More tweaks to the shared asset system

Cesium3DTilesSelection/include/Cesium3DTilesSelection/IPrepareRendererResources.h

@@ -20,7 +20,7 @@ struct Rectangle;
 }
 
 namespace CesiumGltf {
-struct ImageCesium;
+struct ImageAsset;
 struct Model;
 } // namespace CesiumGltf
 

Cesium3DTilesSelection/include/Cesium3DTilesSelection/Tileset.h

@@ -184,10 +184,11 @@ class CESIUM3DTILESSELECTION_API Tileset final {
   /**
    * @brief Returns the {@link SharedAssetDepot} of this tileset.
    */
-  CesiumGltf::SharedAssetSystem& getSharedAssetSystem() noexcept;
+  CesiumGltfReader::GltfSharedAssetSystem& getSharedAssetSystem() noexcept;
 
   /** @copydoc Tileset::getSharedAssetSystem() */
-  const CesiumGltf::SharedAssetSystem& getSharedAssetSystem() const noexcept;
+  const CesiumGltfReader::GltfSharedAssetSystem&
+  getSharedAssetSystem() const noexcept;
 
   /**
    * @brief Updates this view but waits for all tiles that meet sse to finish

Cesium3DTilesSelection/src/TileContentLoadInfo.cpp

@@ -9,8 +9,8 @@ TileContentLoadInfo::TileContentLoadInfo(
     const std::shared_ptr<IPrepareRendererResources>&
         pPrepareRendererResources_,
     const std::shared_ptr<spdlog::logger>& pLogger_,
-    const CesiumUtility::IntrusivePointer<CesiumGltf::SharedAssetSystem>
-        pAssetDepot_,
+    const CesiumUtility::IntrusivePointer<
+        CesiumGltfReader::GltfSharedAssetSystem> pAssetDepot_,
     const TilesetContentOptions& contentOptions_,
     const Tile& tile)
     : asyncSystem(asyncSystem_),

Cesium3DTilesSelection/src/TileContentLoadInfo.h

@@ -9,7 +9,7 @@
 #include <CesiumAsync/AsyncSystem.h>
 #include <CesiumAsync/IAssetAccessor.h>
 #include <CesiumGeometry/Axis.h>
-#include <CesiumGltf/SharedAssetSystem.h>
+#include <CesiumGltfReader/GltfSharedAssetSystem.h>
 
 #include <gsl/span>
 #include <spdlog/fwd.h>
@@ -25,8 +25,8 @@ struct TileContentLoadInfo {
       const std::shared_ptr<IPrepareRendererResources>&
           pPrepareRendererResources,
       const std::shared_ptr<spdlog::logger>& pLogger,
-      const CesiumUtility::IntrusivePointer<CesiumGltf::SharedAssetSystem>
-          maybeAssetDepot,
+      const CesiumUtility::IntrusivePointer<
+          CesiumGltfReader::GltfSharedAssetSystem> maybeAssetDepot,
       const TilesetContentOptions& contentOptions,
       const Tile& tile);
 
@@ -43,7 +43,8 @@ struct TileContentLoadInfo {
   BoundingVolume tileBoundingVolume;
 
   std::optional<BoundingVolume> tileContentBoundingVolume;
-  CesiumUtility::IntrusivePointer<CesiumGltf::SharedAssetSystem> pAssetDepot;
+  CesiumUtility::IntrusivePointer<CesiumGltfReader::GltfSharedAssetSystem>
+      pAssetDepot;
 
   TileRefine tileRefine;
 

Cesium3DTilesSelection/src/Tileset.cpp

@@ -149,11 +149,12 @@ const RasterOverlayCollection& Tileset::getOverlays() const noexcept {
   return this->_pTilesetContentManager->getRasterOverlayCollection();
 }
 
-CesiumGltf::SharedAssetSystem& Tileset::getSharedAssetSystem() noexcept {
+CesiumGltfReader::GltfSharedAssetSystem&
+Tileset::getSharedAssetSystem() noexcept {
   return *this->_pTilesetContentManager->getSharedAssetSystem();
 }
 
-const CesiumGltf::SharedAssetSystem&
+const CesiumGltfReader::GltfSharedAssetSystem&
 Tileset::getSharedAssetSystem() const noexcept {
   return *this->_pTilesetContentManager->getSharedAssetSystem();
 }

