Make tile content loading asynchronous

CHANGES.md

@@ -2,6 +2,9 @@
 
 ### v0.7.1 - ????
 
+##### Additions :tada:
+- Made tile content loading asynchronous and allowed it to make further network requests, to Ion or otherwise.
+
 ##### Fixes :wrench:
 
 - Fixed a bug introduced in v0.7.0 where Bing credits were not being collected.

Cesium3DTilesSelection/include/Cesium3DTilesSelection/ExternalTilesetContent.h

@@ -28,7 +28,7 @@ class CESIUM3DTILESSELECTION_API ExternalTilesetContent final
    * The result will only contain the `childTiles` and the `pNewTileContext`.
    * Other fields will be empty or have default values.
    */
-  std::unique_ptr<TileContentLoadResult>
+  CesiumAsync::Future<std::unique_ptr<TileContentLoadResult>>
   load(const TileContentLoadInput& input) override;
 
 private:

Cesium3DTilesSelection/include/Cesium3DTilesSelection/GltfContent.h

@@ -6,6 +6,7 @@
 #include "Cesium3DTilesSelection/TileContentLoader.h"
 #include "Cesium3DTilesSelection/TileID.h"
 #include "Cesium3DTilesSelection/TileRefine.h"
+#include "CesiumAsync/AsyncSystem.h"
 #include "CesiumGltf/GltfReader.h"
 #include <cstddef>
 #include <glm/mat4x4.hpp>
@@ -27,7 +28,7 @@ class CESIUM3DTILESSELECTION_API GltfContent final : public TileContentLoader {
    * The result will only contain the `model`. Other fields will be
    * empty or have default values.
    */
-  std::unique_ptr<TileContentLoadResult>
+  CesiumAsync::Future<std::unique_ptr<TileContentLoadResult>>
   load(const TileContentLoadInput& input) override;
 
   /**

Cesium3DTilesSelection/include/Cesium3DTilesSelection/TileContentFactory.h

@@ -7,6 +7,7 @@
 #include "Cesium3DTilesSelection/TileContentLoader.h"
 #include "Cesium3DTilesSelection/TileID.h"
 #include "Cesium3DTilesSelection/TileRefine.h"
+#include "CesiumAsync/AsyncSystem.h"
 
 #include <gsl/span>
 #include <spdlog/fwd.h>
@@ -97,7 +98,7 @@ class CESIUM3DTILESSELECTION_API TileContentFactory final {
    * no loader registered for the magic header of the given
    * input, and no loader for the content type of the input.
    */
-  static std::unique_ptr<TileContentLoadResult>
+  static CesiumAsync::Future<std::unique_ptr<TileContentLoadResult>>
   createContent(const TileContentLoadInput& input);
 
 private:

Cesium3DTilesSelection/include/Cesium3DTilesSelection/TileContentLoadInput.h

@@ -7,6 +7,9 @@
 #include "Cesium3DTilesSelection/TileID.h"
 #include "Cesium3DTilesSelection/TileRefine.h"
 #include "Cesium3DTilesSelection/TilesetOptions.h"
+#include "CesiumAsync/AsyncSystem.h"
+#include "CesiumAsync/IAssetAccessor.h"
+#include "CesiumAsync/IAssetRequest.h"
 
 #include <gsl/span>
 #include <spdlog/fwd.h>
@@ -29,46 +32,39 @@ struct CESIUM3DTILESSELECTION_API TileContentLoadInput {
   /**
    * @brief Creates a new, uninitialized instance for the given tile.
    *
-   * The `data`, `contentType` and `url` will have default values,
-   * and have to be initialized before this instance is passed to
-   * one of the loader functions.
+   * The `asyncSystem`, `pLogger`, `pAssetAccessor` and `pRequest` will have
+   * default values, and have to be initialized before this instance is passed
+   * to one of the loader functions.
    *
-   * @param pLogger The logger that will be used
    * @param tile The {@link Tile} that the content belongs to
    */
-  TileContentLoadInput(
-      const std::shared_ptr<spdlog::logger> pLogger,
-      const Tile& tile);
+  TileContentLoadInput(const Tile& tile);
 
   /**
-   * @brief Creates a new instance for the given tile.
+   * @brief Creates a new instance
    *
+   * @param asyncSystem The async system to use for tile content loading.
    * @param pLogger The logger that will be used
-   * @param data The actual data that the tile content will be created from
-   * @param contentType The content type, if the data was received via a
-   * network response
-   * @param url The URL that the data was loaded from
-   * @param tile The {@link Tile} that the content belongs to
+   * @param pAssetAccessor The asset accessor to make further requests with.
+   * @param pRequest The original tile request and its response.
+   * @param data The content data to use. The response data will be used
+   * instead if this is left as `std::nullopt`.
+   * @param tile The {@link Tile} that the content belongs to.
    */
   TileContentLoadInput(
-      const std::shared_ptr<spdlog::logger> pLogger,
-      const gsl::span<const std::byte>& data,
-      const std::string& contentType,
-      const std::string& url,
+      const CesiumAsync::AsyncSystem& asyncSystem,
+      const std::shared_ptr<spdlog::logger>& pLogger,
+      const std::shared_ptr<CesiumAsync::IAssetAccessor>& pAssetAccessor,
+      const std::shared_ptr<CesiumAsync::IAssetRequest>& pRequest,
       const Tile& tile);
 
