初始提交: UE5.3项目基础框架

Plugins/CesiumForUnreal/Source/ThirdParty/include/CesiumGeospatial/GeographicProjection.h

@@ -0,0 +1,155 @@
+#pragma once
+
+#include "Ellipsoid.h"
+#include "GlobeRectangle.h"
+#include "Library.h"
+
+#include <CesiumUtility/Math.h>
+
+#include <glm/vec2.hpp>
+#include <glm/vec3.hpp>
+
+namespace CesiumGeospatial {
+
+class Cartographic;
+
+/**
+ * @brief A map projection where longitude and latitude are mapped using an
+ * {@link Ellipsoid}.
+ *
+ * The longitude and latitude are linearly mapped to X and Y by multiplying them
+ * (in radians) by the {@link Ellipsoid::getMaximumRadius()}. This projection is
+ * commonly known as geographic, equirectangular, equidistant cylindrical, or
+ * plate carrée. It is also known as EPSG:4326.
+ *
+ * @see WebMercatorProjection
+ */
+class CESIUMGEOSPATIAL_API GeographicProjection final {
+public:
+  /**
+   * @brief The maximum bounding rectangle of the geographic projection,
+   * ranging from -PI to PI radians longitude and
+   * from -PI/2 to +PI/2 radians latitude.
+   */
+  static constexpr GlobeRectangle MAXIMUM_GLOBE_RECTANGLE = GlobeRectangle(
+      -CesiumUtility::Math::OnePi,
+      -CesiumUtility::Math::PiOverTwo,
+      CesiumUtility::Math::OnePi,
+      CesiumUtility::Math::PiOverTwo);
+
+  /**
+   * @brief Computes the maximum rectangle that can be covered with this
+   * projection
+   *
+   * @param ellipsoid The {@link Ellipsoid}. Default value:
+   * {@link Ellipsoid::WGS84}.
+   * @return The rectangle
+   */
+  static constexpr CesiumGeometry::Rectangle computeMaximumProjectedRectangle(
+      const Ellipsoid& ellipsoid CESIUM_DEFAULT_ELLIPSOID) noexcept {
+    const double longitudeValue =
+        ellipsoid.getMaximumRadius() * CesiumUtility::Math::OnePi;
+    const double latitudeValue =
+        ellipsoid.getMaximumRadius() * CesiumUtility::Math::PiOverTwo;
+    return CesiumGeometry::Rectangle(
+        -longitudeValue,
+        -latitudeValue,
+        longitudeValue,
+        latitudeValue);
+  }
+
+  /**
+   * @brief Constructs a new instance.
+   *
+   * @param ellipsoid The {@link Ellipsoid}.
+   */
+  GeographicProjection(
+      const Ellipsoid& ellipsoid CESIUM_DEFAULT_ELLIPSOID) noexcept;
+
+  /**
+   * @brief Gets the {@link Ellipsoid}.
+   */
+  const Ellipsoid& getEllipsoid() const noexcept { return this->_ellipsoid; }
+
+  /**
+   * @brief Converts geodedic ellipsoid coordinates to geographic coordinates.
+   *
+   * Converts geodetic ellipsoid coordinates, in radians, to the equivalent
+   * geographic X, Y, Z coordinates expressed in meters.  The height is copied
+   * unmodified to the `z` coordinate.
+   *
+   * @param cartographic The geodetic coordinates in radians.
+   * @returns The equivalent geographic X, Y, Z coordinates, in meters.
+   */
+  glm::dvec3 project(const Cartographic& cartographic) const noexcept;
+
+  /**
+   * @brief Projects a globe rectangle to geographic coordinates.
+   *
+   * This is done by projecting the southwest and northeast corners.
+   *
+   * @param rectangle The globe rectangle to project.
+   * @return The projected rectangle.
+   */
+  CesiumGeometry::Rectangle
+  project(const CesiumGeospatial::GlobeRectangle& rectangle) const noexcept;
+
+  /**
+   * @brief Converts geographic coordinates to geodetic ellipsoid coordinates.
+   *
+   * Converts geographic X and Y coordinates, expressed in meters, to a
+   * {@link Cartographic} containing geodetic ellipsoid coordinates.
+   * The height is set to 0.0.
+   *
+   * @param projectedCoordinates The geographic projected coordinates to
+   * unproject.
+   * @returns The equivalent cartographic coordinates.
+   */
+  Cartographic unproject(const glm::dvec2& projectedCoordinates) const noexcept;
+
+  /**
+   * @brief Converts geographic coordinates to geodetic ellipsoid coordinates.
+   *
+   * Converts geographic X, Y coordinates, expressed in meters, to a
+   * {@link Cartographic} containing geodetic ellipsoid coordinates.
+   * The Z coordinate is copied unmodified to the height.
+   *
+   * @param projectedCoordinates The geographic projected coordinates to
+   * unproject, with height (z) in meters.
+   * @returns The equivalent cartographic coordinates.
+   */
+  Cartographic unproject(const glm::dvec3& projectedCoordinates) const noexcept;
+
+  /**
+   * @brief Unprojects a geographic rectangle to the globe.
+   *
+   * This is done by unprojecting the southwest and northeast corners.
+   *
+   * @param rectangle The rectangle to unproject.
+   * @returns The unprojected rectangle.
+   */
+  CesiumGeospatial::GlobeRectangle
+  unproject(const CesiumGeometry::Rectangle& rectangle) const noexcept;
+
+  /**
+   * @brief Returns `true` if two projections (i.e. their ellipsoids) are equal.
+   */
+  bool operator==(const GeographicProjection& rhs) const noexcept {
+    return this->_ellipsoid == rhs._ellipsoid;
+  };
+
+  /**
+   * @brief Returns `true` if two projections (i.e. their ellipsoids) are *not*
+   * equal.
+   */
+  bool operator!=(const GeographicProjection& rhs) const noexcept {
+    return !(*this == rhs);
+  };
+
+private:
+  Ellipsoid _ellipsoid;
+  double _semimajorAxis;
+  double _oneOverSemimajorAxis;
+};
+
+} // namespace CesiumGeospatial