Cesium3DTilesSelection/src/TilesetContentManager.cpp

@@ -666,7 +666,7 @@ TilesetContentManager::TilesetContentManager(
       _tileLoadsInProgress{0},
       _loadedTilesCount{0},
       _tilesDataUsed{0},
-      _pAssetDepot(new CesiumGltf::SharedAssetSystem()),
+      _pSharedAssets(CesiumGltfReader::GltfSharedAssetSystem::getDefault()),
       _destructionCompletePromise{externals.asyncSystem.createPromise<void>()},
       _destructionCompleteFuture{
           this->_destructionCompletePromise.getFuture().share()},
@@ -696,7 +696,7 @@ TilesetContentManager::TilesetContentManager(
       _tileLoadsInProgress{0},
       _loadedTilesCount{0},
       _tilesDataUsed{0},
-      _pAssetDepot(new CesiumGltf::SharedAssetSystem()),
+      _pSharedAssets(CesiumGltfReader::GltfSharedAssetSystem::getDefault()),
       _destructionCompletePromise{externals.asyncSystem.createPromise<void>()},
       _destructionCompleteFuture{
           this->_destructionCompletePromise.getFuture().share()},
@@ -848,7 +848,7 @@ TilesetContentManager::TilesetContentManager(
       _tileLoadsInProgress{0},
       _loadedTilesCount{0},
       _tilesDataUsed{0},
-      _pAssetDepot(new CesiumGltf::SharedAssetSystem()),
+      _pSharedAssets(CesiumGltfReader::GltfSharedAssetSystem::getDefault()),
       _destructionCompletePromise{externals.asyncSystem.createPromise<void>()},
       _destructionCompleteFuture{
           this->_destructionCompletePromise.getFuture().share()},
@@ -994,7 +994,7 @@ void TilesetContentManager::loadTileContent(
       this->_externals.pAssetAccessor,
       this->_externals.pPrepareRendererResources,
       this->_externals.pLogger,
-      this->_pAssetDepot,
+      this->_pSharedAssets,
       tilesetOptions.contentOptions,
       tile};
 
@@ -1237,9 +1237,9 @@ TilesetContentManager::getTilesetCredits() const noexcept {
   return this->_tilesetCredits;
 }
 
-const CesiumUtility::IntrusivePointer<CesiumGltf::SharedAssetSystem>&
+const CesiumUtility::IntrusivePointer<CesiumGltfReader::GltfSharedAssetSystem>&
 TilesetContentManager::getSharedAssetSystem() const noexcept {
-  return this->_pAssetDepot;
+  return this->_pSharedAssets;
 }
 
 int32_t TilesetContentManager::getNumberOfTilesLoading() const noexcept {

Cesium3DTilesSelection/src/TilesetContentManager.h

@@ -11,7 +11,6 @@
 #include <Cesium3DTilesSelection/TilesetLoadFailureDetails.h>
 #include <Cesium3DTilesSelection/TilesetOptions.h>
 #include <CesiumAsync/IAssetAccessor.h>
-#include <CesiumGltf/SharedAssetDepot.h>
 #include <CesiumUtility/CreditSystem.h>
 #include <CesiumUtility/ReferenceCounted.h>
 
@@ -116,7 +115,8 @@ class TilesetContentManager
 
   const std::vector<CesiumUtility::Credit>& getTilesetCredits() const noexcept;
 
-  const CesiumUtility::IntrusivePointer<CesiumGltf::SharedAssetSystem>&
+  const CesiumUtility::IntrusivePointer<
+      CesiumGltfReader::GltfSharedAssetSystem>&
   getSharedAssetSystem() const noexcept;
 
   int32_t getNumberOfTilesLoading() const noexcept;
@@ -172,7 +172,8 @@ class TilesetContentManager
   int64_t _tilesDataUsed;
 
   // Stores assets that might be shared between tiles.
-  CesiumUtility::IntrusivePointer<CesiumGltf::SharedAssetSystem> _pAssetDepot;
+  CesiumUtility::IntrusivePointer<CesiumGltfReader::GltfSharedAssetSystem>
+      _pSharedAssets;
 
   CesiumAsync::Promise<void> _destructionCompletePromise;
   CesiumAsync::SharedFuture<void> _destructionCompleteFuture;

