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#include "tcenterlinevectP.h"

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

//*********************************
//    Skeleton re-organization
//*********************************

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

//----------------------------------------
//    Skeleton re-organization Globals
//----------------------------------------

namespace
{
VectorizerCoreGlobals *globals;
std::vector<unsigned int> contourFamilyOfOrganized;
JointSequenceGraph *currJSGraph;
ContourFamily *currContourFamily;
};

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

//--------------------------------------
//      Skeleton re-organization
//--------------------------------------

//EXPLANATION:  The raw skeleton data obtained from StraightSkeletonizer
//class need to be grouped in joints and sequences before proceding with
//conversion in quadratics - which works on single sequences.

//NOTE: Due to maxHeight, we have to assume that a single SkeletonGraph can hold
//more connected graphs at once.

//a) Isolate graph-like part of skeleton
//b) Retrieve remaining single sequences.

typedef std::map<UINT, UINT, std::less<UINT>> uintMap;

//void organizeGraphs(SkeletonList* skeleton)
void organizeGraphs(SkeletonList *skeleton, VectorizerCoreGlobals &g)
{
	globals = &g;

	SkeletonList::iterator currGraphPtr;
	Sequence currSequence;
	uintMap jointsMap;
	UINT i, j;

	UINT counter = 0; //We also count current graph number, to associate
					  //organized graphs to their contour family

	contourFamilyOfOrganized.clear();

	for (currGraphPtr = skeleton->begin(); currGraphPtr != skeleton->end(); ++currGraphPtr) {
		SkeletonGraph &currGraph = **currGraphPtr;
		currSequence.m_graphHolder = &currGraph;

		//Separate single Points - can happen only when a single node gets stored in a SkeletonGraph.
		if (currGraph.getNodesCount() == 1) {
			globals->singlePoints.push_back(*currGraph.getNode(0));
			++counter;
			continue;
		}

		//Discriminate between graphs, two-endpoint single sequences, and circular ones
		bool has1DegreePoint = 0;
		for (i = 0; i < currGraph.getNodesCount(); ++i)
			if (currGraph.getNode(i).degree() != 2)
				if (currGraph.getNode(i).degree() == 1)
					has1DegreePoint = 1;
				else
					goto _graph;

		if (has1DegreePoint)
			goto _two_endpoint;
		else
			goto _circulars;

	_two_endpoint : {
		//Find head
		for (i = 0; currGraph.getNode(i).degree() != 1; ++i)
			;

		currSequence.m_head = i;
		currSequence.m_headLink = 0;

		//Find tail
		for (++i; i < currGraph.getNodesCount() &&
				  currGraph.getNode(i).degree() == 2;
			 ++i)
			;
		currSequence.m_tail = i;
		currSequence.m_tailLink = 0;

		globals->singleSequences.push_back(currSequence);

		++counter;
		continue;
	}

	_graph : {
		//Organize Graph-like part
		globals->organizedGraphs.push_back(JointSequenceGraph());
		JointSequenceGraph &JSGraph = globals->organizedGraphs.back();
		contourFamilyOfOrganized.push_back(counter);

		jointsMap.clear();

		//Gather all sequence extremities
		for (i = 0; i < currGraph.getNodesCount(); ++i) {
			if (currGraph.getNode(i).degree() != 2) {
				j = JSGraph.newNode(i);
				//Using a map to keep one-to-one relation between j and i
				jointsMap.insert(uintMap::value_type(i, j));
			}
		}

		//Extract Sequences
		for (i = 0; i < JSGraph.getNodesCount(); ++i) {
			UINT joint = *JSGraph.getNode(i);
			for (j = 0; j < currGraph.getNode(joint).getLinksCount(); ++j) {
				currSequence.m_head = joint;
				currSequence.m_headLink = j;

				//Seek tail
				UINT oldNode = joint, thisNode = currGraph.getNode(joint).getLink(j).getNext();
				while (currGraph.getNode(thisNode).degree() == 2) {
					currGraph.node(thisNode).setAttribute(ORGANIZEGRAPHS_SIGN); //Sign thisNode as part of a JSGraph
					currSequence.advance(oldNode, thisNode);
				}

				currSequence.m_tail = thisNode;
				currSequence.m_tailLink = currGraph.getNode(thisNode).linkOfNode(oldNode);

