camera fixes for assets with large bounding boxes

ios/include/FilamentViewer.hpp

@@ -177,7 +177,7 @@ namespace polyvox {
             void loadPngTexture(string path, ResourceBuffer data);
             void loadTextureFromPath(string path);
             
-            
+            Manipulator<double>* _manipulator = nullptr;
             void _createManipulator();
             uint32_t _lastFrameTimeInNanos;
     };

ios/polyvox_filament.podspec

@@ -13,7 +13,7 @@ A new flutter plugin project.
   s.license          = { :file => '../LICENSE' }
   s.author           = { 'Your Company' => 'email@example.com' }
   s.source           = { :path => '.' }
-  s.source_files = 'Classes/*', 'src/*', 'src/ios/*', 'include/filament/*', 'include/*', 'include/material/*.c'
+  s.source_files = 'Classes/*', 'src/*', "src/camutils/*", 'src/ios/*', 'include/filament/*', 'include/*', 'include/material/*.c'
   s.public_header_files = 'include/SwiftPolyvoxFilamentPlugin-Bridging-Header.h',  'include/PolyvoxFilamentApi.h', 'include/PolyvoxFilamentFFIApi.h', 'include/ResourceBuffer.hpp', 'include/Log.hpp'
   s.dependency 'Flutter' 
   s.platform = :ios, '12.1'
@@ -26,7 +26,7 @@ A new flutter plugin project.
     'OTHER_CFLAGS' => '"-fvisibility=default" "$(inherited)"',
     'USER_HEADER_SEARCH_PATHS' => '"${PODS_ROOT}/../.symlinks/plugins/polyvox_filament/ios/include" "${PODS_ROOT}/../.symlinks/plugins/polyvox_filament/ios/include/filament" "${PODS_ROOT}/../.symlinks/plugins/polyvox_filament/ios/src" "${PODS_ROOT}/../.symlinks/plugins/polyvox_filament/ios/src/image" "${PODS_ROOT}/../.symlinks/plugins/polyvox_filament/ios/src/shaders"  "$(inherited)"',
     'ALWAYS_SEARCH_USER_PATHS' => 'YES',
-    "OTHER_LDFLAGS" =>  '-lfilament -lbackend -lfilameshio -lviewer -lfilamat -lgeometry -lutils -lfilabridge -lgltfio_core -lfilament-iblprefilter -limage -limageio -ltinyexr -lcamutils -lgltfio_core -lfilaflat -ldracodec -libl -lktxreader -lpng -lpng16  -lz -lstb -luberzlib -lsmol-v -luberarchive -lzstd -lstdc++',
+    "OTHER_LDFLAGS" =>  '-lfilament -lbackend -lfilameshio -lviewer -lfilamat -lgeometry -lutils -lfilabridge -lgltfio_core -lfilament-iblprefilter -limage -limageio -ltinyexr -lgltfio_core -lfilaflat -ldracodec -libl -lktxreader -lpng -lpng16  -lz -lstb -luberzlib -lsmol-v -luberarchive -lzstd -lstdc++',
     'LIBRARY_SEARCH_PATHS' => '"${PODS_ROOT}/../.symlinks/plugins/polyvox_filament/ios/lib" "$(inherited)"',
   }
 
@@ -38,7 +38,7 @@ A new flutter plugin project.
     'OTHER_CFLAGS' => '"-fvisibility=default" "$(inherited)"',
     'USER_HEADER_SEARCH_PATHS' => '"${PODS_ROOT}/../.symlinks/plugins/polyvox_filament/ios/include" "${PODS_ROOT}/../.symlinks/plugins/polyvox_filament/ios/include/filament" "${PODS_ROOT}/../.symlinks/plugins/polyvox_filament/ios/src" "${PODS_ROOT}/../.symlinks/plugins/polyvox_filament/ios/src/image" "${PODS_ROOT}/../.symlinks/plugins/polyvox_filament/ios/src/shaders"  "$(inherited)"',
     'ALWAYS_SEARCH_USER_PATHS' => 'YES',
-    "OTHER_LDFLAGS" =>  '-lfilament -lbackend -lfilameshio -lviewer -lfilamat -lgeometry -lutils -lfilabridge -lgltfio_core -lfilament-iblprefilter -limage -limageio -ltinyexr -lcamutils -lgltfio_core -lfilaflat -ldracodec -libl -lktxreader -lpng -lpng16   -lz -lstb -luberzlib -lsmol-v -luberarchive -lzstd -lstdc++',
+    "OTHER_LDFLAGS" =>  '-lfilament -lbackend -lfilameshio -lviewer -lfilamat -lgeometry -lutils -lfilabridge -lgltfio_core -lfilament-iblprefilter -limage -limageio -ltinyexr -lgltfio_core -lfilaflat -ldracodec -libl -lktxreader -lpng -lpng16   -lz -lstb -luberzlib -lsmol-v -luberarchive -lzstd -lstdc++',
     'LIBRARY_SEARCH_PATHS' => '"${PODS_ROOT}/../.symlinks/plugins/polyvox_filament/ios/lib" "$(inherited)"',
   }
 

ios/src/FilamentViewer.cpp

@@ -22,6 +22,7 @@
  * limitations under the License.
  */
 #include <filament/Camera.h>
+
 #include <backend/DriverEnums.h>
 #include <backend/platforms/OpenGLPlatform.h>
 #include <filament/ColorGrading.h>
@@ -86,12 +87,14 @@ using namespace gltfio;
 using namespace utils;
 using namespace image;
 
-namespace filament {
+namespace filament
+{
   class IndirectLight;
   class LightManager;
 } // namespace filament
 
-namespace polyvox {
+namespace polyvox
+{
 
   const double kNearPlane = 0.05;  // 5 cm
   const double kFarPlane = 1000.0; // 1 km
@@ -99,7 +102,8 @@ const double kFarPlane = 1000.0; // 1 km
   // const float kAperture = 1.0f;
   // const float kShutterSpeed = 1.0f;
   // const float kSensitivity = 50.0f;
-struct Vertex {
+  struct Vertex
+  {
     filament::math::float2 position;
     uint32_t color;
   };
@@ -112,7 +116,8 @@ static constexpr float4 sFullScreenTriangleVertices[3] = {
   static const uint16_t sFullScreenTriangleIndices[3] = {0, 1, 2};
 
   FilamentViewer::FilamentViewer(const void *sharedContext, const ResourceLoaderWrapper *const resourceLoaderWrapper, void *const platform, const char *uberArchivePath)
-  : _resourceLoaderWrapper(resourceLoaderWrapper) {
+      : _resourceLoaderWrapper(resourceLoaderWrapper)
+  {
 
     ASSERT_POSTCONDITION(_resourceLoaderWrapper != nullptr, "Resource loader must be non-null");
 
@@ -193,8 +198,7 @@ FilamentViewer::FilamentViewer(const void* sharedContext, const ResourceLoaderWr
         _ncm,
         _engine,
         _scene,
-    uberArchivePath
+        uberArchivePath);
-  );
 
     _imageTexture = Texture::Builder()
                         .width(1)
@@ -203,7 +207,8 @@ FilamentViewer::FilamentViewer(const void* sharedContext, const ResourceLoaderWr
                         .format(Texture::InternalFormat::RGB16F)
                         .sampler(Texture::Sampler::SAMPLER_2D)
                         .build(*_engine);
-  try {
+    try
+    {
       _imageMaterial =
           Material::Builder()
               .package(IMAGE_IMAGE_DATA, IMAGE_IMAGE_SIZE)
@@ -211,7 +216,9 @@ FilamentViewer::FilamentViewer(const void* sharedContext, const ResourceLoaderWr
       _imageMaterial->setDefaultParameter("showImage", 0);
       _imageMaterial->setDefaultParameter("backgroundColor", RgbaType::sRGB, float4(0.5f, 0.5f, 0.5f, 1.0f));
       _imageMaterial->setDefaultParameter("image", _imageTexture, _imageSampler);
-  } catch(...) {
+    }
+    catch (...)
+    {
       Log("Failed to load background image material provider");
       std::rethrow_exception(std::current_exception());
     }
@@ -250,21 +257,25 @@ FilamentViewer::FilamentViewer(const void* sharedContext, const ResourceLoaderWr
     _scene->addEntity(imageEntity);
   }
 
-void FilamentViewer::setPostProcessing(bool enabled) {
+  void FilamentViewer::setPostProcessing(bool enabled)
+  {
     _view->setPostProcessingEnabled(enabled);
   }
 
-void FilamentViewer::setBloom(float strength) {
+  void FilamentViewer::setBloom(float strength)
+  {
     decltype(_view->getBloomOptions()) opts;
     opts.enabled = true;
     opts.strength = strength;
     _view->setBloomOptions(opts);
   }
 
-void FilamentViewer::setToneMapping(ToneMapping toneMapping) {
+  void FilamentViewer::setToneMapping(ToneMapping toneMapping)
+  {
 
     ToneMapper *tm;
-  switch(toneMapping) {
+    switch (toneMapping)
+    {
     case ToneMapping::ACES:
       Log("Setting tone mapping to ACES");
       tm = new ACESToneMapper();
@@ -282,21 +293,22 @@ void FilamentViewer::setToneMapping(ToneMapping toneMapping) {
       return;
     }
 
- 
     auto newColorGrading = ColorGrading::Builder().toneMapper(tm).build(*_engine);
     _view->setColorGrading(newColorGrading);
     _engine->destroy(colorGrading);
     delete tm;
   }
 
-void FilamentViewer::setFrameInterval(float frameInterval) {
+  void FilamentViewer::setFrameInterval(float frameInterval)
+  {
     Renderer::FrameRateOptions fro;
     fro.interval = frameInterval;
     _renderer->setFrameRateOptions(fro);
     Log("Set framerate interval to %f", frameInterval);
   }
 
-int32_t FilamentViewer::addLight(LightManager::Type t, float colour, float intensity, float posX, float posY, float posZ, float dirX, float dirY, float dirZ, bool shadows) {
+  int32_t FilamentViewer::addLight(LightManager::Type t, float colour, float intensity, float posX, float posY, float posZ, float dirX, float dirY, float dirZ, bool shadows)
+  {
     auto light = EntityManager::get().create();
     LightManager::Builder(t)
         .color(Color::cct(colour))
@@ -312,30 +324,37 @@ int32_t FilamentViewer::addLight(LightManager::Type t, float colour, float inten
     return entityId;
   }
 
-void FilamentViewer::removeLight(EntityId entityId) {
+  void FilamentViewer::removeLight(EntityId entityId)
+  {
     Log("Removing light with entity ID %d", entityId);
     auto entity = utils::Entity::import(entityId);
-  if(entity.isNull()) {
+    if (entity.isNull())
+    {
       Log("Error: light entity not found under ID %d", entityId);
-  } else {
+    }
+    else
+    {
       remove(_lights.begin(), _lights.end(), entity);
       _scene->remove(entity);
       EntityManager::get().destroy(1, &entity);
     }
   }
 
-void FilamentViewer::clearLights() {
+  void FilamentViewer::clearLights()
+  {
     Log("Removing all lights");
     _scene->removeEntities(_lights.data(), _lights.size());
     EntityManager::get().destroy(_lights.size(), _lights.data());
     _lights.clear();
   }
 
-static bool endsWith(string path, string ending) {
+  static bool endsWith(string path, string ending)
+  {
     return path.compare(path.length() - ending.length(), ending.length(), ending) == 0;
   }
 
-void FilamentViewer::loadKtx2Texture(string path, ResourceBuffer rb) {
+  void FilamentViewer::loadKtx2Texture(string path, ResourceBuffer rb)
+  {
 
     // TODO - check all this
 
@@ -356,34 +375,36 @@ void FilamentViewer::loadKtx2Texture(string path, ResourceBuffer rb) {
     //           ktxreader::Ktx2Reader::TransferFunction::LINEAR);
   }
 
-void FilamentViewer::loadKtxTexture(string path, ResourceBuffer rb) {
+  void FilamentViewer::loadKtxTexture(string path, ResourceBuffer rb)
+  {
     ktxreader::Ktx1Bundle *bundle =
         new ktxreader::Ktx1Bundle(static_cast<const uint8_t *>(rb.data),
                                   static_cast<uint32_t>(rb.size));
 
-    
     // because the ResourceBuffer will go out of scope before the texture callback is invoked, we need to make a copy to the heap
     ResourceBuffer *rbCopy = new ResourceBuffer(rb);
 
     std::vector<void *> *callbackData = new std::vector<void *>{(void *)_resourceLoaderWrapper, rbCopy};
 
-
     _imageTexture =
-          ktxreader::Ktx1Reader::createTexture(_engine, *bundle, false, [](void* userdata) {
+        ktxreader::Ktx1Reader::createTexture(
+            _engine, *bundle, false, [](void *userdata)
+            {
           std::vector<void*>* vec = (std::vector<void*>*)userdata;
           ResourceLoaderWrapper* loader = (ResourceLoaderWrapper*)vec->at(0);
           ResourceBuffer* rb = (ResourceBuffer*) vec->at(1);
           loader->free(*rb);
           delete rb;
-          delete vec;
+          delete vec; },
-      }, callbackData);
+            callbackData);
 
     auto info = bundle->getInfo();
     _imageWidth = info.pixelWidth;
     _imageHeight = info.pixelHeight;
   }
 
-void FilamentViewer::loadPngTexture(string path, ResourceBuffer rb) {
+  void FilamentViewer::loadPngTexture(string path, ResourceBuffer rb)
+  {
 
     polyvox::StreamBufferAdapter sb((char *)rb.data, (char *)rb.data + rb.size);
 
@@ -392,7 +413,8 @@ void FilamentViewer::loadPngTexture(string path, ResourceBuffer rb) {
     LinearImage *image = new LinearImage(ImageDecoder::decode(
         inputStream, path.c_str(), ImageDecoder::ColorSpace::SRGB));
 
-  if (!image->isValid()) {
+    if (!image->isValid())
+    {
       Log("Invalid image : %s", path.c_str());
       return;
     }
@@ -411,7 +433,8 @@ void FilamentViewer::loadPngTexture(string path, ResourceBuffer rb) {
                         .build(*_engine);
 
     Texture::PixelBufferDescriptor::Callback freeCallback = [](void *buf, size_t,
-                                                            void *data) {
+                                                               void *data)
+    {
       delete reinterpret_cast<LinearImage *>(data);
     };
 
@@ -426,43 +449,54 @@ void FilamentViewer::loadPngTexture(string path, ResourceBuffer rb) {
     _resourceLoaderWrapper->free(rb);
   }
 
-void FilamentViewer::loadTextureFromPath(string path) {
+  void FilamentViewer::loadTextureFromPath(string path)
+  {
     string ktxExt(".ktx");
     string ktx2Ext(".ktx2");
     string pngExt(".png");
 
-  if (path.length() < 5) {
+    if (path.length() < 5)
+    {
       Log("Invalid resource path : %s", path.c_str());
       return;
     }
 
     ResourceBuffer rb = _resourceLoaderWrapper->load(path.c_str());
 
-  if(endsWith(path, ktxExt)) {
+    if (endsWith(path, ktxExt))
+    {
       loadKtxTexture(path, rb);
-  } else if(endsWith(path, ktx2Ext)) {
+    }
+    else if (endsWith(path, ktx2Ext))
+    {
       loadKtx2Texture(path, rb);
-  } else if(endsWith(path, pngExt)) {
+    }
+    else if (endsWith(path, pngExt))
+    {
       loadPngTexture(path, rb);
     }
   }
 
-void FilamentViewer::setBackgroundColor(const float r, const float g, const float b, const float a) {
+  void FilamentViewer::setBackgroundColor(const float r, const float g, const float b, const float a)
+  {
     _imageMaterial->setDefaultParameter("showImage", 0);
     _imageMaterial->setDefaultParameter("backgroundColor", RgbaType::sRGB, float4(r, g, b, a));
     _imageMaterial->setDefaultParameter("transform", _imageScale);
   }
 
-void FilamentViewer::clearBackgroundImage() {
+  void FilamentViewer::clearBackgroundImage()
+  {
     _imageMaterial->setDefaultParameter("showImage", 0);
-  if (_imageTexture) {
+    if (_imageTexture)
+    {
       _engine->destroy(_imageTexture);
       _imageTexture = nullptr;
       Log("Destroyed background image texture");
     }
   }
 
-void FilamentViewer::setBackgroundImage(const char *resourcePath, bool fillHeight) {
+  void FilamentViewer::setBackgroundImage(const char *resourcePath, bool fillHeight)
+  {
 
     string resourcePathString(resourcePath);
 
@@ -477,13 +511,15 @@ void FilamentViewer::setBackgroundImage(const char *resourcePath, bool fillHeigh
     const Viewport &vp = _view->getViewport();
     Log("Image width %d height %d vp width %d height %d", _imageWidth, _imageHeight, vp.width, vp.height);
 
-
     float xScale = float(vp.width) / float(_imageWidth);
 
     float yScale;
-  if(fillHeight) {
+    if (fillHeight)
+    {
       yScale = 1.0f;
-  } else { 
+    }
+    else
+    {
       yScale = float(vp.height) / float(_imageHeight);
     }
 
@@ -492,17 +528,16 @@ void FilamentViewer::setBackgroundImage(const char *resourcePath, bool fillHeigh
     _imageMaterial->setDefaultParameter("transform", _imageScale);
     _imageMaterial->setDefaultParameter("image", _imageTexture, _imageSampler);
     _imageMaterial->setDefaultParameter("showImage", 1);
-  
   }
 
-
   ///
   /// Translates the background image by (x,y) pixels.
   /// If clamp is true, x/y are both clamped so that the left/top and right/bottom sides of the background image
   /// are positioned at a max/min of -1/1 respectively
   /// (i.e. you cannot set a position where the left/top or right/bottom sides would be "inside" the screen coordinate space).
   ///
-void FilamentViewer::setBackgroundImagePosition(float x, float y, bool clamp=false) {
+  void FilamentViewer::setBackgroundImagePosition(float x, float y, bool clamp = false)
+  {
 
     // to translate the background image, we apply a transform to the UV coordinates of the quad texture, not the quad itself (see image.mat).
     // this allows us to set a background colour for the quad when the texture has been translated outside the quad's bounds.
@@ -517,7 +552,8 @@ void FilamentViewer::setBackgroundImagePosition(float x, float y, bool clamp=fal
     // y *= _imageScale[1][1];
 
     // TODO - I haven't updated the clamp calculations to work with scaled image width/height percentages so the below code is probably wrong, don't use it until it's fixed.
-  if(clamp) {
+    if (clamp)
+    {
       Log("Clamping background image translation");
       // first, clamp x/y
       auto xScale = float(_imageWidth) / _view->getViewport().width;
@@ -530,20 +566,26 @@ void FilamentViewer::setBackgroundImagePosition(float x, float y, bool clamp=fal
 
       // we need to clamp x so that it can only be translated between (left side touching viewport left) and (right side touching viewport right)
       // if width is less than viewport, these values are 0/1-xScale respectively
-    if(xScale < 1) {
+      if (xScale < 1)
+      {
         xMin = 0;
         xMax = 1 - xScale;
         // otherwise, these value are (xScale-1 and 1-xScale)
-    } else {
+      }
+      else
+      {
         xMin = 1 - xScale;
         xMax = 0;
       }
 
       // do the same for y
-    if(yScale < 1) {
+      if (yScale < 1)
+      {
         yMin = 0;
         yMax = 1 - yScale;
-    } else {
+      }
+      else
+      {
         yMin = 1 - yScale;
         yMax = 0;
       }
@@ -558,26 +600,27 @@ void FilamentViewer::setBackgroundImagePosition(float x, float y, bool clamp=fal
     y = -y;
     Log("x %f y %f", x, y);
 
-  Log("imageScale %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f ", _imageScale[0][0],_imageScale[0][1],_imageScale[0][2], _imageScale[0][3], \
+    Log("imageScale %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f ", _imageScale[0][0], _imageScale[0][1], _imageScale[0][2], _imageScale[0][3],
-  _imageScale[1][0],_imageScale[1][1],_imageScale[1][2], _imageScale[1][3],\
+        _imageScale[1][0], _imageScale[1][1], _imageScale[1][2], _imageScale[1][3],
-  _imageScale[2][0],_imageScale[2][1],_imageScale[2][2], _imageScale[2][3], \
+        _imageScale[2][0], _imageScale[2][1], _imageScale[2][2], _imageScale[2][3],
         _imageScale[3][0], _imageScale[3][1], _imageScale[3][2], _imageScale[3][3]);
 
     auto transform = math::mat4f::translation(math::float3(x, y, 0.0f)) * _imageScale;
 
