初始提交: UE5.3项目基础框架

Plugins/CesiumForUnreal/Source/ThirdParty/include/CesiumUtility/JsonHelpers.h

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+#pragma once
+
+#include <glm/fwd.hpp>
+#include <rapidjson/fwd.h>
+
+#include <optional>
+#include <string>
+#include <vector>
+
+namespace CesiumUtility {
+
+/**
+ * @brief A collection of helper functions to make reading JSON simpler.
+ */
+class JsonHelpers final {
+public:
+  /**
+   * @brief Attempts to read the value at `key` of `tileJson` as a `double`,
+   * returning std::nullopt if it wasn't found or couldn't be read as a double.
+   *
+   * @param tileJson The JSON object to obtain the scalar property from.
+   * @param key The key of the scalar property to obtain.
+   */
+  static std::optional<double>
+  getScalarProperty(const rapidjson::Value& tileJson, const std::string& key);
+  /**
+   * @brief Attempts to read the value at `key` of `tileJson` as a
+   * `glm::dmat4x4`, returning std::nullopt if it wasn't found or couldn't be
+   * read as a glm::dmat4x4.
+   *
+   * @param tileJson The JSON object to obtain the transform property from.
+   * @param key The key of the transform property.
+   */
+  static std::optional<glm::dmat4x4> getTransformProperty(
+      const rapidjson::Value& tileJson,
+      const std::string& key);
+
+  /**
+   * @brief Obtains an array of numbers from the given JSON.
+   *
+   * If the property is not found, or is not an array, or does contain
+   * elements that are not numbers, then `std::nullopt` is returned.
+   *
+   * If the given expected size is not negative, and the actual size of the
+   * array does not match the expected size, then `nullopt` is returned.
+   *
+   * @param json The JSON object.
+   * @param expectedSize The expected size of the array.
+   * @param key The key (property name) of the array.
+   * @return The array, or `nullopt`.
+   */
+  static std::optional<std::vector<double>> getDoubles(
+      const rapidjson::Value& json,
+      int32_t expectedSize,
+      const std::string& key);
+
+  /**
+   * @brief Attempts to obtain a string from the given key on the JSON object,
+   * returning a default value if this isn't possible.
+   *
+   * @param json The JSON object.
+   * @param key The key (property name) of the string.
+   * @param defaultValue The default value to return if the string property
+   * `key` of `json` couldn't be read.
+   */
+  static std::string getStringOrDefault(
+      const rapidjson::Value& json,
+      const std::string& key,
+      const std::string& defaultValue);
+  /**
+   * @brief Attempts to read `json` as a string, returning a default value if
+   * this isn't possible.
+   *
+   * @param json The JSON value that might be a string.
+   * @param defaultValue The default value to return if `json` couldn't be read
+   * as a string.
+   */
+  static std::string getStringOrDefault(
+      const rapidjson::Value& json,
+      const std::string& defaultValue);
+
+  /**
+   * @brief Attempts to obtain a double from the given key on the JSON object,
+   * returning a default value if this isn't possible.
+   *
+   * @param json The JSON object.
+   * @param key The key (property name) of the double.
+   * @param defaultValue The default value to return if the double property
+   * `key` of `json` couldn't be read.
+   */
+  static double getDoubleOrDefault(
+      const rapidjson::Value& json,
+      const std::string& key,
+      double defaultValue);
+  /**
+   * @brief Attempts to read `json` as a double, returning a default value if
+   * this isn't possible.
+   *
+   * @param json The JSON value that might be a double.
+   * @param defaultValue The default value to return if `json` couldn't be read
+   * as a double.
+   */
+  static double
+  getDoubleOrDefault(const rapidjson::Value& json, double defaultValue);
+
+  /**
+   * @brief Attempts to obtain a uint32_t from the given key on the JSON object,
+   * returning a default value if this isn't possible.
+   *
+   * @param json The JSON object.
+   * @param key The key (property name) of the uint32_t.
+   * @param defaultValue The default value to return if the uint32_t property
+   * `key` of `json` couldn't be read.
+   */
+  static uint32_t getUint32OrDefault(
+      const rapidjson::Value& json,
+      const std::string& key,
+      uint32_t defaultValue);
+  /**
+   * @brief Attempts to read `json` as a uint32_t, returning a default value if
+   * this isn't possible.
+   *
+   * @param json The JSON value that might be a uint32_t.
