galaxis::math Namespace Reference

Classes
struct	EulerAngles
struct	Quaternion

Functions
Quaternion	euler_angles_to_quaternion (EulerAngles const &e)
EulerAngles	quaternion_to_euler (Quaternion const &q)

Function Documentation

euler_angles_to_quaternion()

Quaternion galaxis::math::euler_angles_to_quaternion

(

EulerAngles const &

e

)

Definition at line 23 of file math.hpp.

                                                                { // yaw (Z), pitch (Y), roll (X)
 
      // Abbreviations for the various angular functions
      double cy = cos(e.yaw * 0.5);
      double sy = sin(e.yaw * 0.5);
      double cp = cos(e.pitch * 0.5);
      double sp = sin(e.pitch * 0.5);
      double cr = cos(e.roll * 0.5);
      double sr = sin(e.roll * 0.5);
 
      Quaternion q;
      q.w = cr * cp * cy + sr * sp * sy;
      q.x = sr * cp * cy - cr * sp * sy;
      q.y = cr * sp * cy + sr * cp * sy;
      q.z = cr * cp * sy - sr * sp * cy;
 
      return q;
    }

References galaxis::math::EulerAngles::pitch, galaxis::math::EulerAngles::roll, galaxis::math::Quaternion::w, galaxis::math::Quaternion::x, galaxis::math::Quaternion::y, galaxis::math::EulerAngles::yaw, and galaxis::math::Quaternion::z.

quaternion_to_euler()

EulerAngles galaxis::math::quaternion_to_euler

(

Quaternion const &

q

)

Definition at line 42 of file math.hpp.

                                                         {
      EulerAngles angles;
 
      // roll (x-axis rotation)
      double sinr_cosp = 2 * (q.w * q.x + q.y * q.z);
      double cosr_cosp = 1 - 2 * (q.x * q.x + q.y * q.y);
      angles.roll = std::atan2(sinr_cosp, cosr_cosp);
 
      // pitch (y-axis rotation)
      double sinp = 2 * (q.w * q.y - q.z * q.x);
      if (std::abs(sinp) >= 1)
          angles.pitch = std::copysign(M_PI / 2, sinp); // use 90 degrees if out of range
      else
          angles.pitch = std::asin(sinp);
 
      // yaw (z-axis rotation)
      double siny_cosp = 2 * (q.w * q.z + q.x * q.y);
      double cosy_cosp = 1 - 2 * (q.y * q.y + q.z * q.z);
      angles.yaw = std::atan2(siny_cosp, cosy_cosp);
 
      return angles;
    }

References galaxis::math::EulerAngles::pitch, galaxis::math::EulerAngles::roll, galaxis::math::Quaternion::w, galaxis::math::Quaternion::x, galaxis::math::Quaternion::y, galaxis::math::EulerAngles::yaw, and galaxis::math::Quaternion::z.