-
+    Log("transform %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f ", transform[0][0], transform[0][1], transform[0][2], transform[0][3],
-  Log("transform %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f ", transform[0][0],transform[0][1],transform[0][2], transform[0][3], \
+        transform[1][0], transform[1][1], transform[1][2], transform[1][3],
-  transform[1][0],transform[1][1],transform[1][2], transform[1][3],\
+        transform[2][0], transform[2][1], transform[2][2], transform[2][3],
-  transform[2][0],transform[2][1],transform[2][2], transform[2][3], \
         transform[3][0], transform[3][1], transform[3][2], transform[3][3]);
     _imageMaterial->setDefaultParameter("transform", transform);
   }
 
-FilamentViewer::~FilamentViewer() { 
+  FilamentViewer::~FilamentViewer()
+  {
     clearAssets();
     delete _assetManager;
 
-  for(auto it : _lights) {
+    for (auto it : _lights)
+    {
       _engine->destroy(it);
     }
 
@@ -593,21 +636,26 @@ FilamentViewer::~FilamentViewer() {
 
   Renderer *FilamentViewer::getRenderer() { return _renderer; }
 
-void FilamentViewer::createSwapChain(const void *window, uint32_t width, uint32_t height) {
+  void FilamentViewer::createSwapChain(const void *window, uint32_t width, uint32_t height)
+  {
 #if TARGET_OS_IPHONE
     _swapChain = _engine->createSwapChain((void *)window, filament::backend::SWAP_CHAIN_CONFIG_APPLE_CVPIXELBUFFER);
 #else
-    if(window) {
+    if (window)
+    {
       _swapChain = _engine->createSwapChain((void *)window, filament::backend::SWAP_CHAIN_CONFIG_TRANSPARENT | filament::backend::SWAP_CHAIN_CONFIG_READABLE);
       Log("Created window swapchain.");
-    } else {
+    }
+    else
+    {
       Log("Created headless swapchain.");
       _swapChain = _engine->createSwapChain(width, height, filament::backend::SWAP_CHAIN_CONFIG_TRANSPARENT | filament::backend::SWAP_CHAIN_CONFIG_READABLE);
     }
 #endif
   }
 
-void FilamentViewer::createRenderTarget(intptr_t texture, uint32_t width, uint32_t height) {
+  void FilamentViewer::createRenderTarget(intptr_t texture, uint32_t width, uint32_t height)
+  {
     // Create filament textures and render targets (note the color buffer has the import call)
     _rtColor = filament::Texture::Builder()
                    .width(width)
@@ -633,11 +681,12 @@ void FilamentViewer::createRenderTarget(intptr_t texture, uint32_t width, uint32
     _view->setRenderTarget(_rt);
 
     Log("Set render target for texture id %u to %u x %u", texture, width, height);
-
   }
 
-void FilamentViewer::destroySwapChain() {
+  void FilamentViewer::destroySwapChain()
-  if(_rt) {
+  {
+    if (_rt)
+    {
       _view->setRenderTarget(nullptr);
       _engine->destroy(_rtDepth);
       _engine->destroy(_rtColor);
@@ -646,16 +695,19 @@ void FilamentViewer::destroySwapChain() {
       _rtDepth = nullptr;
       _rtColor = nullptr;
     }
-  if (_swapChain) {
+    if (_swapChain)
+    {
       _engine->destroy(_swapChain);
       _swapChain = nullptr;
       Log("Swapchain destroyed.");
     }
   }
 
-void FilamentViewer::clearAssets() {
+  void FilamentViewer::clearAssets()
+  {
     Log("Clearing all assets");
-  if(_mainCamera) {
+    if (_mainCamera)
+    {
       _view->setCamera(_mainCamera);
     }
 
@@ -664,7 +716,8 @@ void FilamentViewer::clearAssets() {
     Log("Cleared all assets");
   }
 
-void FilamentViewer::removeAsset(EntityId asset) {
+  void FilamentViewer::removeAsset(EntityId asset)
+  {
     Log("Removing asset from scene");
 
     mtx.lock();
@@ -677,7 +730,8 @@ void FilamentViewer::removeAsset(EntityId asset) {
   ///
   /// Set the exposure for the current active camera.
   ///
-void FilamentViewer::setCameraExposure(float aperture, float shutterSpeed, float sensitivity) {
+  void FilamentViewer::setCameraExposure(float aperture, float shutterSpeed, float sensitivity)
+  {
     Camera &cam = _view->getCamera();
     Log("Setting aperture (%03f) shutterSpeed (%03f) and sensitivity (%03f)", aperture, shutterSpeed, sensitivity);
     cam.setExposure(aperture, shutterSpeed, sensitivity);
@@ -686,7 +740,8 @@ void FilamentViewer::setCameraExposure(float aperture, float shutterSpeed, float
   ///
   /// Set the focal length of the active camera.
   ///
-void FilamentViewer::setCameraFocalLength(float focalLength) {
+  void FilamentViewer::setCameraFocalLength(float focalLength)
+  {
     Camera &cam = _view->getCamera();
     _cameraFocalLength = focalLength;
     cam.setLensProjection(_cameraFocalLength, 1.0f, kNearPlane,
@@ -696,7 +751,8 @@ void FilamentViewer::setCameraFocalLength(float focalLength) {
   ///
   /// Set the focus distance of the active camera.
   ///
-void FilamentViewer::setCameraFocusDistance(float focusDistance) {
+  void FilamentViewer::setCameraFocusDistance(float focusDistance)
+  {
     Camera &cam = _view->getCamera();
     _cameraFocusDistance = focusDistance;
     cam.setFocusDistance(_cameraFocusDistance);
@@ -707,15 +763,18 @@ void FilamentViewer::setCameraFocusDistance(float focusDistance) {
   /// N.B. Blender will generally export a three-node hierarchy -
   /// Camera1->Camera_Orientation->Camera2. The correct name will be the Camera_Orientation.
   ///
-bool FilamentViewer::setCamera(EntityId entityId, const char *cameraName) {
+  bool FilamentViewer::setCamera(EntityId entityId, const char *cameraName)
+  {
 
     auto asset = _assetManager->getAssetByEntityId(entityId);
-    if(!asset) {
+    if (!asset)
+    {
       Log("Failed to find asset under entity id %d.", entityId);
       return false;
     }
     size_t count = asset->getCameraEntityCount();
-    if (count == 0) {
+    if (count == 0)
+    {
       Log("No cameras found attached to specified entity.");
       return false;
     }
@@ -724,28 +783,35 @@ bool FilamentViewer::setCamera(EntityId entityId, const char *cameraName) {
 
     utils::Entity target;
 
-    if(!cameraName) {
+    if (!cameraName)
+    {
       auto inst = _ncm->getInstance(cameras[0]);
       const char *name = _ncm->getName(inst);
       target = cameras[0];
       Log("No camera specified, using first camera node found (%s)", name);
-    } else {
+    }
-        for (int j = 0; j < count; j++) {
+    else
+    {
+      for (int j = 0; j < count; j++)
+      {
         auto inst = _ncm->getInstance(cameras[j]);
         const char *name = _ncm->getName(inst);
-            if (strcmp(name, cameraName) == 0) {
+        if (strcmp(name, cameraName) == 0)
+        {
           target = cameras[j];
           break;
         }
       }
     }
-    if(target.isNull()) {
+    if (target.isNull())
+    {
       Log("Unable to locate camera under name %s ", cameraName);
       return false;
     }
 
     Camera *camera = _engine->getCameraComponent(target);
-    if(!camera) {
+    if (!camera)
+    {
       Log("Failed to retrieve camera component for target");
       return false;
     }
@@ -761,11 +827,13 @@ bool FilamentViewer::setCamera(EntityId entityId, const char *cameraName) {
     return true;
   }
 
-void FilamentViewer::loadSkybox(const char *const skyboxPath) {
+  void FilamentViewer::loadSkybox(const char *const skyboxPath)
+  {
 
     removeSkybox();
 
-  if (!skyboxPath) {
+    if (!skyboxPath)
+    {
       Log("No skybox path provided, removed skybox.");
     }
 
@@ -776,7 +844,8 @@ void FilamentViewer::loadSkybox(const char *const skyboxPath) {
     // because this will go out of scope before the texture callback is invoked, we need to make a copy to the heap
     ResourceBuffer *skyboxBufferCopy = new ResourceBuffer(skyboxBuffer);
 
-    if(skyboxBuffer.size <= 0) {
+    if (skyboxBuffer.size <= 0)
+    {
       Log("Could not load skybox resource.");
       return;
     }
@@ -790,37 +859,43 @@ void FilamentViewer::loadSkybox(const char *const skyboxPath) {
                               static_cast<uint32_t>(skyboxBuffer.size));
 
     _skyboxTexture =
-        ktxreader::Ktx1Reader::createTexture(_engine, *skyboxBundle, false, [](void* userdata) {
+        ktxreader::Ktx1Reader::createTexture(
+            _engine, *skyboxBundle, false, [](void *userdata)
+            {
         std::vector<void*>* vec = (std::vector<void*>*)userdata;
         ResourceLoaderWrapper* loader = (ResourceLoaderWrapper*)vec->at(0);
         ResourceBuffer* rb = (ResourceBuffer*) vec->at(1);
         loader->free(*rb);
         delete rb;
         delete vec;
-        Log("Skybox load complete.");
+        Log("Skybox load complete."); },
-        }, callbackData);
+            callbackData);
     _skybox =
         filament::Skybox::Builder().environment(_skyboxTexture).build(*_engine);
 
     _scene->setSkybox(_skybox);
-
   }
 
-void FilamentViewer::removeSkybox() { 
+  void FilamentViewer::removeSkybox()
+  {
     Log("Removing skybox");
     _scene->setSkybox(nullptr);
-  if(_skybox) {
+    if (_skybox)
+    {
       _engine->destroy(_skybox);
       _skybox = nullptr;
     }
-  if(_skyboxTexture) {
+    if (_skyboxTexture)
+    {
       _engine->destroy(_skyboxTexture);
       _skyboxTexture = nullptr;
     }
   }
 
-void FilamentViewer::removeIbl() { 
+  void FilamentViewer::removeIbl()
-  if(_indirectLight) {
+  {
+    if (_indirectLight)
+    {
       _engine->destroy(_indirectLight);
       _engine->destroy(_iblTexture);
       _indirectLight = nullptr;
@@ -829,9 +904,11 @@ void FilamentViewer::removeIbl() {
     _scene->setIndirectLight(nullptr);
   }
 
-void FilamentViewer::loadIbl(const char *const iblPath, float intensity) {
+  void FilamentViewer::loadIbl(const char *const iblPath, float intensity)
+  {
     removeIbl();
-  if (iblPath) {
+    if (iblPath)
+    {
       Log("Loading IBL from %s", iblPath);
 
       // Load IBL.
@@ -839,7 +916,8 @@ void FilamentViewer::loadIbl(const char *const iblPath, float intensity) {
       // because this will go out of scope before the texture callback is invoked, we need to make a copy to the heap
       ResourceBuffer *iblBufferCopy = new ResourceBuffer(iblBuffer);
 
-    if(iblBuffer.size == 0) {
+      if (iblBuffer.size == 0)
+      {
         Log("Error loading IBL, resource could not be loaded.");
         return;
       }
@@ -853,14 +931,16 @@ void FilamentViewer::loadIbl(const char *const iblPath, float intensity) {
       std::vector<void *> *callbackData = new std::vector<void *>{(void *)_resourceLoaderWrapper, iblBufferCopy};
 
       _iblTexture =
-        ktxreader::Ktx1Reader::createTexture(_engine, *iblBundle, false, [](void* userdata) {
+          ktxreader::Ktx1Reader::createTexture(
+              _engine, *iblBundle, false, [](void *userdata)
+              {
             std::vector<void*>* vec = (std::vector<void*>*)userdata;
             ResourceLoaderWrapper* loader = (ResourceLoaderWrapper*)vec->at(0);
             ResourceBuffer* rb = (ResourceBuffer*) vec->at(1);
             loader->free(*rb);
             delete rb;
-            delete vec;
+            delete vec; },
-    }, callbackData);
+              callbackData);
       _indirectLight = IndirectLight::Builder()
                            .reflections(_iblTexture)
                            .irradiance(3, harmonics)
@@ -879,14 +959,17 @@ void FilamentViewer::render(
       uint64_t frameTimeInNanos,
       void *pixelBuffer,
       void (*callback)(void *buf, size_t size, void *data),
-  void* data) {
+      void *data)
+  {
 
-  if (!_view || !_mainCamera || !_swapChain) {
+    if (!_view || !_mainCamera || !_swapChain)
+    {
       Log("Not ready for rendering");
       return;
     }
 
-  if(_frameCount == 60) {
+    if (_frameCount == 60)
+    {
       // Log("1 sec average for asset animation update %f", _elapsed / 60);
       _elapsed = 0;
       _frameCount = 0;
@@ -899,7 +982,18 @@ void FilamentViewer::render(
     _elapsed += tmr.elapsed();
     _frameCount++;
 
-  if(pixelBuffer) {
+    // if a manipulator is active, update the active camera orientation
+    if(_manipulator) {
+      math::double3 eye, target, upward;
+      Camera& cam =_view->getCamera();
+      _manipulator->getLookAt(&eye, &target, &upward);
+      cam.lookAt(eye, target, upward);
+    }
+
+    // TODO - this was an experiment but probably useful to keep for debugging
+    // if pixelBuffer is provided, we will copy the framebuffer into the pixelBuffer.
+    if (pixelBuffer)
+    {
       auto pbd = Texture::PixelBufferDescriptor(
           pixelBuffer, size_t(1024 * 768 * 4),
           Texture::Format::RGBA,
@@ -909,21 +1003,27 @@ void FilamentViewer::render(
       _renderer->render(_view);
       _renderer->readPixels(0, 0, 1024, 768, std::move(pbd));
       _renderer->endFrame();
-  } else {
+    }
+    else
+    {
       // Render the scene, unless the renderer wants to skip the frame.
-    if (_renderer->beginFrame(_swapChain, frameTimeInNanos)) {
+      if (_renderer->beginFrame(_swapChain, frameTimeInNanos))
+      {
         _renderer->render(_view);
         _renderer->endFrame();
-    } else {
+      }
+      else
+      {
         // skipped frame
       }
     }
-  
   }
 
   void FilamentViewer::updateViewportAndCameraProjection(
-    int width, int height, float contentScaleFactor) {
+      int width, int height, float contentScaleFactor)
-  if (!_view || !_mainCamera) {
+  {
+    if (!_view || !_mainCamera)
+    {
       Log("Skipping camera update, no view or camrea");
       return;
     }
@@ -944,20 +1044,24 @@ void FilamentViewer::updateViewportAndCameraProjection(
         contentScaleFactor);
   }
 
-void FilamentViewer::setViewFrustumCulling(bool enabled) { 
+  void FilamentViewer::setViewFrustumCulling(bool enabled)
+  {
     _view->setFrustumCullingEnabled(enabled);
   }
 
-void FilamentViewer::setCameraPosition(float x, float y, float z) {
+  void FilamentViewer::setCameraPosition(float x, float y, float z)
+  {
     Camera &cam = _view->getCamera();
 
     _cameraPosition = math::mat4f::translation(math::float3(x, y, z));
     cam.setModelMatrix(_cameraPosition * _cameraRotation);
   }
 
-void FilamentViewer::moveCameraToAsset(EntityId entityId) {
+  void FilamentViewer::moveCameraToAsset(EntityId entityId)
+  {
     auto asset = _assetManager->getAssetByEntityId(entityId);
-  if(!asset) {
+    if (!asset)
+    {
       Log("Failed to find asset attached to specified entity id.");
       return;
     }
@@ -971,13 +1075,15 @@ void FilamentViewer::moveCameraToAsset(EntityId entityId) {
     Log("Moved camera to %f %f %f, lookAt %f %f %f, near %f far %f", eye[0], eye[1], eye[2], lookAt[0], lookAt[1], lookAt[2], cam.getNear(), cam.getCullingFar());
   }
 
-void FilamentViewer::setCameraRotation(float rads, float x, float y, float z) {
+  void FilamentViewer::setCameraRotation(float rads, float x, float y, float z)
+  {
     Camera &cam = _view->getCamera();
     _cameraRotation = math::mat4f::rotation(rads, math::float3(x, y, z));
     cam.setModelMatrix(_cameraPosition * _cameraRotation);
   }
 
-void FilamentViewer::setCameraModelMatrix(const float* const matrix) {
+  void FilamentViewer::setCameraModelMatrix(const float *const matrix)
+  {
     Camera &cam = _view->getCamera();
 
     mat4 modelMatrix(
@@ -996,75 +1102,123 @@ void FilamentViewer::setCameraModelMatrix(const float* const matrix) {
         matrix[12],
         matrix[13],
         matrix[14],
-   matrix[15]
+        matrix[15]);
-);
     cam.setModelMatrix(modelMatrix);
   }
 
-void FilamentViewer::grabBegin(float x, float y, bool pan) {
+  void FilamentViewer::_createManipulator()
-  if (!_view || !_mainCamera || !_swapChain) {
+  {
-    Log("View not ready, ignoring grab");
+    Camera &cam = _view->getCamera();
-    return;
+    math::double3 home = cam.getPosition();
-  }
+    math::double3 up = cam.getUpVector();
-  _panning = pan;
+    math::double3 target = home + cam.getForwardVector();
-  _startX = x;
+    Viewport const &vp = _view->getViewport();
-  _startY = y;
+    Log("Creating manipulator for viewport size %dx%d with camera norm %f", vp.width, vp.height, norm(home));
+    float zoomSpeed = norm(home) / 10;
+    zoomSpeed = math::clamp(zoomSpeed, 0.1f, 100000.0f);
+
+    _manipulator = Manipulator<double>::Builder()
+                       .viewport(vp.width, vp.height)
+                       .orbitHomePosition(home[0], home[1], home[2])
+                       .upVector(up.x, up.y, up.z)
+                       .zoomSpeed(zoomSpeed)
+                      //  .orbitSpeed(0.0001, 0.0001)
+                       .targetPosition(target[0], target[1], target[2])
+                       .build(Mode::ORBIT);
   }
 
-void FilamentViewer::grabUpdate(float x, float y) {
+  void FilamentViewer::grabBegin(float x, float y, bool pan)
-    if (!_view || !_swapChain) {
+  {
+    if (!_view || !_mainCamera || !_swapChain)
+    {
       Log("View not ready, ignoring grab");
       return;
     }
-    Camera& cam =_view->getCamera();
+    if (!_manipulator)
-    auto eye =  cam.getPosition();
+    {
-    auto target = eye + cam.getForwardVector();
+      _createManipulator();
-    auto upward = cam.getUpVector();
+    }
-    Viewport const& vp = _view->getViewport();
+    if(pan) {
-    if(_panning) {
+      Log("Beginning pan at %f %f", x, y);
-        auto trans = cam.getModelMatrix() * mat4::translation(math::float3 { 50 * (x - _startX) / vp.width, 50 * (y - _startY) / vp.height, 0.0f });
-        cam.setModelMatrix(trans);
     } else { 
-        auto trans = cam.getModelMatrix() * mat4::rotation(0.05,
+      Log("Beginning rotate at %f %f", x, y);
-                                                           math::float3 { (y - _startY) / vp.height, (x - _startX) / vp.width, 0.0f });
-        cam.setModelMatrix(trans);
-    }
-    _startX = x;
-    _startY = y;
-
     }
     
-void FilamentViewer::grabEnd() {
+    _manipulator->grabBegin(x, y, pan);
-  if (!_view || !_mainCamera || !_swapChain) {
+  }
+
+  void FilamentViewer::grabUpdate(float x, float y)
+  {
+    if (!_view || !_swapChain)
+    {
       Log("View not ready, ignoring grab");
       return;
     }
+
+
+    Log("Updating grab at %f %f", x, y);
+
+
+    if (_manipulator)
+    {
+      _manipulator->grabUpdate(x, y);
+    }
+    else
+    {
+      Log("Error - trying to use a manipulator when one is not available. Ensure you call grabBegin before grabUpdate/grabEnd");
+    }
   }
 
-void FilamentViewer::scrollBegin() {
+  void FilamentViewer::grabEnd()
-  // noop
+  {
+    if (!_view || !_mainCamera || !_swapChain)
+    {
+      Log("View not ready, ignoring grab");
+      return;
+    }
+    if (_manipulator)
+    {
+      _manipulator->grabEnd();
+    }
+    else
+    {
+      Log("Error - trying to use a manipulator when one is not available. Ensure you call grabBegin before grabUpdate/grabEnd");
+    }
+    delete _manipulator;
+    _manipulator = nullptr;
   }
 
-void FilamentViewer::scrollUpdate(float x, float y, float delta) {
+  void FilamentViewer::scrollBegin()
-    Camera& cam =_view->getCamera();
+  {
-    Viewport const& vp = _view->getViewport();
+    if (!_manipulator)
-    auto trans = cam.getModelMatrix() * mat4::translation(math::float3 {0.0f, 0.0f, delta });
+    {
-    cam.setModelMatrix(trans);
+      _createManipulator();
+    }
   }
 
