#ifndef RASTER_EDGE_ITERATOR_H
#define RASTER_EDGE_ITERATOR_H

#include "traster.h"

namespace TRop
{
namespace borders
{

//*********************************************************************************************************
//    RasterEdgeIterator class
//*********************************************************************************************************

/*!
  The RasterEdgeIterator class models a forward iterator traversing a border of a
  raster image.
*/
template <typename PixelSelector>
class RasterEdgeIterator
{
public:
	typedef PixelSelector selector_type;
	typedef typename PixelSelector::pixel_type pixel_type;
	typedef typename PixelSelector::value_type value_type;
	typedef TRasterT<pixel_type> raster_type;
	typedef TRasterPT<pixel_type> raster_typeP;

	enum { STRAIGHT = 0x0,
		   LEFT = 0x1,
		   RIGHT = 0x2,
		   AMBIGUOUS = 0x4,
		   AMBIGUOUS_LEFT = LEFT | AMBIGUOUS,
		   AMBIGUOUS_RIGHT = RIGHT | AMBIGUOUS,
		   UNKNOWN = 0x8 };

private:
	raster_typeP m_ras;
	selector_type m_selector;

	int m_lx_1, m_ly_1, m_wrap;

	value_type m_leftColor, m_rightColor, m_elbowColor;
	pixel_type *m_leftPix, *m_rightPix;

	bool m_rightSide;
	int m_turn;

	TPoint m_pos, m_dir;

public:
	RasterEdgeIterator(const raster_typeP &rin, const selector_type &selector,
					   const TPoint &pos, const TPoint &dir, int adherence = RIGHT);

	void setEdge(const TPoint &pos, const TPoint &dir);

	const raster_typeP &raster() const { return m_ras; }
	const selector_type &selector() const { return m_selector; }

	const TPoint &pos() const { return m_pos; }
	const TPoint &dir() const { return m_dir; }

	const value_type &leftColor() const { return m_leftColor; }
	const value_type &rightColor() const { return m_rightColor; }

	const value_type &color() const { return m_rightSide ? m_rightColor : m_leftColor; }
	const value_type &otherColor() const { return m_rightSide ? m_leftColor : m_rightColor; }
	const value_type &elbowColor() const { return m_elbowColor; }

	pixel_type *leftPix() const { return m_leftPix; }
	pixel_type *rightPix() const { return m_rightPix; }

	pixel_type *pix() const { return m_rightSide ? m_rightPix : m_leftPix; }
	pixel_type *otherPix() const { return m_rightSide ? m_leftPix : m_rightPix; }

	int turn() const { return m_turn; }

	void setAdherence(int side) { m_rightSide = (side == RIGHT); }
	int adherence() const { return m_rightSide ? RIGHT : LEFT; }

	RasterEdgeIterator &operator++();

	bool operator==(const RasterEdgeIterator &it) const { return m_pos == it.m_pos && m_dir == it.m_dir; }
	bool operator!=(const RasterEdgeIterator &it) const { return !operator==(it); }

private:
	void pixels(pixel_type *&pixLeft, pixel_type *&pixRight);
	void colors(value_type &leftColor, value_type &rightColor);
	void turn(const value_type &newLeftColor, const value_type &newRightColor);
	void turnLeft()
	{
		int temp = m_dir.x;
		m_dir.x = -m_dir.y;
		m_dir.y = temp;
		m_turn = LEFT;
	}
	void turnRight()
	{
		int temp = m_dir.x;
		m_dir.x = m_dir.y;
		m_dir.y = -temp;
		m_turn = RIGHT;
	}
	void turnAmbiguous(const value_type &newLeftColor, const value_type &newRightColor);
};
}
} // namespace TRop::borders

#endif //RASTER_EDGE_ITERATOR_H

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

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