				JSGraph.newLink(i, jointsMap.find(thisNode)->second, currSequence);
			}
		}
	}

	//NOTE: The following may seem uncommon - you must observe that, *WHEN maxThickness<INF*,
	//      more isolated sequence groups may arise in the SAME SkeletonGraph; so, an organized
	//      graph may contain different unconnected basic graph-structures.
	//      Further, remaining circular sequences may still exist. Therefore:

	//Proceed with remaining circulars extraction

	_circulars : {
		//Extract all circular sequences
		//Find a sequence point
		for (i = 0; i < currGraph.getNodesCount(); ++i) {
			if (!currGraph.getNode(i).hasAttribute(ORGANIZEGRAPHS_SIGN) && currGraph.getNode(i).degree() == 2) {

				unsigned int curr = i, currLink = 0;
				currSequence.next(curr, currLink);

				for (; curr != i; currSequence.next(curr, currLink))
					currGraph.node(curr).setAttribute(ORGANIZEGRAPHS_SIGN);

				//Add sequence
				currSequence.m_head = currSequence.m_tail = i;
				currSequence.m_headLink = 0;
				currSequence.m_tailLink = 1;

				globals->singleSequences.push_back(currSequence);
			}
		}
	}
	}
}

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

//******************************
//       Junction Recovery
//******************************

//EXPLANATION: Junction recovery attempts to reshape skeleton junctions when
//  possible. The original polygons shape must not be exceedingly broken, and
//  no visible shape alteration must found.
//WARNING: Currently not working together with globals->currConfig->m_maxThickness<INF.

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

//------------------
//    Globals
//------------------

namespace
{
const double roadsMaxSlope = 0.3;
const double shapeDistMul = 1;
const double hDiffMul = 0.3;
const double lineDistMul = 1;
const double pullBackMul = 0.2;
}

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

//-------------------------
//    Roads Extraction
//-------------------------

//SMALL ISSUE: The following is currently done for both side
//of a sequence...

inline void findRoads(const Sequence &s)
{

	unsigned int curr, currLink, next;
	unsigned int roadStart, roadStartLink;
	double d, hMax, length;
	bool lowSlope, roadOn = 0;

	curr = s.m_head;
	currLink = s.m_headLink;
	for (; curr != s.m_tail; s.next(curr, currLink)) {
		next = s.m_graphHolder->getNode(curr).getLink(currLink).getNext();

		d = planeDistance(*s.m_graphHolder->getNode(curr), *s.m_graphHolder->getNode(next));
		lowSlope = fabs(s.m_graphHolder->getNode(curr).getLink(currLink)->getSlope()) < roadsMaxSlope ? 1 : 0;

		//Entering event in a *possibile* road axis
		if (!roadOn && lowSlope) {
			length = 0;
			hMax = s.m_graphHolder->getNode(curr)->z;
			roadStart = curr;
			roadStartLink = currLink;
		}

		//Exit event from a          """
		else if (roadOn && !lowSlope && (length > hMax))
			//Then sign ROAD the sequence from roadStart to curr.
			for (; roadStart != curr; s.next(roadStart, roadStartLink))
				s.m_graphHolder->node(roadStart).link(roadStartLink)->setAttribute(SkeletonArc::ROAD);

		//Now update vars
		if (lowSlope) {
			length += d;
			if (hMax < s.m_graphHolder->getNode(next)->z)
				hMax = s.m_graphHolder->getNode(next)->z;
		}

		roadOn = lowSlope;
	}

	//At sequence end, force an exit event
	if (roadOn && (length > hMax))
		for (; roadStart != curr; s.next(roadStart, roadStartLink))
			s.m_graphHolder->node(roadStart).link(roadStartLink)->setAttribute(SkeletonArc::ROAD);
}

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

//Find the 'roads' of the current Graph.
void findRoads(const JointSequenceGraph &JSGraph)
{
	unsigned int i, j;