   /**
    * @brief Creates a new instance.
    *
-   * For many types of tile content, only the `data` field is required. The
-   * other parameters are used for content that can generate child tiles, like
-   * external tilesets or composite tiles.
-   *
+   * @param asyncSystem The async system to use for tile content loading.
    * @param pLogger The logger that will be used
-   * @param data The actual data that the tile content will be created from
-   * @param contentType The content type, if the data was received via a
-   * network response
-   * @param url The URL that the data was loaded from
+   * @param pAssetAccessor The asset accessor to make further requests with.
+   * @param pRequest The original tile request and its response.
    * @param tileID The {@link TileID}
    * @param tileBoundingVolume The tile {@link BoundingVolume}
    * @param tileContentBoundingVolume The tile content {@link BoundingVolume}
@@ -77,10 +73,10 @@ struct CESIUM3DTILESSELECTION_API TileContentLoadInput {
    * @param tileTransform The tile transform
    */
   TileContentLoadInput(
-      const std::shared_ptr<spdlog::logger> pLogger,
-      const gsl::span<const std::byte>& data,
-      const std::string& contentType,
-      const std::string& url,
+      const CesiumAsync::AsyncSystem& asyncSystem,
+      const std::shared_ptr<spdlog::logger>& pLogger,
+      const std::shared_ptr<CesiumAsync::IAssetAccessor>& pAssetAccessor,
+      const std::shared_ptr<CesiumAsync::IAssetRequest>& pRequest,
       const TileID& tileID,
       const BoundingVolume& tileBoundingVolume,
       const std::optional<BoundingVolume>& tileContentBoundingVolume,
@@ -90,36 +86,24 @@ struct CESIUM3DTILESSELECTION_API TileContentLoadInput {
       const TilesetContentOptions& contentOptions);
 
   /**
-   * @brief The logger that receives details of loading errors and warnings.
+   * @brief The async system to use for tile content loading.
    */
-  std::shared_ptr<spdlog::logger> pLogger;
+  CesiumAsync::AsyncSystem asyncSystem;
 
   /**
-   * @brief The raw input data.
-   *
-   * The {@link TileContentFactory} will try to determine the type of the
-   * data using the first four bytes (i.e. the "magic header"). If this
-   * does not succeed, it will try to determine the type based on the
-   * `contentType` field.
+   * @brief The logger that receives details of loading errors and warnings.
    */
-  gsl::span<const std::byte> data;
+  std::shared_ptr<spdlog::logger> pLogger;
 
   /**
-   * @brief The content type.
-   *
-   * If the data was obtained via a HTTP response, then this will be
-   * the `Content-Type` of that response. The {@link TileContentFactory}
-   * will try to interpret the data based on this content type.
-   *
-   * If the data was not directly obtained from an HTTP response, then
-   * this may be the empty string.
+   * @brief The asset accessor to make further requests with.
    */
-  std::string contentType;
+  std::shared_ptr<CesiumAsync::IAssetAccessor> pAssetAccessor;
 
   /**
-   * @brief The source URL.
+   * @brief The asset request and response data for the tile.
    */
-  std::string url;
+  std::shared_ptr<CesiumAsync::IAssetRequest> pRequest;
 
   /**
    * @brief The {@link TileID}.

Cesium3DTilesSelection/include/Cesium3DTilesSelection/TileContentLoader.h

@@ -2,6 +2,11 @@
 
 #include "Cesium3DTilesSelection/TileContentLoadInput.h"
 #include "Cesium3DTilesSelection/TileContentLoadResult.h"
+#include "CesiumAsync/AsyncSystem.h"
+#include "CesiumAsync/IAssetAccessor.h"
+#include <string>
+#include <utility>
+#include <vector>
 
 namespace Cesium3DTilesSelection {
 /**
@@ -20,7 +25,7 @@ class CESIUM3DTILESSELECTION_API TileContentLoader {
    * @return The {@link TileContentLoadResult}. This may be the `nullptr` if the
    * tile content could not be loaded.
    */
-  virtual std::unique_ptr<TileContentLoadResult>
+  virtual CesiumAsync::Future<std::unique_ptr<TileContentLoadResult>>
   load(const TileContentLoadInput& input) = 0;
 };
 } // namespace Cesium3DTilesSelection

Cesium3DTilesSelection/src/Batched3DModelContent.cpp

@@ -1,6 +1,7 @@
 #include "Batched3DModelContent.h"
 #include "Cesium3DTilesSelection/GltfContent.h"
 #include "Cesium3DTilesSelection/spdlog-cesium.h"
+#include "CesiumAsync/IAssetResponse.h"
 #include "CesiumGltf/ModelEXT_feature_metadata.h"
 #include "CesiumUtility/Tracing.h"
 #include "upgradeBatchTableToFeatureMetadata.h"
@@ -74,9 +75,12 @@ rapidjson::Document parseFeatureTableJsonData(
 
 } // namespace
 
-std::unique_ptr<TileContentLoadResult>
+CesiumAsync::Future<std::unique_ptr<TileContentLoadResult>>
 Batched3DModelContent::load(const TileContentLoadInput& input) {
-  return load(input.pLogger, input.url, input.data);
+  return input.asyncSystem.createResolvedFuture(load(
+      input.pLogger,
+      input.pRequest->url(),
+      input.pRequest->response()->data()));
 }
 
 std::unique_ptr<TileContentLoadResult> Batched3DModelContent::load(

Cesium3DTilesSelection/src/Batched3DModelContent.h

@@ -27,7 +27,7 @@ class CESIUM3DTILESSELECTION_API Batched3DModelContent final
    * The result will only contain the `model`. Other fields will be
    * empty or have default values.
    */
-  std::unique_ptr<TileContentLoadResult>
+  CesiumAsync::Future<std::unique_ptr<TileContentLoadResult>>
   load(const TileContentLoadInput& input) override;
 
   /**