Cesium3DTilesSelection/src/TilesetJsonLoader.h

@@ -6,7 +6,7 @@
 #include <Cesium3DTilesSelection/TilesetExternals.h>
 #include <CesiumAsync/Future.h>
 #include <CesiumAsync/IAssetAccessor.h>
-#include <CesiumGltf/SharedAssetSystem.h>
+#include <CesiumGltfReader/GltfSharedAssetSystem.h>
 
 #include <rapidjson/fwd.h>
 
@@ -56,7 +56,8 @@ class TilesetJsonLoader : public TilesetContentLoader {
 private:
   std::string _baseUrl;
   CesiumGeospatial::Ellipsoid _ellipsoid;
-  CesiumUtility::IntrusivePointer<CesiumGltf::SharedAssetSystem> _pAssetDepot;
+  CesiumUtility::IntrusivePointer<CesiumGltfReader::GltfSharedAssetSystem>
+      _pSharedAssets;
 
   /**
    * @brief The axis that was declared as the "up-axis" for glTF content.

Cesium3DTilesSelection/test/SimplePrepareRendererResource.h

@@ -68,7 +68,7 @@ class SimplePrepareRendererResource
   }
 
   virtual void* prepareRasterInLoadThread(
-      CesiumGltf::ImageCesium& /*image*/,
+      CesiumGltf::ImageAsset& /*image*/,
       const std::any& /*rendererOptions*/) override {
     return new AllocationResult{totalAllocation};
   }

Cesium3DTilesSelection/test/TestTilesetContentManager.cpp

@@ -1298,8 +1298,8 @@ TEST_CASE("Test the tileset content manager's post processing for gltf") {
 
       CesiumAsync::Future<LoadedRasterOverlayImage>
       loadTileImage(RasterOverlayTile& overlayTile) override {
-        CesiumUtility::IntrusivePointer<CesiumGltf::ImageCesium> pImage;
-        CesiumGltf::ImageCesium& image = pImage.emplace();
+        CesiumUtility::IntrusivePointer<CesiumGltf::ImageAsset> pImage;
+        CesiumGltf::ImageAsset& image = pImage.emplace();
         image.width = 1;
         image.height = 1;
         image.channels = 1;
@@ -1682,7 +1682,7 @@ TEST_CASE("Test the tileset content manager's post processing for gltf") {
       CHECK(images.size() == 1);
     }
 
-    CHECK(pManager->getSharedAssetSystem()->image().getDistinctCount() == 2);
+    CHECK(pManager->getSharedAssetSystem()->pImage->getDistinctCount() == 2);
 
     // unload the tile content
     for (auto& child : containerTile.getChildren()) {

CesiumGltf/include/CesiumGltf/SharedAsset.h → CesiumAsync/include/CesiumAsync/SharedAsset.h

@@ -1,12 +1,12 @@
 #pragma once
 
-#include <CesiumGltf/SharedAssetDepot.h>
+#include <CesiumAsync/SharedAssetDepot.h>
 #include <CesiumUtility/ExtensibleObject.h>
 #include <CesiumUtility/IntrusivePointer.h>
 
