fix SDL2 dll deployment on windows when using cmake

- move current SDL2 cmake code on windows to separate file
- add a step for dll deployment on windows

CMakeLists.txt

@@ -238,4 +238,3 @@ if(NOT QT_MKSPEC MATCHES "winrt")
 endif()
 
 include(QGCDeploy)
-

cmake/QGCDeploy.cmake

@@ -39,6 +39,11 @@ elseif(WIN32)
 	include(Windeployqt)
 	windeployqt(QGroundControl "QGroundControl-installer.exe")
 
+	add_custom_command(TARGET QGroundControl POST_BUILD
+		COMMAND ${CMAKE_COMMAND} -E
+		copy_if_different $<TARGET_FILE:sdl2> $<TARGET_FILE_DIR:QGroundControl>
+	)
+
 elseif(ANDROID)
 	include(AddQtAndroidApk)
 	add_qt_android_apk(QGroundControl.apk QGroundControl

libs/CMakeLists.txt

@@ -2,6 +2,7 @@ add_subdirectory(libevents)
 add_subdirectory(qtandroidserialport)
 add_subdirectory(shapelib)
 if (WIN32)
+    add_subdirectory(sdl2)
     add_subdirectory(zlib)
 endif (WIN32)
 if (GST_FOUND)

libs/sdl2/CMakeLists.txt

@@ -0,0 +1,16 @@
+set(SDL2_LIB_BASE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/msvc/lib)
+
+add_library(sdl2 SHARED IMPORTED GLOBAL)
+
+if(CMAKE_SIZEOF_VOID_P EQUAL 8)  # 64 bits
+    set(SDL2_LIB_BASE_PATH ${SDL2_LIB_BASE_PATH}/x64)
+elseif(CMAKE_SIZEOF_VOID_P EQUAL 4)  # 32 bits
+    set(SDL2_LIB_BASE_PATH ${SDL2_LIB_BASE_PATH}/x86)
+endif()
+
+target_link_libraries(sdl2 INTERFACE ${SDL2_LIB_BASE_PATH}/SDL2.lib)
+target_include_directories(sdl2 INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/msvc/include)
+set_property(TARGET sdl2 PROPERTY IMPORTED_IMPLIB_RELEASE "${SDL2_LIB_BASE_PATH}/SDL2.lib")
+set_property(TARGET sdl2 PROPERTY IMPORTED_LOCATION_RELEASE "${SDL2_LIB_BASE_PATH}/SDL2.dll")
+set_property(TARGET sdl2 PROPERTY IMPORTED_IMPLIB_DEBUG "${SDL2_LIB_BASE_PATH}/SDL2.lib")
+set_property(TARGET sdl2 PROPERTY IMPORTED_LOCATION_DEBUG "${SDL2_LIB_BASE_PATH}/SDL2.dll")

src/Joystick/CMakeLists.txt

@@ -25,17 +25,7 @@ target_link_libraries(Joystick
 target_include_directories(Joystick PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
 
 if(WIN32)
-        include_directories(${CMAKE_SOURCE_DIR}/libs/sdl2/msvc/include)
-	# Support both 32 and 64 bit builds
-	if (${CMAKE_SIZEOF_VOID_P} MATCHES 8)
-                set(SDL2_LIBRARIES "${CMAKE_SOURCE_DIR}/libs/sdl2/msvc/lib/x64/SDL2.lib;${CMAKE_SOURCE_DIR}/libs/sdl2/msvc/lib/x64/SDL2main.lib")
-	else ()
-                set(SDL2_LIBRARIES "${CMAKE_SOURCE_DIR}/libs/sdl2/msvc/lib/x86/SDL2.lib;${CMAKE_SOURCE_DIR}/libs/sdl2/msvc/lib/x86/SDL2main.lib")
-	endif ()
-
-	string(STRIP "${SDL2_LIBRARIES}" SDL2_LIBRARIES)
-
-	target_link_libraries(Joystick PUBLIC ${SDL2_LIBRARIES})
+	target_link_libraries(Joystick PUBLIC sdl2)
 else()
 	find_package(SDL2 REQUIRED)
 	if (IS_DIRECTORY ${SDL2_INCLUDE_DIRS})