add an external project for SDL 2

CMakeLists.txt

@@ -126,6 +126,9 @@ set(EXTERNAL_PROJECT_PREFIX "project")
 set_property(DIRECTORY PROPERTY EP_PREFIX ${EXTERNAL_PROJECT_PREFIX})
 setup_externals_binary_dir()
 
+# setup for optional external project dependencies
+option(GET_SDL2 "Download SDL2 as external project" 0)
+
 if (WIN32)
   add_paths_to_lib_paths("${QT_DIR}/bin")
 endif ()

cmake/externals/sdl2/CMakeLists.txt

@@ -0,0 +1,50 @@
+set(EXTERNAL_NAME sdl2)
+
+include(ExternalProject)
+
+if (WIN32)
+  ExternalProject_Add(
+    ${EXTERNAL_NAME}
+    URL http://www.libsdl.org/release/SDL2-devel-2.0.3-VC.zip
+    URL_MD5 30a333bcbe94bc5016e8799c73e86233
+    CONFIGURE_COMMAND ""
+    BUILD_COMMAND ""
+    INSTALL_COMMAND ""
+    LOG_DOWNLOAD 1
+  )
+else ()
+  if (ANDROID)
+    set(ANDROID_CMAKE_ARGS "-DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}" "-DANDROID_NATIVE_API_LEVEL=19")
+  endif ()
+  
+  ExternalProject_Add(
+    ${EXTERNAL_NAME}
+    URL http://www.libsdl.org/release/SDL2-2.0.3.tar.gz
+    URL_MD5 fe6c61d2e9df9ef570e7e80c6e822537
+    CMAKE_ARGS ${ANDROID_CMAKE_ARGS} -DCMAKE_INSTALL_PREFIX:PATH=<INSTALL_DIR>
+    LOG_DOWNLOAD 1
+    LOG_CONFIGURE 1
+    LOG_BUILD 1
+  )
+endif ()
+
+string(TOUPPER ${EXTERNAL_NAME} EXTERNAL_NAME_UPPER)
+
+if (WIN32)
+  ExternalProject_Get_Property(${EXTERNAL_NAME} SOURCE_DIR)
+  set(_ROOT_DIR ${SOURCE_DIR})
+  set(_LIB_DIR "${SOURCE_DIR}/lib/x86")
+  set(_LIB_EXT "lib")
+  
+  set(${EXTERNAL_NAME_UPPER}_DLL_PATH ${_LIB_DIR} CACHE PATH "Location of SDL2 DLL")
+else ()
+  ExternalProject_Get_Property(${EXTERNAL_NAME} INSTALL_DIR)
+  set(_ROOT_DIR ${INSTALL_DIR})
+  
+  set(_LIB_DIR ${INSTALL_DIR}/lib)
+  set(_LIB_EXT "so")
+  set(_LIB_PREFIX "lib")
+endif ()
+
+set(${EXTERNAL_NAME_UPPER}_INCLUDE_DIR ${_ROOT_DIR}/include/SDL2 CACHE PATH "Location of SDL2 include directory")
+set(${EXTERNAL_NAME_UPPER}_LIBRARY_TEMP ${_LIB_DIR}/${_LIB_PREFIX}SDL2.${_LIB_EXT} CACHE FILEPATH "Path to SDL2 library")

cmake/modules/FindSDL2.cmake

@@ -163,48 +163,6 @@ ELSE(CMAKE_SIZEOF_VOID_P EQUAL 8)
   endif ()
 ENDIF(CMAKE_SIZEOF_VOID_P EQUAL 8)
 
-IF(NOT SDL2_BUILDING_LIBRARY)
-	IF(NOT ${SDL2_INCLUDE_DIR} MATCHES ".framework")
-		# Non-OS X framework versions expect you to also dynamically link to
-		# SDL2main. This is mainly for Windows and OS X. Other (Unix) platforms
-		# seem to provide SDL2main for compatibility even though they don't
-		# necessarily need it.
-		# Lookup the 64 bit libs on x64
-		IF(CMAKE_SIZEOF_VOID_P EQUAL 8)
-			FIND_LIBRARY(SDL2MAIN_LIBRARY
-				NAMES SDL2main
-				HINTS
-				${SDL2_SEARCH_DIRS}
-				$ENV{SDL2}
-				PATH_SUFFIXES lib64 lib
-				lib/x64
-				x86_64-w64-mingw32/lib
-				PATHS
-				/sw
-				/opt/local
-				/opt/csw
-				/opt
-				)
-			# On 32bit build find the 32bit libs
-		ELSE(CMAKE_SIZEOF_VOID_P EQUAL 8)
-			FIND_LIBRARY(SDL2MAIN_LIBRARY
-				NAMES SDL2main
-				HINTS
-				${SDL2_SEARCH_DIRS}
-				$ENV{SDL2}
-				PATH_SUFFIXES lib
-				lib/x86
-				i686-w64-mingw32/lib
-				PATHS
-				/sw
-				/opt/local
-				/opt/csw
-				/opt
-				)
-		ENDIF(CMAKE_SIZEOF_VOID_P EQUAL 8)
-	ENDIF(NOT ${SDL2_INCLUDE_DIR} MATCHES ".framework")
-ENDIF(NOT SDL2_BUILDING_LIBRARY)
-
 # SDL2 may require threads on your system.
 # The Apple build may not need an explicit flag because one of the
 # frameworks may already provide it.
@@ -222,13 +180,6 @@ ENDIF(MINGW)
 
 SET(SDL2_FOUND "NO")
 	IF(SDL2_LIBRARY_TEMP)
-		# For SDL2main
-		IF(NOT SDL2_BUILDING_LIBRARY)
-			IF(SDL2MAIN_LIBRARY)
-				SET(SDL2_LIBRARY_TEMP ${SDL2MAIN_LIBRARY} ${SDL2_LIBRARY_TEMP})
-			ENDIF(SDL2MAIN_LIBRARY)
-		ENDIF(NOT SDL2_BUILDING_LIBRARY)
-
 		# For OS X, SDL2 uses Cocoa as a backend so it must link to Cocoa.
 		# CMake doesn't display the -framework Cocoa string in the UI even
 		# though it actually is there if I modify a pre-used variable.

interface/CMakeLists.txt

@@ -119,6 +119,8 @@ link_hifi_libraries(shared octree environment gpu model fbx metavoxels networkin
                     audio audio-client animation script-engine physics 
                     render-utils entities-renderer)
 
+add_dependency_external_projects(sdl2)
+
 # perform standard include and linking for found externals
 foreach(EXTERNAL ${OPTIONAL_EXTERNALS})