// CS 4495/7495 Computer Vision
// Jim Rehg
//
// Problem Set 3
// Dynamic Programming for Stereo Correspondence
// 
// Simple implementation of dynamic programming for matching two
// scanlines with ordering constraints. The primary differences
// between this and a "real" implementation are: (1) We match single
// pixel values rather than considering an SSD window around each
// match point, (2) We consider all possible disparity values for each
// pixel rather than a limited range.

#define SCANLEN 9
#define TBLSIZE (SCANLEN + 1)
#define OCCLUDE_COST 1

// Information about a single cell in the grid

class Cell
{
public:
	enum State // Possible states for each cell parent
	{
		Initialized = -1,
		Matched,
		Occluded,
		Disoccluded
	};

	double cost;	// cost of reaching this cell
	State parent; // parent cell

	Cell() {cost = -1.0; parent = State::Initialized;};
	~Cell() {};
	void setMin(double _cost, State _parent) {
		cost = _cost; parent = _parent;
	}
	void updateMin(double _cost, State _parent) { 
		if (_cost < cost) {cost = _cost; parent = _parent;};
	};
};


// Grid data structure

class Lattice
{
public:
	Cell tbl[TBLSIZE][TBLSIZE];

	Lattice() {};
	~Lattice() {};
	void initBoundary();
	void forwardPass(int leftscan[SCANLEN], int rightscan[SCANLEN]);
	double backChain(char pathmap[TBLSIZE][TBLSIZE]);
};