Fix Linux build process

Update to use SDL2 2.0.9
Add `XML_DEV_RANDOM` flag to expath linux build
Fix compilation error in `zl-gfx`

cmake/cmake/third-party/expat/CMakeLists.txt

@@ -16,6 +16,10 @@ if ( BUILD_HTML )
   set ( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DHAVE_MEMMOVE=1 " )
 endif ( BUILD_HTML )
 
+if ( BUILD_LINUX )
+  set ( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DHAVE_MEMMOVE=1 -DXML_DEV_URANDOM" )
+endif ( BUILD_LINUX )
+
 set ( EXPAT_INCLUDES "${CMAKE_CURRENT_SOURCE_DIR}" )
 
 file ( GLOB_RECURSE EXPAT_SOURCES "${CMAKE_CURRENT_SOURCE_DIR}/*.c" )

cmake/cmake/third-party/sdl2/CMakeLists.txt

@@ -2,13 +2,13 @@ cmake_minimum_required ( VERSION 3.0 )
 project ( SDL2-static )
 include(ExternalProject)
 
-set (SDL2_SOURCE_DIR "${MOAI_ROOT}/3rdparty/sdl2-2.0.4")
+set (SDL2_SOURCE_DIR "${MOAI_ROOT}/3rdparty/sdl2-2.0.9")
 set (SDL2_BINARY_DIR "${CMAKE_CURRENT_BINARY_DIR}/binarydir")
 ExternalProject_Add(sdl2
    SOURCE_DIR "${SDL2_SOURCE_DIR}"
    CMAKE_ARGS "-DCMAKE_INSTALL_PREFIX=${CMAKE_CURRENT_BINARY_DIR}/install"  -DSDL_SHARED=OFF -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE} -DLIBC=ON
    CMAKE_CACHE_ARGS "-DSDL2_SOURCE_DIR:string=${SDL2_SOURCE_DIR}" "-DSDL2_BINARY_DIR:string=${SDL2_BINARY_DIR}" "-DSDL_STATIC:bool=on" "-DSDL_SHARED:bool=off" 
-   PREFIX "${CMAKE_CURRENT_BINARY_DIR}/sdl2-2.0.4"
+   PREFIX "${CMAKE_CURRENT_BINARY_DIR}/sdl2-2.0.9"
    INSTALL_DIR "${CMAKE_CURRENT_BINARY_DIR}/install"
 )
 

src/zl-gfx/ZLGfxDevice.cpp

@@ -124,7 +124,7 @@ void ZLGfxDevice::Initialize () {
 
 		// if framebuffer object is not in code, check to see if it's available as
 		// an extension and remap to core function pointers if so
-		if (( isOpenGLES == false ) && ( majorVersion < 3 )) {
+		if (( isOpenGLES == false ) && ( sMajorVersion < 3 )) {
 
 			if ( glewIsSupported ( "GL_EXT_framebuffer_object" )) {