[macOS] Workaround for changing vsync at runtime in Vulkan mode

lib/framework/wzapp.h

@@ -91,6 +91,7 @@ bool wzChangeWindowMode(WINDOW_MODE mode, bool silent = false);
 WINDOW_MODE wzGetCurrentWindowMode();
 bool wzIsFullscreen();
 void wzSetWindowIsResizable(bool resizable);
+void wzPostChangedSwapInterval();
 bool wzIsWindowResizable();
 bool wzChangeDisplayScale(unsigned int displayScale);
 bool wzChangeCursorScale(unsigned int cursorScale);

lib/sdl/main_sdl.cpp

@@ -790,6 +790,39 @@ WINDOW_MODE wzGetToggleFullscreenMode()
 	return altEnterToggleFullscreenMode;
 }
 
+void wzPostChangedSwapInterval()
+{
+#ifdef WZ_OS_MAC
+	if (WZbackend == video_backend::vulkan)
+	{
+		// If using Vulkan backend (and, thus, MoltenVK),
+		// Workaround MoltenVK issue (doesn't seem to fully accept the recreated swapchain until window resize event?)
+		// - Trigger a window resize event (regardless of current window mode)
+		auto currentMode = wzGetCurrentWindowMode();
+		switch (currentMode)
+		{
+			case WINDOW_MODE::desktop_fullscreen:
+			case WINDOW_MODE::fullscreen:
+				if (wzChangeWindowMode(WINDOW_MODE::windowed))
+				{
+					wzChangeWindowMode(currentMode);
+				}
+				break;
+			case WINDOW_MODE::windowed:
+				int currWidth = 0, currHeight = 0;
+				SDL_GetWindowSize(WZwindow, &currWidth, &currHeight);
+
+				// set one bigger than current size
+				SDL_SetWindowSize(WZwindow, currWidth+1, currHeight+1);
+
+				// restore the old windowed size
+				SDL_SetWindowSize(WZwindow, currWidth, currHeight);
+				break;
+		}
+	}
+#endif
+}
+
 bool wzChangeWindowMode(WINDOW_MODE mode, bool silent)
 {
 	auto previousMode = wzGetCurrentWindowMode();

src/frontend.cpp

@@ -2221,6 +2221,7 @@ void seqVsyncMode()
 	{
 		// succeeded changing vsync mode
 		saveCurrentSwapMode(currentVsyncMode);
+		wzPostChangedSwapInterval();
 	}
 }