-void FilamentViewer::scrollEnd() {
+  void FilamentViewer::scrollUpdate(float x, float y, float delta)
-  // noop  
+  {
+    if (_manipulator)
+    {
+      _manipulator->scroll(int(x), int(y), delta);
+    }
+    else
+    {
+      Log("Error - trying to use a manipulator when one is not available. Ensure you call grabBegin before grabUpdate/grabEnd");
+    }
   }
 
-void FilamentViewer::pick(uint32_t x, uint32_t y, EntityId* entityId) {
+  void FilamentViewer::scrollEnd()
-  Log("Picking at %d,%d", x, y);
+  {
+    delete _manipulator;
+    _manipulator = nullptr;
+  }
+
+  void FilamentViewer::pick(uint32_t x, uint32_t y, EntityId *entityId)
+  {
     _view->pick(x, y, [=](filament::View::PickingQueryResult const &result) {
-      
         *entityId = Entity::smuggle(result.renderable);
-        Log("Got result %d", *entityId);
     });
   }
 
 } // namespace polyvox
-
-  

ios/src/camutils/Bookmark.cpp

@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <camutils/Bookmark.h>
+#include <camutils/Manipulator.h>
+
+#include <math/scalar.h>
+#include <math/vec3.h>
+
+using namespace filament::math;
+
+namespace filament {
+namespace camutils {
+
+template <typename FLOAT>
+Bookmark<FLOAT> Bookmark<FLOAT>::interpolate(Bookmark<FLOAT> a, Bookmark<FLOAT> b, double t) {
+    Bookmark<FLOAT> result;
+    using float3 = filament::math::vec3<FLOAT>;
+
+    if (a.mode == Mode::MAP) {
+        assert(b.mode == Mode::MAP);
+        const double rho = sqrt(2.0);
+        const double rho2 = 2, rho4 = 4;
+        const double ux0 = a.map.center.x, uy0 = a.map.center.y, w0 = a.map.extent;
+        const double ux1 = b.map.center.x, uy1 = b.map.center.y, w1 = b.map.extent;
+        const double dx = ux1 - ux0, dy = uy1 - uy0, d2 = dx * dx + dy * dy, d1 = sqrt(d2);
+        const double b0 = (w1 * w1 - w0 * w0 + rho4 * d2) / (2.0 * w0 * rho2 * d1);
+        const double b1 = (w1 * w1 - w0 * w0 - rho4 * d2) / (2.0 * w1 * rho2 * d1);
+        const double r0 = log(sqrt(b0 * b0 + 1.0) - b0);
+        const double r1 = log(sqrt(b1 * b1 + 1) - b1);
+        const double dr = r1 - r0;
+        const int valid = !std::isnan(dr) && dr != 0;
+        const double S = (valid ? dr : log(w1 / w0)) / rho;
+        const double s = t * S;
+
+        // This performs Van Wijk interpolation to animate between two waypoints on a map.
+        if (valid) {
+            const double coshr0 = cosh(r0);
+            const double u = w0 / (rho2 * d1) * (coshr0 * tanh(rho * s + r0) - sinh(r0));
+            Bookmark<FLOAT> result;
+            result.map.center.x = ux0 + u * dx;
+            result.map.center.y = uy0 + u * dy;
+            result.map.extent = w0 * coshr0 / cosh(rho * s + r0);
+            return result;
+        }
+
+        // For degenerate cases, fall back to a simplified interpolation method.
+        result.map.center.x = ux0 + t * dx;
+        result.map.center.y = uy0 + t * dy;
+        result.map.extent = w0 * exp(rho * s);
+        return result;
+}
+
+    assert(b.mode == Mode::ORBIT);
+    result.orbit.phi = lerp(a.orbit.phi, b.orbit.phi, FLOAT(t));
+    result.orbit.theta = lerp(a.orbit.theta, b.orbit.theta, FLOAT(t));
+    result.orbit.distance = lerp(a.orbit.distance, b.orbit.distance, FLOAT(t));
+    result.orbit.pivot = lerp(a.orbit.pivot, b.orbit.pivot, float3(t));
+    return result;
+}
+
+// Uses the Van Wijk method to suggest a duration for animating between two waypoints on a map.
+// This does not have units, so just use it as a multiplier.
+template <typename FLOAT>
+double Bookmark<FLOAT>::duration(Bookmark<FLOAT> a, Bookmark<FLOAT> b) {
+    assert(a.mode == Mode::ORBIT && b.mode == Mode::ORBIT);
+    const double rho = sqrt(2.0);
+    const double rho2 = 2, rho4 = 4;
+    const double ux0 = a.map.center.x, uy0 = a.map.center.y, w0 = a.map.extent;
+    const double ux1 = b.map.center.x, uy1 = b.map.center.y, w1 = b.map.extent;
+    const double dx = ux1 - ux0, dy = uy1 - uy0, d2 = dx * dx + dy * dy, d1 = sqrt(d2);
+    const double b0 = (w1 * w1 - w0 * w0 + rho4 * d2) / (2.0 * w0 * rho2 * d1);
+    const double b1 = (w1 * w1 - w0 * w0 - rho4 * d2) / (2.0 * w1 * rho2 * d1);
+    const double r0 = log(sqrt(b0 * b0 + 1.0) - b0);
+    const double r1 = log(sqrt(b1 * b1 + 1) - b1);
+    const double dr = r1 - r0;
+    const int valid = !std::isnan(dr) && dr != 0;
+    const double S = (valid ? dr : log(w1 / w0)) / rho;
+    return fabs(S);
+}
+
+template class Bookmark<float>;
+
+} // namespace camutils
+} // namespace filament

ios/src/camutils/FreeFlightManipulator.h

@@ -0,0 +1,206 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef CAMUTILS_FREEFLIGHT_MANIPULATOR_H
+#define CAMUTILS_FREEFLIGHT_MANIPULATOR_H
+
+#include <camutils/Manipulator.h>
+
+#include <math/scalar.h>
+#include <math/mat3.h>
+#include <math/mat4.h>
+#include <math/quat.h>
+
+#include <cmath>
+
+namespace filament {
+namespace camutils {
+
+using namespace filament::math;
+
+template<typename FLOAT>
+class FreeFlightManipulator : public Manipulator<FLOAT> {
+public:
+    using vec2 = filament::math::vec2<FLOAT>;
+    using vec3 = filament::math::vec3<FLOAT>;
+    using vec4 = filament::math::vec4<FLOAT>;
+    using Bookmark = filament::camutils::Bookmark<FLOAT>;
+    using Base = Manipulator<FLOAT>;
+    using Config = typename Base::Config;
+
+    FreeFlightManipulator(Mode mode, const Config& props) : Base(mode, props) {
+        setProperties(props);
+        Base::mEye = Base::mProps.flightStartPosition;
+        const auto pitch = Base::mProps.flightStartPitch;
+        const auto yaw = Base::mProps.flightStartYaw;
+        mTargetEuler = {pitch, yaw};
+        updateTarget(pitch, yaw);
+    }
+
+    void setProperties(const Config& props) override {
+        Config resolved = props;
+
+        if (resolved.flightPanSpeed == vec2(0, 0)) {
+            resolved.flightPanSpeed = vec2(0.01, 0.01);
+        }
+        if (resolved.flightMaxSpeed == 0.0) {
+            resolved.flightMaxSpeed = 10.0;
+        }
+        if (resolved.flightSpeedSteps == 0) {
+            resolved.flightSpeedSteps = 80;
+        }
+
+        Base::setProperties(resolved);
+    }
+
+    void updateTarget(FLOAT pitch, FLOAT yaw) {
+        Base::mTarget = Base::mEye + (mat3::eulerZYX(0, yaw, pitch) * vec3(0.0, 0.0, -1.0));
+    }
+
+    void grabBegin(int x, int y, bool strafe) override {
+        mGrabWin = {x, y};
+        mGrabbing = true;
+        mGrabEuler = mTargetEuler;
+    }
+
+    void grabUpdate(int x, int y) override {
+        if (!mGrabbing) {
+            return;
+        }
+
+        const vec2 del = mGrabWin - vec2{x, y};
+
+        const auto& grabPitch = mGrabEuler.x;
+        const auto& grabYaw = mGrabEuler.y;
+        auto& pitch = mTargetEuler.x;
+        auto& yaw = mTargetEuler.y;
+
+        constexpr double EPSILON = 0.001;
+
+        auto panSpeed = Base::mProps.flightPanSpeed;
+        constexpr FLOAT minPitch = (-F_PI_2 + EPSILON);
+        constexpr FLOAT maxPitch = ( F_PI_2 - EPSILON);
+        pitch = clamp(grabPitch + del.y * -panSpeed.y, minPitch, maxPitch);
+        yaw = fmod(grabYaw + del.x * panSpeed.x, 2.0 * F_PI);
+
+        updateTarget(pitch, yaw);
+    }
+
+    void grabEnd() override {
+        mGrabbing = false;
+    }
+
+    void keyDown(typename Base::Key key) override {
+        mKeyDown[(int) key] = true;
+    }
+
+    void keyUp(typename Base::Key key) override {
+        mKeyDown[(int) key] = false;
+    }
+
+    void scroll(int x, int y, FLOAT scrolldelta) override {
+        const FLOAT halfSpeedSteps = Base::mProps.flightSpeedSteps / 2;
+        mScrollWheel = clamp(mScrollWheel + scrolldelta, -halfSpeedSteps, halfSpeedSteps);
+        // Normalize the scroll position from -1 to 1 and calculate the move speed, in world
+        // units per second.
+        mScrollPositionNormalized = (mScrollWheel + halfSpeedSteps) / halfSpeedSteps - 1.0;
+        mMoveSpeed = pow(Base::mProps.flightMaxSpeed, mScrollPositionNormalized);
+    }
+
+    void update(FLOAT deltaTime) override {
+        vec3 forceLocal { 0.0, 0.0, 0.0 };
+
+        if (mKeyDown[(int) Base::Key::FORWARD]) {
+            forceLocal += vec3{  0.0,  0.0, -1.0 };
+        }
+        if (mKeyDown[(int) Base::Key::LEFT]) {
+            forceLocal += vec3{ -1.0,  0.0,  0.0 };
+        }
+        if (mKeyDown[(int) Base::Key::BACKWARD]) {
+            forceLocal += vec3{  0.0,  0.0,  1.0 };
+        }
+        if (mKeyDown[(int) Base::Key::RIGHT]) {
+            forceLocal += vec3{  1.0,  0.0,  0.0 };
+        }
+
+        const mat4 orientation = mat4::lookAt(Base::mEye, Base::mTarget, Base::mProps.upVector);
+        vec3 forceWorld = (orientation * vec4{ forceLocal, 0.0f }).xyz;
+
+        if (mKeyDown[(int) Base::Key::UP]) {
+            forceWorld += vec3{  0.0,  1.0,  0.0 };
+        }
+        if (mKeyDown[(int) Base::Key::DOWN]) {
+            forceWorld += vec3{  0.0, -1.0,  0.0 };
+        }
+
+        forceWorld *= mMoveSpeed;
+
+        const auto dampingFactor = Base::mProps.flightMoveDamping;
+        if (dampingFactor == 0.0) {
+            // Without damping, we simply treat the force as our velocity.
+            mEyeVelocity = forceWorld;
+        } else {
+            // The dampingFactor acts as "friction", which acts upon the camera in the direction
+            // opposite its velocity.
+            // Force is also multiplied by the dampingFactor, to "make up" for the friction.
+            // This ensures that the max velocity still approaches mMoveSpeed;
+            vec3 velocityDelta = (forceWorld - mEyeVelocity) * dampingFactor;
+            mEyeVelocity += velocityDelta * deltaTime;
+        }
+
+        const vec3 positionDelta = mEyeVelocity * deltaTime;
+
+        Base::mEye += positionDelta;
+        Base::mTarget += positionDelta;
+    }
+
+    Bookmark getCurrentBookmark() const override {
+        Bookmark bookmark;
+        bookmark.flight.position = Base::mEye;
+        bookmark.flight.pitch = mTargetEuler.x;
+        bookmark.flight.yaw = mTargetEuler.y;
+        return bookmark;
+    }
+
+    Bookmark getHomeBookmark() const override {
+        Bookmark bookmark;
+        bookmark.flight.position = Base::mProps.flightStartPosition;
+        bookmark.flight.pitch = Base::mProps.flightStartPitch;
+        bookmark.flight.yaw = Base::mProps.flightStartYaw;
+        return bookmark;
+    }
+
+    void jumpToBookmark(const Bookmark& bookmark) override {
+        Base::mEye = bookmark.flight.position;
+        updateTarget(bookmark.flight.pitch, bookmark.flight.yaw);
+    }
+
+private:
+    vec2 mGrabWin;
+    vec2 mTargetEuler;  // (pitch, yaw)
+    vec2 mGrabEuler;    // (pitch, yaw)
+    bool mKeyDown[(int) Base::Key::COUNT] = {false};
+    bool mGrabbing = false;
+    FLOAT mScrollWheel = 0.0f;
+    FLOAT mScrollPositionNormalized = 0.0f;
+    FLOAT mMoveSpeed = 1.0f;
+    vec3 mEyeVelocity;
+};
+
+} // namespace camutils
+} // namespace filament
+
+#endif /* CAMUTILS_FREEFLIGHT_MANIPULATOR_H */

ios/src/camutils/Manipulator.cpp

@@ -0,0 +1,324 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <camutils/Manipulator.h>
+
+#include <math/scalar.h>
+
+#include "FreeFlightManipulator.h"
+#include "MapManipulator.h"
+#include "OrbitManipulator.h"
+
+using namespace filament::math;
+
+namespace filament {
+namespace camutils {
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::viewport(int width, int height) {
+    details.viewport[0] = width;
+    details.viewport[1] = height;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::targetPosition(FLOAT x, FLOAT y, FLOAT z) {
+    details.targetPosition = {x, y, z};
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::upVector(FLOAT x, FLOAT y, FLOAT z) {
+    details.upVector = {x, y, z};
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::zoomSpeed(FLOAT val) {
+    details.zoomSpeed = val;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::orbitHomePosition(FLOAT x, FLOAT y, FLOAT z) {
+    details.orbitHomePosition = {x, y, z};
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::orbitSpeed(FLOAT x, FLOAT y) {
+    details.orbitSpeed = {x, y};
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::fovDirection(Fov fov) {
+    details.fovDirection = fov;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::fovDegrees(FLOAT degrees) {
+    details.fovDegrees = degrees;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::farPlane(FLOAT distance) {
+    details.farPlane = distance;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::mapExtent(FLOAT worldWidth, FLOAT worldHeight) {
+    details.mapExtent = {worldWidth, worldHeight};
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::mapMinDistance(FLOAT mindist) {
+    details.mapMinDistance = mindist;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::flightStartPosition(FLOAT x, FLOAT y, FLOAT z) {
+    details.flightStartPosition = {x, y, z};
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::flightStartOrientation(FLOAT pitch, FLOAT yaw) {
+    details.flightStartPitch = pitch;
+    details.flightStartYaw = yaw;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::flightMaxMoveSpeed(FLOAT maxSpeed) {
+    details.flightMaxSpeed = maxSpeed;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::flightSpeedSteps(int steps) {
+    details.flightSpeedSteps = steps;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::flightPanSpeed(FLOAT x, FLOAT y) {
+    details.flightPanSpeed = {x, y};
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::flightMoveDamping(FLOAT damping) {
+    details.flightMoveDamping = damping;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::groundPlane(FLOAT a, FLOAT b, FLOAT c, FLOAT d) {
+    details.groundPlane = {a, b, c, d};
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::raycastCallback(RayCallback cb, void* userdata) {
+    details.raycastCallback = cb;
+    details.raycastUserdata = userdata;
+    return *this;
+}
+
+template <typename FLOAT>
+Manipulator<FLOAT>* Manipulator<FLOAT>::Builder::build(Mode mode) {
+    switch (mode) {
+        case Mode::FREE_FLIGHT:
+            return new FreeFlightManipulator<FLOAT>(mode, details);
+        case Mode::MAP:
+            return new MapManipulator<FLOAT>(mode, details);
+        case Mode::ORBIT:
+            return new OrbitManipulator<FLOAT>(mode, details);
+    }
+}
+
+template <typename FLOAT>
+Manipulator<FLOAT>::Manipulator(Mode mode, const Config& props) : mMode(mode) {
+    setProperties(props);
+}
+
+template <typename FLOAT>
+void Manipulator<FLOAT>::setProperties(const Config& props) {
+    mProps = props;
+
+    if (mProps.zoomSpeed == FLOAT(0)) {
+        mProps.zoomSpeed = 0.01;
+    }
+
+    if (mProps.upVector == vec3(0)) {
+        mProps.upVector = vec3(0, 1, 0);
+    }
+
+    if (mProps.fovDegrees == FLOAT(0)) {
+        mProps.fovDegrees = 33;
+    }
+
+    if (mProps.farPlane == FLOAT(0)) {
+        mProps.farPlane = 5000;
+    }
+
+    if (mProps.mapExtent == vec2(0)) {
+        mProps.mapExtent = vec2(512);
+    }
+}
+
+template <typename FLOAT>
+void Manipulator<FLOAT>::setViewport(int width, int height) {
+    Config props = mProps;
+    props.viewport[0] = width;
+    props.viewport[1] = height;
+    setProperties(props);
+}
+
+template <typename FLOAT>
+void Manipulator<FLOAT>::getLookAt(vec3* eyePosition, vec3* targetPosition, vec3* upward) const {
+    *targetPosition = mTarget;
+    *eyePosition = mEye;
+    const vec3 gaze = normalize(mTarget - mEye);
+    const vec3 right = cross(gaze, mProps.upVector);
+    *upward = cross(right, gaze);
+}
+
+template<typename FLOAT>
+static bool raycastPlane(const filament::math::vec3<FLOAT>& origin,
+        const filament::math::vec3<FLOAT>& dir, FLOAT* t, void* userdata) {
+    using vec3 = filament::math::vec3<FLOAT>;
+    using vec4 = filament::math::vec4<FLOAT>;
+    auto props = (const typename Manipulator<FLOAT>::Config*) userdata;
+    const vec4 plane = props->groundPlane;
+    const vec3 n = vec3(plane[0], plane[1], plane[2]);
+    const vec3 p0 = n * plane[3];
+    const FLOAT denom = -dot(n, dir);
+    if (denom > 1e-6) {
+        const vec3 p0l0 = p0 - origin;
+        *t = dot(p0l0, n) / -denom;
+        return *t >= 0;
+    }
+    return false;
+}
+
+template <typename FLOAT>
+void Manipulator<FLOAT>::getRay(int x, int y, vec3* porigin, vec3* pdir) const {
+    const vec3 gaze = normalize(mTarget - mEye);
+    const vec3 right = normalize(cross(gaze, mProps.upVector));
+    const vec3 upward = cross(right, gaze);
+    const FLOAT width = mProps.viewport[0];
+    const FLOAT height = mProps.viewport[1];
+    const FLOAT fov = mProps.fovDegrees * F_PI / 180.0;
+
+    // Remap the grid coordinate into [-1, +1] and shift it to the pixel center.
+    const FLOAT u = 2.0 * (0.5 + x) / width - 1.0;
+    const FLOAT v = 2.0 * (0.5 + y) / height - 1.0;
+
+    // Compute the tangent of the field-of-view angle as well as the aspect ratio.
+    const FLOAT tangent = tan(fov / 2.0);
+    const FLOAT aspect = width / height;
+
+    // Adjust the gaze so it goes through the pixel of interest rather than the grid center.
+    vec3 dir = gaze;
+    if (mProps.fovDirection == Fov::VERTICAL) {
+        dir += right * tangent * u * aspect;
+        dir += upward * tangent * v;
+    } else {
+        dir += right * tangent * u;
+        dir += upward * tangent * v / aspect;
+    }
+    dir = normalize(dir);
+
+    *porigin = mEye;
+    *pdir = dir;
+}
+
+template <typename FLOAT>
+bool Manipulator<FLOAT>::raycast(int x, int y, vec3* result) const {
+    vec3 origin, dir;
+    getRay(x, y, &origin, &dir);
+
+    // Choose either the user's callback function or the plane intersector.
+    auto callback = mProps.raycastCallback;
+    auto fallback = raycastPlane<FLOAT>;
+    void* userdata = mProps.raycastUserdata;
+    if (!callback) {
+        callback = fallback;
+        userdata = (void*) &mProps;
+    }
+
+    // If the ray misses, then try the fallback function.
+    FLOAT t;
+    if (!callback(mEye, dir, &t, userdata)) {
+        if (callback == fallback || !fallback(mEye, dir, &t, (void*) &mProps)) {
+            return false;
+        }
+    }
+
+    *result = mEye + dir * t;
+    return true;
+}
+
+template <typename FLOAT>
+filament::math::vec3<FLOAT> Manipulator<FLOAT>::raycastFarPlane(int x, int y) const {
+    const filament::math::vec3<FLOAT> gaze = normalize(mTarget - mEye);
+    const vec3 right = cross(gaze, mProps.upVector);
+    const vec3 upward = cross(right, gaze);
+    const FLOAT width = mProps.viewport[0];
+    const FLOAT height = mProps.viewport[1];
+    const FLOAT fov = mProps.fovDegrees * math::F_PI / 180.0;
+
+    // Remap the grid coordinate into [-1, +1] and shift it to the pixel center.
+    const FLOAT u = 2.0 * (0.5 + x) / width - 1.0;
+    const FLOAT v = 2.0 * (0.5 + y) / height - 1.0;
+
+    // Compute the tangent of the field-of-view angle as well as the aspect ratio.
+    const FLOAT tangent = tan(fov / 2.0);
+    const FLOAT aspect = width / height;
+
+    // Adjust the gaze so it goes through the pixel of interest rather than the grid center.
+    vec3 dir = gaze;
+    if (mProps.fovDirection == Fov::VERTICAL) {
+        dir += right * tangent * u * aspect;
+        dir += upward * tangent * v;
+    } else {
+        dir += right * tangent * u;
+        dir += upward * tangent * v / aspect;
+    }
+    return mEye + dir * mProps.farPlane;
+}
+
+template <typename FLOAT>
+void Manipulator<FLOAT>::keyDown(Manipulator<FLOAT>::Key key) { }
+
+template <typename FLOAT>
+void Manipulator<FLOAT>::keyUp(Manipulator<FLOAT>::Key key) { }
+
+template <typename FLOAT>
+void Manipulator<FLOAT>::update(FLOAT deltaTime) { }
+
+template class Manipulator<float>;
+template class Manipulator<double>;
+
+} // namespace camutils
+} // namespace filament

