初始提交: UE5.3项目基础框架

Plugins/CesiumForUnreal/Source/ThirdParty/include/CesiumGltfReader/GltfReader.h

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+#pragma once
+
+#include "CesiumGltfReader/ImageDecoder.h"
+#include "CesiumGltfReader/Library.h"
+
+#include <CesiumAsync/AsyncSystem.h>
+#include <CesiumAsync/Future.h>
+#include <CesiumAsync/HttpHeaders.h>
+#include <CesiumAsync/IAssetAccessor.h>
+#include <CesiumGltf/ImageAsset.h>
+#include <CesiumGltf/Ktx2TranscodeTargets.h>
+#include <CesiumGltf/Model.h>
+#include <CesiumGltfReader/GltfSharedAssetSystem.h>
+#include <CesiumJsonReader/IExtensionJsonHandler.h>
+#include <CesiumJsonReader/JsonReaderOptions.h>
+
+#include <functional>
+#include <memory>
+#include <optional>
+#include <span>
+#include <string>
+#include <vector>
+
+namespace CesiumGltfReader {
+
+/**
+ * @brief The result of reading a glTF model with
+ * {@link GltfReader::readGltf}.
+ */
+struct CESIUMGLTFREADER_API GltfReaderResult {
+  /**
+   * @brief The read model, or std::nullopt if the model could not be read.
+   */
+  std::optional<CesiumGltf::Model> model;
+
+  /**
+   * @brief Errors, if any, that occurred during the load process.
+   */
+  std::vector<std::string> errors;
+
+  /**
+   * @brief Warnings, if any, that occurred during the load process.
+   */
+  std::vector<std::string> warnings;
+};
+
+/**
+ * @brief Options for how to read a glTF.
+ */
+struct CESIUMGLTFREADER_API GltfReaderOptions {
+  /**
+   * @brief Whether data URLs in buffers and images should be automatically
+   * decoded as part of the load process.
+   */
+  bool decodeDataUrls = true;
+
+  /**
+   * @brief Whether data URLs should be cleared after they are successfully
+   * decoded.
+   *
+   * This reduces the memory usage of the model.
+   */
+  bool clearDecodedDataUrls = true;
+
+  /**
+   * @brief Whether embedded images in {@link CesiumGltf::Model::buffers} should be
+   * automatically decoded as part of the load process.
+   *
+   * The {@link CesiumGltf::ImageSpec::mimeType} property is ignored, and instead the
+   * [stb_image](https://github.com/nothings/stb) library is used to decode
+   * images in `JPG`, `PNG`, `TGA`, `BMP`, `PSD`, `GIF`, `HDR`, or `PIC` format.
+   */
+  bool decodeEmbeddedImages = true;
+
+  /**
+   * @brief Whether external images should be resolved.
+   */
+  bool resolveExternalImages = true;
+
+  /**
+   * @brief Whether geometry compressed using the `KHR_draco_mesh_compression`
+   * extension should be automatically decoded as part of the load process.
+   */
+  bool decodeDraco = true;
+
+  /**
+   * @brief Whether the mesh data are decompressed as part of the load process,
+   * or left in the compressed format according to the EXT_meshopt_compression
+   * extension
+   */
+  bool decodeMeshOptData = true;
+
+  /**
+   * @brief Whether the quantized mesh data are dequantized and converted to
+   * floating-point values when loading, according to the KHR_mesh_quantization
+   * extension.
+   */
+  bool dequantizeMeshData = true;
+
+  /**
+   * @brief  Whether the texture coordinates of a texture are transformed or
+   * not, according to the KHR_texture_transform extension
+   */
+  bool applyTextureTransform = true;
+
+  /**
+   * @brief For each possible input transmission format, this struct names
+   * the ideal target gpu-compressed pixel format to transcode to.
+   */
+  CesiumGltf::Ktx2TranscodeTargets ktx2TranscodeTargets;
+
+  /**
+   * The shared asset system that will be used to store all of the shared assets
+   * that might appear in this glTF.
+   */
+  CesiumUtility::IntrusivePointer<GltfSharedAssetSystem> pSharedAssetSystem =
+      GltfSharedAssetSystem::getDefault();
+
+  /**
+   * @brief Whether the `schemaUri` property of `EXT_structural_metadata` will
+   * be properly resolved. If false, any external schemas will be ignored.