+   * @param defaultValue The default value to return if `json` couldn't be read
+   * as a uint32_t.
+   */
+  static uint32_t
+  getUint32OrDefault(const rapidjson::Value& json, uint32_t defaultValue);
+
+  /**
+   * @brief Attempts to obtain a int32_t from the given key on the JSON object,
+   * returning a default value if this isn't possible.
+   *
+   * @param json The JSON object.
+   * @param key The key (property name) of the int32_t.
+   * @param defaultValue The default value to return if the int32_t property
+   * `key` of `json` couldn't be read.
+   */
+  static int32_t getInt32OrDefault(
+      const rapidjson::Value& json,
+      const std::string& key,
+      int32_t defaultValue);
+  /**
+   * @brief Attempts to read `json` as a int32_t, returning a default value if
+   * this isn't possible.
+   *
+   * @param json The JSON value that might be a int32_t.
+   * @param defaultValue The default value to return if `json` couldn't be read
+   * as a int32_t.
+   */
+  static int32_t
+  getInt32OrDefault(const rapidjson::Value& json, int32_t defaultValue);
+
+  /**
+   * @brief Attempts to obtain a uint64_t from the given key on the JSON object,
+   * returning a default value if this isn't possible.
+   *
+   * @param json The JSON object.
+   * @param key The key (property name) of the uint64_t.
+   * @param defaultValue The default value to return if the uint64_t property
+   * `key` of `json` couldn't be read.
+   */
+  static uint64_t getUint64OrDefault(
+      const rapidjson::Value& json,
+      const std::string& key,
+      uint64_t defaultValue);
+  /**
+   * @brief Attempts to read `json` as a uint64_t, returning a default value if
+   * this isn't possible.
+   *
+   * @param json The JSON value that might be a uint64_t.
+   * @param defaultValue The default value to return if `json` couldn't be read
+   * as a uint64_t.
+   */
+  static uint64_t
+  getUint64OrDefault(const rapidjson::Value& json, uint64_t defaultValue);
+
+  /**
+   * @brief Attempts to obtain a int64_t from the given key on the JSON object,
+   * returning a default value if this isn't possible.
+   *
+   * @param json The JSON object.
+   * @param key The key (property name) of the int64_t.
+   * @param defaultValue The default value to return if the int64_t property
+   * `key` of `json` couldn't be read.
+   */
+  static int64_t getInt64OrDefault(
+      const rapidjson::Value& json,
+      const std::string& key,
+      int64_t defaultValue);
+  /**
+   * @brief Attempts to read `json` as a int64_t, returning a default value if
+   * this isn't possible.
+   *
+   * @param json The JSON value that might be a int64_t.
+   * @param defaultValue The default value to return if `json` couldn't be read
+   * as a int64_t.
+   */
+  static int64_t
+  getInt64OrDefault(const rapidjson::Value& json, int64_t defaultValue);
+
+  /**
+   * @brief Attempts to obtain a bool from the given key on the JSON object,
+   * returning a default value if this isn't possible.
+   *
+   * @param json The JSON object.
+   * @param key The key (property name) of the bool.
+   * @param defaultValue The default value to return if the bool property
+   * `key` of `json` couldn't be read.
+   */
+  static bool getBoolOrDefault(
+      const rapidjson::Value& json,
+      const std::string& key,
+      bool defaultValue);
+  /**
+   * @brief Attempts to read `json` as a bool, returning a default value if
+   * this isn't possible.
+   *
+   * @param json The JSON value that might be a bool.
+   * @param defaultValue The default value to return if `json` couldn't be read
+   * as a bool.
+   */
+  static bool getBoolOrDefault(const rapidjson::Value& json, bool defaultValue);
+
+  /**
+   * @brief Attempts to read an array of strings from the property `key` of
+   * `json`, returning an empty vector if this isn't possible.
+   *
+   * @param json The JSON object.
+   * @param key The key (property name) of the string array.
+   */
+  static std::vector<std::string>
+  getStrings(const rapidjson::Value& json, const std::string& key);
+
+  /**
+   * @brief Attempts to read an int64_t array from the property `key` of
+   * `json`, returning an empty vector if this isn't possible.
+   *
+   * @param json The JSON object.
+   * @param key The key (property name) of the int64_t array.
+   */
+  static std::vector<int64_t>
+  getInt64s(const rapidjson::Value& json, const std::string& key);
+};
+
+} // namespace CesiumUtility