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authormarha <marha@users.sourceforge.net>2009-10-08 13:15:52 +0000
committermarha <marha@users.sourceforge.net>2009-10-08 13:15:52 +0000
commita0c4815433ccd57322f4f7703ca35e9ccfa59250 (patch)
treef5213802ec12adb86ec3136001c1c29fe5343700 /mesalib/src/glu/sgi/libnurbs/nurbtess/monoChain.cc
parentc73dc01b6de45612b24dc2dd34fba24d81ebf46c (diff)
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Added MesaLib-7.6
Diffstat (limited to 'mesalib/src/glu/sgi/libnurbs/nurbtess/monoChain.cc')
-rw-r--r--mesalib/src/glu/sgi/libnurbs/nurbtess/monoChain.cc934
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diff --git a/mesalib/src/glu/sgi/libnurbs/nurbtess/monoChain.cc b/mesalib/src/glu/sgi/libnurbs/nurbtess/monoChain.cc
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+++ b/mesalib/src/glu/sgi/libnurbs/nurbtess/monoChain.cc
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+/*
+** License Applicability. Except to the extent portions of this file are
+** made subject to an alternative license as permitted in the SGI Free
+** Software License B, Version 1.1 (the "License"), the contents of this
+** file are subject only to the provisions of the License. You may not use
+** this file except in compliance with the License. You may obtain a copy
+** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
+** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
+**
+** http://oss.sgi.com/projects/FreeB
+**
+** Note that, as provided in the License, the Software is distributed on an
+** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
+** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
+** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
+** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
+**
+** Original Code. The Original Code is: OpenGL Sample Implementation,
+** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
+** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
+** Copyright in any portions created by third parties is as indicated
+** elsewhere herein. All Rights Reserved.
+**
+** Additional Notice Provisions: The application programming interfaces
+** established by SGI in conjunction with the Original Code are The
+** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
+** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
+** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
+** Window System(R) (Version 1.3), released October 19, 1998. This software
+** was created using the OpenGL(R) version 1.2.1 Sample Implementation
+** published by SGI, but has not been independently verified as being
+** compliant with the OpenGL(R) version 1.2.1 Specification.
+**
+*/
+/*
+*/
+
+#include "gluos.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <GL/gl.h>
+
+#include "glimports.h"
+#include "zlassert.h"
+
+#include "monoChain.h"
+#include "quicksort.h"
+#include "searchTree.h"
+#include "polyUtil.h"
+
+#ifndef max
+#define max(a,b) ((a>b)? a:b)
+#endif
+#ifndef min
+#define min(a,b) ((a>b)? b:a)
+#endif
+
+extern Int isCusp(directedLine *v);
