Fixed #include of DXGI header

Fixes #13
diff --git a/src/D3D12MemAlloc.h b/src/D3D12MemAlloc.h
index d340b81..a8c3799 100644
--- a/src/D3D12MemAlloc.h
+++ b/src/D3D12MemAlloc.h
@@ -637,6 +637,13 @@
   are not going to be included into this repository.

 */

 

+// If using this library on a platform different than Windows PC or want to use different version of DXGI,

+// you should include D3D12-compatible headers before this library on your own and define this macro.

+#ifndef D3D12MA_D3D12_HEADERS_ALREADY_INCLUDED

+    #include <d3d12.h>

+    #include <dxgi1_4.h>

+#endif

+

 // Define this macro to 0 to disable usage of DXGI 1.4 (needed for IDXGIAdapter3 and query for memory budget).

 #ifndef D3D12MA_DXGI_1_4

     #ifdef __IDXGIAdapter3_INTERFACE_DEFINED__

@@ -646,13 +653,6 @@
     #endif

 #endif

 

-// If using this library on a platform different than Windows PC, you should

-// include D3D12-compatible header before this library on your own and define this macro.

-#ifndef D3D12MA_D3D12_HEADERS_ALREADY_INCLUDED

-    #include <d3d12.h>

-    #include <dxgi.h>

-#endif

-

 /*

 When defined to value other than 0, the library will try to use

 D3D12_SMALL_RESOURCE_PLACEMENT_ALIGNMENT or D3D12_SMALL_MSAA_RESOURCE_PLACEMENT_ALIGNMENT