Initial support for building for Windows with OpenWatcom

src/core/windows/SDL_windows.h

@@ -30,6 +30,8 @@
 #ifndef UNICODE
 #define UNICODE 1
 #endif
+#undef WINVER
+#define WINVER 0x0501
 #undef _WIN32_WINNT
 #define _WIN32_WINNT  0x501   /* Need 0x410 for AlphaBlend() and 0x500 for EnumDisplayDevices(), 0x501 for raw input */
 #endif

src/dynapi/SDL_dynapi.h

@@ -61,7 +61,7 @@
 #define SDL_DYNAMIC_API 0  /* vitasdk doesn't support dynamic linking */
 #elif defined(__NGAGE__)
 #define SDL_DYNAMIC_API 0  /* The N-Gage doesn't support dynamic linking either */
-#elif defined(__OS2__)
+#elif defined(__OS2__) || defined(__WATCOMC__)
 #define SDL_DYNAMIC_API 0  /* see github bugs #5667 and #5669 */
 #elif defined(DYNAPI_NEEDS_DLOPEN) && !defined(HAVE_DLOPEN)
 #define SDL_DYNAMIC_API 0  /* we need dlopen(), but don't have it.... */

src/render/direct3d/SDL_render_d3d.c

@@ -41,6 +41,13 @@
 
 #include "SDL_shaders_d3d.h"
 
+#ifdef __WATCOMC__
+/* FIXME: Remove this once https://github.com/open-watcom/open-watcom-v2/pull/868 is merged */
+#define D3DBLENDOP_REVSUBTRACT 3
+/* FIXME: Remove this once https://github.com/open-watcom/open-watcom-v2/pull/869 is merged */
+#define D3DERR_UNSUPPORTEDCOLOROPERATION MAKE_D3DHRESULT( 2073 )
+#endif
+
 typedef struct
 {
     SDL_Rect viewport;

src/video/windows/SDL_windowsvideo.c

@@ -35,6 +35,22 @@
 #include "SDL_windowsshape.h"
 #include "SDL_windowsvulkan.h"
 
+#ifdef D3D_DEBUG_INFO
+#ifndef D3D_SDK_VERSION
+#define D3D_SDK_VERSION   (32 | 0x80000000)
+#endif
+#ifndef D3D9b_SDK_VERSION
+#define D3D9b_SDK_VERSION (31 | 0x80000000)
+#endif
+#else /**/
+#ifndef D3D_SDK_VERSION
+#define D3D_SDK_VERSION   32
+#endif
+#ifndef D3D9b_SDK_VERSION
+#define D3D9b_SDK_VERSION 31
+#endif
+#endif
+
 /* Initialization/Query functions */
 static int WIN_VideoInit(_THIS);
 static void WIN_VideoQuit(_THIS);