	//For all Sequence of currGraph, extract roads
	for (i = 0; i < JSGraph.getNodesCount(); ++i) {
		for (j = 0; j < JSGraph.getNode(i).getLinksCount(); ++j)
			//if(JSGraph.getNode(i).getLink(j)->isForward())
			findRoads(*JSGraph.getNode(i).getLink(j));
	}
}

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

//----------------------------------
//    Junction Recovery Classes
//----------------------------------

//Entering point of a Sequence inside a Junction Area
class EnteringSequence : public Sequence
{
public:
	TPointD m_direction; //In this case, we keep
	double m_height;	 //separated (x,y) and z coords.

	//Also store indices toward the next (outer) joint
	unsigned int m_initialJoint;
	unsigned int m_outerLink;

	EnteringSequence() {}
	EnteringSequence(const Sequence &s) : Sequence(s) {}
};

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

class JunctionArea
{
public:
	std::vector<EnteringSequence> m_enteringSequences;
	std::vector<unsigned int> m_jointsAbsorbed;
	TPointD m_newJointPosition;

	JunctionArea() {}

	//Initialize Junction Area
	void expandArea(unsigned int initial);

	//Calculate and evaluate area
	bool checkShape();
	bool solveJunctionPosition();
	bool makeHeights();
	bool calculateReconstruction();

	//Substitute area over old configuration
	bool sequencesPullBack();
	void apply();
};

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

//----------------------------
//    Expansion Procedure
//----------------------------

//Junction Area expansion procedure
inline void JunctionArea::expandArea(unsigned int initial)
{
	unsigned int a;
	unsigned int curr, currLink;
	unsigned int i, iLink, iNext;

	m_jointsAbsorbed.push_back(initial);
	currJSGraph->node(initial).setAttribute(JointSequenceGraph::REACHED); //Nodes absorbed gets signed

	for (a = 0; a < m_jointsAbsorbed.size(); ++a) {
		//Extract a joint from vector
		curr = m_jointsAbsorbed[a];

		for (currLink = 0; currLink < currJSGraph->getNode(curr).getLinksCount(); ++currLink) {
			Sequence &s = *currJSGraph->node(curr).link(currLink);
			if (s.m_graphHolder->getNode(s.m_head).getLink(s.m_headLink).getAccess()) {
				//Expand into all nearby sequences, until a ROAD is found
				i = s.m_head;
				iLink = s.m_headLink;
				for (; i != s.m_tail && !s.m_graphHolder->getNode(i).getLink(iLink)->hasAttribute(SkeletonArc::ROAD);
					 s.next(i, iLink))
					;

				//If the sequence has been completely run, include next joint in the
				//expansion procedure AND sign it as 'REACHED'
				if (i == s.m_tail) {
					iNext = currJSGraph->getNode(curr).getLink(currLink).getNext();
					if (!currJSGraph->node(iNext).hasAttribute(JointSequenceGraph::REACHED)) {
						currJSGraph->node(iNext).setAttribute(JointSequenceGraph::REACHED);
						m_jointsAbsorbed.push_back(iNext);
					}
					//Negate access to this sequence
					s.m_graphHolder->node(s.m_tail).link(s.m_tailLink).setAccess(0);
					s.m_graphHolder->node(s.m_head).link(s.m_headLink).setAccess(0);
				} else {
					//Initialize and copy the entering sequence found
					m_enteringSequences.push_back(EnteringSequence(s));
					m_enteringSequences.back().m_head = i;
					m_enteringSequences.back().m_headLink = iLink;

					//Initialize entering directions
					iNext = s.m_graphHolder->getNode(i).getLink(iLink).getNext();
					m_enteringSequences.back().m_direction =
						planeProjection(*s.m_graphHolder->getNode(i) - *s.m_graphHolder->getNode(iNext));
					m_enteringSequences.back().m_direction =
						m_enteringSequences.back().m_direction * (1 / norm(m_enteringSequences.back().m_direction));

					//Initialize entering height / slope
					m_enteringSequences.back().m_height = s.m_graphHolder->getNode(i)->z;

