fix: update imgui helpers (#98)

update supportsViewports to correctly return false for swithc
add supportsWindowedFullscreen method

Co-authored-by: briaguya <briaguya@alice>

src/menu/ImGuiImpl.cpp

@@ -312,7 +312,25 @@ void ImGuiRenderDrawData(ImDrawData* data) {
     }
 }
 
+bool supportsWindowedFullscreen() {
+#ifdef __SWITCH__
+    return false;
+#endif
+
+    // We don't yet support windowed fullscreen on DirectX
+    switch (impl.backend) {
+        case Backend::SDL:
+            return true;
+        default:
+            return false;
+    }
+}
+
 bool supportsViewports() {
+#ifdef __SWITCH__
+    return false;
+#endif
+
     switch (impl.backend) {
         case Backend::DX11:
             return true;

src/menu/ImGuiImpl.h

@@ -66,6 +66,7 @@ typedef struct {
     WindowDrawFunc drawFunc;
 } CustomWindow;
 
+bool supportsWindowedFullscreen();
 bool supportsViewports();
 
 void Init(WindowImpl window_impl);