+extern Int deleteRepeatDiagonals(Int num_diagonals, directedLine** diagonal_vertices, directedLine** new_vertices);
+
+//for debug purpose only
+#if 0 // UNUSED
+static void drawDiagonals(Int num_diagonals, directedLine** diagonal_vertices)
+{
+ Int i;
+ for(i=0; i<num_diagonals; i++)
+ {
+ glBegin(GL_LINE);
+ glVertex2fv(diagonal_vertices[2*i]->head());
+ glVertex2fv(diagonal_vertices[2*i+1]->head());
+ glEnd();
+ }
+}
+#endif
+
+/*given (x_1, y_1) and (x_2, y_2), and y
+ *return x such that (x,y) is on the line
+ */
+inline Real intersectHoriz(Real x1, Real y1, Real x2, Real y2, Real y)
+{
+ return ((y2==y1)? (x1+x2)*0.5 : x1 + ((y-y1)/(y2-y1)) * (x2-x1));
+}
+
+//compare the heads of the two chains
+static int compChainHeadInY(monoChain* mc1, monoChain* mc2)
+{
+ return compV2InY(mc1->getHead()->head(), mc2->getHead()->head());
+}
+
+monoChain::monoChain(directedLine* cHead, directedLine* cTail)
+{
+ chainHead = cHead;
+ chainTail = cTail;
+ next = this;
+ prev = this;
+
+ nextPolygon = NULL;
+
+ //compute bounding box
+ directedLine* temp;
+ minX = maxX = chainTail->head()[0];
+ minY = maxY = chainTail->head()[1];
+
+ for(temp=chainHead; temp!=cTail; temp = temp->getNext())
+ {
+ if(temp->head()[0] < minX)
+ minX = temp->head()[0];
+ if(temp->head()[0] > maxX)
+ maxX = temp->head()[0];
+
+ if(temp->head()[1] < minY)
+ minY = temp->head()[1];
+ if(temp->head()[1] > maxY)
+ maxY = temp->head()[1];
+ }
+
+ //check whether the chain is increasing or decreasing
+ if(chainHead->compInY(chainTail) <0)
+ isIncrease = 1;
+ else
+ isIncrease = 0;
+
+ //initilize currrent, this is used for accelerating search
+ if(isIncrease)
+ current = chainHead;
+ else
+ current = chainTail;
+
+ isKey = 0;
+}
+
+//insert a new line between prev and this
+void monoChain::insert(monoChain* nc)
+{
+ nc->next = this;
+ nc->prev = prev;
+ prev->next = nc;
+ prev = nc;
+}
+
+void monoChain::deleteLoop()
+{
+ monoChain *temp, *tempNext;
+ prev->next = NULL;
+ for(temp=this; temp != NULL; temp = tempNext)
+ {
+ tempNext = temp->next;
+ delete temp;
+ }
+}
+
+void monoChain::deleteLoopList()
+{
+ monoChain *temp, *tempNext;
+ for(temp=this; temp != NULL; temp = tempNext)
+ {
+ tempNext = temp->nextPolygon;
+ temp->deleteLoop();
+ }
+}
+
+Int monoChain::toArraySingleLoop(monoChain** array, Int index)
+{
+ monoChain *temp;
+ array[index++] = this;
+ for(temp = next; temp != this; temp = temp->next)
+ {
+ array[index++] = temp;
+ }
+ return index;
+}
+
+monoChain** monoChain::toArrayAllLoops(Int& num_chains)
+{
+ num_chains = numChainsAllLoops();
+ monoChain **ret = (monoChain**) malloc(sizeof(monoChain*) * num_chains);
+ assert(ret);
+ monoChain *temp;
+ Int index = 0;
+ for(temp = this; temp != NULL; temp=temp->nextPolygon){
+ index = temp->toArraySingleLoop(ret, index);
+ }
+ return ret;
+}
+
+Int monoChain::numChainsSingleLoop()
+{
+ Int ret=0;
+ monoChain* temp;
+ if(next == this) return 1;
+ ret = 1;
+ for(temp=next; temp != this; temp = temp->next)
+ ret++;
+ return ret;
+}
+
+Int monoChain::numChainsAllLoops()
+{
+ Int ret=0;