					//Also store pointer to link toward the joint at the end of sequence
					m_enteringSequences.back().m_initialJoint = curr;
					m_enteringSequences.back().m_outerLink = currLink;
				}
			}
		}
	}
}

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

//-----------------------
//    Area Shape Test
//-----------------------

inline bool JunctionArea::checkShape()
{
	std::vector<EnteringSequence>::iterator a, b;
	unsigned int node, contour, first, last, n;
	TPointD A, A1, B, B1, P, P1;
	bool result = 1;

	//First, sign all outgoing arcs' m_leftGeneratingNode as end of
	//control procedure
	for (a = m_enteringSequences.begin(); a != m_enteringSequences.end(); ++a) {
		node = a->m_graphHolder->getNode(a->m_head).getLink(a->m_headLink)->getLeftGenerator();
		contour = a->m_graphHolder->getNode(a->m_head).getLink(a->m_headLink)->getLeftContour();

		(*currContourFamily)[contour][node].setAttribute(ContourNode::JR_RESERVED);
	}

	//Now, check shape
	for (a = m_enteringSequences.begin(), b = m_enteringSequences.end() - 1;
		 a != m_enteringSequences.end(); b = a, ++a) {
		//Initialize contour check
		first = a->m_graphHolder->getNode(a->m_head).getLink(a->m_headLink)->getRightGenerator();
		//last= b->m_graphHolder->getNode(b->m_head).getLink(b->m_headLink)
		//  ->getLeftGenerator();
		contour = a->m_graphHolder->getNode(a->m_head).getLink(a->m_headLink)->getRightContour();
		n = (*currContourFamily)[contour].size();

		//Better this effective way to find the last
		unsigned int numChecked = 0;
		for (last = first; !(*currContourFamily)[contour][last].hasAttribute(ContourNode::JR_RESERVED) && numChecked < n; last = (last + 1) % n, ++numChecked)
			;

		//Security check
		if (numChecked == n)
			return 0;

		A = planeProjection((*currContourFamily)[contour][first].m_position);
		A1 = planeProjection((*currContourFamily)[contour][(first + 1) % n].m_position);
		B = planeProjection((*currContourFamily)[contour][last].m_position);
		B1 = planeProjection((*currContourFamily)[contour][(last + 1) % n].m_position);

		for (node = first; !(*currContourFamily)[contour][node].hasAttribute(ContourNode::JR_RESERVED);
			 node = (node + 1) % n) {
			P = planeProjection((*currContourFamily)[contour][node].m_position);
			P1 = planeProjection((*currContourFamily)[contour][(node + 1) % n].m_position);

			//EXPLANATION:
			//Segment P-P1  must be included in fat lines passing for A-A1 or B-B1
			result &=
				(fabs(cross(P - A, normalize(A1 - A))) < a->m_height * shapeDistMul &&
				 fabs(cross(P1 - A, normalize(A1 - A))) < a->m_height * shapeDistMul)

				||

				(fabs(cross(P - B, normalize(B1 - B))) < b->m_height * shapeDistMul &&
				 fabs(cross(P1 - B, normalize(B1 - B))) < b->m_height * shapeDistMul);
		}
	}

	//Finally, restore nodes attributes
	for (a = m_enteringSequences.begin(); a != m_enteringSequences.end(); ++a) {
		node = a->m_graphHolder->getNode(a->m_head).getLink(a->m_headLink)->getLeftGenerator();
		contour = a->m_graphHolder->getNode(a->m_head).getLink(a->m_headLink)->getLeftContour();

		(*currContourFamily)[contour][node].clearAttribute(ContourNode::JR_RESERVED);
	}

	return result;
}

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

//--------------------------------------------
//    Solve new junction position problem
//--------------------------------------------

inline bool JunctionArea::solveJunctionPosition()
{
	std::vector<EnteringSequence>::iterator a;
	double Sx2 = 0, Sy2 = 0, Sxy = 0;
	TPointD P, v, b;
	double h;

