GltfConverters.h

#pragma once
 
#include <Cesium3DTilesContent/GltfConverterResult.h>
#include <Cesium3DTilesContent/Library.h>
#include <CesiumAsync/Future.h>
#include <CesiumAsync/IAssetAccessor.h>
#include <CesiumGeometry/Axis.h>
#include <CesiumGltfReader/GltfReader.h>
 
#include <optional>
#include <span>
#include <string>
#include <string_view>
 
namespace Cesium3DTilesContent {
 
struct AssetFetcherResult {
  std::vector<std::byte> bytes;
  CesiumUtility::ErrorList errorList;
};
 
struct CESIUM3DTILESCONTENT_API AssetFetcher {
  AssetFetcher(
      const CesiumAsync::AsyncSystem& asyncSystem_,
      const std::shared_ptr<CesiumAsync::IAssetAccessor>& pAssetAccessor_,
      const std::string& baseUrl_,
      const glm::dmat4 tileTransform_,
      const std::vector<CesiumAsync::IAssetAccessor::THeader>& requestHeaders_,
      CesiumGeometry::Axis upAxis_)
      : asyncSystem(asyncSystem_),
        pAssetAccessor(pAssetAccessor_),
        baseUrl(baseUrl_),
        tileTransform(tileTransform_),
        requestHeaders(requestHeaders_),
        upAxis(upAxis_) {}
 
  CesiumAsync::Future<AssetFetcherResult>
  get(const std::string& relativeUrl) const;
 
  CesiumAsync::AsyncSystem asyncSystem;
  std::shared_ptr<CesiumAsync::IAssetAccessor> pAssetAccessor;
  std::string baseUrl;
  glm::dmat4 tileTransform;
  std::vector<CesiumAsync::IAssetAccessor::THeader> requestHeaders;
  CesiumGeometry::Axis upAxis;
};
 
class CESIUM3DTILESCONTENT_API GltfConverters {
public:
  using ConverterFunction = CesiumAsync::Future<GltfConverterResult> (*)(
      const std::span<const std::byte>& content,
      const CesiumGltfReader::GltfReaderOptions& options,
      const AssetFetcher& subprocessor);
 
  static void
  registerMagic(const std::string& magic, ConverterFunction converter);
 
  static void registerFileExtension(
      const std::string& fileExtension,
      ConverterFunction converter);
 
  static ConverterFunction
  getConverterByFileExtension(const std::string& filePath);
 
  static ConverterFunction
  getConverterByMagic(const std::span<const std::byte>& content);
 
  static CesiumAsync::Future<GltfConverterResult> convert(
      const std::string& filePath,
      const std::span<const std::byte>& content,
      const CesiumGltfReader::GltfReaderOptions& options,
      const AssetFetcher& assetFetcher);
 
  static CesiumAsync::Future<GltfConverterResult> convert(
      const std::span<const std::byte>& content,
      const CesiumGltfReader::GltfReaderOptions& options,
      const AssetFetcher& assetFetcher);
 
private:
  static std::string toLowerCase(const std::string_view& str);
 
  static std::string getFileExtension(const std::string_view& filePath);
 
  static ConverterFunction getConverterByFileExtension(
      const std::string& filePath,
      std::string& fileExtension);
 
  static ConverterFunction getConverterByMagic(
      const std::span<const std::byte>& content,
      std::string& magic);
 
  static std::unordered_map<std::string, ConverterFunction> _loadersByMagic;
  static std::unordered_map<std::string, ConverterFunction>
      _loadersByFileExtension;
};
} // namespace Cesium3DTilesContent