+   */
+  bool resolveExternalStructuralMetadata = true;
+};
+
+/**
+ * @brief Reads glTF models and images.
+ */
+class CESIUMGLTFREADER_API GltfReader {
+public:
+  /**
+   * @brief Constructs a new instance.
+   */
+  GltfReader();
+
+  /**
+   * @brief Gets the options controlling how the JSON is read.
+   */
+  CesiumJsonReader::JsonReaderOptions& getOptions();
+
+  /**
+   * @brief Gets the options controlling how the JSON is read.
+   */
+  const CesiumJsonReader::JsonReaderOptions& getExtensions() const;
+
+  /**
+   * @brief Reads a glTF or binary glTF (GLB) from a buffer.
+   *
+   * @param data The buffer from which to read the glTF.
+   * @param options Options for how to read the glTF.
+   * @return The result of reading the glTF.
+   */
+  GltfReaderResult readGltf(
+      const std::span<const std::byte>& data,
+      const GltfReaderOptions& options = GltfReaderOptions()) const;
+
+  /**
+   * @brief Reads a glTF or binary glTF file from a URL and resolves external
+   * buffers and images.
+   *
+   * @param asyncSystem The async system to use for resolving external data.
+   * @param url The url for reading the file.
+   * @param headers http headers needed to make the request.
+   * @param pAssetAccessor The asset accessor to use to make the necessary
+   * requests.
+   * @param options Options for how to read the glTF.
+   */
+  CesiumAsync::Future<GltfReaderResult> loadGltf(
+      const CesiumAsync::AsyncSystem& asyncSystem,
+      const std::string& url,
+      const std::vector<CesiumAsync::IAssetAccessor::THeader>& headers,
+      const std::shared_ptr<CesiumAsync::IAssetAccessor>& pAssetAccessor,
+      const GltfReaderOptions& options = GltfReaderOptions()) const;
+
+  /**
+   * @brief Performs post-load processing on a glTF. The specific operations
+   * performed are controlled by the provided `options`.
+   *
+   * @param readGltf The result of reading the glTF.
+   * @param options The options to use in post-processing.
+   */
+  void
+  postprocessGltf(GltfReaderResult& readGltf, const GltfReaderOptions& options);
+
+  /**
+   * @brief Accepts the result of {@link readGltf} and resolves any remaining
+   * external buffers and images.
+   *
+   * @param asyncSystem The async system to use for resolving external data.
+   * @param baseUrl The base url that all the external uris are relative to.
+   * @param headers The http headers needed to make any external data requests.
+   * @param pAssetAccessor The asset accessor to use to request the external
+   * buffers and images.
+   * @param options Options for how to read the glTF.
+   * @param result The result of the synchronous readGltf invocation.
+   */
+  static CesiumAsync::Future<GltfReaderResult> resolveExternalData(
+      const CesiumAsync::AsyncSystem& asyncSystem,
+      const std::string& baseUrl,
+      const CesiumAsync::HttpHeaders& headers,
+      const std::shared_ptr<CesiumAsync::IAssetAccessor>& pAssetAccessor,
+      const GltfReaderOptions& options,
+      GltfReaderResult&& result);
+
+  /**
+   * @brief Reads an Image from a buffer.
+   * @deprecated Use {@link ImageDecoder::readImage} instead.
+   */
+  [[deprecated(
+      "Use ImageDecoder::readImage instead.")]] static ImageReaderResult
+  readImage(
+      const std::span<const std::byte>& data,
+      const CesiumGltf::Ktx2TranscodeTargets& ktx2TranscodeTargets);
+
+  /**
+   * @brief Generate mipmaps for this image.
+   * @deprecated Use {@link ImageDecoder::generateMipMaps} instead.
+   */
+  [[deprecated("Use ImageDecoder::generateMipMaps instead.")]] static std::
+      optional<std::string>
+      generateMipMaps(CesiumGltf::ImageAsset& image);
+
+private:
+  CesiumJsonReader::JsonReaderOptions _context;
+};
+
+} // namespace CesiumGltfReader