+ monoChain *temp;
+ for(temp =this; temp != NULL; temp = temp->nextPolygon)
+ ret += temp->numChainsSingleLoop();
+ return ret;
+}
+
+//update 'current'
+Real monoChain::chainIntersectHoriz(Real y)
+{
+ directedLine* temp;
+ if(isIncrease)
+ {
+ for(temp= current; temp != chainTail; temp = temp->getNext())
+ {
+ if(temp->head()[1] > y)
+ break;
+ }
+ current = temp->getPrev();
+ }
+ else
+ {
+ for(temp = current; temp != chainHead; temp = temp->getPrev())
+ {
+ if(temp->head()[1] > y)
+ break;
+ }
+ current = temp->getNext();
+ }
+ return intersectHoriz(current->head()[0], current->head()[1], current->tail()[0], current->tail()[1], y);
+}
+
+monoChain* directedLineLoopToMonoChainLoop(directedLine* loop)
+{
+ directedLine *temp;
+ monoChain *ret=NULL;
+
+ //find the first cusp
+ directedLine *prevCusp=NULL;
+ directedLine *firstCusp;
+
+ if(isCusp(loop))
+ prevCusp = loop;
+ else
+ {
+ for(temp = loop->getNext(); temp != loop; temp = temp->getNext())
+ if(isCusp(temp))
+ break;
+ prevCusp = temp;
+ }
+ firstCusp = prevCusp;
+//printf("first cusp is (%f,%f), (%f,%f), (%f,%f)\n", prevCusp->getPrev()->head()[0], prevCusp->getPrev()->head()[1], prevCusp->head()[0], prevCusp->head()[1], prevCusp->tail()[0], prevCusp->tail()[1]);
+
+ for(temp = prevCusp->getNext(); temp != loop; temp = temp->getNext())
+ {
+ if(isCusp(temp))
+ {
+//printf("the cusp is (%f,%f), (%f,%f), (%f,%f)\n", temp->getPrev()->head()[0], temp->getPrev()->head()[1], temp->head()[0], temp->head()[1], temp->tail()[0], temp->tail()[1]);
+ if(ret == NULL)
+ {
+ ret = new monoChain(prevCusp, temp);
+ }
+ else
+ ret->insert(new monoChain(prevCusp, temp));
+ prevCusp = temp;
+ }
+ }
+ ret->insert(new monoChain(prevCusp, firstCusp));
+
+ return ret;
+}
+
+monoChain* directedLineLoopListToMonoChainLoopList(directedLine* list)
+{
+ directedLine* temp;
+ monoChain* mc;
+ monoChain* mcEnd;
+ mc = directedLineLoopToMonoChainLoop(list);
+ mcEnd = mc;
+ for(temp = list->getNextPolygon(); temp != NULL; temp = temp->getNextPolygon())
+ {
+ monoChain *newLoop = directedLineLoopToMonoChainLoop(temp);
+ mcEnd->setNextPolygon(newLoop);
+ mcEnd = newLoop;
+ }
+ return mc;
+}
+
+/*compare two edges of a polygon.
+ *edge A < edge B if there is a horizontal line so that the intersection
+ *with A is to the left of the intersection with B.
+ *This function is used in sweepY for the dynamic search tree insertion to
+ *order the edges.
+ * Implementation: (x_1,y_1) and (x_2, y_2)
+ */
+static Int compEdges(directedLine *e1, directedLine *e2)
+{
+ Real* head1 = e1->head();
+ Real* tail1 = e1->tail();
+ Real* head2 = e2->head();
+ Real* tail2 = e2->tail();
+/*
+ Real h10 = head1[0];
+ Real h11 = head1[1];
+ Real t10 = tail1[0];
+ Real t11 = tail1[1];
+ Real h20 = head2[0];
+ Real h21 = head2[1];
+ Real t20 = tail2[0];
+ Real t21 = tail2[1];
+*/
+ Real e1_Ymax, e1_Ymin, e2_Ymax, e2_Ymin;
+/*
+ if(h11>t11) {
+ e1_Ymax= h11;
+ e1_Ymin= t11;
+ }
+ else{
+ e1_Ymax = t11;
+ e1_Ymin = h11;
+ }
+
+ if(h21>t21) {
+ e2_Ymax= h21;
+ e2_Ymin= t21;
+ }
+ else{
+ e2_Ymax = t21;
+ e2_Ymin = h21;
+ }
+*/
