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retina.h

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#ifndef __RETINA_H__
#define __RETINA_H__

#include <assert.h>
#include <algorithm>

#include "genericalgs.h"
#include "robj.h"
#include "neuralregion.h"
#include "matrix.h"
#include "allocatingpointer.h"



/******************************************************************************/
/* General-purpose utility functions                                          */
/******************************************************************************/

template <class Matrix>
void draw(Matrix& area, const Retinal_Obj* obj,
          const typename Matrix::value_type xoff=0.5,
          const typename Matrix::value_type yoff=0.5,
          const typename Matrix::value_type size_scale=1.0)
{
  if (!obj) return;
  
  typedef typename Matrix::value_type T;
  typedef typename Matrix::size_type  Subscript;

  obj->update();
  const T s=1/size_scale;
  const T xo=xoff*s;
  const T yo=yoff*s;
  for (Subscript r=0; r<area.nrows(); r++) {
    const T y   = (area.nrows()-r-1)*s+yo; 
    for (Subscript c=0; c<area.ncols(); c++) {
      const T x   = c*s+xo;
      const T act = (obj? obj->activation(x,y) : 0);
      area[r][c]=act;
    }
  }
  //cout << gnuplot(area, "Area after draw") << endl;
}



/******************************************************************************/
/* Retina classes                                                             */
/******************************************************************************/


class Retina : public NeuralRegion {
public:
  Retina(string name_i, Dimensions dims,
         ActivationFunction* actfn_=0,
         Activity size_scale_=1.0)
    : NeuralRegion(name_i, dims), world_model(0), actfn(actfn_),
      xo(dims.xoffset), yo(dims.yoffset), size_scale(size_scale_) { }
  
  virtual ~Retina() { };

  virtual void activate(bool=false,bool=false,bool=false) {
    draw(output, world_model, xo, yo, size_scale);
    if (actfn) (*actfn)(output,output);
  }

  void set_input(const Retinal_Obj* const obj) {  world_model=obj;  };

  virtual bool is_plastic() const  {  return false;  }
  
  double size_connection_bytes()   const {  return 0;  }
  double size_unique_connections() const {  return 0;  }

  /* virtual void backproject() { } */

protected:
  const Retinal_Obj* world_model;
  const OwningPointer<ActivationFunction> actfn;
  const Activity xo,yo; 
  const Activity size_scale;
};


#endif

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