初始提交: UE5.3项目基础框架

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

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+#pragma once
+
+#include "AxisAlignedBox.h"
+#include "BoundingSphere.h"
+#include "CullingResult.h"
+#include "Library.h"
+
+#include <glm/mat3x3.hpp>
+#include <glm/vec3.hpp>
+
+namespace CesiumGeometry {
+
+class Plane;
+
+/**
+ * @brief A bounding volume defined as a closed and convex cuboid with any
+ * orientation.
+ *
+ * @see BoundingSphere
+ * @see BoundingRegion
+ */
+class CESIUMGEOMETRY_API OrientedBoundingBox final {
+public:
+  /**
+   * @brief Constructs a new instance.
+   *
+   * @param center The center of the box.
+   * @param halfAxes The three orthogonal half-axes of the bounding box.
+   * Equivalently, the transformation matrix to rotate and scale a 2x2x2 cube
+   * centered at the origin.
+   *
+   * @snippet TestOrientedBoundingBox.cpp Constructor
+   */
+  OrientedBoundingBox(
+      const glm::dvec3& center,
+      const glm::dmat3& halfAxes) noexcept
+      : _center(center),
+        _halfAxes(halfAxes),
+        // TODO: what should we do if halfAxes is singular?
+        _inverseHalfAxes(glm::inverse(halfAxes)),
+        _lengths(
+            2.0 * glm::length(_halfAxes[0]),
+            2.0 * glm::length(_halfAxes[1]),
+            2.0 * glm::length(_halfAxes[2])) {}
+
+  /**
+   * @brief Gets the center of the box.
+   */
+  constexpr const glm::dvec3& getCenter() const noexcept {
+    return this->_center;
+  }
+
+  /**
+   * @brief Gets the three orthogonal half-axes of the bounding box.
+   * Equivalently, the transformation matrix to rotate and scale a 2x2x2 cube
+   * centered at the origin.
+   */
+  constexpr const glm::dmat3& getHalfAxes() const noexcept {
+    return this->_halfAxes;
+  }
+
+  /**
+   * @brief Gets the inverse transformation matrix, to rotate from world space
+   * to local space relative to the box.
+   */
+  constexpr const glm::dmat3& getInverseHalfAxes() const noexcept {
+    return this->_inverseHalfAxes;
+  }
+
+  /**
+   * @brief Gets the lengths of the box on each local axis respectively.
+   */
+  constexpr const glm::dvec3& getLengths() const noexcept {
+    return this->_lengths;
+  }
+
+  /**
+   * @brief Determines on which side of a plane the bounding box is located.
+   *
+   * @param plane The plane to test against.
+   * @return The {@link CullingResult}:
+   *  * `Inside` if the entire box is on the side of the plane the normal is
+   * pointing.
+   *  * `Outside` if the entire box is on the opposite side.
+   *  * `Intersecting` if the box intersects the plane.
+   */
+  CullingResult intersectPlane(const Plane& plane) const noexcept;
+
+  /**
+   * @brief Computes the distance squared from a given position to the closest
+   * point on this bounding volume. The bounding volume and the position must be
+   * expressed in the same coordinate system.
+   *
+   * @param position The position
+   * @return The estimated distance squared from the bounding box to the point.
+   *
+   * @snippet TestOrientedBoundingBox.cpp distanceSquaredTo
+   */
+  double
+  computeDistanceSquaredToPosition(const glm::dvec3& position) const noexcept;
+
+  /**
+   * @brief Computes whether the given position is contained within the bounding
+   * box.
+   *
+   * @param position The position.
+   * @return Whether the position is contained within the bounding box.
+   */
+  bool contains(const glm::dvec3& position) const noexcept;
+
+  /**
+   * @brief Transforms this bounding box to another coordinate system using a
+   * 4x4 matrix.
+   *
+   * @param transformation The transformation.
+   * @return The oriented bounding box in the new coordinate system.
+   */
+  OrientedBoundingBox
+  transform(const glm::dmat4& transformation) const noexcept;
+
+  /**
+   * @brief Converts this oriented bounding box to an axis-aligned bounding box.
+   */
+  AxisAlignedBox toAxisAligned() const noexcept;
+
+  /**
+   * @brief Converts this oriented bounding box to a bounding sphere.
+   */
+  BoundingSphere toSphere() const noexcept;
+
+  /**
+   * @brief Creates an oriented bounding box from the given axis-aligned
+   * bounding box.
+   */
+  static OrientedBoundingBox
+  fromAxisAligned(const AxisAlignedBox& axisAligned) noexcept;
+
+  /**
+   * @brief Creates an oriented bounding box from the given bounding sphere.
+   */
+  static OrientedBoundingBox fromSphere(const BoundingSphere& sphere) noexcept;
+
+private:
+  glm::dvec3 _center;
+  glm::dmat3 _halfAxes;
+  glm::dmat3 _inverseHalfAxes;
+  glm::dvec3 _lengths;
+};
+
+} // namespace CesiumGeometry