Set FlatScene's AttrDataBlock object back after evaluating the scene.

Also adds the ability to create a FlatScene without any data, which is
needed so we can create FlatScene then pass it to a function as reference
to be filled (as we will do in Maya).

Issue #114

src/mmscenegraph/cppbind/include/mmscenegraph/_cxxbridge.h

@@ -1165,6 +1165,8 @@ MMSCENEGRAPH_API_EXPORT ::rust::Box<::mmscenegraph::ShimSceneGraph> shim_create_
 
 MMSCENEGRAPH_API_EXPORT ::rust::Box<::mmscenegraph::ShimFlatScene> shim_bake_scene_graph(const ::rust::Box<::mmscenegraph::ShimSceneGraph> &sg, const ::rust::Box<::mmscenegraph::ShimEvaluationObjects> &eval_objects) noexcept;
 
+MMSCENEGRAPH_API_EXPORT ::rust::Box<::mmscenegraph::ShimFlatScene> shim_create_flat_scene_box() noexcept;
+
 MMSCENEGRAPH_API_EXPORT ::rust::Box<::mmscenegraph::ShimEvaluationObjects> shim_create_evaluation_objects_box() noexcept;
 
 MMSCENEGRAPH_API_EXPORT void foo(::std::uint32_t number) noexcept;

src/mmscenegraph/cppbind/include/mmscenegraph/flatscene.h

@@ -34,6 +34,9 @@ namespace mmscenegraph {
 class FlatScene {
 public:
 
+    MMSCENEGRAPH_API_EXPORT
+    FlatScene() noexcept;
+
     MMSCENEGRAPH_API_EXPORT
     FlatScene(rust::Box<ShimFlatScene> flat_scene) noexcept;
 
@@ -64,7 +67,7 @@ class FlatScene {
     MMSCENEGRAPH_API_EXPORT
     void
     evaluate(
-        AttrDataBlock &attrdb,
+        AttrDataBlock &attrDataBlock,
         std::vector<FrameValue> &frames
     ) noexcept;
 

src/mmscenegraph/cppbind/src/_cxxbridge.cpp

@@ -1282,6 +1282,8 @@ ::std::size_t mmscenegraph$cxxbridge1$ShimFlatScene$num_deviations(const ::mmsce
 void mmscenegraph$cxxbridge1$ShimFlatScene$evaluate(::mmscenegraph::ShimFlatScene &self, const ::rust::Box<::mmscenegraph::ShimAttrDataBlock> &attrdb, ::rust::Slice<const ::std::uint32_t> frame_list) noexcept;
 
 ::mmscenegraph::ShimFlatScene *mmscenegraph$cxxbridge1$shim_bake_scene_graph(const ::rust::Box<::mmscenegraph::ShimSceneGraph> &sg, const ::rust::Box<::mmscenegraph::ShimEvaluationObjects> &eval_objects) noexcept;
+
+::mmscenegraph::ShimFlatScene *mmscenegraph$cxxbridge1$shim_create_flat_scene_box() noexcept;
 ::std::size_t mmscenegraph$cxxbridge1$ShimEvaluationObjects$operator$sizeof() noexcept;
 ::std::size_t mmscenegraph$cxxbridge1$ShimEvaluationObjects$operator$alignof() noexcept;
 
@@ -1681,6 +1683,10 @@ MMSCENEGRAPH_API_EXPORT ::rust::Box<::mmscenegraph::ShimFlatScene> shim_bake_sce
   return ::rust::Box<::mmscenegraph::ShimFlatScene>::from_raw(mmscenegraph$cxxbridge1$shim_bake_scene_graph(sg, eval_objects));
 }
 
+MMSCENEGRAPH_API_EXPORT ::rust::Box<::mmscenegraph::ShimFlatScene> shim_create_flat_scene_box() noexcept {
+  return ::rust::Box<::mmscenegraph::ShimFlatScene>::from_raw(mmscenegraph$cxxbridge1$shim_create_flat_scene_box());
+}
+
 ::std::size_t ShimEvaluationObjects::layout::size() noexcept {
   return mmscenegraph$cxxbridge1$ShimEvaluationObjects$operator$sizeof();
 }

src/mmscenegraph/cppbind/src/cxxbridge.rs

@@ -22,6 +22,7 @@ use crate::attrdatablock::shim_create_attr_data_block_box;
 use crate::attrdatablock::ShimAttrDataBlock;
 use crate::evaluationobjects::shim_create_evaluation_objects_box;
 use crate::evaluationobjects::ShimEvaluationObjects;
+use crate::flatscene::shim_create_flat_scene_box;
 use crate::flatscene::ShimFlatScene;
 use crate::scenebake::shim_bake_scene_graph;
 use crate::scenegraph::shim_create_scene_graph_box;
@@ -309,6 +310,8 @@ pub mod ffi {
             sg: &Box<ShimSceneGraph>,
             eval_objects: &Box<ShimEvaluationObjects>,
         ) -> Box<ShimFlatScene>;
+
+        fn shim_create_flat_scene_box() -> Box<ShimFlatScene>;
     }
 
     extern "Rust" {

src/mmscenegraph/cppbind/src/flatscene.cpp

@@ -65,12 +65,14 @@ FlatScene::num_deviations() const noexcept {
 
 void
 FlatScene::evaluate(
-        AttrDataBlock &attrdb,
+        AttrDataBlock &attrDataBlock,
         std::vector<FrameValue> &frames
 ) noexcept {
-    auto attrdb_inner = attrdb.get_inner();
+    auto attrDataBlock_inner = attrDataBlock.get_inner();
     rust::Slice<const FrameValue> frames_slice{frames.data(), frames.size()};
-    return inner_->evaluate(attrdb_inner, frames_slice);
+    inner_->evaluate(attrDataBlock_inner, frames_slice);
+
+    attrDataBlock.set_inner(attrDataBlock_inner);
 }
 
 } // namespace mmscenegraph

src/mmscenegraph/cppbind/src/flatscene.rs

@@ -67,7 +67,37 @@ impl ShimFlatScene {
         attrdb: &ShimAttrDataBlock,
         frame_list: &[CoreFrameValue],
     ) {
-        let attrdb = attrdb.get_inner();
-        self.inner.evaluate(attrdb, frame_list)
+        self.inner.evaluate(attrdb.get_inner(), frame_list)
     }
 }
+
+pub fn shim_create_flat_scene_box() -> Box<ShimFlatScene> {
+    println!("shim_create_flat_scene_box()");
+    let bnd_ids = Vec::new();
+    let cam_ids = Vec::new();
+    let mkr_ids = Vec::new();
+    let mkr_cam_indices = Vec::new();
+    let mkr_bnd_indices = Vec::new();
+    let tfm_attr_list = Vec::new();
+    let rotate_order_list = Vec::new();
+    let cam_attr_list = Vec::new();
+    let mkr_attr_list = Vec::new();
+    let tfm_node_ids = Vec::new();
+    let tfm_node_indices = Vec::new();
+    let tfm_node_parent_indices = Vec::new();
+    let core_flat_scene = CoreFlatScene::new(
+        bnd_ids,
+        cam_ids,
+        mkr_ids,
+        mkr_cam_indices,
+        mkr_bnd_indices,
+        tfm_attr_list,
+        rotate_order_list,
+        cam_attr_list,
+        mkr_attr_list,
+        tfm_node_ids,
+        tfm_node_indices,
+        tfm_node_parent_indices,
+    );
+    Box::new(ShimFlatScene::new(core_flat_scene))
+}