	//Build preliminary sums for the linear system
	for (a = m_enteringSequences.begin(); a != m_enteringSequences.end(); ++a) {
		h = a->m_height;
		v = a->m_direction;
		P = planeProjection(*a->m_graphHolder->getNode(a->m_head));

		//Height-weighted problem
		Sx2 += sq(v.x) * h;
		Sy2 += sq(v.y) * h;
		Sxy += v.x * v.y * h;
		b.x += h * (sq(v.y) * P.x - (v.x * v.y * P.y));
		b.y += h * (sq(v.x) * P.y - (v.x * v.y * P.x));
	}

	//First check problem determinant
	double det = Sx2 * Sy2 - sq(Sxy);
	if (fabs(det) < 0.1)
		return 0;

	//Now construct linear system
	TAffine M(Sx2 / det, Sxy / det, 0, Sxy / det, Sy2 / det, 0);

	m_newJointPosition = M * b;

	//Finally, check if J is too far from the line extensions of the entering
	//sequences
	for (a = m_enteringSequences.begin(); a != m_enteringSequences.end(); ++a) {
		P = planeProjection(*a->m_graphHolder->getNode(a->m_head));
		if (tdistance(m_newJointPosition, a->m_direction, P) > a->m_height * lineDistMul)
			return 0;
	}

	return 1;
}

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

//---------------------------------------
//    Calculate optimal joint heights
//---------------------------------------

//Globals

namespace
{
const std::vector<EnteringSequence> *currEnterings;
const std::vector<unsigned int> *heightIndicesPtr;

std::vector<double> *optHeights;
double optMeanError;
double hMax;
}

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

inline bool checkCircles(std::vector<double> &heights)
{
	unsigned int i, j;
	double cos, sin, frac;
	TPointD vi, vj;

	//Execute test on angle-consecutive EnteringSequences couples
	for (j = 0, i = currEnterings->size() - 1; j < currEnterings->size(); i = j, ++j) {
		vi = (*currEnterings)[i].m_direction;
		vj = (*currEnterings)[j].m_direction;

		sin = cross(vi, vj);

		if (heights[i] == heights[j])
			goto test_against_max_height;

		frac = heights[i] / heights[j];
		if (sin < 0)
			return 0;
		cos = vi * vj;

		if (cos < 0 && (frac < -cos || frac > (-1 / cos)))
			return 0;

	test_against_max_height:
		//Reusing cos
		cos = (sin < 0.1) ? tmax(heights[i], heights[j]) : norm((vi * (heights[j] / sin)) + (vj * (heights[i] / sin)));
		if (cos < hMax)
			return 0;
	}

	return 1;
}

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

inline void tryConfiguration(const std::vector<unsigned int> &bounds)
{
	std::vector<double> currHeights(currEnterings->size());
	double mean, currMeanError = 0;
	unsigned int i, j, first, end;

	for (i = 0, first = 0; i <= bounds.size(); first = end, ++i) {

		end = i < bounds.size() ? end = bounds[i] + 1 : currEnterings->size();

		//Calculate mean from first (included) to end (not included)
		for (j = first, mean = 0; j < end; ++j)
			mean += (*currEnterings)[(*heightIndicesPtr)[j]].m_height;

		mean /= end - first;

		//Check if the distance from extremities to mean is tolerable
		if (tmax((*currEnterings)[(*heightIndicesPtr)[end - 1]].m_height - mean,
				 mean - (*currEnterings)[(*heightIndicesPtr)[first]].m_height) > hDiffMul * mean)
			return;

		//Calculate squared error to mean
		for (j = first; j < end; ++j)
			currMeanError +=
				sq((*currEnterings)[(*heightIndicesPtr)[j]].m_height - mean);

		//Set calculated currHeights
		for (j = first; j < end; ++j)
			currHeights[(*heightIndicesPtr)[j]] = mean;
	}

	//Update current maximum height
	hMax = mean; //Global

	//If this configuration could be better than current, launch circle test
	if (optHeights->empty() || currMeanError < optMeanError) {
		if (checkCircles(currHeights)) {
			(*optHeights) = currHeights;
			optMeanError = currMeanError;
		}
	}
}

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

class hLess
{
public:
	std::vector<EnteringSequence> &m_entSequences;

	hLess(std::vector<EnteringSequence> &v) : m_entSequences(v) {}

	inline bool operator()(unsigned int a, unsigned int b)
	{
		return m_entSequences[a].m_height < m_entSequences[b].m_height;
	}
};

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

//EXPLANATION: We build intervals on which height means are done.
//Their right Interval Bounds are supposed INCLUDED.

