C++ 使用 glm 实现 Cartesian3.fromDegrees

C++ 使用 glm 实现 Cartesian3.fromDegrees

#include <glm/glm.hpp>
#define _USE_MATH_DEFINES
#include <cmath>

namespace FastBVH
{
  float RADIANS_PER_DEGREE = M_PI / 180.0;
  // 定义地球半径的平方（可以用你自己的椭球模型）
  const glm::dvec3 defaultRadiiSquared = glm::dvec3(6378137.0f * 6378137.0f, 6378137.0f * 6378137.0f, 6356752.3f * 6356752.3f);

  class Cartesian3
  {
  public:
    static glm::dvec3 fromRadians(double longitude, double latitude, double height)
    {
      const glm::dvec3 &radiiSquared = defaultRadiiSquared;

      double cosLatitude = std::cos(latitude);
      glm::dvec3 scratchN(cosLatitude * std::cos(longitude), cosLatitude * std::sin(longitude), std::sin(latitude));

      scratchN = glm::normalize(scratchN);

      glm::dvec3 scratchK = radiiSquared * scratchN;

      double gamma = std::sqrt(dot(scratchN, scratchK));
      scratchK = scratchK / gamma;

      scratchN = scratchN * height;

      return scratchK + scratchN;
    }

    static glm::dvec3 fromDegrees(double longitude, double latitude, double height)
    {
      longitude = longitude * RADIANS_PER_DEGREE;
      latitude = latitude * RADIANS_PER_DEGREE;
      return fromRadians(longitude, latitude, height);
    }
  };
}