add camera utils to API

ios/src/FilamentViewer.cpp

@@ -121,6 +121,7 @@ FilamentViewer::FilamentViewer(void *layer, LoadResource loadResource,
   Entity camera = EntityManager::get().create();
 
   _mainCamera = _engine->createCamera(camera);
+
   Log("Main camera created");
   _view = _engine->createView();
   _view->setScene(_scene);
@@ -133,6 +134,8 @@ FilamentViewer::FilamentViewer(void *layer, LoadResource loadResource,
   _view->setColorGrading(colorGrading);
 
   _cameraFocalLength = 28.0f;
+  _mainCamera->setLensProjection(_cameraFocalLength, 1.0f, kNearPlane,
+                                 kFarPlane);
   _mainCamera->setExposure(kAperture, kShutterSpeed, kSensitivity);
   #if TARGET_OS_IPHONE
     _swapChain = _engine->createSwapChain(layer, filament::backend::SWAP_CHAIN_CONFIG_APPLE_CVPIXELBUFFER);
@@ -435,6 +438,25 @@ void FilamentViewer::removeAsset(SceneAsset *asset) {
   mtx.unlock();
 }
 
+///
+/// Set the focal length of the active camera.
+///
+void FilamentViewer::setCameraFocalLength(float focalLength) {
+  Camera& cam =_view->getCamera();
+  _cameraFocalLength = focalLength;
+  cam.setLensProjection(_cameraFocalLength, 1.0f, kNearPlane,
+                                 kFarPlane);                            
+}
+
+///
+/// Set the focus distance of the active camera.
+///
+void FilamentViewer::setCameraFocusDistance(float focusDistance) {
+  Camera& cam =_view->getCamera();
+  _cameraFocusDistance = focusDistance;
+  cam.setFocusDistance(_cameraFocusDistance);                           
+}
+
 ///
 /// Sets the active camera to the first GLTF camera node found in the hierarchy.
 /// Useful when your asset only has one camera.

ios/src/FilamentViewer.hpp

@@ -76,6 +76,8 @@ namespace polyvox {
 
             void setCameraPosition(float x, float y, float z);
             void setCameraRotation(float rads, float x, float y, float z);
+            void setCameraFocalLength(float fl);
+            void setCameraFocusDistance(float focusDistance);
 
         private:
             void createImageRenderable();
@@ -120,7 +122,8 @@ namespace polyvox {
 
             bool _actualSize = false;     
             
-            float _cameraFocalLength = 0.0f;
+            float _cameraFocalLength = 28.0f;
+            float _cameraFocusDistance = 0.0f;
 
             // these flags relate to the textured quad we use for rendering unlit background images
             Texture* _imageTexture = nullptr;

ios/src/PolyvoxFilamentApi.cpp

@@ -57,11 +57,15 @@ extern "C" {
   }
 
   void set_camera_position(void* viewer, float x, float y, float z) {
-    return ((FilamentViewer*)viewer)->setCameraPosition(x, y, z);
+    ((FilamentViewer*)viewer)->setCameraPosition(x, y, z);
   }
 
   void set_camera_rotation(void* viewer, float rads, float x, float y, float z) {
-    return ((FilamentViewer*)viewer)->setCameraRotation(rads, x, y, z);
+    ((FilamentViewer*)viewer)->setCameraRotation(rads, x, y, z);
+  }
+
+  void set_camera_focal_length(void* viewer, float focalLength) {
+    ((FilamentViewer*)viewer)->setCameraFocalLength(focalLength);
   }
 
   void render(

ios/src/PolyvoxFilamentApi.hpp

@@ -60,5 +60,7 @@ void stop_animation(void* asset, int index);
 void set_camera_position(void* viewer, float x, float y, float z);
 
 void set_camera_rotation(void* viewer, float rads, float x, float y, float z);
+void set_camera_focal_length(void* viewer, float focalLength);
+void set_camera_focus_distance(void* viewer, float focusDistance);
       
 #endif