//Example: heights[]= {1, 2, 3, 4}; rightIntervalBounds[]={0, 2};
//  =>  do height means on: {1}, {2,3}, {4}. (*)

//After means are calculated, a test on the obtained configuration is
//performed. Among those configurations which pass the test, the one
//with rightIntervalBounds.size()->min and, on same sizes,
//currMeanError->min is the 'best' configuration possible.
//If no height configuration pass the test, reconstruction fails.

//(*) NOTE: The right Interval Bounds will never include index n-1, which
//interferes with push_backs.

inline bool JunctionArea::makeHeights()
{
	std::vector<unsigned int> heightOrderedIndices;
	std::vector<unsigned int> rightIntervalBounds;
	std::vector<double> optimalHeights;

	unsigned int i, n, m;

	//Sort entering sequences' indices for increasing height/thickness
	heightOrderedIndices.resize(m_enteringSequences.size());
	for (i = 0; i < m_enteringSequences.size(); ++i)
		heightOrderedIndices[i] = i;
	sort(heightOrderedIndices.begin(), heightOrderedIndices.end(),
		 hLess(m_enteringSequences));

	//Initialize globals/references
	currEnterings = &m_enteringSequences;
	heightIndicesPtr = &heightOrderedIndices;

	optMeanError = 0;
	optHeights = &optimalHeights;

	//Now build height-mean configurations and launch their tests
	n = m_enteringSequences.size();

	//The m=0 case is done first, apart
	rightIntervalBounds.resize(0);
	tryConfiguration(rightIntervalBounds);
	for (m = 1; m < n && optimalHeights.empty(); ++m) {
		//Initialize bounds
		rightIntervalBounds.resize(1);
		rightIntervalBounds[0] = 0;

		while (!rightIntervalBounds.empty()) {
			//Fill bounds if necessary
			while (rightIntervalBounds.size() < m)
				rightIntervalBounds.push_back(rightIntervalBounds.back() + 1);

			tryConfiguration(rightIntervalBounds);

			//'Advance' configuration: increment last index and pop those
			//exceeding valid size. If bounds gets empty, done all configs
			//with m+1 intervals.
			while ((++rightIntervalBounds.back(),
					rightIntervalBounds.back() < n - 1 - (m - rightIntervalBounds.size()) ? 0 : (rightIntervalBounds.pop_back(),
																								 !rightIntervalBounds.empty())))
				;
		}
	}

	if (!optimalHeights.empty()) {
		for (i = 0; i < n; ++i)
			m_enteringSequences[i].m_height = optimalHeights[i];
		return 1;
	}

	return 0;
}

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

//------------------------------
//    Area Calculation Main
//------------------------------

class EntSequenceLess
{
public:
	EntSequenceLess() {}

	inline bool operator()(const EnteringSequence &a, const EnteringSequence &b)
	{
		//m_direction is normalized, therefore:
		return a.m_direction.y >= 0 ? b.m_direction.y >= 0 ? a.m_direction.x > b.m_direction.x : 1 : b.m_direction.y < 0 ? a.m_direction.x < b.m_direction.x : 0;
	}
};

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

bool JunctionArea::calculateReconstruction()
{
	unsigned int i;

	if (m_enteringSequences.size() == 0)
		return 0;

	//Apply preliminary tests for this Junction Area

	// a) Check if endpoints got absorbed by the expansion process
	for (i = 0; i < m_jointsAbsorbed.size(); ++i)
		if (currJSGraph->getNode(m_jointsAbsorbed[i]).degree() == 1)
			return 0;

	// b) Check if the contours shape resembles that of a crossing

	sort(m_enteringSequences.begin(), m_enteringSequences.end(),
		 EntSequenceLess());

	if (!checkShape())
		return 0;

