filamentapp: fix vulkan dependency (#6987)

Fixes #6983

libs/filamentapp/include/filamentapp/FilamentApp.h

@@ -49,10 +49,12 @@ class ImGuiHelper;
 class IBL;
 class MeshAssimp;
 
+#if defined(FILAMENT_DRIVER_SUPPORTS_VULKAN)
 // For customizing the vulkan backend
 namespace filament::backend {
 class VulkanPlatform;
 }
+#endif
 
 class FilamentApp {
 public:
@@ -250,7 +252,9 @@ private:
     float mCameraNear = 0.1f;
     float mCameraFar = 100.0f;
 
+#if defined(FILAMENT_DRIVER_SUPPORTS_VULKAN)
     filament::backend::VulkanPlatform* mVulkanPlatform = nullptr;
+#endif
 };
 
 #endif // TNT_FILAMENT_SAMPLE_FILAMENTAPP_H

libs/filamentapp/src/FilamentApp.cpp

@@ -44,7 +44,9 @@
 #include <filament/DebugRegistry.h>
 #endif
 
+#if defined(FILAMENT_DRIVER_SUPPORTS_VULKAN)
 #include <backend/platforms/VulkanPlatform.h>
+#endif
 
 #include <filagui/ImGuiHelper.h>
 
@@ -64,6 +66,7 @@ namespace {
 
 using namespace filament::backend;
 
+#if defined(FILAMENT_DRIVER_SUPPORTS_VULKAN)
 class FilamentAppVulkanPlatform : public VulkanPlatform {
 public:
     FilamentAppVulkanPlatform(std::string const& gpuHint) {
@@ -85,6 +88,7 @@ public:
 private:
     VulkanPlatform::GPUPreference mPreference;
 };
+#endif
 
 } // anonymous namespace
 
@@ -473,9 +477,11 @@ void FilamentApp::run(const Config& config, SetupCallback setupCallback,
     Engine::destroy(&mEngine);
     mEngine = nullptr;
 
+#if defined(FILAMENT_DRIVER_SUPPORTS_VULKAN)
     if (mVulkanPlatform) {
         delete mVulkanPlatform;
     }
+#endif
 }
 
 // RELATIVE_ASSET_PATH is set inside samples/CMakeLists.txt and used to support multi-configuration
@@ -584,11 +590,13 @@ FilamentApp::Window::Window(FilamentApp* filamentApp,
         #endif
 
         if (backend == Engine::Backend::VULKAN) {
-            mFilamentApp->mVulkanPlatform = new FilamentAppVulkanPlatform(config.vulkanGPUHint);
-            return Engine::Builder()
-                    .backend(backend)
-                    .platform(mFilamentApp->mVulkanPlatform)
-                    .build();
+            #if defined(FILAMENT_DRIVER_SUPPORTS_VULKAN)
+                mFilamentApp->mVulkanPlatform = new FilamentAppVulkanPlatform(config.vulkanGPUHint);
+                return Engine::Builder()
+                        .backend(backend)
+                        .platform(mFilamentApp->mVulkanPlatform)
+                        .build();
+            #endif
         }
         return Engine::Builder().backend(backend).build();
     };