lpContour.h

#ifndef __LP_CONTOUR_H
#define __LP_CONTOUR_H
#include <cassert>
#include <iostream>
#include <bitset>
#include <vector>
#include <utility>
#include <unordered_set>
#include <unordered_map>
#include <boost/dynamic_bitset.hpp>

namespace lp
{
	/* Move along a contour: 4 possibles: top (0), right(1), bottom (2), left(3). */
	using Move = std::bitset<2>;
	/* A contour is a list of moves represented by a pair of bits*/
	using Contour = boost::dynamic_bitset<>;
 
	using ContourIndex = boost::dynamic_bitset<>::size_type;

	/* Index of a cell in the grid */
	using CellIndex = std::size_t;

	/* List of cell indices */
	using CellLists = std::unordered_set<CellIndex>;
	
	struct BoundingBox
	{
		std::size_t m_UX;
		std::size_t m_UY;
		std::size_t m_W;
		std::size_t m_H;
	};

	class ContourOperations
	{
	public:
		/* Methods to fill a contour. */
		static void Push0(Contour& contour); // Push a move to the top.
		static void Push1(Contour& contour); // Push a move to the right.
		static void Push2(Contour& contour); // Push a move to the bottom.
		static void Push3(Contour& contour); // Push a move to the left.
		
		/* Methods to access to elements of a contour. */
		static Move GetMove2(ContourIndex idx, const Contour& contour); // Retrieve a move
		static short GetMove10(const Move& m); // Transform the move into a 10 base number (0,1,2 or 3).

		/* Main methods */
		static void MergeContour(Contour& mergedContour,
								 BoundingBox& mergedBoundingBox,
								 Contour& contour1,
								 Contour& contour2,
								 BoundingBox& bbox1,
								 BoundingBox& bbox2,
								 const CellIndex cid1,
								 const CellIndex cid2,
								 const std::size_t gridSizeX);
		
		static void GenerateBorderCells(CellLists& borderCells, // From a contour, the smallest id of the cell
										const Contour& contour, // belonging to the shape and the size of the grid,
										const CellIndex startCellId, // this method returns the ids of the border cells
										const std::size_t gridSizeX); // of the shape.

		static void CreateNewContour(Contour& newContour,
									 const CellIndex startCellId,
									 const std::vector<bool>& cellMatrix,
									 const std::size_t bboxWidth,
									 const std::size_t bboxHeight);

		/* Utilities methods */