simplification pass over os core layer; simplification pass over base arena; set up build.sh; stub out new spot for linux os core

src/os/os_inc.c

@@ -1,33 +1,27 @@
-// Copyright (c) 2024 Epic Games Tools
-// Licensed under the MIT license (https://opensource.org/license/mit/)
-
-////////////////////////////////
-// NOTE(allen): Include OS features for extra features and target OS
-
-#include "core/os_core.c"
-
-#if OS_FEATURE_SOCKET
-#include "socket/os_socket.c"
-#endif
-
-#if OS_FEATURE_GRAPHICAL
-#include "gfx/os_gfx.c"
-#endif
-
-#if OS_WINDOWS
-# include "core/win32/os_core_win32.c"
-# if OS_FEATURE_SOCKET
-#  include "socket/win32/os_socket_win32.c"
-# endif
-# if OS_FEATURE_GRAPHICAL && !OS_GFX_STUB
-#  include "gfx/win32/os_gfx_win32.c"
-# endif
-#elif OS_LINUX
-# include "core/linux/os_core_linux.c"
-#else
-# error no OS layer setup
-#endif
-
-#if OS_GFX_STUB
-#include "gfx/stub/os_gfx_stub.c"
-#endif
+// Copyright (c) 2024 Epic Games Tools
+// Licensed under the MIT license (https://opensource.org/license/mit/)
+
+#include "os/core/os_core.c"
+#if OS_FEATURE_GRAPHICAL
+# include "os/gfx/os_gfx.c"
+#endif
+
+#if OS_WINDOWS
+# include "os/core/win32/os_core_win32.c"
+#elif OS_LINUX
+# include "os/core/linux/os_core_linux.c"
+#else
+# error OS core layer not implemented for this operating system.
+#endif
+
+#if OS_FEATURE_GRAPHICAL
+# if OS_GFX_STUB
+#  include "os/gfx/stub/os_gfx_stub.c"
+# elif OS_WINDOWS
+#  include "os/gfx/win32/os_gfx_win32.c"
+# elif OS_LINUX
+#  include "os/gfx/linux/os_gfx_linux.c"
+# else
+#  error OS graphical layer not implemented for this operating system.
+# endif
+#endif