make Android use new API, add delete_viewer method

ios/src/FilamentViewer.cpp

@@ -334,7 +334,26 @@ void FilamentViewer::setBackgroundImage(const char *resourcePath) {
                                       float3(1.0f));
 }
 
-FilamentViewer::~FilamentViewer() { cleanup(); }
+FilamentViewer::~FilamentViewer() { 
+  clearAssets();
+  _resourceLoader->asyncCancelLoad();
+  Log("c1");
+  _materialProvider->destroyMaterials();
+  Log("c2");
+  AssetLoader::destroy(&_assetLoader);
+  Log("c3");
+  delete _sceneAssetLoader;
+  _engine->destroy(_view);
+  Log("c4");
+  _engine->destroy(_scene);
+  Log("c5");
+  _engine->destroy(_renderer);
+  Log("c6");
+  _engine->destroy(_swapChain);
+  Log("c7");
+  Engine::destroy(&_engine); // clears engine*
+  Log("c8");
+}
 
 Renderer *FilamentViewer::getRenderer() { return _renderer; }
 
@@ -529,12 +548,6 @@ void FilamentViewer::loadIbl(const char *const iblPath) {
   }
 }
 
-void FilamentViewer::cleanup() {
-  _resourceLoader->asyncCancelLoad();
-  _materialProvider->destroyMaterials();
-  AssetLoader::destroy(&_assetLoader);
-};
-
 void FilamentViewer::render() {
 
   if (!_view || !_mainCamera || !_swapChain) {

ios/src/PolyvoxFilamentApi.cpp

@@ -3,6 +3,7 @@
 
 #include "ResourceBuffer.hpp"
 #include "FilamentViewer.hpp"
+#include "Log.hpp"
 
 using namespace polyvox;
 
@@ -15,6 +16,14 @@ extern "C" {
     return nullptr;
   }
 
+  
+  void filament_viewer_delete(void* viewer) {
+    delete((FilamentViewer*)viewer);
+    Log(
+      "deleted"
+    );
+  }
+
   void set_background_image(void* viewer, const char* path) {
     ((FilamentViewer*)viewer)->setBackgroundImage(path);
   }

ios/src/PolyvoxFilamentApi.hpp

@@ -7,6 +7,7 @@ typedef struct ResourceBuffer ResourceBuffer;
 
 //ResourceBuffer create_resource_buffer(const void* data, const uint32_t size, const uint32_t id);
 void* filament_viewer_new(void* texture, void* loadResource, void* freeResource);
+void* filament_viewer_delete(void* viewer);
 void set_background_image(void* viewer, const char* path);
 void load_skybox(void* viewer, const char* skyboxPath);
 void load_ibl(void* viewer, const char* iblPath);