ios/src/camutils/MapManipulator.h

@@ -0,0 +1,197 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef CAMUTILS_MAP_MANIPULATOR_H
+#define CAMUTILS_MAP_MANIPULATOR_H
+
+#include <camutils/Manipulator.h>
+
+#include <math/vec3.h>
+
+namespace filament {
+namespace camutils {
+
+template<typename FLOAT>
+class MapManipulator : public Manipulator<FLOAT> {
+public:
+    using vec2 = math::vec2<FLOAT>;
+    using vec3 = math::vec3<FLOAT>;
+    using vec4 = math::vec4<FLOAT>;
+    using Bookmark = filament::camutils::Bookmark<FLOAT>;
+    using Base = Manipulator<FLOAT>;
+    using Config = typename Manipulator<FLOAT>::Config;
+
+    MapManipulator(Mode mode, const Config& props) : Manipulator<FLOAT>(mode, props) {
+        const FLOAT width = Base::mProps.mapExtent.x;
+        const FLOAT height = Base::mProps.mapExtent.y;
+        const bool horiz = Base::mProps.fovDirection == Fov::HORIZONTAL;
+        const vec3 targetToEye = Base::mProps.groundPlane.xyz;
+        const FLOAT halfExtent = (horiz ? width : height) / 2.0;
+        const FLOAT fov = Base::mProps.fovDegrees * math::F_PI / 180.0;
+        const FLOAT distance = halfExtent / tan(fov / 2.0);
+        Base::mTarget = Base::mProps.targetPosition;
+        Base::mEye = Base::mTarget + distance * targetToEye;
+    }
+
+    void grabBegin(int x, int y, bool strafe) override {
+        if (strafe || !Base::raycast(x, y, &mGrabScene)) {
+            return;
+        }
+        mGrabFar = Base::raycastFarPlane(x, y);
+        mGrabEye = Base::mEye;
+        mGrabTarget = Base::mTarget;
+        mGrabbing = true;
+    }
+
+    void grabUpdate(int x, int y) override {
+        if (mGrabbing) {
+            const FLOAT ulen = distance(mGrabScene, mGrabEye);
+            const FLOAT vlen = distance(mGrabFar, mGrabScene);
+            const vec3 translation = (mGrabFar - Base::raycastFarPlane(x, y)) * ulen / vlen;
+            const vec3 eyePosition = mGrabEye + translation;
+            const vec3 targetPosition = mGrabTarget + translation;
+            moveWithConstraints(eyePosition, targetPosition);
+        }
+    }
+
+    void grabEnd() override {
+        mGrabbing = false;
+    }
+
+    void scroll(int x, int y, FLOAT scrolldelta) override {
+        vec3 grabScene;
+        if (!Base::raycast(x, y, &grabScene)) {
+            return;
+        }
+
+        // Find the direction of travel for the dolly. We do not normalize since it
+        // is desirable to move faster when further away from the targetPosition.
+        vec3 u = grabScene - Base::mEye;
+
+        // Prevent getting stuck when zooming in.
+        if (scrolldelta < 0) {
+            const FLOAT distanceToSurface = length(u);
+            if (distanceToSurface < Base::mProps.zoomSpeed) {
+                return;
+            }
+        }
+
+        u *= -scrolldelta * Base::mProps.zoomSpeed;
+
+        const vec3 eyePosition = Base::mEye + u;
+        const vec3 targetPosition = Base::mTarget + u;
+        moveWithConstraints(eyePosition, targetPosition);
+    }
+
+    Bookmark getCurrentBookmark() const override {
+        const vec3 dir = normalize(Base::mTarget - Base::mEye);
+
+        FLOAT distance;
+        raycastPlane(Base::mEye, dir, &distance);
+
+        const FLOAT fov = Base::mProps.fovDegrees * math::F_PI / 180.0;
+        const FLOAT halfExtent = distance * tan(fov / 2.0);
+
+        vec3 targetPosition = Base::mEye + dir * distance;
+
+        const vec3 targetToEye = Base::mProps.groundPlane.xyz;
+        const vec3 uvec = cross(Base::mProps.upVector, targetToEye);
+        const vec3 vvec = cross(targetToEye, uvec);
+        const vec3 centerToTarget = targetPosition - Base::mProps.targetPosition;
+
+        Bookmark bookmark;
+        bookmark.mode = Mode::MAP;
+        bookmark.map.extent = halfExtent * 2.0;
+        bookmark.map.center.x = dot(uvec, centerToTarget);
+        bookmark.map.center.y = dot(vvec, centerToTarget);
+
+        bookmark.orbit.theta = 0;
+        bookmark.orbit.phi = 0;
+        bookmark.orbit.pivot = Base::mProps.targetPosition +
+                uvec * bookmark.map.center.x +
+                vvec * bookmark.map.center.y;
+        bookmark.orbit.distance = halfExtent / tan(fov / 2.0);
+
+        return bookmark;
+    }
+
+    Bookmark getHomeBookmark() const override {
+        const FLOAT fov = Base::mProps.fovDegrees * math::F_PI / 180.0;
+        const FLOAT width = Base::mProps.mapExtent.x;
+        const FLOAT height = Base::mProps.mapExtent.y;
+        const bool horiz = Base::mProps.fovDirection == Fov::HORIZONTAL;
+
+        Bookmark bookmark;
+        bookmark.mode = Mode::MAP;
+        bookmark.map.extent = horiz ? width : height;
+        bookmark.map.center.x = 0;
+        bookmark.map.center.y = 0;
+
+        bookmark.orbit.theta = 0;
+        bookmark.orbit.phi = 0;
+        bookmark.orbit.pivot = Base::mTarget;
+        bookmark.orbit.distance = 0.5 * bookmark.map.extent / tan(fov / 2.0);
+
+        // TODO: Add optional boundary constraints here.
+
+        return bookmark;
+    }
+
+    void jumpToBookmark(const Bookmark& bookmark) override {
+        const vec3 targetToEye = Base::mProps.groundPlane.xyz;
+        const FLOAT halfExtent = bookmark.map.extent / 2.0;
+        const FLOAT fov = Base::mProps.fovDegrees * math::F_PI / 180.0;
+        const FLOAT distance = halfExtent / tan(fov / 2.0);
+        vec3 uvec = cross(Base::mProps.upVector, targetToEye);
+        vec3 vvec = cross(targetToEye, uvec);
+        uvec = normalize(uvec) * bookmark.map.center.x;
+        vvec = normalize(vvec) * bookmark.map.center.y;
+        Base::mTarget = Base::mProps.targetPosition + uvec + vvec;
+        Base::mEye = Base::mTarget + distance * targetToEye;
+    }
+
+private:
+    bool raycastPlane(const vec3& origin, const vec3& dir, FLOAT* t) const {
+        const vec4 plane = Base::mProps.groundPlane;
+        const vec3 n = vec3(plane[0], plane[1], plane[2]);
+        const vec3 p0 = n * plane[3];
+        const FLOAT denom = -dot(n, dir);
+        if (denom > 1e-6) {
+            const vec3 p0l0 = p0 - origin;
+            *t = dot(p0l0, n) / -denom;
+            return *t >= 0;
+        }
+        return false;
+    }
+
+    void moveWithConstraints(vec3 eye, vec3 targetPosition) {
+        Base::mEye = eye;
+        Base::mTarget = targetPosition;
+        // TODO: Add optional boundary constraints here.
+    }
+
+private:
+    bool mGrabbing = false;
+    vec3 mGrabScene;
+    vec3 mGrabFar;
+    vec3 mGrabEye;
+    vec3 mGrabTarget;
+};
+
+} // namespace camutils
+} // namespace filament
+
+#endif /* CAMUTILS_MAP_MANIPULATOR_H */

ios/src/camutils/OrbitManipulator.h

@@ -0,0 +1,201 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef CAMUTILS_ORBIT_MANIPULATOR_H
+#define CAMUTILS_ORBIT_MANIPULATOR_H
+
+#include <camutils/Manipulator.h>
+
+#include <math/scalar.h>
+
+#define MAX_PHI (F_PI / 2.0 - 0.001)
+
+namespace filament {
+namespace camutils {
+
+using namespace filament::math;
+
+template<typename FLOAT>
+class OrbitManipulator : public Manipulator<FLOAT> {
+public:
+    using vec2 = filament::math::vec2<FLOAT>;
+    using vec3 = filament::math::vec3<FLOAT>;
+    using vec4 = filament::math::vec4<FLOAT>;
+    using Bookmark = filament::camutils::Bookmark<FLOAT>;
+    using Base = Manipulator<FLOAT>;
+    using Config = typename Base::Config;
+
+    enum GrabState { INACTIVE, ORBITING, PANNING };
+
+    OrbitManipulator(Mode mode, const Config& props) : Base(mode, props) {
+        setProperties(props);
+        Base::mEye = Base::mProps.orbitHomePosition;
+        mPivot = Base::mTarget = Base::mProps.targetPosition;
+    }
+
+    void setProperties(const Config& props) override {
+        Config resolved = props;
+
+        if (resolved.orbitHomePosition == vec3(0)) {
+            resolved.orbitHomePosition = vec3(0, 0, 1);
+        }
+
+        if (resolved.orbitSpeed == vec2(0)) {
+            resolved.orbitSpeed = vec2(0.01);
+        }
+
+        // By default, place the ground plane so that it aligns with the targetPosition position.
+        // This is used only when PANNING.
+        if (resolved.groundPlane == vec4(0)) {
+            const FLOAT d = length(resolved.targetPosition);
+            const vec3 n = normalize(resolved.orbitHomePosition - resolved.targetPosition);
+            resolved.groundPlane = vec4(n, -d);
+        }
+
+        Base::setProperties(resolved);
+    }
+
+    void grabBegin(int x, int y, bool strafe) override {
+        mGrabState = strafe ? PANNING : ORBITING;
+        mGrabPivot = mPivot;
+        mGrabEye = Base::mEye;
+        mGrabTarget = Base::mTarget;
+        mGrabBookmark = getCurrentBookmark();
+        mGrabWinX = x;
+        mGrabWinY = y;
+        mGrabFar = Base::raycastFarPlane(x, y);
+        Base::raycast(x, y, &mGrabScene);
+    }
+
+    void grabUpdate(int x, int y) override {
+        const int delx = mGrabWinX - x;
+        const int dely = mGrabWinY - y;
+
+        if (mGrabState == ORBITING) {
+            Bookmark bookmark = getCurrentBookmark();
+
+            const FLOAT theta = delx * Base::mProps.orbitSpeed.x;
+            const FLOAT phi = dely * Base::mProps.orbitSpeed.y;
+            const FLOAT maxPhi = MAX_PHI;
+
+            bookmark.orbit.phi = clamp(mGrabBookmark.orbit.phi + phi, -maxPhi, +maxPhi);
+            bookmark.orbit.theta = mGrabBookmark.orbit.theta + theta;
+
+            jumpToBookmark(bookmark);
+        }
+
+        if (mGrabState == PANNING) {
+            const FLOAT ulen = distance(mGrabScene, mGrabEye);
+            const FLOAT vlen = distance(mGrabFar, mGrabScene);
+            const vec3 translation = (mGrabFar - Base::raycastFarPlane(x, y)) * ulen / vlen;
+            mPivot = mGrabPivot + translation;
+            Base::mEye = mGrabEye + translation;
+            Base::mTarget = mGrabTarget + translation;
+        }
+    }
+
+    void grabEnd() override {
+        mGrabState = INACTIVE;
+    }
+
+    void scroll(int x, int y, FLOAT scrolldelta) override {
+        const vec3 gaze = normalize(Base::mTarget - Base::mEye);
+        const vec3 movement = gaze * Base::mProps.zoomSpeed * -scrolldelta;
+        const vec3 v0 = mPivot - Base::mEye;
+        Base::mEye += movement;
+        Base::mTarget += movement;
+        const vec3 v1 = mPivot - Base::mEye;
+
+        // Check if the camera has moved past the point of interest.
+        if (dot(v0, v1) < 0) {
+            mFlipped = !mFlipped;
+        }
+    }
+
+    Bookmark getCurrentBookmark() const override {
+        Bookmark bookmark;
+        bookmark.mode = Mode::ORBIT;
+        const vec3 pivotToEye = Base::mEye - mPivot;
+        const FLOAT d = length(pivotToEye);
+        const FLOAT x = pivotToEye.x / d;
+        const FLOAT y = pivotToEye.y / d;
+        const FLOAT z = pivotToEye.z / d;
+
+        bookmark.orbit.phi = asin(y);
+        bookmark.orbit.theta = atan2(x, z);
+        bookmark.orbit.distance = mFlipped ? -d : d;
+        bookmark.orbit.pivot = mPivot;
+
+        const FLOAT fov = Base::mProps.fovDegrees * math::F_PI / 180.0;
+        const FLOAT halfExtent = d * tan(fov / 2.0);
+        const vec3 targetToEye = Base::mProps.groundPlane.xyz;
+        const vec3 uvec = cross(Base::mProps.upVector, targetToEye);
+        const vec3 vvec = cross(targetToEye, uvec);
+        const vec3 centerToTarget = mPivot - Base::mProps.targetPosition;
+
+        bookmark.map.extent = halfExtent * 2;
+        bookmark.map.center.x = dot(uvec, centerToTarget);
+        bookmark.map.center.y = dot(vvec, centerToTarget);
+
+        return bookmark;
+    }
+
+    Bookmark getHomeBookmark() const override {
+        Bookmark bookmark;
+        bookmark.mode = Mode::ORBIT;
+        bookmark.orbit.phi = FLOAT(0);
+        bookmark.orbit.theta = FLOAT(0);
+        bookmark.orbit.pivot = Base::mProps.targetPosition;
+        bookmark.orbit.distance = distance(Base::mProps.targetPosition, Base::mProps.orbitHomePosition);
+
+        const FLOAT fov = Base::mProps.fovDegrees * math::F_PI / 180.0;
+        const FLOAT halfExtent = bookmark.orbit.distance * tan(fov / 2.0);
+
+        bookmark.map.extent = halfExtent * 2;
+        bookmark.map.center.x = 0;
+        bookmark.map.center.y = 0;
+
+        return bookmark;
+    }
+
+    void jumpToBookmark(const Bookmark& bookmark) override {
+        mPivot = bookmark.orbit.pivot;
+        const FLOAT x = sin(bookmark.orbit.theta) * cos(bookmark.orbit.phi);
+        const FLOAT y = sin(bookmark.orbit.phi);
+        const FLOAT z = cos(bookmark.orbit.theta) * cos(bookmark.orbit.phi);
+        Base::mEye = mPivot + vec3(x, y, z) * abs(bookmark.orbit.distance);
+        mFlipped = bookmark.orbit.distance < 0;
+        Base::mTarget = Base::mEye + vec3(x, y, z) * (mFlipped ? 1.0 : -1.0);
+    }
+
+private:
+    GrabState mGrabState = INACTIVE;
+    bool mFlipped = false;
+    vec3 mGrabPivot;
+    vec3 mGrabScene;
+    vec3 mGrabFar;
+    vec3 mGrabEye;
+    vec3 mGrabTarget;
+    Bookmark mGrabBookmark;
+    int mGrabWinX;
+    int mGrabWinY;
+    vec3 mPivot;
+};
+
+} // namespace camutils
+} // namespace filament
+
+#endif /* CAMUTILS_ORBIT_MANIPULATOR_H */

lib/filament_controller.dart

@@ -197,7 +197,7 @@ abstract class FilamentController {
   ///
   /// Called by `FilamentGestureDetector`. You probably don't want to call this yourself.
   ///
-  Future zoomUpdate(double z);
+  Future zoomUpdate(double x, double y, double z);
 
   ///
   /// Called by `FilamentGestureDetector`. You probably don't want to call this yourself.

lib/filament_controller_ffi.dart

@@ -191,16 +191,45 @@ class FilamentControllerFFI extends FilamentController {
     _isReadyForScene.complete(true);
   }
 
+  ///
+  /// I'm not exactly sure how to resize the backing textures on all platforms.
+  /// So for now, I'm sticking with the safe option when the widget is resized: destroying the swapchain, recreating the textures, and creating a new swapchain.
+  ///
   @override
   Future resize(int width, int height, {double scaleFactor = 1.0}) async {
     _resizing = true;
     setRendering(false);
+    _lib.destroy_swap_chain(_viewer!);
+    await destroyTexture();
     size = ui.Size(width * _pixelRatio, height * _pixelRatio);
-    _textureId = await _channel
+
-        .invokeMethod("resize", [size.width, size.height, scaleFactor]);
+    var textures =
-    _textureIdController.add(_textureId);
+        await _channel.invokeMethod("createTexture", [size.width, size.height]);
+    var flutterTextureId = textures[0];
+    _textureId = flutterTextureId;
+
+    // void* on iOS (pointer to pixel buffer), void* on Android (pointer to native window), null on Windows/macOS
+    var surfaceAddress = textures[1] as int? ?? 0;
+
+    // null on iOS/Android, void* on MacOS (pointer to metal texture), GLuid on Windows/Linux
+    var nativeTexture = textures[2] as int? ?? 0;
+
+    _lib.create_swap_chain_ffi(
+        _viewer!,
+        Pointer<Void>.fromAddress(surfaceAddress),
+        size.width.toInt(),
+        size.height.toInt());
+    if (nativeTexture != 0) {
+      assert(surfaceAddress == 0);
+      print("Creating render target from native texture  $nativeTexture");
+      _lib.create_render_target_ffi(
+          _viewer!, nativeTexture, size.width.toInt(), size.height.toInt());
+    }
+
     _lib.update_viewport_and_camera_projection_ffi(
-        _viewer!, size.width.toInt(), size.height.toInt(), scaleFactor);
+        _viewer!, size.width.toInt(), size.height.toInt(), 1.0);
+
+    _textureIdController.add(_textureId);
     _resizing = false;
     setRendering(true);
   }
@@ -553,11 +582,11 @@ class FilamentControllerFFI extends FilamentController {
   }
 
   @override
-  Future zoomUpdate(double z) async {
+  Future zoomUpdate(double x, double y, double z) async {
     if (_viewer == null || _resizing) {
       throw Exception("No viewer available, ignoring");
     }
-    _lib.scroll_update(_viewer!, 0.0, 0.0, z);
+    _lib.scroll_update(_viewer!, x, y, z);
   }
 
   @override

lib/filament_controller_method_channel.dart

@@ -434,11 +434,11 @@ class FilamentControllerMethodChannel extends FilamentController {
     await _channel.invokeMethod("scrollBegin");
   }
 
-  Future zoomUpdate(double z) async {
+  Future zoomUpdate(double x, double y, double z) async {
     if (_viewer == null || _resizing) {
       throw Exception("No viewer available, ignoring");
     }
-    await _channel.invokeMethod("scrollUpdate", [0.0, 0.0, z]);
+    await _channel.invokeMethod("scrollUpdate", [x, y, z]);
   }
 
   Future zoomEnd() async {

lib/widgets/filament_gesture_detector.dart

@@ -38,15 +38,12 @@ class FilamentGestureDetector extends StatelessWidget {
   ///
   final bool listenerEnabled;
 
