#ifndef BORDERS_EXTRACTOR_H
#define BORDERS_EXTRACTOR_H

#include "traster.h"
#include "runsmap.h"

#include "raster_edge_iterator.h"

namespace TRop
{
namespace borders
{

//*******************************************************************
//    Pixel Selector model
//*******************************************************************

/*!
  This class is just a stub for pixel selector classes.

  Pixel Selectors are objects used in raster borders recognition
  to interpret a raster's pixels and direct edge iterators.
\n\n
  The main purpose of this class is that of distinguishing pixels
  from their <I> values <\I>. Values are the actual entities recognized
  in the borders extraction process - adjacent pixels that are cast to
  the same value will be included in the same border.
\n\n
  For example, if we want to extract the borders of a fullcolor image
  that separate bright areas from dark ones, we can just have a pixel selector
  cast each pixel to the integer value 0 if the pixel's value is below the
  brigthness threshold, and 1 if above.
\n\n
  Also, pixel selectors tell whether pixels are to be intended as
  completely transparent (virtual pixels outside the raster boundaries are).
*/
template <typename Pix, typename Val>
class pixel_selector
{
public:
	typedef Pix pixel_type; //!< The pixel type naming the selector
	typedef Val value_type; //!< A value type representing pixel contents.
							//!< Typically the pixel itself.

public:
	value_type value(const pixel_type &pix) const;
	bool equal(const pixel_type &a, const pixel_type &b) const
	{
		return value(a) == value(b);
	}

	value_type transparent() const;
	bool transparent(const pixel_type &pix) const
	{
		return value(pix) == transparent();
	}

	//! Returns whether a border point must be read or not (corners are always read).
	bool skip(const value_type &prevLeftValue, const value_type &leftValue) const { return true; }
};

//----------------------------------------------------------------------------------

enum RunType { _BORDER_LEFT = 0x20,
			   _BORDER_RIGHT = 0x10,
			   _HIERARCHY_INCREASE = 0x8,
			   _HIERARCHY_DECREASE = 0x4 };

//----------------------------------------------------------------------------------

/*!
  Reads the borders of the input raster, according to the specified selector.
  Outputs the borders by supplying a container reader with the raster edge iterators
  corresponding to border vertices. The runsmap used in the process can be
  returned in output.
*/
template <typename Pixel, typename PixelSelector, typename ContainerReader>
void readBorders(const TRasterPT<Pixel> &raster, const PixelSelector &selector,
				 ContainerReader &reader, RunsMapP *rasterRunsMap = 0);

//=====================================================================================

template <typename PixelSelector, typename Mesh, typename ContainersReader>
void readMeshes(const TRasterPT<typename PixelSelector::pixel_type> &raster, const PixelSelector &selector,
				ContainersReader &meshesDataReader, RunsMapP *rasterRunsMap = 0);
}
} //namespace TRop::borders

#endif //BORDERS_EXTRACTOR_H

//=====================================================================================

#ifdef INCLUDE_HPP
#include "borders_extractor.hpp"
#endif //INCLUDE_HPP