#ifndef iScissor_H
#define iScissor_H

#include "imgflt.h"

const int INITIAL = 0;
const int ACTIVE = 1;
const int EXPANDED = 2;

// added by dewey
const double SQRT2 = 1.4142135623730950488016887242097;
const double SQINV = 1.0/SQRT2;

// The eight filter kernels

const double kernels[8][9] = {
	{ // 0
		0.0000, 0.0000, 0.0000 ,
		0.0000, 0.0000, 0.0000 ,
		0.0000, 0.0000, 0.0000 
	},
	{ // 1
		0.0000, 0.0000, 0.0000 ,
		0.0000, 0.0000, 0.0000 ,
		0.0000, 0.0000, 0.0000 
	},
	{ // 2
		0.0000, 0.0000, 0.0000 ,
		0.0000, 0.0000, 0.0000 ,
		0.0000, 0.0000, 0.0000 
	},
	{ // 3
		0.0000, 0.0000, 0.0000 ,
		0.0000, 0.0000, 0.0000 ,
		0.0000, 0.0000, 0.0000 
	},
	{ // 4
		0.0000, 0.0000, 0.0000 ,
		0.0000, 0.0000, 0.0000 ,
		0.0000, 0.0000, 0.0000 
	},
	{ // 5
		0.0000, 0.0000, 0.0000 ,
		0.0000, 0.0000, 0.0000 ,
		0.0000, 0.0000, 0.0000 
	},
	{ // 6
		0.0000, 0.0000, 0.0000 ,
		0.0000, 0.0000, 0.0000 ,
		0.0000, 0.0000, 0.0000 
	},
	{ // 7
		0.0000, 0.0000, 0.0000 ,
		0.0000, 0.0000, 0.0000 ,
		0.0000, 0.0000, 0.0000 
	}

};

// end added by dewey

struct Node 
{
	//column and row:	remember the position of the node in original image so that its neighboring nodes can be located. 
	//linkCost:			contains the costs of each link, as described in project page and in the SIGGRAPH95 paper.
	//state:			used to tag the node as being INITIAL, ACTIVE, or EXPANDED during the min-cost tree computation.
	//totalCost:		the minimum total cost from this node to the seed node. 
	//prevNode:			points to its predecessor along the minimum cost path from the seed to that node.

	int column, row;
	double linkCost[8];
	int state;
	double totalCost;
	Node *prevNode;

	Node () {prevNode=NULL;}
	// this function helps to locate neighboring node in node buffer. 
	void nbrNodeOffset(int &offsetX, int &offsetY, int linkIndex)
	{
		/*
		 *  321
		 *  4 0
		 *  567
		 */

		if (linkIndex==0)
		{
			offsetX = 1;
			offsetY = 0;
		}
		else if (linkIndex==1)
		{
			offsetX = 1;
			offsetY = -1;
		}
		else if (linkIndex==2)
		{
			offsetX = 0;
			offsetY = -1;
		}
		else if (linkIndex==3)
		{
			offsetX = -1;
			offsetY = -1;
		}
		else if (linkIndex==4)
		{
			offsetX = -1;
			offsetY = 0;
		}
		else if (linkIndex==5)
		{
			offsetX = -1;
			offsetY = 1;
		}
		else if (linkIndex==6)
		{
			offsetX = 0;
			offsetY = 1;
		}
		else if (linkIndex==7)
		{
			offsetX = 1;
			offsetY = 1;
		}
	}

	// used by the binary heap operation, 
	// pqIndex is the index of this node in the heap.
	// you don't need to know about it to finish the assignment;

	int pqIndex;

	int &Index(void)
	{ return pqIndex; }

	int Index(void) const 
	{ return pqIndex; }
};

inline bool operator < (const Node &a, const Node &b)
{
	return a.totalCost<b.totalCost;
}





void InitNodeBuf(Node *nodes, const unsigned char *img, int width, int height);
// added by dewey
double CrossCorrelate(const double filterKernel[3][3], const unsigned char* img, int imgWidth, int imgHeight, int x, int y, int c);
// end added by dewey
void LiveWireDP(int seedX, int seedY, Node *nodes, int width, int height, const unsigned char *selection, int expanded);

void MinimumPath(CTypedPtrDblList <Node> *path, int freePtX, int freePtY, Node *nodes, int width, int height);

void SeedSnap(int &x, int &y, unsigned char *img, int width, int height);






inline void DigitizeCost(unsigned char *cst, double lCost)
{ cst[0] = cst[1] = cst[2] = (unsigned char)(floor(__max(0.0,__min(255.0,lCost)))); }

void MakeCostGraph(unsigned char *costGraph, const Node *nodes, const unsigned char *img, int width, int height);

//students don't need this data structure in assignment for the required work. 
struct Seed
{
	int x,y;
	int seed; //seed = 1, if it is a seed, otherwise, it is a ordinary contour location;

	Seed(int i, int j)
	{ x=i; y = j; }
	Seed(int i, int j, int s)
	{ x=i; y = j; seed = s; } 
	Seed(void)
	{}
};

#endif