初始提交: UE5.3项目基础框架

Plugins/CesiumForUnreal/Source/ThirdParty/include/CesiumGeometry/QuadtreeTileID.h

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+#pragma once
+
+#include "Library.h"
+
+#include <cstdint>
+#include <functional>
+
+namespace CesiumGeometry {
+class QuadtreeTilingScheme;
+
+/**
+ * @brief Uniquely identifies a node in a quadtree.
+ *
+ * This is one form of a {@link Cesium3DTilesSelection::TileID}.
+ *
+ * The identifier is composed of the level (with 0 being the level of the root
+ * tile), the x- and y-coordinate of the tile, referring to a grid coordinate
+ * system at the respective level.
+ */
+struct CESIUMGEOMETRY_API QuadtreeTileID final {
+
+  /**
+   * @brief Creates a new instance.
+   *
+   * @param level_ The level of the node, with 0 being the root
+   * @param x_ The x-coordinate of the tile
+   * @param y_ The y-coordinate of the tile
+   */
+  constexpr QuadtreeTileID(uint32_t level_, uint32_t x_, uint32_t y_) noexcept
+      : level(level_), x(x_), y(y_) {}
+
+  /**
+   * @brief Returns `true` if two identifiers are equal.
+   */
+  constexpr bool operator==(const QuadtreeTileID& other) const noexcept {
+    return this->level == other.level && this->x == other.x &&
+           this->y == other.y;
+  }
+
+  /**
+   * @brief Returns `true` if two identifiers are *not* equal.
+   */
+  constexpr bool operator!=(const QuadtreeTileID& other) const noexcept {
+    return !(*this == other);
+  }
+
+  /**
+   * @brief Computes the inverse y-coordinate of this tile ID.
+   *
+   * This will compute the inverse y-coordinate of this tile ID, based
+   * on the given tiling scheme, which provides the number of tiles
+   * in y-direction for the level of this tile ID.
+   *
+   * @param tilingScheme The {@link QuadtreeTilingScheme}.
+   * @return The inverted y-coordinate.
+   */
+  uint32_t
+  computeInvertedY(const QuadtreeTilingScheme& tilingScheme) const noexcept;
+
+  /**
+   * @brief Gets the ID of the parent of the tile with this ID.
+   *
+   * If this method is called on a level zero tile, it returns itself.
+   *
+   * @return The ID of the parent tile.
+   */
+  constexpr QuadtreeTileID getParent() const noexcept {
+    if (this->level == 0) {
+      return *this;
+    }
+    return QuadtreeTileID(this->level - 1, this->x >> 1, this->y >> 1);
+  }
+
+  /**
+   * @brief The level of this tile ID, with 0 being the root tile.
+   */
+  uint32_t level;
+
+  /**
+   * @brief The x-coordinate of this tile ID.
+   */
+  uint32_t x;
+
+  /**
+   * @brief The y-coordinate of this tile ID.
+   */
+  uint32_t y;
+};
+
+/**
+ * @brief A node of a tile hierarchy that was created by upsampling the tile
+ * content of a parent node.
+ */
+struct CESIUMGEOMETRY_API UpsampledQuadtreeNode final {
+
+  /**
+   * @brief The {@link QuadtreeTileID} for this tree node.
+   */
+  QuadtreeTileID tileID;
+};
+} // namespace CesiumGeometry
+
+namespace std {
+
+/**
+ * @brief A hash function for {@link CesiumGeometry::QuadtreeTileID} objects.
+ */
+template <> struct hash<CesiumGeometry::QuadtreeTileID> {
+
+  /**
+   * @brief A specialization of the `std::hash` template for
+   * {@link CesiumGeometry::QuadtreeTileID} objects.
+   */
+  size_t operator()(const CesiumGeometry::QuadtreeTileID& key) const noexcept;
+};
+} // namespace std