初始提交: UE5.3项目基础框架

Plugins/CesiumForUnreal/Source/ThirdParty/include/CesiumQuantizedMeshTerrain/QuantizedMeshLoader.h

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+#pragma once
+
+#include "Library.h"
+
+#include <CesiumGeometry/QuadtreeTileID.h>
+#include <CesiumGeometry/QuadtreeTileRectangularRange.h>
+#include <CesiumGeospatial/BoundingRegion.h>
+#include <CesiumGeospatial/Ellipsoid.h>
+#include <CesiumGltf/Model.h>
+#include <CesiumUtility/ErrorList.h>
+
+#include <rapidjson/document.h>
+
+#include <cstddef>
+#include <memory>
+#include <optional>
+#include <span>
+#include <vector>
+
+namespace CesiumAsync {
+class IAssetRequest;
+}
+
+namespace CesiumQuantizedMeshTerrain {
+
+/**
+ * @brief The results of a \ref QuantizedMeshLoader::load operation, containing
+ * either the loaded model, an improved bounding region for the tile, and
+ * available quadtree tiles discovered, if the load succeeded - or the request
+ * made and the errors that were returned, if the load failed.
+ */
+struct QuantizedMeshLoadResult {
+  /**
+   * @brief The glTF model to be rendered for this tile.
+   *
+   * If this is `std::nullopt`, the tile cannot be rendered.
+   * If it has a value but the model is blank, the tile can
+   * be "rendered", but it is rendered as nothing.
+   */
+  std::optional<CesiumGltf::Model> model;
+
+  /**
+   * @brief An improved bounding region for this tile.
+   *
+   * If this is available, then it is more accurate than the one the tile used
+   * originally.
+   */
+  std::optional<CesiumGeospatial::BoundingRegion> updatedBoundingVolume{};
+
+  /**
+   * @brief Available quadtree tiles discovered as a result of loading this
+   * tile.
+   */
+  std::vector<CesiumGeometry::QuadtreeTileRectangularRange>
+      availableTileRectangles{};
+
+  /**
+   * @brief The request that was used to download the tile content, if any.
+   *
+   * This field is only populated when there are request-related errors.
+   */
+  std::shared_ptr<CesiumAsync::IAssetRequest> pRequest;
+
+  /**
+   * @brief The errors and warnings reported while loading this tile.
+   */
+  CesiumUtility::ErrorList errors;
+};
+
+/**
+ * @brief The metadata of a Quantized Mesh tile, returned by \ref
+ * QuantizedMeshLoader::loadMetadata.
+ */
+struct QuantizedMeshMetadataResult {
+  /**
+   * @brief Information about the availability of child tiles.
+   */
+  std::vector<CesiumGeometry::QuadtreeTileRectangularRange> availability;
+
+  /**
+   * @brief The errors and warnings reported while loading this tile, if any.
+   */
+  CesiumUtility::ErrorList errors;
+};
+
+/**
+ * @brief Loads `quantized-mesh-1.0` terrain data.
+ */
+class CESIUMQUANTIZEDMESHTERRAIN_API QuantizedMeshLoader final {
+public:
+  /**
+   * @brief Create a {@link QuantizedMeshLoadResult} from the given data.
+   *
+   * @param tileID The tile ID.
+   * @param tileBoundingVolume The tile bounding volume.
+   * @param url The URL from which the data was loaded.
+   * @param data The actual tile data.
+   * @param enableWaterMask If true, will attempt to load a water mask from the
+   * quantized mesh data.
+   * @param ellipsoid The ellipsoid to use for this quantized mesh.
+   * @return The {@link QuantizedMeshLoadResult}
+   */
+  static QuantizedMeshLoadResult load(
+      const CesiumGeometry::QuadtreeTileID& tileID,
+      const CesiumGeospatial::BoundingRegion& tileBoundingVolume,
+      const std::string& url,
+      const std::span<const std::byte>& data,
+      bool enableWaterMask,
+      const CesiumGeospatial::Ellipsoid& ellipsoid CESIUM_DEFAULT_ELLIPSOID);
+
+  /**
+   * @brief Parses the metadata (tile availability) from the given
+   * quantized-mesh terrain tile data.
+   *
+   * @param data The actual tile data.
+   * @param tileID The tile ID.
+   * @return The parsed metadata.
+   */
+  static QuantizedMeshMetadataResult loadMetadata(
+      const std::span<const std::byte>& data,
+      const CesiumGeometry::QuadtreeTileID& tileID);
+
+  /**
+   * @brief Extracts tile availability information from a parsed layer.json
+   * or tile metadata extension.
+   *
+   * The actual availability information will be found in a property called
+   * `available`.
+   *
+   * @param layerJson The RapidJSON document containing the layer.json.
+   * @param startingLevel The first tile level number to which the availability
+   * information applies.
+   * @return The availability.
+   */
+  static QuantizedMeshMetadataResult loadAvailabilityRectangles(
+      const rapidjson::Document& layerJson,
+      uint32_t startingLevel);
+};
+
+} // namespace CesiumQuantizedMeshTerrain