+
+ if(head1[1]>tail1[1]) {
+ e1_Ymax= head1[1];
+ e1_Ymin= tail1[1];
+ }
+ else{
+ e1_Ymax = tail1[1];
+ e1_Ymin = head1[1];
+ }
+
+ if(head2[1]>tail2[1]) {
+ e2_Ymax= head2[1];
+ e2_Ymin= tail2[1];
+ }
+ else{
+ e2_Ymax = tail2[1];
+ e2_Ymin = head2[1];
+ }
+
+
+ /*Real e1_Ymax = max(head1[1], tail1[1]);*/ /*max(e1->head()[1], e1->tail()[1]);*/
+ /*Real e1_Ymin = min(head1[1], tail1[1]);*/ /*min(e1->head()[1], e1->tail()[1]);*/
+ /*Real e2_Ymax = max(head2[1], tail2[1]);*/ /*max(e2->head()[1], e2->tail()[1]);*/
+ /*Real e2_Ymin = min(head2[1], tail2[1]);*/ /*min(e2->head()[1], e2->tail()[1]);*/
+
+ Real Ymax = min(e1_Ymax, e2_Ymax);
+ Real Ymin = max(e1_Ymin, e2_Ymin);
+
+ Real y = 0.5*(Ymax + Ymin);
+
+/* Real x1 = intersectHoriz(e1->head()[0], e1->head()[1], e1->tail()[0], e1->tail()[1], y);
+ Real x2 = intersectHoriz(e2->head()[0], e2->head()[1], e2->tail()[0], e2->tail()[1], y);
+*/
+/*
+ Real x1 = intersectHoriz(h10, h11, t10, t11, y);
+ Real x2 = intersectHoriz(h20, h21, t20, t21, y);
+*/
+ Real x1 = intersectHoriz(head1[0], head1[1], tail1[0], tail1[1], y);
+ Real x2 = intersectHoriz(head2[0], head2[1], tail2[0], tail2[1], y);
+
+ if(x1<= x2) return -1;
+ else return 1;
+}
+
+Int compChains(monoChain* mc1, monoChain* mc2)
+{
+ Real y;
+ assert(mc1->isKey || mc2->isKey);
+ if(mc1->isKey)
+ y = mc1->keyY;
+ else
+ y = mc2->keyY;
+ directedLine *d1 = mc1->find(y);
+ directedLine *d2 = mc2->find(y);
+ mc2->find(y);
+// Real x1 = mc1->chainIntersectHoriz(y);
+// Real x2 = mc2->chainIntersectHoriz(y);
+ return compEdges(d1, d2);
+}
+
+//this function modifies current for efficiency
+directedLine* monoChain::find(Real y)
+{
+ directedLine *ret;
+ directedLine *temp;
+ assert(current->head()[1] <= y);
+ if(isIncrease)
+ {
+ assert(chainTail->head()[1] >=y);
+ for(temp=current; temp!=chainTail; temp = temp->getNext())
+ {
+ if(temp->head()[1] > y)
+ break;
+ }
+ current = temp->getPrev();
+ ret = current;
+ }
+ else
+ {
+ for(temp=current; temp != chainHead; temp = temp->getPrev())
+ {
+ if(temp->head()[1] > y)
+ break;
+ }
+ current = temp->getNext();
+ ret = temp;
+ }
+ return ret;
+}
+
+void monoChain::printOneChain()
+{
+ directedLine* temp;
+ for(temp = chainHead; temp != chainTail; temp = temp->getNext())
+ {
+ printf("(%f,%f) ", temp->head()[0], temp->head()[1]);
+ }
+ printf("(%f,%f) \n", chainTail->head()[0], chainTail->head()[1]);
+}
+
+void monoChain::printChainLoop()
+{
+ monoChain* temp;
+ this->printOneChain();
+ for(temp = next; temp != this; temp = temp->next)
+ {
+ temp->printOneChain();
+ }
+ printf("\n");
+}
+
+void monoChain::printAllLoops()
+{
+ monoChain* temp;
+ for(temp=this; temp != NULL; temp = temp->nextPolygon)
+ temp->printChainLoop();
+}
+
+//return 1 if error occures
+Int MC_sweepY(Int nVertices, monoChain** sortedVertices, sweepRange** ret_ranges)
+{
+ Int i;
+ Real keyY;
+ Int errOccur=0;
+//printf("enter MC_sweepY\n");
+//printf("nVertices=%i\n", nVertices);
+ /*for each vertex in the sorted list, update the binary search tree.
+ *and store the range information for each vertex.
