arc-ball/ArcBall.hpp

#ifndef IAUNS_ARC_BALL_H
#define IAUNS_ARC_BALL_H

#include <stdint.h>

#include <glm/glm.hpp>
#include <glm/gtc/quaternion.hpp>
#include <glm/gtc/type_ptr.hpp>
#include <glm/gtc/matrix_inverse.hpp>
#include <glm/gtc/matrix_transform.hpp>

namespace CPM_ARC_BALL_NS {

class ArcBall
{
public:
  ArcBall(const glm::vec3& center, glm::float_t radius,
          const glm::mat4& screenToTCS = glm::mat4());
  virtual ~ArcBall();
  
  void beginDrag(const glm::vec2& mouseScreenCoords);

  void drag(const glm::vec2& mouseScreenCoords);

  glm::mat4 getTransformation() const;

private:

  glm::vec3 mouseOnSphere(const glm::vec3& tscMouse);

  static glm::quat quatFromUnitSphere(const glm::vec3& from, const glm::vec3& to);

  glm::vec3     mCenter;        
  glm::float_t  mRadius;        

  glm::quat     mQNow;          


  glm::quat     mQDown;         
  glm::quat     mQDrag;         


  glm::vec3     mVNow;          
  glm::vec3     mVDown;         
  glm::vec3     mVSphereFrom;   
  glm::vec3     mVSphereTo;     

  glm::mat4     mMatNow;        

  glm::mat4     mScreenToTCS;
};

} // namespace CPM_ARC_BALL_NS 

#endif