 #include <atomic>
 
-namespace CesiumGltf {
+namespace CesiumAsync {
 
 /**
  * @brief An asset that is potentially shared between multiple objects, such as
@@ -19,31 +19,57 @@ namespace CesiumGltf {
  * @tparam T The type that is _deriving_ from this class. For example, you
  * should declare your class as
  * `class MyClass : public SharedAsset<MyClass> { ... };`
+ *
+ * @remarks @parblock
+ * A `SharedAsset` can be in one of three possible states:
+ *
+ * **Independent Asset**
+ * An independent asset isn't affiliated with an asset depot at all.
+ * Its lifetime is controlled exclusively by IntrusivePointer / reference
+ * counting. When the asset's reference count goes to zero, it deletes itself.
+ * An independent asset's `_pDepot` is nullptr.
+ *
+ * **Active Depot Asset**
+ * This is an asset that is owned by an asset depot and that is in use, meaning
+ * it has a reference count greater than zero. The asset depot owns the asset
+ * via an `std::unique_ptr`, not via adding to the reference count. So when the
+ * reference count goes to zero, only the asset depot itself still has a
+ * reference to it, so it becomes an inactive depot asset.
+ *
+ * **Inactive Depot Asset**
+ * This is also an asset that is owned by the asset depot, but there are no
+ * other references to it (it has a reference count of zero). It is found in the
+ * asset depot's `deletionCandidates` list. When a reference to it is added, it
+ * is removed from `deletionCandidates` and it becomes an active depot asset.
+ * @endparblock
  */
 template <typename T>
-class CESIUMGLTF_API SharedAsset : public CesiumUtility::ExtensibleObject {
+class CESIUMASYNC_API SharedAsset : public CesiumUtility::ExtensibleObject {
 public:
-  SharedAsset() = default;
-  ~SharedAsset() { CESIUM_ASSERT(this->_referenceCount == 0); }
-
-  // Assets can be copied, but the fresh instance has no references and is not
-  // in the asset depot.
+  /**
+   * Assets can be copied, but the fresh instance has no references and is not
+   * in the asset depot.
+   */
   SharedAsset(const SharedAsset& rhs)
       : ExtensibleObject(rhs),
         _referenceCount(0),
         _pDepot(nullptr),
         _uniqueAssetId() {}
 
-  // After a move construction, the content of the asset is moved to the new
-  // instance, but the asset depot still references the old instance.
+  /**
+   * After a move construction, the content of the asset is moved to the new
+   * instance, but the asset depot still references the old instance.
+   */
   SharedAsset(SharedAsset&& rhs)
       : ExtensibleObject(std::move(rhs)),
         _referenceCount(0),
         _pDepot(nullptr),
         _uniqueAssetId() {}
 
-  // Assignment does not affect the asset's relationship with the depot, but is
-  // useful to assign the data in derived classes.
+  /**
+   * Assignment does not affect the asset's relationship with the depot, but is
+   * useful to assign the data in derived classes.
+   */
   SharedAsset& operator=(const SharedAsset& rhs) {
     CesiumUtility::ExtensibleObject::operator=(rhs);
     return *this;
@@ -88,26 +114,39 @@ class CESIUMGLTF_API SharedAsset : public CesiumUtility::ExtensibleObject {
   }
 
   /**
-   * @brief Determines if this image is shareable because it is managed by an
-   * asset depot. An image that is not shareable can be understood to be
-   * exclusively owned by, for example, the glTF that references it. If it is
-   * shareable, then potentially multiple glTFs reference it.
-   *
-   * An example of a non-shareable asset is an image embedded in a Binary glTF
-   * (GLB) buffer. An example of a shareable asset is an image referenced in a
-   * glTF by URI.
+   * @brief Gets the shared asset depot that owns this asset, or nullptr if this
+   * asset is independent of an asset depot.
+   */
+  const SharedAssetDepot<T>* getDepot() const { return this->_pDepot; }
+
+  /**
+   * @brief Gets the shared asset depot that owns this asset, or nullptr if this
+   * asset is independent of an asset depot.
    */
-  bool isShareable() const { return this->_pDepot != nullptr; }
+  SharedAssetDepot<T>* getDepot() { return this->_pDepot; }
 
+  /**
+   * @brief Gets the unique ID of this asset, if it {@link isShareable}.
+   *
+   * If this asset is not shareable, this method will return an empty string.
+   */
   const std::string& getUniqueAssetId() const { return this->_uniqueAssetId; }
 
+protected:
+  SharedAsset() = default;
+  ~SharedAsset() { CESIUM_ASSERT(this->_referenceCount == 0); }
+
 private:
   mutable std::atomic<std::int32_t> _referenceCount{0};
-  SharedAssetDepot<T>* _pDepot;
-  std::string _uniqueAssetId;
+  SharedAssetDepot<T>* _pDepot{nullptr};
+  std::string _uniqueAssetId{};
+
+  // The size of this asset when it was counted by the depot. This is stored so
+  // that the exact same size can be subtracted later.
+  int64_t _sizeInDepot{0};
 
-  // To allow the depot to modify _pDepot and _uniqueAssetId.
+  // To allow the depot to modify _pDepot, _uniqueAssetId, and _sizeInDepot.
   friend class SharedAssetDepot<T>;
 };
 
-} // namespace CesiumGltf
+} // namespace CesiumAsync