+ */
+ treeNode* searchTree = NULL;
+//printf("nVertices=%i\n", nVertices);
+ for(i=0; i<nVertices; i++)
+ {
+ monoChain* vert = sortedVertices[i];
+ keyY = vert->getHead()->head()[1]; //the sweep line
+ directedLine *dline = vert->getHead();
+ directedLine *dlinePrev = dline->getPrev();
+ if(isBelow(dline, dline) && isBelow(dline, dlinePrev))
+ {
+//printf("case 1\n");
+ //this<v and prev < v
+ //delete both edges
+ vert->isKey = 1;
+ vert->keyY = keyY;
+ treeNode* thisNode = TreeNodeFind(searchTree, vert, (Int (*) (void *, void *))compChains);
+ vert->isKey = 0;
+
+ vert->getPrev()->isKey = 1;
+ vert->getPrev()->keyY = keyY;
+ treeNode* prevNode = TreeNodeFind(searchTree, vert->getPrev(), (Int (*) (void *, void *))compChains);
+ vert->getPrev()->isKey = 0;
+
+ if(cuspType(dline) == 1)//interior cusp
+ {
+
+ treeNode* leftEdge = TreeNodePredecessor(prevNode);
+ treeNode* rightEdge = TreeNodeSuccessor(thisNode);
+ if(leftEdge == NULL || rightEdge == NULL)
+ {
+ errOccur = 1;
+ goto JUMP_HERE;
+ }
+
+ directedLine* leftEdgeDline = ((monoChain* ) leftEdge->key)->find(keyY);
+
+
+
+ directedLine* rightEdgeDline = ((monoChain* ) rightEdge->key)->find(keyY);
+
+ ret_ranges[i] = sweepRangeMake(leftEdgeDline, 1, rightEdgeDline, 1);
+ }
+ else /*exterior cusp*/
+ {
+ ret_ranges[i] = sweepRangeMake( dline, 1, dlinePrev, 1);
+ }
+
+ searchTree = TreeNodeDeleteSingleNode(searchTree, thisNode);
+ searchTree = TreeNodeDeleteSingleNode(searchTree, prevNode);
+
+ }
+ else if(isAbove(dline, dline) && isAbove(dline, dlinePrev))
+ {
+//printf("case 2\n");
+ //insert both edges
+ treeNode* thisNode = TreeNodeMake(vert);
+ treeNode* prevNode = TreeNodeMake(vert->getPrev());
+
+ vert->isKey = 1;
+ vert->keyY = keyY;
+ searchTree = TreeNodeInsert(searchTree, thisNode, (Int (*) (void *, void *))compChains);
+ vert->isKey = 0;
+
+ vert->getPrev()->isKey = 1;
+ vert->getPrev()->keyY = keyY;
+ searchTree = TreeNodeInsert(searchTree, prevNode, (Int (*) (void *, void *))compChains);
+ vert->getPrev()->isKey = 0;
+
+ if(cuspType(dline) == 1) //interior cusp
+ {
+//printf("cuspType is 1\n");
+ treeNode* leftEdge = TreeNodePredecessor(thisNode);
+ treeNode* rightEdge = TreeNodeSuccessor(prevNode);
+ if(leftEdge == NULL || rightEdge == NULL)
+ {
+ errOccur = 1;
+ goto JUMP_HERE;
+ }
+//printf("leftEdge is %i, rightEdge is %i\n", leftEdge, rightEdge);
+ directedLine* leftEdgeDline = ((monoChain*) leftEdge->key)->find(keyY);
+ directedLine* rightEdgeDline = ((monoChain*) rightEdge->key)->find(keyY);
+ ret_ranges[i] = sweepRangeMake( leftEdgeDline, 1, rightEdgeDline, 1);
+ }
+ else //exterior cusp
+ {
+//printf("cuspType is not 1\n");
+ ret_ranges[i] = sweepRangeMake(dlinePrev, 1, dline, 1);
+ }
+ }
+ else
+ {
+//printf("%i,%i\n", isAbove(dline, dline), isAbove(dline, dlinePrev));
+ errOccur = 1;
+ goto JUMP_HERE;
+
+ fprintf(stderr, "error in MC_sweepY\n");
+ exit(1);
+ }
+ }
+
+ JUMP_HERE:
+ //finally clean up space: delete the search tree
+ TreeNodeDeleteWholeTree(searchTree);
+ return errOccur;
+}
+
+void MC_findDiagonals(Int total_num_edges, monoChain** sortedVertices,
+ sweepRange** ranges, Int& num_diagonals,
+ directedLine** diagonal_vertices)
+{
+ Int i,j,k;
+ k=0;
+ //reset 'current' of all the monoChains
+ for(i=0; i<total_num_edges; i++)
+ sortedVertices[i]->resetCurrent();
+
+ for(i=0; i<total_num_edges; i++)
+ {
+ directedLine* vert = sortedVertices[i]->getHead();
+ directedLine* thisEdge = vert;
+ directedLine* prevEdge = vert->getPrev();
+ if(isBelow(vert, thisEdge) && isBelow(vert, prevEdge) && compEdges(prevEdge, thisEdge)<0)
+ {
+ //this is an upward interior cusp
+ diagonal_vertices[k++] = vert;
+
+ directedLine* leftEdge = ranges[i]->left;
+ directedLine* rightEdge = ranges[i]->right;
+
+ directedLine* leftVert = leftEdge;
+ directedLine* rightVert = rightEdge->getNext();
