Fix broken Alt+Tab behavior on Windows

app/streaming/video/ffmpeg-renderers/dxva2.cpp

@@ -608,6 +608,13 @@ bool DXVA2Renderer::initialize(SDL_Window* window, int videoFormat, int width, i
         return false;
     }
 
+    // For some reason, using Direct3D9Ex breaks this with multi-monitor setups.
+    // When focus is lost, the window is minimized then immediately restored without
+    // input focus. This glitches out the renderer and a bunch of other stuff.
+    // Direct3D9Ex itself seems to have this minimize on focus loss behavior on its
+    // own, so just disable SDL's handling of the focus loss event.
+    SDL_SetHint(SDL_HINT_VIDEO_MINIMIZE_ON_FOCUS_LOSS, "0");
+
     return true;
 }