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/home/slang/XVision2/src/Tracking/XVFeature.h

// *** BEGIN_XVISION2_COPYRIGHT_NOTICE ***
// *** END_XVISION2_COPYRIGHT_NOTICE ***

//-----------------------------------------------------------------------------
//
//  XVFeature.h
//
//  Sam Lang - 2.02.01
//
//-----------------------------------------------------------------------------


#ifndef _XVFEATURE_H_
#define _XVFEATURE_H_

// Whatever types you decide to use for the STATE and ERROR of the XVStatePair,
// the STATE type should be able to handle the operators + and - (adding or
// subtracting two states)
// and the ERROR type should be able to handle the logical operator &&
// Also, You don't have to use the XVStatePair class to represent your states
// in XVFeature and XVTracker, but if you don't, the class that you use should
// also support the operators + and -
// Abstractly, subtacting two states should give you a change in state (delta state)
// or adding a change in state to a state should give you a new state.
//

template <class ST, class ER>
class XVStatePair {

  typedef ST STATE;
  typedef ER ERROR;

 public:
  
  STATE state;
  ERROR error;

  XVStatePair(STATE s, ERROR e) : state(s), error(e) {}
  XVStatePair() {}
};

#define _XVSTATEPAIR_BIN_OP_(_OP_) \
template <class ST, class ER> \
XVStatePair<ST, ER> operator _OP_ (const XVStatePair<ST, ER> & s1, const XVStatePair<ST, ER> & s2){ \
  XVStatePair<ST, ER> newS; \
  newS.state = s1.state _OP_ s2.state; \
  newS.error = s1.error && s2.error; \
  return newS; \
}

_XVSTATEPAIR_BIN_OP_(+);
_XVSTATEPAIR_BIN_OP_(-);

#include <XVInteractive.h>

template <class IMTYPE, class STATETYPE>
class XVFeature {

 protected:

  STATETYPE currentState;
  bool  view;

 public:

  typedef STATETYPE STATE;
  typedef IMTYPE IMAGE;

  XVFeature() {}
  XVFeature(STATE init) : currentState(init) {}
  
  virtual void initState(STATE init) { currentState = init; view = true; }

  virtual STATE step(const IMTYPE &) = 0;
  
  // sets the state of this feature, then finds the next state from that
  virtual STATE step(const IMTYPE & im, const STATE & st){

    currentState = st;
    return this->step(im);    
  };

  virtual STATE getState(){ return currentState; }
  virtual void  setState(STATE & s){ currentState = s; };

  virtual bool inView(){ return view; }

  virtual STATE interactiveInit(XVInteractive &, const IMTYPE &) = 0;
  virtual void show(XVDrawable &) = 0;
};

#define _REGISTER_XVFEATURE_(_IM_TYPE_, _STATE_TYPE_) \
template class XVFeature<_IM_TYPE_, _STATE_TYPE_ >;

#endif

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