+ assert(leftVert->head()[1] >= vert->head()[1]);
+ assert(rightVert->head()[1] >= vert->head()[1]);
+ directedLine* minVert = (leftVert->head()[1] <= rightVert->head()[1])?leftVert:rightVert;
+ Int found = 0;
+ for(j=i+1; j<total_num_edges; j++)
+ {
+ if(sortedVertices[j]->getHead()->head()[1] > minVert->head()[1])
+ break;
+
+ if(sweepRangeEqual(ranges[i], ranges[j]))
+ {
+ found = 1;
+ break;
+ }
+ }
+
+ if(found)
+ diagonal_vertices[k++] = sortedVertices[j]->getHead();
+ else
+ diagonal_vertices[k++] = minVert;
+ }
+ else if(isAbove(vert, thisEdge) && isAbove(vert, prevEdge) && compEdges(prevEdge, thisEdge)>0)
+ {
+ //downward interior cusp
+ diagonal_vertices[k++] = vert;
+ directedLine* leftEdge = ranges[i]->left;
+ directedLine* rightEdge = ranges[i]->right;
+ directedLine* leftVert = leftEdge->getNext();
+ directedLine* rightVert = rightEdge;
+ assert(leftVert->head()[1] <= vert->head()[1]);
+ assert(rightVert->head()[1] <= vert->head()[1]);
+ directedLine* maxVert = (leftVert->head()[1] > rightVert->head()[1])? leftVert:rightVert;
+ Int found=0;
+ for(j=i-1; j>=0; j--)
+ {
+ if(sortedVertices[j]->getHead()->head()[1] < maxVert->head()[1])
+ break;
+ if(sweepRangeEqual(ranges[i], ranges[j]))
+ {
+ found = 1;
+ break;
+ }
+ }
+ if(found)
+ diagonal_vertices[k++] = sortedVertices[j]->getHead();
+ else
+ diagonal_vertices[k++] = maxVert;
+ }
+ }
+ num_diagonals = k/2;
+}
+
+
+
+
+directedLine* MC_partitionY(directedLine *polygons, sampledLine **retSampledLines)
+{
+//printf("enter mc_partitionY\n");
+ Int total_num_chains = 0;
+ monoChain* loopList = directedLineLoopListToMonoChainLoopList(polygons);
+ monoChain** array = loopList->toArrayAllLoops(total_num_chains);
+
+ if(total_num_chains<=2) //there is just one single monotone polygon
+ {
+ loopList->deleteLoopList();
+ free(array);
+ *retSampledLines = NULL;
+ return polygons;
+ }
+
+//loopList->printAllLoops();
+//printf("total_num_chains=%i\n", total_num_chains);
+ quicksort( (void**)array, 0, total_num_chains-1, (Int (*)(void*, void*))compChainHeadInY);
+//printf("after quicksort\n");
+
+ sweepRange** ranges = (sweepRange**)malloc(sizeof(sweepRange*) * (total_num_chains));
+ assert(ranges);
+
+ if(MC_sweepY(total_num_chains, array, ranges))
+ {
+ loopList->deleteLoopList();
+ free(array);
+ *retSampledLines = NULL;
+ return NULL;
+ }
+//printf("after MC_sweepY\n");
+
+
+ Int num_diagonals;
+ /*number diagonals is < total_num_edges*total_num_edges*/
+ directedLine** diagonal_vertices = (directedLine**) malloc(sizeof(directedLine*) * total_num_chains*2/*total_num_edges*/);
+ assert(diagonal_vertices);
+
+//printf("before call MC_findDiagonales\n");
+
+ MC_findDiagonals(total_num_chains, array, ranges, num_diagonals, diagonal_vertices);
+//printf("after call MC_findDia, num_diagnla=%i\n", num_diagonals);
+
+ directedLine* ret_polygons = polygons;
+ sampledLine* newSampledLines = NULL;
+ Int i,k;
+
+ num_diagonals=deleteRepeatDiagonals(num_diagonals, diagonal_vertices, diagonal_vertices);
+
+
+
+//drawDiagonals(num_diagonals, diagonal_vertices);
+//printf("diagoanls are \n");
+//for(i=0; i<num_diagonals; i++)
+// {
+// printf("(%f,%f)\n", diagonal_vertices[2*i]->head()[0], diagonal_vertices[2*i]->head()[1]);
+// printf("**(%f,%f)\n", diagonal_vertices[2*i+1]->head()[0], diagonal_vertices[2*i+1]->head()[1]);
+// }
+
+ Int *removedDiagonals=(Int*)malloc(sizeof(Int) * num_diagonals);
+ for(i=0; i<num_diagonals; i++)
+ removedDiagonals[i] = 0;
+// printf("first pass\n");
+
+
+ for(i=0,k=0; i<num_diagonals; i++,k+=2)
+ {
+
+
+ directedLine* v1=diagonal_vertices[k];
+ directedLine* v2=diagonal_vertices[k+1];
+ directedLine* ret_p1;
+ directedLine* ret_p2;
+
+ /*we ahve to determine whether v1 and v2 belong to the same polygon before
+ *their structure are modified by connectDiagonal().
