camera.h

// This camera stuff mostly by ehsu

#ifndef CAMERA_H
#define CAMERA_H

#include "vec.h"
//
#include "mat.h"

//==========[ class Camera ]===================================================

typedef enum {
  kActionNone,
  kActionTranslate,
  kActionRotate,
  kActionZoom,
  kActionTwist,
} MouseAction_t;

class Camera {

protected:
  float mElevation;
  float mAzimuth;
  float mDolly;
  float mTwist; // Not implemented yet

  Vec3f mLookAt;

  Vec3f mPosition;
  Vec3f mUpVector;
  bool mDirtyTransform;

  void calculateViewingTransformParameters();

  Vec3f mLastMousePosition;
  MouseAction_t mCurrentMouseAction;

public:
  //---[ Constructors ]----------------------------------

  // defaults to (0,0,0) facing down negative z axis
  Camera();

  //---[ Settings ]--------------------------------------

  inline void setElevation(float elevation) {
    // don't want elevation to be negative
    if (elevation < 0)
      elevation += 6.28318530717f;
    mElevation = elevation;
    mDirtyTransform = true;
  }
  inline float getElevation() const { return mElevation; }

  inline void setAzimuth(float azimuth) {
    mAzimuth = azimuth;
    mDirtyTransform = true;
  }
  inline float getAzimuth() const { return mAzimuth; }

  inline void setDolly(float dolly) {
    mDolly = dolly;
    mDirtyTransform = true;
  }
  inline float getDolly() const { return mDolly; }

  inline void setTwist(float twist) {
    mTwist = twist;
    mDirtyTransform = true;
  }
  inline float getTwist() const { return mTwist; }

  inline void setLookAt(const Vec3f &lookAt) {
    mLookAt = lookAt;
    mDirtyTransform = true;
  }
  inline Vec3f getLookAt() const { return mLookAt; }

  //---[ Interactive Adjustment ]------------------------
  // these should be used from a mouse event handling routine that calls
  // the startX method on a mouse down, updateX on mouse move and finally
  // endX on mouse up.
  //-----------------------------------------------------
  void clickMouse(MouseAction_t action, int x, int y);
  void dragMouse(int x, int y);
  void releaseMouse(int x, int y);

  //---[ Viewing Transform ]--------------------------------
  void applyViewingTransform();

  // gluLookAt equivalent
  void lookAt(Vec3f eye, Vec3f at, Vec3f up);
};

#endif