-  final double zoomDelta;
-
   const FilamentGestureDetector(
       {Key? key,
       required this.controller,
       this.child,
       this.showControlOverlay = false,
-      this.listenerEnabled = true,
+      this.listenerEnabled = true})
-      this.zoomDelta = 1})
       : super(key: key);
 
   @override

lib/widgets/filament_gesture_detector_desktop.dart

@@ -32,15 +32,12 @@ class FilamentGestureDetectorDesktop extends StatefulWidget {
   ///
   final bool listenerEnabled;
 
-  final double zoomDelta;
-
   const FilamentGestureDetectorDesktop(
       {Key? key,
       required this.controller,
       this.child,
       this.showControlOverlay = false,
-      this.listenerEnabled = true,
+      this.listenerEnabled = true})
-      this.zoomDelta = 1})
       : super(key: key);
 
   @override
@@ -71,15 +68,18 @@ class _FilamentGestureDetectorDesktopState
   ///
   /// Scroll-wheel on desktop, interpreted as zoom
   ///
-  void _zoom(PointerScrollEvent pointerSignal) {
+  void _zoom(PointerScrollEvent pointerSignal) async {
     _scrollTimer?.cancel();
-    widget.controller.zoomBegin();
+    await widget.controller.zoomBegin();
-    widget.controller.zoomUpdate(pointerSignal.scrollDelta.dy > 0
+    await widget.controller.zoomUpdate(
-        ? widget.zoomDelta
+        pointerSignal.localPosition.dx,
-        : -widget.zoomDelta);
+        pointerSignal.localPosition.dy,
-    _scrollTimer = Timer(const Duration(milliseconds: 100), () {
+        pointerSignal.scrollDelta.dy > 0 ? 1 : -1);
-      widget.controller.zoomEnd();
+
-      _scrollTimer = null;
+    // we don't want to end the zoom in the same frame, because this will destroy the camera manipulator (and cancel the zoom update).
+    // here, we just defer calling [zoomEnd] for 100ms to ensure the update is propagated through.
+    _scrollTimer = Timer(Duration(milliseconds: 100), () async {
+      await widget.controller.zoomEnd();
     });
   }
 
@@ -108,7 +108,8 @@ class _FilamentGestureDetectorDesktopState
           // if this is the first move event, we need to call rotateStart/panStart to set the first coordinates
           if (!_pointerMoving) {
             if (d.buttons == kTertiaryButton) {
-              widget.controller.rotateStart(d.position.dx, d.position.dy);
+              widget.controller
+                  .rotateStart(d.localPosition.dx, d.localPosition.dy);
             } else {
               widget.controller
                   .panStart(d.localPosition.dx, d.localPosition.dy);
@@ -117,7 +118,8 @@ class _FilamentGestureDetectorDesktopState
           // set the _pointerMoving flag so we don't call rotateStart/panStart on future move events
           _pointerMoving = true;
           if (d.buttons == kTertiaryButton) {
-            widget.controller.rotateUpdate(d.position.dx, d.position.dy);
+            widget.controller
+                .rotateUpdate(d.localPosition.dx, d.localPosition.dy);
           } else {
             widget.controller.panUpdate(d.localPosition.dx, d.localPosition.dy);
           }

lib/widgets/filament_gesture_detector_mobile.dart

@@ -158,8 +158,8 @@ class _FilamentGestureDetectorMobileState
               },
               onScaleUpdate: (ScaleUpdateDetails d) async {
                 if (d.pointerCount == 2) {
-                  widget.controller
+                  widget.controller.zoomUpdate(d.localFocalPoint.dx,
-                      .zoomUpdate(d.horizontalScale > 1 ? 0.1 : -0.1);
+                      d.localFocalPoint.dy, d.horizontalScale > 1 ? 0.1 : -0.1);
                 } else if (!_scaling) {
                   if (_rotateOnPointerMove) {
                     widget.controller

macos/Classes/SwiftPolyvoxFilamentPlugin.swift

@@ -64,8 +64,10 @@ public class SwiftPolyvoxFilamentPlugin: NSObject, FlutterPlugin, FlutterTexture
 
     var markTextureFrameAvailable : @convention(c) (UnsafeMutableRawPointer?) -> () = { instancePtr in
         let instance:SwiftPolyvoxFilamentPlugin = Unmanaged<SwiftPolyvoxFilamentPlugin>.fromOpaque(instancePtr!).takeUnretainedValue()
+        if(instance.flutterTextureId != nil) {
             instance.registry.textureFrameAvailable(instance.flutterTextureId!)
         }
+    }
     
     public func copyPixelBuffer() -> Unmanaged<CVPixelBuffer>? {
         if(pixelBuffer == nil) {
@@ -142,6 +144,10 @@ public class SwiftPolyvoxFilamentPlugin: NSObject, FlutterPlugin, FlutterTexture
                             Int(width), Int(height),
                             0,
                             &cvMetalTexture);
+            if(cvret != 0) { 
+                result(FlutterError())
+                return
+            }
             metalTexture = CVMetalTextureGetTexture(cvMetalTexture!);
             let pixelBufferPtr = CVPixelBufferGetBaseAddress(pixelBuffer!);
             let pixelBufferAddress = Int(bitPattern:pixelBufferPtr);
@@ -160,13 +166,7 @@ public class SwiftPolyvoxFilamentPlugin: NSObject, FlutterPlugin, FlutterTexture
             let args = call.arguments as! [Any]
             let width = UInt32(args[0] as! Int64)
             let height = UInt32(args[1] as! Int64)
-            if(self.flutterTextureId != nil) {
+            result(FlutterMethodNotImplemented)
-                self.registry.unregisterTexture(self.flutterTextureId!)
-            }
-            createPixelBuffer(width: Int(width), height:Int(height))
-            let metalTextureId = Int(bitPattern:Unmanaged.passUnretained(metalTexture!).toOpaque())
-            print("Resized to \(args[0])x\(args[1])")
-            result(self.flutterTextureId);
         default:
             result(FlutterMethodNotImplemented)
         }

macos/include/FilamentViewer.hpp

@@ -177,7 +177,7 @@ namespace polyvox {
             void loadPngTexture(string path, ResourceBuffer data);
             void loadTextureFromPath(string path);
             
-            
+            Manipulator<double>* _manipulator = nullptr;
             void _createManipulator();
             uint32_t _lastFrameTimeInNanos;
     };

macos/polyvox_filament.podspec

@@ -14,7 +14,7 @@ A new Flutter plugin project.
   s.author           = { 'Your Company' => 'email@example.com' }
 
   s.source           = { :path => '.' }
-  s.source_files = 'Classes/*', 'src/*', 'include/filament/*', 'include/*', 'include/material/*.c'
+  s.source_files = 'Classes/*', 'src/*', "src/camutils/*", 'include/filament/*', 'include/*', 'include/material/*.c'
   s.public_header_files = 'include/SwiftPolyvoxFilamentPlugin-Bridging-Header.h',  'include/PolyvoxFilamentApi.h', 'include/PolyvoxFilamentFFIApi.h', 'include/ResourceBuffer.hpp' #, 'include/filament/*'
   s.dependency 'FlutterMacOS'
 
@@ -38,7 +38,7 @@ A new Flutter plugin project.
     'OTHER_CFLAGS' => '"-fvisibility=default" "$(inherited)"',
     'USER_HEADER_SEARCH_PATHS' => '"${PODS_TARGET_SRCROOT}/include" "${PODS_TARGET_SRCROOT}/include/filament" "$(inherited)"',
     'ALWAYS_SEARCH_USER_PATHS' => 'YES',
-    "OTHER_LDFLAGS" =>  '-lfilament -lbackend -lfilameshio -lviewer -lfilamat -lgeometry -lutils -lfilabridge -lgltfio_core -lfilament-iblprefilter -limage -limageio -ltinyexr -lcamutils -lgltfio_core -lfilaflat -ldracodec -libl -lktxreader -lpng -lz -lstb -luberzlib -lsmol-v -luberarchive -lzstd -lvkshaders -lbluegl -lbluevk -lbasis_transcoder -lmeshoptimizer',
+    "OTHER_LDFLAGS" =>  '-lfilament -lbackend -lfilameshio -lviewer -lfilamat -lgeometry -lutils -lfilabridge -lgltfio_core -lfilament-iblprefilter -limage -limageio -ltinyexr -lgltfio_core -lfilaflat -ldracodec -libl -lktxreader -lpng -lz -lstb -luberzlib -lsmol-v -luberarchive -lzstd -lvkshaders -lbluegl -lbluevk -lbasis_transcoder -lmeshoptimizer',
     'LIBRARY_SEARCH_PATHS' => '"${PODS_TARGET_SRCROOT}/lib" "$(inherited)"',
   }
   s.swift_version = '5.0'

macos/src/FilamentViewer.cpp

@@ -22,6 +22,7 @@
  * limitations under the License.
  */
 #include <filament/Camera.h>
+
 #include <backend/DriverEnums.h>
 #include <backend/platforms/OpenGLPlatform.h>
 #include <filament/ColorGrading.h>
@@ -86,12 +87,14 @@ using namespace gltfio;
 using namespace utils;
 using namespace image;
 
-namespace filament {
+namespace filament
+{
   class IndirectLight;
   class LightManager;
 } // namespace filament
 
-namespace polyvox {
+namespace polyvox
+{
 
   const double kNearPlane = 0.05;  // 5 cm
   const double kFarPlane = 1000.0; // 1 km
@@ -99,7 +102,8 @@ const double kFarPlane = 1000.0; // 1 km
   // const float kAperture = 1.0f;
   // const float kShutterSpeed = 1.0f;
   // const float kSensitivity = 50.0f;
-struct Vertex {
+  struct Vertex
+  {
     filament::math::float2 position;
     uint32_t color;
   };
@@ -112,7 +116,8 @@ static constexpr float4 sFullScreenTriangleVertices[3] = {
   static const uint16_t sFullScreenTriangleIndices[3] = {0, 1, 2};
 
   FilamentViewer::FilamentViewer(const void *sharedContext, const ResourceLoaderWrapper *const resourceLoaderWrapper, void *const platform, const char *uberArchivePath)
-  : _resourceLoaderWrapper(resourceLoaderWrapper) {
+      : _resourceLoaderWrapper(resourceLoaderWrapper)
+  {
 
     ASSERT_POSTCONDITION(_resourceLoaderWrapper != nullptr, "Resource loader must be non-null");
 
@@ -193,8 +198,7 @@ FilamentViewer::FilamentViewer(const void* sharedContext, const ResourceLoaderWr
         _ncm,
         _engine,
         _scene,
-    uberArchivePath
+        uberArchivePath);
-  );
 
     _imageTexture = Texture::Builder()
                         .width(1)
@@ -203,7 +207,8 @@ FilamentViewer::FilamentViewer(const void* sharedContext, const ResourceLoaderWr
                         .format(Texture::InternalFormat::RGB16F)
                         .sampler(Texture::Sampler::SAMPLER_2D)
                         .build(*_engine);
-  try {
+    try
+    {
       _imageMaterial =
           Material::Builder()
               .package(IMAGE_IMAGE_DATA, IMAGE_IMAGE_SIZE)
@@ -211,7 +216,9 @@ FilamentViewer::FilamentViewer(const void* sharedContext, const ResourceLoaderWr
       _imageMaterial->setDefaultParameter("showImage", 0);
       _imageMaterial->setDefaultParameter("backgroundColor", RgbaType::sRGB, float4(0.5f, 0.5f, 0.5f, 1.0f));
       _imageMaterial->setDefaultParameter("image", _imageTexture, _imageSampler);
-  } catch(...) {
+    }
+    catch (...)
+    {
       Log("Failed to load background image material provider");
       std::rethrow_exception(std::current_exception());
     }
@@ -250,21 +257,25 @@ FilamentViewer::FilamentViewer(const void* sharedContext, const ResourceLoaderWr
     _scene->addEntity(imageEntity);
   }
 
-void FilamentViewer::setPostProcessing(bool enabled) {
+  void FilamentViewer::setPostProcessing(bool enabled)
+  {
     _view->setPostProcessingEnabled(enabled);
   }
 
-void FilamentViewer::setBloom(float strength) {
+  void FilamentViewer::setBloom(float strength)
+  {
     decltype(_view->getBloomOptions()) opts;
     opts.enabled = true;
     opts.strength = strength;
     _view->setBloomOptions(opts);
   }
 
-void FilamentViewer::setToneMapping(ToneMapping toneMapping) {
+  void FilamentViewer::setToneMapping(ToneMapping toneMapping)
+  {
 
     ToneMapper *tm;
-  switch(toneMapping) {
+    switch (toneMapping)
+    {
     case ToneMapping::ACES:
       Log("Setting tone mapping to ACES");
       tm = new ACESToneMapper();
@@ -282,21 +293,22 @@ void FilamentViewer::setToneMapping(ToneMapping toneMapping) {
       return;
     }
 
- 
     auto newColorGrading = ColorGrading::Builder().toneMapper(tm).build(*_engine);
     _view->setColorGrading(newColorGrading);
     _engine->destroy(colorGrading);
     delete tm;
   }
 
-void FilamentViewer::setFrameInterval(float frameInterval) {
+  void FilamentViewer::setFrameInterval(float frameInterval)
+  {
     Renderer::FrameRateOptions fro;
     fro.interval = frameInterval;
     _renderer->setFrameRateOptions(fro);
     Log("Set framerate interval to %f", frameInterval);
   }
 
-int32_t FilamentViewer::addLight(LightManager::Type t, float colour, float intensity, float posX, float posY, float posZ, float dirX, float dirY, float dirZ, bool shadows) {
+  int32_t FilamentViewer::addLight(LightManager::Type t, float colour, float intensity, float posX, float posY, float posZ, float dirX, float dirY, float dirZ, bool shadows)
+  {
     auto light = EntityManager::get().create();
     LightManager::Builder(t)
         .color(Color::cct(colour))
@@ -312,30 +324,37 @@ int32_t FilamentViewer::addLight(LightManager::Type t, float colour, float inten
     return entityId;
   }
 
-void FilamentViewer::removeLight(EntityId entityId) {
+  void FilamentViewer::removeLight(EntityId entityId)
+  {
     Log("Removing light with entity ID %d", entityId);
     auto entity = utils::Entity::import(entityId);
-  if(entity.isNull()) {
+    if (entity.isNull())
+    {
       Log("Error: light entity not found under ID %d", entityId);
-  } else {
+    }
+    else
+    {
       remove(_lights.begin(), _lights.end(), entity);
       _scene->remove(entity);
       EntityManager::get().destroy(1, &entity);
     }
   }
 
-void FilamentViewer::clearLights() {
+  void FilamentViewer::clearLights()
+  {
     Log("Removing all lights");
     _scene->removeEntities(_lights.data(), _lights.size());
     EntityManager::get().destroy(_lights.size(), _lights.data());
     _lights.clear();
   }
 
-static bool endsWith(string path, string ending) {
+  static bool endsWith(string path, string ending)
+  {
     return path.compare(path.length() - ending.length(), ending.length(), ending) == 0;
   }
 
-void FilamentViewer::loadKtx2Texture(string path, ResourceBuffer rb) {
+  void FilamentViewer::loadKtx2Texture(string path, ResourceBuffer rb)
+  {
 
     // TODO - check all this
 
@@ -356,34 +375,36 @@ void FilamentViewer::loadKtx2Texture(string path, ResourceBuffer rb) {
     //           ktxreader::Ktx2Reader::TransferFunction::LINEAR);
   }
 
-void FilamentViewer::loadKtxTexture(string path, ResourceBuffer rb) {
+  void FilamentViewer::loadKtxTexture(string path, ResourceBuffer rb)
+  {
     ktxreader::Ktx1Bundle *bundle =
         new ktxreader::Ktx1Bundle(static_cast<const uint8_t *>(rb.data),
                                   static_cast<uint32_t>(rb.size));
 
-    
     // because the ResourceBuffer will go out of scope before the texture callback is invoked, we need to make a copy to the heap
     ResourceBuffer *rbCopy = new ResourceBuffer(rb);
 
     std::vector<void *> *callbackData = new std::vector<void *>{(void *)_resourceLoaderWrapper, rbCopy};
 
-
     _imageTexture =
-          ktxreader::Ktx1Reader::createTexture(_engine, *bundle, false, [](void* userdata) {
+        ktxreader::Ktx1Reader::createTexture(
+            _engine, *bundle, false, [](void *userdata)
+            {
           std::vector<void*>* vec = (std::vector<void*>*)userdata;
           ResourceLoaderWrapper* loader = (ResourceLoaderWrapper*)vec->at(0);
           ResourceBuffer* rb = (ResourceBuffer*) vec->at(1);
           loader->free(*rb);
           delete rb;
-          delete vec;
+          delete vec; },
-      }, callbackData);
+            callbackData);
 
     auto info = bundle->getInfo();
     _imageWidth = info.pixelWidth;
     _imageHeight = info.pixelHeight;
   }
 
-void FilamentViewer::loadPngTexture(string path, ResourceBuffer rb) {
+  void FilamentViewer::loadPngTexture(string path, ResourceBuffer rb)
+  {
 
     polyvox::StreamBufferAdapter sb((char *)rb.data, (char *)rb.data + rb.size);
 
@@ -392,7 +413,8 @@ void FilamentViewer::loadPngTexture(string path, ResourceBuffer rb) {
     LinearImage *image = new LinearImage(ImageDecoder::decode(
         inputStream, path.c_str(), ImageDecoder::ColorSpace::SRGB));
 
-  if (!image->isValid()) {
+    if (!image->isValid())
+    {
       Log("Invalid image : %s", path.c_str());
       return;
     }
@@ -411,7 +433,8 @@ void FilamentViewer::loadPngTexture(string path, ResourceBuffer rb) {
                         .build(*_engine);
 
     Texture::PixelBufferDescriptor::Callback freeCallback = [](void *buf, size_t,
-                                                            void *data) {
+                                                               void *data)
+    {
       delete reinterpret_cast<LinearImage *>(data);
     };
 
@@ -426,43 +449,54 @@ void FilamentViewer::loadPngTexture(string path, ResourceBuffer rb) {
     _resourceLoaderWrapper->free(rb);
   }
 
-void FilamentViewer::loadTextureFromPath(string path) {
+  void FilamentViewer::loadTextureFromPath(string path)
+  {
     string ktxExt(".ktx");
     string ktx2Ext(".ktx2");
     string pngExt(".png");
 
-  if (path.length() < 5) {
+    if (path.length() < 5)
+    {
       Log("Invalid resource path : %s", path.c_str());
       return;
     }
 
     ResourceBuffer rb = _resourceLoaderWrapper->load(path.c_str());
 
-  if(endsWith(path, ktxExt)) {
+    if (endsWith(path, ktxExt))
+    {
       loadKtxTexture(path, rb);
-  } else if(endsWith(path, ktx2Ext)) {
+    }
+    else if (endsWith(path, ktx2Ext))
+    {
       loadKtx2Texture(path, rb);
-  } else if(endsWith(path, pngExt)) {
+    }
+    else if (endsWith(path, pngExt))
+    {
       loadPngTexture(path, rb);
     }
   }
 
-void FilamentViewer::setBackgroundColor(const float r, const float g, const float b, const float a) {
+  void FilamentViewer::setBackgroundColor(const float r, const float g, const float b, const float a)
+  {
     _imageMaterial->setDefaultParameter("showImage", 0);
     _imageMaterial->setDefaultParameter("backgroundColor", RgbaType::sRGB, float4(r, g, b, a));
     _imageMaterial->setDefaultParameter("transform", _imageScale);
   }
 
-void FilamentViewer::clearBackgroundImage() {
+  void FilamentViewer::clearBackgroundImage()
+  {
     _imageMaterial->setDefaultParameter("showImage", 0);
-  if (_imageTexture) {
+    if (_imageTexture)
+    {
       _engine->destroy(_imageTexture);
       _imageTexture = nullptr;
       Log("Destroyed background image texture");
     }
   }
 
-void FilamentViewer::setBackgroundImage(const char *resourcePath, bool fillHeight) {
+  void FilamentViewer::setBackgroundImage(const char *resourcePath, bool fillHeight)
+  {
 
     string resourcePathString(resourcePath);
 
@@ -477,13 +511,15 @@ void FilamentViewer::setBackgroundImage(const char *resourcePath, bool fillHeigh
     const Viewport &vp = _view->getViewport();
     Log("Image width %d height %d vp width %d height %d", _imageWidth, _imageHeight, vp.width, vp.height);
 
-
     float xScale = float(vp.width) / float(_imageWidth);
 
     float yScale;
-  if(fillHeight) {
+    if (fillHeight)
+    {
       yScale = 1.0f;
-  } else { 
+    }
+    else
+    {
       yScale = float(vp.height) / float(_imageHeight);
     }
 