+ */
+/*
+ directedLine *root1 = v1->findRoot();
+ directedLine *root2 = v2->findRoot();
+ assert(root1);
+ assert(root2);
+*/
+
+directedLine* root1 = v1->rootLinkFindRoot();
+directedLine* root2 = v2->rootLinkFindRoot();
+
+ if(root1 != root2)
+ {
+
+ removedDiagonals[i] = 1;
+ sampledLine* generatedLine;
+
+
+
+ v1->connectDiagonal(v1,v2, &ret_p1, &ret_p2, &generatedLine, ret_polygons);
+
+
+
+ newSampledLines = generatedLine->insert(newSampledLines);
+/*
+ ret_polygons = ret_polygons->cutoffPolygon(root1);
+
+ ret_polygons = ret_polygons->cutoffPolygon(root2);
+ ret_polygons = ret_p1->insertPolygon(ret_polygons);
+root1->rootLinkSet(ret_p1);
+root2->rootLinkSet(ret_p1);
+ret_p1->rootLinkSet(NULL);
+ret_p2->rootLinkSet(ret_p1);
+*/
+ ret_polygons = ret_polygons->cutoffPolygon(root2);
+
+
+
+root2->rootLinkSet(root1);
+ret_p1->rootLinkSet(root1);
+ret_p2->rootLinkSet(root1);
+
+ /*now that we have connected the diagonal v1 and v2,
+ *we have to check those unprocessed diagonals which
+ *have v1 or v2 as an end point. Notice that the head of v1
+ *has the same coodinates as the head of v2->prev, and the head of
+ *v2 has the same coordinate as the head of v1->prev.
+ *Suppose these is a diagonal (v1, x). If (v1,x) is still a valid
+ *diagonal, then x should be on the left hand side of the directed line: *v1->prev->head -- v1->head -- v1->tail. Otherwise, (v1,x) should be
+ *replaced by (v2->prev, x), that is, x is on the left of
+ * v2->prev->prev->head, v2->prev->head, v2->prev->tail.
