Add compile time endianess

cmake/targets/linux.cmake

@@ -2,6 +2,20 @@
 find_package(SDL2 REQUIRED)
 find_package(OpenGL REQUIRED)
 
+# Setup endianess at compile time to optimize.
+include(TestBigEndian)
+test_big_endian(IS_BIG_ENDIAN)
+if(IS_BIG_ENDIAN)
+  target_compile_definitions(${DUSK_LIBRARY_TARGET_NAME} PUBLIC
+    DUSK_PLATFORM_ENDIAN_BIG
+  )
+else()
+  target_compile_definitions(${DUSK_LIBRARY_TARGET_NAME} PUBLIC
+    DUSK_PLATFORM_ENDIAN_LITTLE
+  )
+endif()
+
+# Link required libraries.
 target_link_libraries(${DUSK_LIBRARY_TARGET_NAME} PUBLIC 
   SDL2
   pthread
@@ -10,6 +24,7 @@ target_link_libraries(${DUSK_LIBRARY_TARGET_NAME} PUBLIC
   m
 )
 
+# Define platform-specific macros.
 target_compile_definitions(${DUSK_LIBRARY_TARGET_NAME} PUBLIC
   DUSK_SDL2
   DUSK_OPENGL