@@ -492,17 +528,16 @@ void FilamentViewer::setBackgroundImage(const char *resourcePath, bool fillHeigh
     _imageMaterial->setDefaultParameter("transform", _imageScale);
     _imageMaterial->setDefaultParameter("image", _imageTexture, _imageSampler);
     _imageMaterial->setDefaultParameter("showImage", 1);
-  
   }
 
-
   ///
   /// Translates the background image by (x,y) pixels.
   /// If clamp is true, x/y are both clamped so that the left/top and right/bottom sides of the background image
   /// are positioned at a max/min of -1/1 respectively
   /// (i.e. you cannot set a position where the left/top or right/bottom sides would be "inside" the screen coordinate space).
   ///
-void FilamentViewer::setBackgroundImagePosition(float x, float y, bool clamp=false) {
+  void FilamentViewer::setBackgroundImagePosition(float x, float y, bool clamp = false)
+  {
 
     // to translate the background image, we apply a transform to the UV coordinates of the quad texture, not the quad itself (see image.mat).
     // this allows us to set a background colour for the quad when the texture has been translated outside the quad's bounds.
@@ -517,7 +552,8 @@ void FilamentViewer::setBackgroundImagePosition(float x, float y, bool clamp=fal
     // y *= _imageScale[1][1];
 
     // TODO - I haven't updated the clamp calculations to work with scaled image width/height percentages so the below code is probably wrong, don't use it until it's fixed.
-  if(clamp) {
+    if (clamp)
+    {
       Log("Clamping background image translation");
       // first, clamp x/y
       auto xScale = float(_imageWidth) / _view->getViewport().width;
@@ -530,20 +566,26 @@ void FilamentViewer::setBackgroundImagePosition(float x, float y, bool clamp=fal
 
       // we need to clamp x so that it can only be translated between (left side touching viewport left) and (right side touching viewport right)
       // if width is less than viewport, these values are 0/1-xScale respectively
-    if(xScale < 1) {
+      if (xScale < 1)
+      {
         xMin = 0;
         xMax = 1 - xScale;
         // otherwise, these value are (xScale-1 and 1-xScale)
-    } else {
+      }
+      else
+      {
         xMin = 1 - xScale;
         xMax = 0;
       }
 
       // do the same for y
-    if(yScale < 1) {
+      if (yScale < 1)
+      {
         yMin = 0;
         yMax = 1 - yScale;
-    } else {
+      }
+      else
+      {
         yMin = 1 - yScale;
         yMax = 0;
       }
@@ -558,26 +600,27 @@ void FilamentViewer::setBackgroundImagePosition(float x, float y, bool clamp=fal
     y = -y;
     Log("x %f y %f", x, y);
 
-  Log("imageScale %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f ", _imageScale[0][0],_imageScale[0][1],_imageScale[0][2], _imageScale[0][3], \
+    Log("imageScale %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f ", _imageScale[0][0], _imageScale[0][1], _imageScale[0][2], _imageScale[0][3],
-  _imageScale[1][0],_imageScale[1][1],_imageScale[1][2], _imageScale[1][3],\
+        _imageScale[1][0], _imageScale[1][1], _imageScale[1][2], _imageScale[1][3],
-  _imageScale[2][0],_imageScale[2][1],_imageScale[2][2], _imageScale[2][3], \
+        _imageScale[2][0], _imageScale[2][1], _imageScale[2][2], _imageScale[2][3],
         _imageScale[3][0], _imageScale[3][1], _imageScale[3][2], _imageScale[3][3]);
 
     auto transform = math::mat4f::translation(math::float3(x, y, 0.0f)) * _imageScale;
 
-
+    Log("transform %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f ", transform[0][0], transform[0][1], transform[0][2], transform[0][3],
-  Log("transform %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f %f ", transform[0][0],transform[0][1],transform[0][2], transform[0][3], \
+        transform[1][0], transform[1][1], transform[1][2], transform[1][3],
-  transform[1][0],transform[1][1],transform[1][2], transform[1][3],\
+        transform[2][0], transform[2][1], transform[2][2], transform[2][3],
-  transform[2][0],transform[2][1],transform[2][2], transform[2][3], \
         transform[3][0], transform[3][1], transform[3][2], transform[3][3]);
     _imageMaterial->setDefaultParameter("transform", transform);
   }
 
-FilamentViewer::~FilamentViewer() { 
+  FilamentViewer::~FilamentViewer()
+  {
     clearAssets();
     delete _assetManager;
 
-  for(auto it : _lights) {
+    for (auto it : _lights)
+    {
       _engine->destroy(it);
     }
 
@@ -593,21 +636,26 @@ FilamentViewer::~FilamentViewer() {
 
   Renderer *FilamentViewer::getRenderer() { return _renderer; }
 
-void FilamentViewer::createSwapChain(const void *window, uint32_t width, uint32_t height) {
+  void FilamentViewer::createSwapChain(const void *window, uint32_t width, uint32_t height)
+  {
 #if TARGET_OS_IPHONE
     _swapChain = _engine->createSwapChain((void *)window, filament::backend::SWAP_CHAIN_CONFIG_APPLE_CVPIXELBUFFER);
 #else
-    if(window) {
+    if (window)
+    {
       _swapChain = _engine->createSwapChain((void *)window, filament::backend::SWAP_CHAIN_CONFIG_TRANSPARENT | filament::backend::SWAP_CHAIN_CONFIG_READABLE);
       Log("Created window swapchain.");
-    } else {
+    }
+    else
+    {
       Log("Created headless swapchain.");
       _swapChain = _engine->createSwapChain(width, height, filament::backend::SWAP_CHAIN_CONFIG_TRANSPARENT | filament::backend::SWAP_CHAIN_CONFIG_READABLE);
     }
 #endif
   }
 
-void FilamentViewer::createRenderTarget(intptr_t texture, uint32_t width, uint32_t height) {
+  void FilamentViewer::createRenderTarget(intptr_t texture, uint32_t width, uint32_t height)
+  {
     // Create filament textures and render targets (note the color buffer has the import call)
     _rtColor = filament::Texture::Builder()
                    .width(width)
@@ -633,11 +681,12 @@ void FilamentViewer::createRenderTarget(intptr_t texture, uint32_t width, uint32
     _view->setRenderTarget(_rt);
 
     Log("Set render target for texture id %u to %u x %u", texture, width, height);
-
   }
 
-void FilamentViewer::destroySwapChain() {
+  void FilamentViewer::destroySwapChain()
-  if(_rt) {
+  {
+    if (_rt)
+    {
       _view->setRenderTarget(nullptr);
       _engine->destroy(_rtDepth);
       _engine->destroy(_rtColor);
@@ -646,16 +695,19 @@ void FilamentViewer::destroySwapChain() {
       _rtDepth = nullptr;
       _rtColor = nullptr;
     }
-  if (_swapChain) {
+    if (_swapChain)
+    {
       _engine->destroy(_swapChain);
       _swapChain = nullptr;
       Log("Swapchain destroyed.");
     }
   }
 
-void FilamentViewer::clearAssets() {
+  void FilamentViewer::clearAssets()
+  {
     Log("Clearing all assets");
-  if(_mainCamera) {
+    if (_mainCamera)
+    {
       _view->setCamera(_mainCamera);
     }
 
@@ -664,7 +716,8 @@ void FilamentViewer::clearAssets() {
     Log("Cleared all assets");
   }
 
-void FilamentViewer::removeAsset(EntityId asset) {
+  void FilamentViewer::removeAsset(EntityId asset)
+  {
     Log("Removing asset from scene");
 
     mtx.lock();
@@ -677,7 +730,8 @@ void FilamentViewer::removeAsset(EntityId asset) {
   ///
   /// Set the exposure for the current active camera.
   ///
-void FilamentViewer::setCameraExposure(float aperture, float shutterSpeed, float sensitivity) {
+  void FilamentViewer::setCameraExposure(float aperture, float shutterSpeed, float sensitivity)
+  {
     Camera &cam = _view->getCamera();
     Log("Setting aperture (%03f) shutterSpeed (%03f) and sensitivity (%03f)", aperture, shutterSpeed, sensitivity);
     cam.setExposure(aperture, shutterSpeed, sensitivity);
@@ -686,7 +740,8 @@ void FilamentViewer::setCameraExposure(float aperture, float shutterSpeed, float
   ///
   /// Set the focal length of the active camera.
   ///
-void FilamentViewer::setCameraFocalLength(float focalLength) {
+  void FilamentViewer::setCameraFocalLength(float focalLength)
+  {
     Camera &cam = _view->getCamera();
     _cameraFocalLength = focalLength;
     cam.setLensProjection(_cameraFocalLength, 1.0f, kNearPlane,
@@ -696,7 +751,8 @@ void FilamentViewer::setCameraFocalLength(float focalLength) {
   ///
   /// Set the focus distance of the active camera.
   ///
-void FilamentViewer::setCameraFocusDistance(float focusDistance) {
+  void FilamentViewer::setCameraFocusDistance(float focusDistance)
+  {
     Camera &cam = _view->getCamera();
     _cameraFocusDistance = focusDistance;
     cam.setFocusDistance(_cameraFocusDistance);
@@ -707,15 +763,18 @@ void FilamentViewer::setCameraFocusDistance(float focusDistance) {
   /// N.B. Blender will generally export a three-node hierarchy -
   /// Camera1->Camera_Orientation->Camera2. The correct name will be the Camera_Orientation.
   ///
-bool FilamentViewer::setCamera(EntityId entityId, const char *cameraName) {
+  bool FilamentViewer::setCamera(EntityId entityId, const char *cameraName)
+  {
 
     auto asset = _assetManager->getAssetByEntityId(entityId);
-    if(!asset) {
+    if (!asset)
+    {
       Log("Failed to find asset under entity id %d.", entityId);
       return false;
     }
     size_t count = asset->getCameraEntityCount();
-    if (count == 0) {
+    if (count == 0)
+    {
       Log("No cameras found attached to specified entity.");
       return false;
     }
@@ -724,28 +783,35 @@ bool FilamentViewer::setCamera(EntityId entityId, const char *cameraName) {
 
     utils::Entity target;
 
-    if(!cameraName) {
+    if (!cameraName)
+    {
       auto inst = _ncm->getInstance(cameras[0]);
       const char *name = _ncm->getName(inst);
       target = cameras[0];
       Log("No camera specified, using first camera node found (%s)", name);
-    } else {
+    }
-        for (int j = 0; j < count; j++) {
+    else
+    {
+      for (int j = 0; j < count; j++)
+      {
         auto inst = _ncm->getInstance(cameras[j]);
         const char *name = _ncm->getName(inst);
-            if (strcmp(name, cameraName) == 0) {
+        if (strcmp(name, cameraName) == 0)
+        {
           target = cameras[j];
           break;
         }
       }
     }
-    if(target.isNull()) {
+    if (target.isNull())
+    {
       Log("Unable to locate camera under name %s ", cameraName);
       return false;
     }
 
     Camera *camera = _engine->getCameraComponent(target);
-    if(!camera) {
+    if (!camera)
+    {
       Log("Failed to retrieve camera component for target");
       return false;
     }
@@ -761,11 +827,13 @@ bool FilamentViewer::setCamera(EntityId entityId, const char *cameraName) {
     return true;
   }
 
-void FilamentViewer::loadSkybox(const char *const skyboxPath) {
+  void FilamentViewer::loadSkybox(const char *const skyboxPath)
+  {
 
     removeSkybox();
 
-  if (!skyboxPath) {
+    if (!skyboxPath)
+    {
       Log("No skybox path provided, removed skybox.");
     }
 
@@ -776,7 +844,8 @@ void FilamentViewer::loadSkybox(const char *const skyboxPath) {
     // because this will go out of scope before the texture callback is invoked, we need to make a copy to the heap
     ResourceBuffer *skyboxBufferCopy = new ResourceBuffer(skyboxBuffer);
 
-    if(skyboxBuffer.size <= 0) {
+    if (skyboxBuffer.size <= 0)
+    {
       Log("Could not load skybox resource.");
       return;
     }
@@ -790,37 +859,43 @@ void FilamentViewer::loadSkybox(const char *const skyboxPath) {
                               static_cast<uint32_t>(skyboxBuffer.size));
 
     _skyboxTexture =
-        ktxreader::Ktx1Reader::createTexture(_engine, *skyboxBundle, false, [](void* userdata) {
+        ktxreader::Ktx1Reader::createTexture(
+            _engine, *skyboxBundle, false, [](void *userdata)
+            {
         std::vector<void*>* vec = (std::vector<void*>*)userdata;
         ResourceLoaderWrapper* loader = (ResourceLoaderWrapper*)vec->at(0);
         ResourceBuffer* rb = (ResourceBuffer*) vec->at(1);
         loader->free(*rb);
         delete rb;
         delete vec;
-        Log("Skybox load complete.");
+        Log("Skybox load complete."); },
-        }, callbackData);
+            callbackData);
     _skybox =
         filament::Skybox::Builder().environment(_skyboxTexture).build(*_engine);
 
     _scene->setSkybox(_skybox);
-
   }
 
-void FilamentViewer::removeSkybox() { 
+  void FilamentViewer::removeSkybox()
+  {
     Log("Removing skybox");
     _scene->setSkybox(nullptr);
-  if(_skybox) {
+    if (_skybox)
+    {
       _engine->destroy(_skybox);
       _skybox = nullptr;
     }
-  if(_skyboxTexture) {
+    if (_skyboxTexture)
+    {
       _engine->destroy(_skyboxTexture);
       _skyboxTexture = nullptr;
     }
   }
 
-void FilamentViewer::removeIbl() { 
+  void FilamentViewer::removeIbl()
-  if(_indirectLight) {
+  {
+    if (_indirectLight)
+    {
       _engine->destroy(_indirectLight);
       _engine->destroy(_iblTexture);
       _indirectLight = nullptr;
@@ -829,9 +904,11 @@ void FilamentViewer::removeIbl() {
     _scene->setIndirectLight(nullptr);
   }
 
-void FilamentViewer::loadIbl(const char *const iblPath, float intensity) {
+  void FilamentViewer::loadIbl(const char *const iblPath, float intensity)
+  {
     removeIbl();
-  if (iblPath) {
+    if (iblPath)
+    {
       Log("Loading IBL from %s", iblPath);
 
       // Load IBL.
@@ -839,7 +916,8 @@ void FilamentViewer::loadIbl(const char *const iblPath, float intensity) {
       // because this will go out of scope before the texture callback is invoked, we need to make a copy to the heap
       ResourceBuffer *iblBufferCopy = new ResourceBuffer(iblBuffer);
 
-    if(iblBuffer.size == 0) {
+      if (iblBuffer.size == 0)
+      {
         Log("Error loading IBL, resource could not be loaded.");
         return;
       }
@@ -853,14 +931,16 @@ void FilamentViewer::loadIbl(const char *const iblPath, float intensity) {
       std::vector<void *> *callbackData = new std::vector<void *>{(void *)_resourceLoaderWrapper, iblBufferCopy};
 
       _iblTexture =
-        ktxreader::Ktx1Reader::createTexture(_engine, *iblBundle, false, [](void* userdata) {
+          ktxreader::Ktx1Reader::createTexture(
+              _engine, *iblBundle, false, [](void *userdata)
+              {
             std::vector<void*>* vec = (std::vector<void*>*)userdata;
             ResourceLoaderWrapper* loader = (ResourceLoaderWrapper*)vec->at(0);
             ResourceBuffer* rb = (ResourceBuffer*) vec->at(1);
             loader->free(*rb);
             delete rb;
-            delete vec;
+            delete vec; },
-    }, callbackData);
+              callbackData);
       _indirectLight = IndirectLight::Builder()
                            .reflections(_iblTexture)
                            .irradiance(3, harmonics)
@@ -879,14 +959,17 @@ void FilamentViewer::render(
       uint64_t frameTimeInNanos,
       void *pixelBuffer,
       void (*callback)(void *buf, size_t size, void *data),
-  void* data) {
+      void *data)
+  {
 
-  if (!_view || !_mainCamera || !_swapChain) {
+    if (!_view || !_mainCamera || !_swapChain)
+    {
       Log("Not ready for rendering");
       return;
     }
 
-  if(_frameCount == 60) {
+    if (_frameCount == 60)
+    {
       // Log("1 sec average for asset animation update %f", _elapsed / 60);
       _elapsed = 0;
       _frameCount = 0;
@@ -899,7 +982,18 @@ void FilamentViewer::render(
     _elapsed += tmr.elapsed();
     _frameCount++;
 
-  if(pixelBuffer) {
+    // if a manipulator is active, update the active camera orientation
+    if(_manipulator) {
+      math::double3 eye, target, upward;
+      Camera& cam =_view->getCamera();
+      _manipulator->getLookAt(&eye, &target, &upward);
+      cam.lookAt(eye, target, upward);
+    }
+
+    // TODO - this was an experiment but probably useful to keep for debugging
+    // if pixelBuffer is provided, we will copy the framebuffer into the pixelBuffer.
+    if (pixelBuffer)
+    {
       auto pbd = Texture::PixelBufferDescriptor(
           pixelBuffer, size_t(1024 * 768 * 4),
           Texture::Format::RGBA,
@@ -909,21 +1003,27 @@ void FilamentViewer::render(
       _renderer->render(_view);
       _renderer->readPixels(0, 0, 1024, 768, std::move(pbd));
       _renderer->endFrame();
-  } else {
+    }
+    else
+    {
       // Render the scene, unless the renderer wants to skip the frame.
-    if (_renderer->beginFrame(_swapChain, frameTimeInNanos)) {
+      if (_renderer->beginFrame(_swapChain, frameTimeInNanos))
+      {
         _renderer->render(_view);
         _renderer->endFrame();
-    } else {
+      }
+      else
+      {
         // skipped frame
       }
     }
-  
   }
 
   void FilamentViewer::updateViewportAndCameraProjection(
-    int width, int height, float contentScaleFactor) {
+      int width, int height, float contentScaleFactor)
-  if (!_view || !_mainCamera) {
+  {
+    if (!_view || !_mainCamera)
+    {
       Log("Skipping camera update, no view or camrea");
       return;
     }
@@ -944,20 +1044,24 @@ void FilamentViewer::updateViewportAndCameraProjection(
         contentScaleFactor);
   }
 
-void FilamentViewer::setViewFrustumCulling(bool enabled) { 
+  void FilamentViewer::setViewFrustumCulling(bool enabled)
+  {
     _view->setFrustumCullingEnabled(enabled);
   }
 
-void FilamentViewer::setCameraPosition(float x, float y, float z) {
+  void FilamentViewer::setCameraPosition(float x, float y, float z)
+  {
     Camera &cam = _view->getCamera();
 
     _cameraPosition = math::mat4f::translation(math::float3(x, y, z));
     cam.setModelMatrix(_cameraPosition * _cameraRotation);
   }
 
-void FilamentViewer::moveCameraToAsset(EntityId entityId) {
+  void FilamentViewer::moveCameraToAsset(EntityId entityId)
+  {
     auto asset = _assetManager->getAssetByEntityId(entityId);
-  if(!asset) {
+    if (!asset)
+    {
       Log("Failed to find asset attached to specified entity id.");
       return;
     }
@@ -971,13 +1075,15 @@ void FilamentViewer::moveCameraToAsset(EntityId entityId) {
     Log("Moved camera to %f %f %f, lookAt %f %f %f, near %f far %f", eye[0], eye[1], eye[2], lookAt[0], lookAt[1], lookAt[2], cam.getNear(), cam.getCullingFar());
   }
 
-void FilamentViewer::setCameraRotation(float rads, float x, float y, float z) {
+  void FilamentViewer::setCameraRotation(float rads, float x, float y, float z)
+  {
     Camera &cam = _view->getCamera();
     _cameraRotation = math::mat4f::rotation(rads, math::float3(x, y, z));
     cam.setModelMatrix(_cameraPosition * _cameraRotation);
   }
 
-void FilamentViewer::setCameraModelMatrix(const float* const matrix) {
+  void FilamentViewer::setCameraModelMatrix(const float *const matrix)
+  {
     Camera &cam = _view->getCamera();
 
     mat4 modelMatrix(
@@ -996,75 +1102,123 @@ void FilamentViewer::setCameraModelMatrix(const float* const matrix) {
         matrix[12],
         matrix[13],
         matrix[14],
-   matrix[15]
+        matrix[15]);
-);
     cam.setModelMatrix(modelMatrix);
   }
 