+ */
+ Int ii, kk;
+ for(ii=0, kk=0; ii<num_diagonals; ii++, kk+=2)
+ if( removedDiagonals[ii]==0)
+ {
+ directedLine* d1=diagonal_vertices[kk];
+ directedLine* d2=diagonal_vertices[kk+1];
+ /*check d1, and replace diagonal_vertices[kk] if necessary*/
+ if(d1 == v1) {
+ /*check if d2 is to left of v1->prev->head:v1->head:v1->tail*/
+ if(! pointLeft2Lines(v1->getPrev()->head(),
+ v1->head(), v1->tail(), d2->head()))
+ {
+/*
+ assert(pointLeft2Lines(v2->getPrev()->getPrev()->head(),
+ v2->getPrev()->head(),
+ v2->getPrev()->tail(), d2->head()));
+*/
+ diagonal_vertices[kk] = v2->getPrev();
+ }
+ }
+ if(d1 == v2) {
+ /*check if d2 is to left of v2->prev->head:v2->head:v2->tail*/
+ if(! pointLeft2Lines(v2->getPrev()->head(),
+ v2->head(), v2->tail(), d2->head()))
+ {
+/*
+ assert(pointLeft2Lines(v1->getPrev()->getPrev()->head(),
+ v1->getPrev()->head(),
+ v1->getPrev()->tail(), d2->head()));
+*/
+ diagonal_vertices[kk] = v1->getPrev();
+ }
+ }
+ /*check d2 and replace diagonal_vertices[k+1] if necessary*/
+ if(d2 == v1) {
+ /*check if d1 is to left of v1->prev->head:v1->head:v1->tail*/
+ if(! pointLeft2Lines(v1->getPrev()->head(),
+ v1->head(), v1->tail(), d1->head()))
+ {
+/* assert(pointLeft2Lines(v2->getPrev()->getPrev()->head(),
+ v2->getPrev()->head(),
+ v2->getPrev()->tail(), d1->head()));
+*/
+ diagonal_vertices[kk+1] = v2->getPrev();
+ }
+ }
+ if(d2 == v2) {
+ /*check if d1 is to left of v2->prev->head:v2->head:v2->tail*/
+ if(! pointLeft2Lines(v2->getPrev()->head(),
+ v2->head(), v2->tail(), d1->head()))
+ {
+/* assert(pointLeft2Lines(v1->getPrev()->getPrev()->head(),
+ v1->getPrev()->head(),
+ v1->getPrev()->tail(), d1->head()));
+*/
+ diagonal_vertices[kk+1] = v1->getPrev();
+ }
+ }
+ }
+}/*end if (root1 not equal to root 2)*/
+}
+
+ /*second pass, now all diagoals should belong to the same polygon*/
+//printf("second pass: \n");
+
+// for(i=0; i<num_diagonals; i++)
+// printf("%i ", removedDiagonals[i]);
+
+
+ for(i=0,k=0; i<num_diagonals; i++, k += 2)
+ if(removedDiagonals[i] == 0)
+ {
+
+
+ directedLine* v1=diagonal_vertices[k];
+ directedLine* v2=diagonal_vertices[k+1];
+
+
+
+ directedLine* ret_p1;
+ directedLine* ret_p2;
+
+ /*we ahve to determine whether v1 and v2 belong to the same polygon before
+ *their structure are modified by connectDiagonal().
+ */
+ directedLine *root1 = v1->findRoot();
+/*
+ directedLine *root2 = v2->findRoot();
+
+
+
+ assert(root1);
+ assert(root2);
+ assert(root1 == root2);
+ */
+ sampledLine* generatedLine;
+
+
+
+ v1->connectDiagonal(v1,v2, &ret_p1, &ret_p2, &generatedLine, ret_polygons);
+ newSampledLines = generatedLine->insert(newSampledLines);
+
+ ret_polygons = ret_polygons->cutoffPolygon(root1);
+
+ ret_polygons = ret_p1->insertPolygon(ret_polygons);
+
+ ret_polygons = ret_p2->insertPolygon(ret_polygons);
+
+
+
+ for(Int j=i+1; j<num_diagonals; j++)
+ {
+ if(removedDiagonals[j] ==0)
+ {
+
+ directedLine* temp1=diagonal_vertices[2*j];
+ directedLine* temp2=diagonal_vertices[2*j+1];
+ if(temp1==v1 || temp1==v2 || temp2==v1 || temp2==v2)
+ if(! temp1->samePolygon(temp1, temp2))
+ {
+ /*if temp1 and temp2 are in different polygons,
+ *then one of them must be v1 or v2.
+ */
+
+
+
+ assert(temp1==v1 || temp1 == v2 || temp2==v1 || temp2 ==v2);
+ if(temp1==v1)
+ {
+ diagonal_vertices[2*j] = v2->getPrev();
+ }
+ if(temp2==v1)
+ {
+ diagonal_vertices[2*j+1] = v2->getPrev();
+ }
+ if(temp1==v2)
+ {
+ diagonal_vertices[2*j] = v1->getPrev();
+ }
+ if(temp2==v2)
+ {
+ diagonal_vertices[2*j+1] = v1->getPrev();
+ }
+ }
+ }
+ }
+
+ }
+
+
+ //clean up
+ loopList->deleteLoopList();
+ free(array);
+ free(ranges);
+ free(diagonal_vertices);
+ free(removedDiagonals);
+
+ *retSampledLines = newSampledLines;
+ return ret_polygons;
+}
+
+