	// c) Build the new junction Point plane position
	if (!solveJunctionPosition())
		return 0;

	// d) Build joint optimal heights (each for entering sequence...)
	if (!makeHeights())
		return 0;

	return 1;
}

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

//---------------------------
//    Sequences Pull Back
//---------------------------

//EXPLANATION: We have to insure that connecting entering sequences to the
//new junction point happens *smoothly*. In order to do this, wh withdraw
//entering sequences along the enterin road, until the angle given by the
//connecting line and the entering direction is small.
//However, sequence pull back can be done only under some constraints:
//  * we have to remain inside a road axis
//  * ........................ a given fat line around the entering direction

inline bool JunctionArea::sequencesPullBack()
{
	std::vector<EnteringSequence>::iterator a;
	double alongLinePosition, distanceFromLine;
	unsigned int i, iLink, tail;
	TPointD P;

	for (a = m_enteringSequences.begin(); a != m_enteringSequences.end(); ++a) {
		i = a->m_head;
		iLink = a->m_headLink;
		//NOTE: updated tails are stored this way, *DONT* look in a->m_tail
		//because these typically store old infos
		tail = currJSGraph->getNode(a->m_initialJoint).getLink(a->m_outerLink)->m_tail;
		P = planeProjection(*a->m_graphHolder->getNode(a->m_head));

		while (i != tail) {
			alongLinePosition = a->m_direction * (m_newJointPosition - P);
			distanceFromLine = tdistance(m_newJointPosition, a->m_direction, P);

			if (alongLinePosition >= 0 && (distanceFromLine / alongLinePosition) <= 0.5)
				goto found_pull_back;

			//We then take the next arc and check it

			if (!a->m_graphHolder->getNode(i).getLink(iLink)->hasAttribute(SkeletonArc::ROAD))
				return 0; //Pull back failed

			a->next(i, iLink);

			P = planeProjection(*a->m_graphHolder->getNode(i));
			if (tdistance(P, a->m_direction, m_newJointPosition) >
				tmax(pullBackMul * a->m_height, 1.0))
				return 0; //Pull back failed
		}

		//Now checking opposite sequence extremity
		if (alongLinePosition < 0 || (distanceFromLine / alongLinePosition) > 0.5)
			return 0;

	found_pull_back:

		a->m_head = i;
		a->m_headLink = iLink;
	}

	return 1;
}

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

//----------------------------------------------
//    Substitute new junction configuration
//----------------------------------------------

void JunctionArea::apply()
{
	std::vector<EnteringSequence>::iterator a;
	unsigned int newJoint, newSkeletonNode;
	unsigned int head, headLink, tail, tailLink;
	unsigned int outerJoint, outerLink;
	unsigned int i, next, nextLink;

	//First, check if Entering Sequences pullback is possible
	if (!sequencesPullBack())
		return;

	//Then, we can substitute the old configuration
	//First, sign as 'ELIMINATED' all absorbed joints
	for (i = 0; i < m_jointsAbsorbed.size(); ++i)
		currJSGraph->node(m_jointsAbsorbed[i]).setAttribute(JointSequenceGraph::ELIMINATED);

	newJoint = currJSGraph->newNode();

	for (a = m_enteringSequences.begin(); a != m_enteringSequences.end(); ++a) {
		//Initialize infos
		newSkeletonNode = a->m_graphHolder
							  ->newNode(T3DPointD(m_newJointPosition, a->m_height));

		//Retrieve sequence infos to substitute
		//NOTE: We update *tail* infos in currJSGraph sequences after each "apply"

		const JointSequenceGraph::Link &tempLink =
			currJSGraph->getNode(a->m_initialJoint).getLink(a->m_outerLink);

		head = tempLink->m_head;
		headLink = tempLink->m_headLink;
		tail = tempLink->m_tail;
		tailLink = tempLink->m_tailLink;

		outerJoint = tempLink.getNext();