-void FilamentViewer::grabBegin(float x, float y, bool pan) {
+  void FilamentViewer::_createManipulator()
-  if (!_view || !_mainCamera || !_swapChain) {
+  {
-    Log("View not ready, ignoring grab");
+    Camera &cam = _view->getCamera();
-    return;
+    math::double3 home = cam.getPosition();
-  }
+    math::double3 up = cam.getUpVector();
-  _panning = pan;
+    math::double3 target = home + cam.getForwardVector();
-  _startX = x;
+    Viewport const &vp = _view->getViewport();
-  _startY = y;
+    Log("Creating manipulator for viewport size %dx%d with camera norm %f", vp.width, vp.height, norm(home));
+    float zoomSpeed = norm(home) / 10;
+    zoomSpeed = math::clamp(zoomSpeed, 0.1f, 100000.0f);
+
+    _manipulator = Manipulator<double>::Builder()
+                       .viewport(vp.width, vp.height)
+                       .orbitHomePosition(home[0], home[1], home[2])
+                       .upVector(up.x, up.y, up.z)
+                       .zoomSpeed(zoomSpeed)
+                      //  .orbitSpeed(0.0001, 0.0001)
+                       .targetPosition(target[0], target[1], target[2])
+                       .build(Mode::ORBIT);
   }
 
-void FilamentViewer::grabUpdate(float x, float y) {
+  void FilamentViewer::grabBegin(float x, float y, bool pan)
-    if (!_view || !_swapChain) {
+  {
+    if (!_view || !_mainCamera || !_swapChain)
+    {
       Log("View not ready, ignoring grab");
       return;
     }
-    Camera& cam =_view->getCamera();
+    if (!_manipulator)
-    auto eye =  cam.getPosition();
+    {
-    auto target = eye + cam.getForwardVector();
+      _createManipulator();
-    auto upward = cam.getUpVector();
+    }
-    Viewport const& vp = _view->getViewport();
+    if(pan) {
-    if(_panning) {
+      Log("Beginning pan at %f %f", x, y);
-        auto trans = cam.getModelMatrix() * mat4::translation(math::float3 { 50 * (x - _startX) / vp.width, 50 * (y - _startY) / vp.height, 0.0f });
-        cam.setModelMatrix(trans);
     } else { 
-        auto trans = cam.getModelMatrix() * mat4::rotation(0.05,
+      Log("Beginning rotate at %f %f", x, y);
-                                                           math::float3 { (y - _startY) / vp.height, (x - _startX) / vp.width, 0.0f });
-        cam.setModelMatrix(trans);
-    }
-    _startX = x;
-    _startY = y;
-
     }
     
-void FilamentViewer::grabEnd() {
+    _manipulator->grabBegin(x, y, pan);
-  if (!_view || !_mainCamera || !_swapChain) {
+  }
+
+  void FilamentViewer::grabUpdate(float x, float y)
+  {
+    if (!_view || !_swapChain)
+    {
       Log("View not ready, ignoring grab");
       return;
     }
+
+
+    Log("Updating grab at %f %f", x, y);
+
+
+    if (_manipulator)
+    {
+      _manipulator->grabUpdate(x, y);
+    }
+    else
+    {
+      Log("Error - trying to use a manipulator when one is not available. Ensure you call grabBegin before grabUpdate/grabEnd");
+    }
   }
 
-void FilamentViewer::scrollBegin() {
+  void FilamentViewer::grabEnd()
-  // noop
+  {
+    if (!_view || !_mainCamera || !_swapChain)
+    {
+      Log("View not ready, ignoring grab");
+      return;
+    }
+    if (_manipulator)
+    {
+      _manipulator->grabEnd();
+    }
+    else
+    {
+      Log("Error - trying to use a manipulator when one is not available. Ensure you call grabBegin before grabUpdate/grabEnd");
+    }
+    delete _manipulator;
+    _manipulator = nullptr;
   }
 
-void FilamentViewer::scrollUpdate(float x, float y, float delta) {
+  void FilamentViewer::scrollBegin()
-    Camera& cam =_view->getCamera();
+  {
-    Viewport const& vp = _view->getViewport();
+    if (!_manipulator)
-    auto trans = cam.getModelMatrix() * mat4::translation(math::float3 {0.0f, 0.0f, delta });
+    {
-    cam.setModelMatrix(trans);
+      _createManipulator();
+    }
   }
 
-void FilamentViewer::scrollEnd() {
+  void FilamentViewer::scrollUpdate(float x, float y, float delta)
-  // noop  
+  {
+    if (_manipulator)
+    {
+      _manipulator->scroll(int(x), int(y), delta);
+    }
+    else
+    {
+      Log("Error - trying to use a manipulator when one is not available. Ensure you call grabBegin before grabUpdate/grabEnd");
+    }
   }
 
-void FilamentViewer::pick(uint32_t x, uint32_t y, EntityId* entityId) {
+  void FilamentViewer::scrollEnd()
-  Log("Picking at %d,%d", x, y);
+  {
+    delete _manipulator;
+    _manipulator = nullptr;
+  }
+
+  void FilamentViewer::pick(uint32_t x, uint32_t y, EntityId *entityId)
+  {
     _view->pick(x, y, [=](filament::View::PickingQueryResult const &result) {
-      
         *entityId = Entity::smuggle(result.renderable);
-        Log("Got result %d", *entityId);
     });
   }
 
 } // namespace polyvox
-
-  

macos/src/camutils/Bookmark.cpp

@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <camutils/Bookmark.h>
+#include <camutils/Manipulator.h>
+
+#include <math/scalar.h>
+#include <math/vec3.h>
+
+using namespace filament::math;
+
+namespace filament {
+namespace camutils {
+
+template <typename FLOAT>
+Bookmark<FLOAT> Bookmark<FLOAT>::interpolate(Bookmark<FLOAT> a, Bookmark<FLOAT> b, double t) {
+    Bookmark<FLOAT> result;
+    using float3 = filament::math::vec3<FLOAT>;
+
+    if (a.mode == Mode::MAP) {
+        assert(b.mode == Mode::MAP);
+        const double rho = sqrt(2.0);
+        const double rho2 = 2, rho4 = 4;
+        const double ux0 = a.map.center.x, uy0 = a.map.center.y, w0 = a.map.extent;
+        const double ux1 = b.map.center.x, uy1 = b.map.center.y, w1 = b.map.extent;
+        const double dx = ux1 - ux0, dy = uy1 - uy0, d2 = dx * dx + dy * dy, d1 = sqrt(d2);
+        const double b0 = (w1 * w1 - w0 * w0 + rho4 * d2) / (2.0 * w0 * rho2 * d1);
+        const double b1 = (w1 * w1 - w0 * w0 - rho4 * d2) / (2.0 * w1 * rho2 * d1);
+        const double r0 = log(sqrt(b0 * b0 + 1.0) - b0);
+        const double r1 = log(sqrt(b1 * b1 + 1) - b1);
+        const double dr = r1 - r0;
+        const int valid = !std::isnan(dr) && dr != 0;
+        const double S = (valid ? dr : log(w1 / w0)) / rho;
+        const double s = t * S;
+
+        // This performs Van Wijk interpolation to animate between two waypoints on a map.
+        if (valid) {
+            const double coshr0 = cosh(r0);
+            const double u = w0 / (rho2 * d1) * (coshr0 * tanh(rho * s + r0) - sinh(r0));
+            Bookmark<FLOAT> result;
+            result.map.center.x = ux0 + u * dx;
+            result.map.center.y = uy0 + u * dy;
+            result.map.extent = w0 * coshr0 / cosh(rho * s + r0);
+            return result;
+        }
+
+        // For degenerate cases, fall back to a simplified interpolation method.
+        result.map.center.x = ux0 + t * dx;
+        result.map.center.y = uy0 + t * dy;
+        result.map.extent = w0 * exp(rho * s);
+        return result;
+}
+
+    assert(b.mode == Mode::ORBIT);
+    result.orbit.phi = lerp(a.orbit.phi, b.orbit.phi, FLOAT(t));
+    result.orbit.theta = lerp(a.orbit.theta, b.orbit.theta, FLOAT(t));
+    result.orbit.distance = lerp(a.orbit.distance, b.orbit.distance, FLOAT(t));
+    result.orbit.pivot = lerp(a.orbit.pivot, b.orbit.pivot, float3(t));
+    return result;
+}
+
+// Uses the Van Wijk method to suggest a duration for animating between two waypoints on a map.
+// This does not have units, so just use it as a multiplier.
+template <typename FLOAT>
+double Bookmark<FLOAT>::duration(Bookmark<FLOAT> a, Bookmark<FLOAT> b) {
+    assert(a.mode == Mode::ORBIT && b.mode == Mode::ORBIT);
+    const double rho = sqrt(2.0);
+    const double rho2 = 2, rho4 = 4;
+    const double ux0 = a.map.center.x, uy0 = a.map.center.y, w0 = a.map.extent;
+    const double ux1 = b.map.center.x, uy1 = b.map.center.y, w1 = b.map.extent;
+    const double dx = ux1 - ux0, dy = uy1 - uy0, d2 = dx * dx + dy * dy, d1 = sqrt(d2);
+    const double b0 = (w1 * w1 - w0 * w0 + rho4 * d2) / (2.0 * w0 * rho2 * d1);
+    const double b1 = (w1 * w1 - w0 * w0 - rho4 * d2) / (2.0 * w1 * rho2 * d1);
+    const double r0 = log(sqrt(b0 * b0 + 1.0) - b0);
+    const double r1 = log(sqrt(b1 * b1 + 1) - b1);
+    const double dr = r1 - r0;
+    const int valid = !std::isnan(dr) && dr != 0;
+    const double S = (valid ? dr : log(w1 / w0)) / rho;
+    return fabs(S);
+}
+
+template class Bookmark<float>;
+
+} // namespace camutils
+} // namespace filament

macos/src/camutils/FreeFlightManipulator.h

@@ -0,0 +1,206 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef CAMUTILS_FREEFLIGHT_MANIPULATOR_H
+#define CAMUTILS_FREEFLIGHT_MANIPULATOR_H
+
+#include <camutils/Manipulator.h>
+
+#include <math/scalar.h>
+#include <math/mat3.h>
+#include <math/mat4.h>
+#include <math/quat.h>
+
+#include <cmath>
+
+namespace filament {
+namespace camutils {
+
+using namespace filament::math;
+
+template<typename FLOAT>
+class FreeFlightManipulator : public Manipulator<FLOAT> {
+public:
+    using vec2 = filament::math::vec2<FLOAT>;
+    using vec3 = filament::math::vec3<FLOAT>;
+    using vec4 = filament::math::vec4<FLOAT>;
+    using Bookmark = filament::camutils::Bookmark<FLOAT>;
+    using Base = Manipulator<FLOAT>;
+    using Config = typename Base::Config;
+
+    FreeFlightManipulator(Mode mode, const Config& props) : Base(mode, props) {
+        setProperties(props);
+        Base::mEye = Base::mProps.flightStartPosition;
+        const auto pitch = Base::mProps.flightStartPitch;
+        const auto yaw = Base::mProps.flightStartYaw;
+        mTargetEuler = {pitch, yaw};
+        updateTarget(pitch, yaw);
+    }
+
+    void setProperties(const Config& props) override {
+        Config resolved = props;
+
+        if (resolved.flightPanSpeed == vec2(0, 0)) {
+            resolved.flightPanSpeed = vec2(0.01, 0.01);
+        }
+        if (resolved.flightMaxSpeed == 0.0) {
+            resolved.flightMaxSpeed = 10.0;
+        }
+        if (resolved.flightSpeedSteps == 0) {
+            resolved.flightSpeedSteps = 80;
+        }
+
+        Base::setProperties(resolved);
+    }
+
+    void updateTarget(FLOAT pitch, FLOAT yaw) {
+        Base::mTarget = Base::mEye + (mat3::eulerZYX(0, yaw, pitch) * vec3(0.0, 0.0, -1.0));
+    }
+
+    void grabBegin(int x, int y, bool strafe) override {
+        mGrabWin = {x, y};
+        mGrabbing = true;
+        mGrabEuler = mTargetEuler;
+    }
+
+    void grabUpdate(int x, int y) override {
+        if (!mGrabbing) {
+            return;
+        }
+
+        const vec2 del = mGrabWin - vec2{x, y};
+
+        const auto& grabPitch = mGrabEuler.x;
+        const auto& grabYaw = mGrabEuler.y;
+        auto& pitch = mTargetEuler.x;
+        auto& yaw = mTargetEuler.y;
+
+        constexpr double EPSILON = 0.001;
+
+        auto panSpeed = Base::mProps.flightPanSpeed;
+        constexpr FLOAT minPitch = (-F_PI_2 + EPSILON);
+        constexpr FLOAT maxPitch = ( F_PI_2 - EPSILON);
+        pitch = clamp(grabPitch + del.y * -panSpeed.y, minPitch, maxPitch);
+        yaw = fmod(grabYaw + del.x * panSpeed.x, 2.0 * F_PI);
+
+        updateTarget(pitch, yaw);
+    }
+
+    void grabEnd() override {
+        mGrabbing = false;
+    }
+
+    void keyDown(typename Base::Key key) override {
+        mKeyDown[(int) key] = true;
+    }
+
+    void keyUp(typename Base::Key key) override {
+        mKeyDown[(int) key] = false;
+    }
+
+    void scroll(int x, int y, FLOAT scrolldelta) override {
+        const FLOAT halfSpeedSteps = Base::mProps.flightSpeedSteps / 2;
+        mScrollWheel = clamp(mScrollWheel + scrolldelta, -halfSpeedSteps, halfSpeedSteps);
+        // Normalize the scroll position from -1 to 1 and calculate the move speed, in world
+        // units per second.
+        mScrollPositionNormalized = (mScrollWheel + halfSpeedSteps) / halfSpeedSteps - 1.0;
+        mMoveSpeed = pow(Base::mProps.flightMaxSpeed, mScrollPositionNormalized);
+    }
+
+    void update(FLOAT deltaTime) override {
+        vec3 forceLocal { 0.0, 0.0, 0.0 };
+
+        if (mKeyDown[(int) Base::Key::FORWARD]) {
+            forceLocal += vec3{  0.0,  0.0, -1.0 };
+        }
+        if (mKeyDown[(int) Base::Key::LEFT]) {
+            forceLocal += vec3{ -1.0,  0.0,  0.0 };
+        }
+        if (mKeyDown[(int) Base::Key::BACKWARD]) {
+            forceLocal += vec3{  0.0,  0.0,  1.0 };
+        }
+        if (mKeyDown[(int) Base::Key::RIGHT]) {
+            forceLocal += vec3{  1.0,  0.0,  0.0 };
+        }
+
+        const mat4 orientation = mat4::lookAt(Base::mEye, Base::mTarget, Base::mProps.upVector);
+        vec3 forceWorld = (orientation * vec4{ forceLocal, 0.0f }).xyz;
+
+        if (mKeyDown[(int) Base::Key::UP]) {
+            forceWorld += vec3{  0.0,  1.0,  0.0 };
+        }
+        if (mKeyDown[(int) Base::Key::DOWN]) {
+            forceWorld += vec3{  0.0, -1.0,  0.0 };
+        }
+
+        forceWorld *= mMoveSpeed;
+
+        const auto dampingFactor = Base::mProps.flightMoveDamping;
+        if (dampingFactor == 0.0) {
+            // Without damping, we simply treat the force as our velocity.
+            mEyeVelocity = forceWorld;
+        } else {
+            // The dampingFactor acts as "friction", which acts upon the camera in the direction
+            // opposite its velocity.
+            // Force is also multiplied by the dampingFactor, to "make up" for the friction.
+            // This ensures that the max velocity still approaches mMoveSpeed;
+            vec3 velocityDelta = (forceWorld - mEyeVelocity) * dampingFactor;
+            mEyeVelocity += velocityDelta * deltaTime;
+        }
+
+        const vec3 positionDelta = mEyeVelocity * deltaTime;
+
+        Base::mEye += positionDelta;
+        Base::mTarget += positionDelta;
+    }
+
+    Bookmark getCurrentBookmark() const override {
+        Bookmark bookmark;
+        bookmark.flight.position = Base::mEye;
+        bookmark.flight.pitch = mTargetEuler.x;
+        bookmark.flight.yaw = mTargetEuler.y;
+        return bookmark;
+    }
+
+    Bookmark getHomeBookmark() const override {
+        Bookmark bookmark;
+        bookmark.flight.position = Base::mProps.flightStartPosition;
+        bookmark.flight.pitch = Base::mProps.flightStartPitch;
+        bookmark.flight.yaw = Base::mProps.flightStartYaw;
+        return bookmark;
+    }
+
+    void jumpToBookmark(const Bookmark& bookmark) override {
+        Base::mEye = bookmark.flight.position;
+        updateTarget(bookmark.flight.pitch, bookmark.flight.yaw);
+    }
+
+private:
+    vec2 mGrabWin;
+    vec2 mTargetEuler;  // (pitch, yaw)
+    vec2 mGrabEuler;    // (pitch, yaw)
+    bool mKeyDown[(int) Base::Key::COUNT] = {false};
+    bool mGrabbing = false;
+    FLOAT mScrollWheel = 0.0f;
+    FLOAT mScrollPositionNormalized = 0.0f;
+    FLOAT mMoveSpeed = 1.0f;
+    vec3 mEyeVelocity;
+};
+
+} // namespace camutils
+} // namespace filament
+
+#endif /* CAMUTILS_FREEFLIGHT_MANIPULATOR_H */

