cmake changes to make SDL optional in the future

CMakeLists.txt

 
 #################################################################
 
-# Configuration Header file
-configure_file (
-    "${PROJECT_SOURCE_DIR}/cmake/Config.h.in"
-    "${PROJECT_BINARY_DIR}/Config.h"
-)
-
 # Include directories
 include_directories ("${PROJECT_SOURCE_DIR}/include")
 include_directories ("${PROJECT_BINARY_DIR}")

cmake/Config.h.in

 #define VERSION "OpenRaider-@OpenRaider_VERSION_MAJOR@.@OpenRaider_VERSION_MINOR@.@OpenRaider_VERSION_MICRO@@OpenRaider_VERSION_RELEASE@ (@CMAKE_BUILD_TYPE@)"
 #define BUILD_HOST "@OpenRaider_BUILD_HOST@"
+

include/WindowSDL.h

 #ifndef _WINDOW_SDL_H_
 #define _WINDOW_SDL_H_
 
+#include "SDL.h"
+
 #include "Window.h"
 
 /*!
     unsigned int mHeight;
     bool mFullscreen;
     bool mMousegrab;
+
+    SDL_Window *mWindow;      //!< This is the pointer to the SDL surface
+    SDL_GLContext mGLContext; //!< The OpenGL Context
 };
 
 #endif

src/CMakeLists.txt

+# Add SDL2 Library
+find_package (SDL2)
+include_directories (SYSTEM ${SDL2_INCLUDE_DIR})
+set (LIBS ${LIBS} ${SDL2_LIBRARY})
+
+# Add SDL2_ttf Library
+find_package (SDL2TTF)
+include_directories (SYSTEM ${SDL2TTF_INCLUDE_DIR})
+set (LIBS ${LIBS} ${SDL2TTF_LIBRARY})
+
+# Add OpenGL Library
+find_package (OpenGL REQUIRED)
+include_directories (SYSTEM ${OPENGL_INCLUDE_DIRS})
+set (LIBS ${LIBS} ${OPENGL_LIBRARIES})
+
+# Add OpenAL Library
+find_package (OpenAL REQUIRED)
+include_directories (SYSTEM ${OPENAL_INCLUDE_DIRS})
+set (LIBS ${LIBS} ${OPENAL_LIBRARIES})
+
+# Add ALUT Library
+find_package (ALUT REQUIRED)
+include_directories (SYSTEM ${ALUT_INCLUDE_DIRS})
+set (LIBS ${LIBS} ${ALUT_LIBRARIES})
+
+# Add Z Library
+find_package (ZLIB REQUIRED)
+include_directories (SYSTEM ${ZLIB_INCLUDE_DIRS})
+set (LIBS ${LIBS} ${ZLIB_LIBRARIES})
+
+#################################################################
+
 # Set Source files
 set (SRCS ${SRCS} "main.cpp")
 set (SRCS ${SRCS} "OpenRaider.cpp")
 set (SRCS ${SRCS} "Sound.cpp")
-set (SRCS ${SRCS} "WindowSDL.cpp")
+
+# Select available Windowing library
+if (SDL2_FOUND AND SDL2TTF_FOUND)
+    set (SRCS ${SRCS} "WindowSDL.cpp")
+else (SDL2_FOUND AND SDL2TTF_FOUND)
+    # Currently only SDL2 support
+    message (FATAL_ERROR "SDL2 and SDL2-TTF are required!")
+endif (SDL2_FOUND AND SDL2TTF_FOUND)
+
+#################################################################
+
+# Configuration Header file
+configure_file (
+    "${PROJECT_SOURCE_DIR}/cmake/Config.h.in"
+    "${PROJECT_BINARY_DIR}/Config.h"
+)
 
 #################################################################
 
 # Add Math Library
 set (LIBS ${LIBS} m)
 
-# Add SDL2 Library
-find_package (SDL2 REQUIRED)
-include_directories (SYSTEM ${SDL2_INCLUDE_DIR})
-set (LIBS ${LIBS} ${SDL2_LIBRARY})
-
-# Add SDL2_ttf Library
-find_package (SDL2TTF REQUIRED)
-include_directories (SYSTEM ${SDL2TTF_INCLUDE_DIR})
-set (LIBS ${LIBS} ${SDL2TTF_LIBRARY})
-
-# Add OpenGL Library
-find_package (OpenGL REQUIRED)
-include_directories (SYSTEM ${OPENGL_INCLUDE_DIRS})
-set (LIBS ${LIBS} ${OPENGL_LIBRARIES})
-
-# Add OpenAL Library
-find_package (OpenAL REQUIRED)
-include_directories (SYSTEM ${OPENAL_INCLUDE_DIRS})
-set (LIBS ${LIBS} ${OPENAL_LIBRARIES})
-
-# Add ALUT Library
-find_package (ALUT REQUIRED)
-include_directories (SYSTEM ${ALUT_INCLUDE_DIRS})
-set (LIBS ${LIBS} ${ALUT_LIBRARIES})
-
-# Add Z Library
-find_package (ZLIB REQUIRED)
-include_directories (SYSTEM ${ZLIB_INCLUDE_DIRS})
-set (LIBS ${LIBS} ${ZLIB_LIBRARIES})
-
 # Add utils Library
 set (LIBS ${LIBS} OpenRaider_math)
 set (LIBS ${LIBS} OpenRaider_utils)