[WIN32SS] Introduce the NATIVE_REACTX define and disable some Dx calls

The code itself isn't wrong but we're entirely missing the logic needed
to make it work. This leads to spontaneous crashes with video drivers and
various unity games.

win32ss/CMakeLists.txt

@@ -4,6 +4,10 @@ set(USE_DIBLIB FALSE)
 # Give WIN32 subsystem its own project.
 PROJECT(WIN32SS)
 
+if (NATIVE_REACTX)
+    add_definitions(-DNATIVE_REACTX)
+endif()
+
 add_subdirectory(drivers)
 
 if(USE_DIBLIB)

win32ss/gdi/eng/pdevobj.c

@@ -337,6 +337,7 @@ PDEVOBJ_pSurface(
     return ppdev->pSurface;
 }
 
+#ifdef NATIVE_REACTX
 BOOL
 PDEVOBJ_bEnableDirectDraw(
     _Inout_ PPDEVOBJ ppdev)
@@ -385,6 +386,7 @@ PDEVOBJ_vSwitchDirectDraw(
     TRACE("DxDdDynamicModeChange(ppdev %p, ppdev2 %p)\n", ppdev, ppdev2);
     pfnDdDynamicModeChange((HDEV)ppdev, (HDEV)ppdev2, 0);
 }
+#endif
 
 VOID
 PDEVOBJ_vEnableDisplay(
@@ -415,7 +417,9 @@ PDEVOBJ_bDisableDisplay(
     if (ppdev->flFlags & PDEV_DISABLED)
         return TRUE;
 
+#ifdef NATIVE_REACTX
     PDEVOBJ_vSuspendDirectDraw(ppdev);
+#endif
 
     TRACE("DrvAssertMode(dhpdev %p, FALSE)\n", ppdev->dhpdev);
     assertVal = ppdev->pfn.AssertMode(ppdev->dhpdev, FALSE);
@@ -600,6 +604,7 @@ PDEVOBJ_Create(
         return NULL;
     }
 
+#ifdef NATIVE_REACTX
     /* Enable DirectDraw */
     if (!PDEVOBJ_bEnableDirectDraw(ppdev))
     {
@@ -608,6 +613,7 @@ PDEVOBJ_Create(
         EngUnloadImage(pldev);
         return NULL;
     }
+#endif
 
     /* Remove some acceleration capabilities from driver */
     PDEVOBJ_vFilterDriverHooks(ppdev);
@@ -692,8 +698,10 @@ PDEVOBJ_bDynamicModeChange(
     ppdev->pfn.CompletePDEV(ppdev->dhpdev, (HDEV)ppdev);
     ppdev2->pfn.CompletePDEV(ppdev2->dhpdev, (HDEV)ppdev2);
 
+#ifdef NATIVE_REACTX
     /* Switch DirectDraw mode */
     PDEVOBJ_vSwitchDirectDraw(ppdev, ppdev2);
+#endif
 
     return TRUE;
 }
@@ -724,8 +732,10 @@ PDEVOBJ_bSwitchMode(
     if (!PDEVOBJ_bDisableDisplay(ppdev))
     {
         DPRINT1("PDEVOBJ_bDisableDisplay() failed\n");
+#ifdef NATIVE_REACTX
         /* Resume DirectDraw in case of failure */
         PDEVOBJ_vResumeDirectDraw(ppdev);
+#endif
         goto leave;
     }
 
@@ -745,11 +755,11 @@ PDEVOBJ_bSwitchMode(
         PDEVOBJ_vRelease(ppdevTmp);
         goto leave2;
     }
-
+#ifdef NATIVE_REACTX
     /* 4. Temporarily suspend DirectDraw for mode change */
     PDEVOBJ_vSuspendDirectDraw(ppdev);
     PDEVOBJ_vSuspendDirectDraw(ppdevTmp);
-
+#endif
     /* 5. Switch the PDEVs */
     if (!PDEVOBJ_bDynamicModeChange(ppdev, ppdevTmp))
     {
@@ -758,17 +768,18 @@ PDEVOBJ_bSwitchMode(
         goto leave2;
     }
 
+#ifdef NATIVE_REACTX
     /* 6. Resume DirectDraw */
     PDEVOBJ_vResumeDirectDraw(ppdev);
     PDEVOBJ_vResumeDirectDraw(ppdevTmp);
-
+#endif
     /* Release temp PDEV */
     PDEVOBJ_vRelease(ppdevTmp);
-
+#ifdef NATIVE_REACTX
     /* Re-initialize DirectDraw data */
     ppdev->pEDDgpl->hDev = (HDEV)ppdev;
     ppdev->pEDDgpl->dhpdev = ppdev->dhpdev;
-
+#endif
     /* Update primary display capabilities */
     if (ppdev == gpmdev->ppdevGlobal)
     {