macos/src/camutils/Manipulator.cpp

@@ -0,0 +1,324 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <camutils/Manipulator.h>
+
+#include <math/scalar.h>
+
+#include "FreeFlightManipulator.h"
+#include "MapManipulator.h"
+#include "OrbitManipulator.h"
+
+using namespace filament::math;
+
+namespace filament {
+namespace camutils {
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::viewport(int width, int height) {
+    details.viewport[0] = width;
+    details.viewport[1] = height;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::targetPosition(FLOAT x, FLOAT y, FLOAT z) {
+    details.targetPosition = {x, y, z};
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::upVector(FLOAT x, FLOAT y, FLOAT z) {
+    details.upVector = {x, y, z};
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::zoomSpeed(FLOAT val) {
+    details.zoomSpeed = val;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::orbitHomePosition(FLOAT x, FLOAT y, FLOAT z) {
+    details.orbitHomePosition = {x, y, z};
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::orbitSpeed(FLOAT x, FLOAT y) {
+    details.orbitSpeed = {x, y};
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::fovDirection(Fov fov) {
+    details.fovDirection = fov;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::fovDegrees(FLOAT degrees) {
+    details.fovDegrees = degrees;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::farPlane(FLOAT distance) {
+    details.farPlane = distance;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::mapExtent(FLOAT worldWidth, FLOAT worldHeight) {
+    details.mapExtent = {worldWidth, worldHeight};
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::mapMinDistance(FLOAT mindist) {
+    details.mapMinDistance = mindist;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::flightStartPosition(FLOAT x, FLOAT y, FLOAT z) {
+    details.flightStartPosition = {x, y, z};
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::flightStartOrientation(FLOAT pitch, FLOAT yaw) {
+    details.flightStartPitch = pitch;
+    details.flightStartYaw = yaw;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::flightMaxMoveSpeed(FLOAT maxSpeed) {
+    details.flightMaxSpeed = maxSpeed;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::flightSpeedSteps(int steps) {
+    details.flightSpeedSteps = steps;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::flightPanSpeed(FLOAT x, FLOAT y) {
+    details.flightPanSpeed = {x, y};
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::flightMoveDamping(FLOAT damping) {
+    details.flightMoveDamping = damping;
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::groundPlane(FLOAT a, FLOAT b, FLOAT c, FLOAT d) {
+    details.groundPlane = {a, b, c, d};
+    return *this;
+}
+
+template <typename FLOAT> typename
+Manipulator<FLOAT>::Builder& Manipulator<FLOAT>::Builder::raycastCallback(RayCallback cb, void* userdata) {
+    details.raycastCallback = cb;
+    details.raycastUserdata = userdata;
+    return *this;
+}
+
+template <typename FLOAT>
+Manipulator<FLOAT>* Manipulator<FLOAT>::Builder::build(Mode mode) {
+    switch (mode) {
+        case Mode::FREE_FLIGHT:
+            return new FreeFlightManipulator<FLOAT>(mode, details);
+        case Mode::MAP:
+            return new MapManipulator<FLOAT>(mode, details);
+        case Mode::ORBIT:
+            return new OrbitManipulator<FLOAT>(mode, details);
+    }
+}
+
+template <typename FLOAT>
+Manipulator<FLOAT>::Manipulator(Mode mode, const Config& props) : mMode(mode) {
+    setProperties(props);
+}
+
+template <typename FLOAT>
+void Manipulator<FLOAT>::setProperties(const Config& props) {
+    mProps = props;
+
+    if (mProps.zoomSpeed == FLOAT(0)) {
+        mProps.zoomSpeed = 0.01;
+    }
+
+    if (mProps.upVector == vec3(0)) {
+        mProps.upVector = vec3(0, 1, 0);
+    }
+
+    if (mProps.fovDegrees == FLOAT(0)) {
+        mProps.fovDegrees = 33;
+    }
+
+    if (mProps.farPlane == FLOAT(0)) {
+        mProps.farPlane = 5000;
+    }
+
+    if (mProps.mapExtent == vec2(0)) {
+        mProps.mapExtent = vec2(512);
+    }
+}
+
+template <typename FLOAT>
+void Manipulator<FLOAT>::setViewport(int width, int height) {
+    Config props = mProps;
+    props.viewport[0] = width;
+    props.viewport[1] = height;
+    setProperties(props);
+}
+
+template <typename FLOAT>
+void Manipulator<FLOAT>::getLookAt(vec3* eyePosition, vec3* targetPosition, vec3* upward) const {
+    *targetPosition = mTarget;
+    *eyePosition = mEye;
+    const vec3 gaze = normalize(mTarget - mEye);
+    const vec3 right = cross(gaze, mProps.upVector);
+    *upward = cross(right, gaze);
+}
+
+template<typename FLOAT>
+static bool raycastPlane(const filament::math::vec3<FLOAT>& origin,
+        const filament::math::vec3<FLOAT>& dir, FLOAT* t, void* userdata) {
+    using vec3 = filament::math::vec3<FLOAT>;
+    using vec4 = filament::math::vec4<FLOAT>;
+    auto props = (const typename Manipulator<FLOAT>::Config*) userdata;
+    const vec4 plane = props->groundPlane;
+    const vec3 n = vec3(plane[0], plane[1], plane[2]);
+    const vec3 p0 = n * plane[3];
+    const FLOAT denom = -dot(n, dir);
+    if (denom > 1e-6) {
+        const vec3 p0l0 = p0 - origin;
+        *t = dot(p0l0, n) / -denom;
+        return *t >= 0;
+    }
+    return false;
+}
+
+template <typename FLOAT>
+void Manipulator<FLOAT>::getRay(int x, int y, vec3* porigin, vec3* pdir) const {
+    const vec3 gaze = normalize(mTarget - mEye);
+    const vec3 right = normalize(cross(gaze, mProps.upVector));
+    const vec3 upward = cross(right, gaze);
+    const FLOAT width = mProps.viewport[0];
+    const FLOAT height = mProps.viewport[1];
+    const FLOAT fov = mProps.fovDegrees * F_PI / 180.0;
+
+    // Remap the grid coordinate into [-1, +1] and shift it to the pixel center.
+    const FLOAT u = 2.0 * (0.5 + x) / width - 1.0;
+    const FLOAT v = 2.0 * (0.5 + y) / height - 1.0;
+
+    // Compute the tangent of the field-of-view angle as well as the aspect ratio.
+    const FLOAT tangent = tan(fov / 2.0);
+    const FLOAT aspect = width / height;
+
+    // Adjust the gaze so it goes through the pixel of interest rather than the grid center.
+    vec3 dir = gaze;
+    if (mProps.fovDirection == Fov::VERTICAL) {
+        dir += right * tangent * u * aspect;
+        dir += upward * tangent * v;
+    } else {
+        dir += right * tangent * u;
+        dir += upward * tangent * v / aspect;
+    }
+    dir = normalize(dir);
+
+    *porigin = mEye;
+    *pdir = dir;
+}
+
+template <typename FLOAT>
+bool Manipulator<FLOAT>::raycast(int x, int y, vec3* result) const {
+    vec3 origin, dir;
+    getRay(x, y, &origin, &dir);
+
+    // Choose either the user's callback function or the plane intersector.
+    auto callback = mProps.raycastCallback;
+    auto fallback = raycastPlane<FLOAT>;
+    void* userdata = mProps.raycastUserdata;
+    if (!callback) {
+        callback = fallback;
+        userdata = (void*) &mProps;
+    }
+
+    // If the ray misses, then try the fallback function.
+    FLOAT t;
+    if (!callback(mEye, dir, &t, userdata)) {
+        if (callback == fallback || !fallback(mEye, dir, &t, (void*) &mProps)) {
+            return false;
+        }
+    }
+
+    *result = mEye + dir * t;
+    return true;
+}
+
+template <typename FLOAT>
+filament::math::vec3<FLOAT> Manipulator<FLOAT>::raycastFarPlane(int x, int y) const {
+    const filament::math::vec3<FLOAT> gaze = normalize(mTarget - mEye);
+    const vec3 right = cross(gaze, mProps.upVector);
+    const vec3 upward = cross(right, gaze);
+    const FLOAT width = mProps.viewport[0];
+    const FLOAT height = mProps.viewport[1];
+    const FLOAT fov = mProps.fovDegrees * math::F_PI / 180.0;
+
+    // Remap the grid coordinate into [-1, +1] and shift it to the pixel center.
+    const FLOAT u = 2.0 * (0.5 + x) / width - 1.0;
+    const FLOAT v = 2.0 * (0.5 + y) / height - 1.0;
+
+    // Compute the tangent of the field-of-view angle as well as the aspect ratio.
+    const FLOAT tangent = tan(fov / 2.0);
+    const FLOAT aspect = width / height;
+
+    // Adjust the gaze so it goes through the pixel of interest rather than the grid center.
+    vec3 dir = gaze;
+    if (mProps.fovDirection == Fov::VERTICAL) {
+        dir += right * tangent * u * aspect;
+        dir += upward * tangent * v;
+    } else {
+        dir += right * tangent * u;
+        dir += upward * tangent * v / aspect;
+    }
+    return mEye + dir * mProps.farPlane;
+}
+
+template <typename FLOAT>
+void Manipulator<FLOAT>::keyDown(Manipulator<FLOAT>::Key key) { }
+
+template <typename FLOAT>
+void Manipulator<FLOAT>::keyUp(Manipulator<FLOAT>::Key key) { }
+
+template <typename FLOAT>
+void Manipulator<FLOAT>::update(FLOAT deltaTime) { }
+
+template class Manipulator<float>;
+template class Manipulator<double>;
+
+} // namespace camutils
+} // namespace filament

macos/src/camutils/MapManipulator.h

@@ -0,0 +1,197 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef CAMUTILS_MAP_MANIPULATOR_H
+#define CAMUTILS_MAP_MANIPULATOR_H
+
+#include <camutils/Manipulator.h>
+
+#include <math/vec3.h>
+
+namespace filament {
+namespace camutils {
+
+template<typename FLOAT>
+class MapManipulator : public Manipulator<FLOAT> {
+public:
+    using vec2 = math::vec2<FLOAT>;
+    using vec3 = math::vec3<FLOAT>;
+    using vec4 = math::vec4<FLOAT>;
+    using Bookmark = filament::camutils::Bookmark<FLOAT>;
+    using Base = Manipulator<FLOAT>;
+    using Config = typename Manipulator<FLOAT>::Config;
+
+    MapManipulator(Mode mode, const Config& props) : Manipulator<FLOAT>(mode, props) {
+        const FLOAT width = Base::mProps.mapExtent.x;
+        const FLOAT height = Base::mProps.mapExtent.y;
+        const bool horiz = Base::mProps.fovDirection == Fov::HORIZONTAL;
+        const vec3 targetToEye = Base::mProps.groundPlane.xyz;
+        const FLOAT halfExtent = (horiz ? width : height) / 2.0;
+        const FLOAT fov = Base::mProps.fovDegrees * math::F_PI / 180.0;
+        const FLOAT distance = halfExtent / tan(fov / 2.0);
+        Base::mTarget = Base::mProps.targetPosition;
+        Base::mEye = Base::mTarget + distance * targetToEye;
+    }
+
+    void grabBegin(int x, int y, bool strafe) override {
+        if (strafe || !Base::raycast(x, y, &mGrabScene)) {
+            return;
+        }
+        mGrabFar = Base::raycastFarPlane(x, y);
+        mGrabEye = Base::mEye;
+        mGrabTarget = Base::mTarget;
+        mGrabbing = true;
+    }
+
+    void grabUpdate(int x, int y) override {
+        if (mGrabbing) {
+            const FLOAT ulen = distance(mGrabScene, mGrabEye);
+            const FLOAT vlen = distance(mGrabFar, mGrabScene);
+            const vec3 translation = (mGrabFar - Base::raycastFarPlane(x, y)) * ulen / vlen;
+            const vec3 eyePosition = mGrabEye + translation;
+            const vec3 targetPosition = mGrabTarget + translation;
+            moveWithConstraints(eyePosition, targetPosition);
+        }
+    }
+
+    void grabEnd() override {
+        mGrabbing = false;
+    }
+
+    void scroll(int x, int y, FLOAT scrolldelta) override {
+        vec3 grabScene;
+        if (!Base::raycast(x, y, &grabScene)) {
+            return;
+        }
+
+        // Find the direction of travel for the dolly. We do not normalize since it
+        // is desirable to move faster when further away from the targetPosition.
+        vec3 u = grabScene - Base::mEye;
+
+        // Prevent getting stuck when zooming in.
+        if (scrolldelta < 0) {
+            const FLOAT distanceToSurface = length(u);
+            if (distanceToSurface < Base::mProps.zoomSpeed) {
+                return;
+            }
+        }
+
+        u *= -scrolldelta * Base::mProps.zoomSpeed;
+
+        const vec3 eyePosition = Base::mEye + u;
+        const vec3 targetPosition = Base::mTarget + u;
+        moveWithConstraints(eyePosition, targetPosition);
+    }
+
+    Bookmark getCurrentBookmark() const override {
+        const vec3 dir = normalize(Base::mTarget - Base::mEye);
+
+        FLOAT distance;
+        raycastPlane(Base::mEye, dir, &distance);
+
+        const FLOAT fov = Base::mProps.fovDegrees * math::F_PI / 180.0;
+        const FLOAT halfExtent = distance * tan(fov / 2.0);
+
+        vec3 targetPosition = Base::mEye + dir * distance;
+
+        const vec3 targetToEye = Base::mProps.groundPlane.xyz;
+        const vec3 uvec = cross(Base::mProps.upVector, targetToEye);
+        const vec3 vvec = cross(targetToEye, uvec);
+        const vec3 centerToTarget = targetPosition - Base::mProps.targetPosition;
+
+        Bookmark bookmark;
+        bookmark.mode = Mode::MAP;
+        bookmark.map.extent = halfExtent * 2.0;
+        bookmark.map.center.x = dot(uvec, centerToTarget);
+        bookmark.map.center.y = dot(vvec, centerToTarget);
+
+        bookmark.orbit.theta = 0;
+        bookmark.orbit.phi = 0;
+        bookmark.orbit.pivot = Base::mProps.targetPosition +
+                uvec * bookmark.map.center.x +
+                vvec * bookmark.map.center.y;
+        bookmark.orbit.distance = halfExtent / tan(fov / 2.0);
+
+        return bookmark;
+    }
+
+    Bookmark getHomeBookmark() const override {
+        const FLOAT fov = Base::mProps.fovDegrees * math::F_PI / 180.0;
+        const FLOAT width = Base::mProps.mapExtent.x;
+        const FLOAT height = Base::mProps.mapExtent.y;
+        const bool horiz = Base::mProps.fovDirection == Fov::HORIZONTAL;
+
+        Bookmark bookmark;
+        bookmark.mode = Mode::MAP;
+        bookmark.map.extent = horiz ? width : height;
+        bookmark.map.center.x = 0;
+        bookmark.map.center.y = 0;
+
+        bookmark.orbit.theta = 0;
+        bookmark.orbit.phi = 0;
+        bookmark.orbit.pivot = Base::mTarget;
+        bookmark.orbit.distance = 0.5 * bookmark.map.extent / tan(fov / 2.0);
+
+        // TODO: Add optional boundary constraints here.
+
+        return bookmark;
+    }
+
+    void jumpToBookmark(const Bookmark& bookmark) override {
+        const vec3 targetToEye = Base::mProps.groundPlane.xyz;
+        const FLOAT halfExtent = bookmark.map.extent / 2.0;
+        const FLOAT fov = Base::mProps.fovDegrees * math::F_PI / 180.0;
+        const FLOAT distance = halfExtent / tan(fov / 2.0);
+        vec3 uvec = cross(Base::mProps.upVector, targetToEye);
+        vec3 vvec = cross(targetToEye, uvec);
+        uvec = normalize(uvec) * bookmark.map.center.x;
+        vvec = normalize(vvec) * bookmark.map.center.y;
+        Base::mTarget = Base::mProps.targetPosition + uvec + vvec;
+        Base::mEye = Base::mTarget + distance * targetToEye;
+    }
+
+private:
+    bool raycastPlane(const vec3& origin, const vec3& dir, FLOAT* t) const {
+        const vec4 plane = Base::mProps.groundPlane;
+        const vec3 n = vec3(plane[0], plane[1], plane[2]);
+        const vec3 p0 = n * plane[3];
+        const FLOAT denom = -dot(n, dir);
+        if (denom > 1e-6) {
+            const vec3 p0l0 = p0 - origin;
+            *t = dot(p0l0, n) / -denom;
+            return *t >= 0;
+        }
+        return false;
+    }
+
+    void moveWithConstraints(vec3 eye, vec3 targetPosition) {
+        Base::mEye = eye;
+        Base::mTarget = targetPosition;
+        // TODO: Add optional boundary constraints here.
+    }
+
+private:
+    bool mGrabbing = false;
+    vec3 mGrabScene;
+    vec3 mGrabFar;
+    vec3 mGrabEye;
+    vec3 mGrabTarget;
+};
+
+} // namespace camutils
+} // namespace filament
+
+#endif /* CAMUTILS_MAP_MANIPULATOR_H */

macos/src/camutils/OrbitManipulator.h

@@ -0,0 +1,201 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef CAMUTILS_ORBIT_MANIPULATOR_H
+#define CAMUTILS_ORBIT_MANIPULATOR_H
+
+#include <camutils/Manipulator.h>
+
+#include <math/scalar.h>
+
+#define MAX_PHI (F_PI / 2.0 - 0.001)
+
+namespace filament {
+namespace camutils {
+
+using namespace filament::math;
+
+template<typename FLOAT>
+class OrbitManipulator : public Manipulator<FLOAT> {
+public:
+    using vec2 = filament::math::vec2<FLOAT>;
+    using vec3 = filament::math::vec3<FLOAT>;
+    using vec4 = filament::math::vec4<FLOAT>;
+    using Bookmark = filament::camutils::Bookmark<FLOAT>;
+    using Base = Manipulator<FLOAT>;
+    using Config = typename Base::Config;
+
+    enum GrabState { INACTIVE, ORBITING, PANNING };
+
+    OrbitManipulator(Mode mode, const Config& props) : Base(mode, props) {
+        setProperties(props);
+        Base::mEye = Base::mProps.orbitHomePosition;
+        mPivot = Base::mTarget = Base::mProps.targetPosition;
+    }
+
+    void setProperties(const Config& props) override {
+        Config resolved = props;
+
+        if (resolved.orbitHomePosition == vec3(0)) {
+            resolved.orbitHomePosition = vec3(0, 0, 1);
+        }
+
+        if (resolved.orbitSpeed == vec2(0)) {
+            resolved.orbitSpeed = vec2(0.01);
+        }
+
+        // By default, place the ground plane so that it aligns with the targetPosition position.
+        // This is used only when PANNING.
+        if (resolved.groundPlane == vec4(0)) {
+            const FLOAT d = length(resolved.targetPosition);
+            const vec3 n = normalize(resolved.orbitHomePosition - resolved.targetPosition);
+            resolved.groundPlane = vec4(n, -d);
+        }
+
+        Base::setProperties(resolved);
+    }
+
+    void grabBegin(int x, int y, bool strafe) override {
+        mGrabState = strafe ? PANNING : ORBITING;
+        mGrabPivot = mPivot;
+        mGrabEye = Base::mEye;
+        mGrabTarget = Base::mTarget;
+        mGrabBookmark = getCurrentBookmark();
+        mGrabWinX = x;
+        mGrabWinY = y;
+        mGrabFar = Base::raycastFarPlane(x, y);
+        Base::raycast(x, y, &mGrabScene);
+    }
+
+    void grabUpdate(int x, int y) override {
+        const int delx = mGrabWinX - x;
+        const int dely = mGrabWinY - y;
+
+        if (mGrabState == ORBITING) {
+            Bookmark bookmark = getCurrentBookmark();
+
+            const FLOAT theta = delx * Base::mProps.orbitSpeed.x;
+            const FLOAT phi = dely * Base::mProps.orbitSpeed.y;
+            const FLOAT maxPhi = MAX_PHI;
+
+            bookmark.orbit.phi = clamp(mGrabBookmark.orbit.phi + phi, -maxPhi, +maxPhi);
+            bookmark.orbit.theta = mGrabBookmark.orbit.theta + theta;
+
+            jumpToBookmark(bookmark);
+        }
+
+        if (mGrabState == PANNING) {
+            const FLOAT ulen = distance(mGrabScene, mGrabEye);
+            const FLOAT vlen = distance(mGrabFar, mGrabScene);
+            const vec3 translation = (mGrabFar - Base::raycastFarPlane(x, y)) * ulen / vlen;
+            mPivot = mGrabPivot + translation;
+            Base::mEye = mGrabEye + translation;
+            Base::mTarget = mGrabTarget + translation;
+        }
+    }
+
+    void grabEnd() override {
+        mGrabState = INACTIVE;
+    }
+
+    void scroll(int x, int y, FLOAT scrolldelta) override {
+        const vec3 gaze = normalize(Base::mTarget - Base::mEye);
+        const vec3 movement = gaze * Base::mProps.zoomSpeed * -scrolldelta;
+        const vec3 v0 = mPivot - Base::mEye;
+        Base::mEye += movement;
+        Base::mTarget += movement;
+        const vec3 v1 = mPivot - Base::mEye;
+
+        // Check if the camera has moved past the point of interest.
+        if (dot(v0, v1) < 0) {
+            mFlipped = !mFlipped;
+        }
+    }
+
+    Bookmark getCurrentBookmark() const override {
+        Bookmark bookmark;
+        bookmark.mode = Mode::ORBIT;
+        const vec3 pivotToEye = Base::mEye - mPivot;
+        const FLOAT d = length(pivotToEye);
+        const FLOAT x = pivotToEye.x / d;
+        const FLOAT y = pivotToEye.y / d;
+        const FLOAT z = pivotToEye.z / d;
+
+        bookmark.orbit.phi = asin(y);
+        bookmark.orbit.theta = atan2(x, z);
+        bookmark.orbit.distance = mFlipped ? -d : d;
+        bookmark.orbit.pivot = mPivot;
+
+        const FLOAT fov = Base::mProps.fovDegrees * math::F_PI / 180.0;
+        const FLOAT halfExtent = d * tan(fov / 2.0);
+        const vec3 targetToEye = Base::mProps.groundPlane.xyz;
+        const vec3 uvec = cross(Base::mProps.upVector, targetToEye);
+        const vec3 vvec = cross(targetToEye, uvec);
+        const vec3 centerToTarget = mPivot - Base::mProps.targetPosition;
+
+        bookmark.map.extent = halfExtent * 2;
+        bookmark.map.center.x = dot(uvec, centerToTarget);
+        bookmark.map.center.y = dot(vvec, centerToTarget);
+
+        return bookmark;
+    }
+
+    Bookmark getHomeBookmark() const override {
+        Bookmark bookmark;
+        bookmark.mode = Mode::ORBIT;
+        bookmark.orbit.phi = FLOAT(0);
+        bookmark.orbit.theta = FLOAT(0);
+        bookmark.orbit.pivot = Base::mProps.targetPosition;
+        bookmark.orbit.distance = distance(Base::mProps.targetPosition, Base::mProps.orbitHomePosition);
+
+        const FLOAT fov = Base::mProps.fovDegrees * math::F_PI / 180.0;
+        const FLOAT halfExtent = bookmark.orbit.distance * tan(fov / 2.0);
+
+        bookmark.map.extent = halfExtent * 2;
+        bookmark.map.center.x = 0;
+        bookmark.map.center.y = 0;
+
+        return bookmark;
+    }
+
+    void jumpToBookmark(const Bookmark& bookmark) override {
+        mPivot = bookmark.orbit.pivot;
+        const FLOAT x = sin(bookmark.orbit.theta) * cos(bookmark.orbit.phi);
+        const FLOAT y = sin(bookmark.orbit.phi);
+        const FLOAT z = cos(bookmark.orbit.theta) * cos(bookmark.orbit.phi);
+        Base::mEye = mPivot + vec3(x, y, z) * abs(bookmark.orbit.distance);
+        mFlipped = bookmark.orbit.distance < 0;
+        Base::mTarget = Base::mEye + vec3(x, y, z) * (mFlipped ? 1.0 : -1.0);
+    }
+
+private:
+    GrabState mGrabState = INACTIVE;
+    bool mFlipped = false;
+    vec3 mGrabPivot;
+    vec3 mGrabScene;
+    vec3 mGrabFar;
+    vec3 mGrabEye;
+    vec3 mGrabTarget;
+    Bookmark mGrabBookmark;
+    int mGrabWinX;
+    int mGrabWinY;
+    vec3 mPivot;
+};
+
+} // namespace camutils
+} // namespace filament
+
+#endif /* CAMUTILS_ORBIT_MANIPULATOR_H */