUM)
 
+if(NOT SAVETOOL_USE_SYSTEM_LIBZIP)
     set(ENABLE_COMMONCRYPTO OFF CACHE BOOL "" FORCE)
     set(ENABLE_GNUTLS OFF CACHE BOOL "" FORCE)
     set(ENABLE_MBEDTLS OFF CACHE BOOL "" FORCE)
@@ -99,12 +112,16 @@ if(NOT SAVETOOL_USE_SYSTEM_LIBS)
     set(BUILD_EXAMPLES OFF CACHE BOOL "" FORCE)
     set(BUILD_DOC OFF CACHE BOOL "" FORCE)
     add_subdirectory(third-party/libzip EXCLUDE_FROM_ALL)
+endif(NOT SAVETOOL_USE_SYSTEM_LIBZIP)
 
+if(NOT SAVETOOL_USE_SYSTEM_EFSW)
     set(VERBOSE OFF CACHE BOOL "" FORCE)
     set(BUILD_TEST_APP OFF CACHE BOOL "" FORCE)
     set(EFSW_INSTALL OFF CACHE BOOL "" FORCE)
     add_subdirectory(third-party/efsw EXCLUDE_FROM_ALL)
+endif(NOT SAVETOOL_USE_SYSTEM_EFSW)
 
+if(NOT SAVETOOL_USE_SYSTEM_LIBCURL)
     set(BUILD_CURL_EXE OFF CACHE BOOL "" FORCE)
     set(ENABLE_UNICODE ON CACHE BOOL "" FORCE)
     set(ENABLE_INET_PTON OFF CACHE BOOL "" FORCE)
@@ -118,6 +135,6 @@ if(NOT SAVETOOL_USE_SYSTEM_LIBS)
     set(CURL_USE_SCHANNEL ON CACHE BOOL "" FORCE)
     set(CURL_USE_LIBSSH2 OFF CACHE BOOL "" FORCE) # For some reason, even when HTTP_ONLY is set to ON, libcurl will try to link to libssh2.
     add_subdirectory(third-party/curl EXCLUDE_FROM_ALL)
-endif(NOT SAVETOOL_USE_SYSTEM_LIBS)
+endif(NOT SAVETOOL_USE_SYSTEM_LIBCURL)
 
 add_subdirectory(src)

src/CMakeLists.txt

@@ -26,11 +26,18 @@ if(CORRADE_TARGET_WINDOWS)
 endif()
 find_package(Magnum REQUIRED GL Sdl2Application)
 find_package(MagnumIntegration REQUIRED ImGui)
-if(SAVETOOL_USE_SYSTEM_LIBS)
+
+if(SAVETOOL_USE_SYSTEM_LIBZIP)
     find_package(libzip REQUIRED)
+endif(SAVETOOL_USE_SYSTEM_LIBZIP)
+
+if(SAVETOOL_USE_SYSTEM_EFSW)
     find_package(efsw REQUIRED)
+endif(SAVETOOL_USE_SYSTEM_EFSW)
+
+if(SAVETOOL_USE_SYSTEM_LIBCURL)
     find_package(CURL REQUIRED HTTPS)
-endif()
+endif(SAVETOOL_USE_SYSTEM_LIBCURL)
 
 set_directory_properties(PROPERTIES CORRADE_USE_PEDANTIC_FLAGS ON)
 
@@ -247,10 +254,16 @@ target_link_libraries(MassBuilderSaveTool PRIVATE
     CURL::libcurl_static
 )
 
-if(SAVETOOL_USE_SYSTEM_LIBS)
+if(SAVETOOL_USE_SYSTEM_LIBZIP)
-    target_link_libraries(MassBuilderSaveTool PRIVATE libzip::zip efsw::efsw)
+    target_link_libraries(MassBuilderSaveTool PRIVATE libzip::zip)
 else()
-    target_link_libraries(MassBuilderSaveTool PRIVATE zip efsw)
+    target_link_libraries(MassBuilderSaveTool PRIVATE zip)
+endif()
+
+if(SAVETOOL_USE_SYSTEM_EFSW)
+    target_link_libraries(MassBuilderSaveTool PRIVATE efsw::efsw)
+else()
+    target_link_libraries(MassBuilderSaveTool PRIVATE efsw)
 endif()
 
 if(CORRADE_TARGET_WINDOWS)