		//Find outerLink - from outerJoint to a->m_initialJoint
		for (i = 0; (currJSGraph->getNode(outerJoint).getLink(i)->m_tail != head) ||
					(currJSGraph->getNode(outerJoint).getLink(i)->m_tailLink != headLink);
			 ++i)
			;
		outerLink = i;

		//Now, provide skeleton linkages
		//NOTE: Discriminate between the following cases
		// a) m_head->degree == 2
		// b) m_head == m_tail
		// c) m_head == original m_head - or, (m_head!=m_tail && m_head->deg>2)

		if (a->m_graphHolder->getNode(a->m_head).degree() == 2) {
			a->m_graphHolder->newLink(newSkeletonNode, a->m_head);

			a->m_graphHolder->node(a->m_head).link(!a->m_headLink).setNext(newSkeletonNode);
			a->m_graphHolder->node(a->m_head).link(!a->m_headLink)->setAttribute(SkeletonArc::ROAD);
			//Better clear road attribute or set it?
		} else if (a->m_head == tail) {
			a->m_graphHolder->newLink(newSkeletonNode, tail);

			a->m_graphHolder->node(tail).link(tailLink).setNext(newSkeletonNode);
			a->m_graphHolder->node(tail).link(tailLink)->setAttribute(SkeletonArc::ROAD);
		} else //(a->m_head == head)
		{
			//In this case, better introduce further a new substitute of head
			unsigned int newHead = a->m_graphHolder
									   ->newNode(T3DPointD(*a->m_graphHolder->getNode(a->m_head)));

			a->m_graphHolder->newLink(newSkeletonNode, newHead);
			a->m_graphHolder->newLink(newHead, newSkeletonNode);

			//Link newHead on the other side
			next = a->m_graphHolder
					   ->getNode(head)
					   .getLink(headLink)
					   .getNext();
			nextLink = a->m_graphHolder->getNode(next).linkOfNode(head);

			a->m_graphHolder->newLink(newHead, next);
			a->m_graphHolder->node(next).link(nextLink).setNext(newHead);
		}

		//Finally, update joint linkings and sequence tails.
		Sequence newSequence;

		newSequence.m_graphHolder = a->m_graphHolder;
		newSequence.m_head = newSkeletonNode;
		newSequence.m_headLink = 0;
		newSequence.m_tail = tail;
		newSequence.m_tailLink = tailLink;

		currJSGraph->node(outerJoint).link(outerLink).setNext(newJoint);
		currJSGraph->node(outerJoint).link(outerLink)->m_tail = newSkeletonNode;
		currJSGraph->node(outerJoint).link(outerLink)->m_tailLink = 0;

		currJSGraph->newLink(newJoint, outerJoint, newSequence);
	}
}

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

//-------------------------------
//    Junction Recovery Main
//-------------------------------

//EXPLANATION: Junction Recovery attempts reconstruction of badly-behaved
//crossings in the raw skeleton of the image.

//void inline junctionRecovery(Contours* polygons)
void junctionRecovery(Contours *polygons, VectorizerCoreGlobals &g)
{
	globals = &g;

	unsigned int i, j;
	std::vector<JunctionArea> junctionAreasList;

	//For all joints not processed by the Recoverer, launch a new junction
	//area reconstruction
	for (i = 0; i < globals->organizedGraphs.size(); ++i) {
		currJSGraph = &globals->organizedGraphs[i];
		currContourFamily = &(*polygons)[contourFamilyOfOrganized[i]];
		junctionAreasList.clear();

		//First, graph roads are found and signed on the skeleton
		findRoads(*currJSGraph);

		//Then, junction areas are identified and reconstructions are calculated
		for (j = 0; j < currJSGraph->getNodesCount(); ++j)
			if (!currJSGraph->getNode(j).hasAttribute(JointSequenceGraph::REACHED)) {
				junctionAreasList.push_back(JunctionArea());
				junctionAreasList.back().expandArea(j);
				if (!junctionAreasList.back().calculateReconstruction())
					junctionAreasList.pop_back();
			}

		//Finally, reconstructions are substituted inside the skeleton
		for (j = 0; j < junctionAreasList.size(); ++j)
			junctionAreasList[j].apply();
	}
}