Trackball.hpp

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#ifndef DART_GUI_TRACKBALL_HPP_
#define DART_GUI_TRACKBALL_HPP_

#include <Eigen/Core>
#include <Eigen/Geometry>

namespace dart {
namespace gui {

class Trackball
{
public:
  // To get byte-aligned Eigen vectors
  EIGEN_MAKE_ALIGNED_OPERATOR_NEW

  Trackball();

  Trackball(const Eigen::Vector2d& _center, double _radius);

  void startBall(double _x, double _y);

  void updateBall(double _x, double _y);

  void applyGLRotation();

  void draw(int _winWidth, int _winHeight);

  void setTrackball(const Eigen::Vector2d& _center, const double _radius);

  void setCenter(const Eigen::Vector2d& _center);

  void setRadius(const double _radius);

  void setQuaternion(const Eigen::Quaterniond& _q);

  Eigen::Quaterniond getCurrQuat() const;

  Eigen::Matrix3d getRotationMatrix() const;

  Eigen::Vector2d getCenter() const;

  double getRadius() const;

private:
  Eigen::Vector3d mouseOnSphere(double _mouseX, double _mouseY) const;

  Eigen::Quaterniond quatFromVectors(
      const Eigen::Vector3d& _from, const Eigen::Vector3d& _to) const;

  Eigen::Vector2d mCenter;

  double mRadius;

  Eigen::Vector3d mStartPos;

  Eigen::Quaterniond mCurrQuat;
};

} // namespace gui
} // namespace dart

#endif // DART_GUI_TRACKBALL_HPP_