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Diffstat (limited to 'src/glu/sgi/libnurbs/nurbtess/sampleMonoPoly.cc')
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diff --git a/src/glu/sgi/libnurbs/nurbtess/sampleMonoPoly.cc b/src/glu/sgi/libnurbs/nurbtess/sampleMonoPoly.cc new file mode 100644 index 00000000000..1ddfa2ce45e --- /dev/null +++ b/src/glu/sgi/libnurbs/nurbtess/sampleMonoPoly.cc @@ -0,0 +1,2425 @@ +/* +** 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. +** +** $Date: 2001/03/17 00:25:41 $ $Revision: 1.1 $ +*/ +/* +** $Header: /home/krh/git/sync/mesa-cvs-repo/Mesa/src/glu/sgi/libnurbs/nurbtess/sampleMonoPoly.cc,v 1.1 2001/03/17 00:25:41 brianp Exp $ +*/ + +#include "gluos.h" +#include <stdlib.h> +#include <stdio.h> +#include <math.h> + +#ifndef max +#define max(a,b) ((a>b)? a:b) +#endif +#ifndef min +#define min(a,b) ((a>b)? b:a) +#endif + +#include <GL/gl.h> + +#include "glimports.h" +#include "zlassert.h" +#include "sampleMonoPoly.h" +#include "sampleComp.h" +#include "polyDBG.h" +#include "partitionX.h" + + +#define ZERO 0.00001 + +//#define MYDEBUG + +//#define SHORTEN_GRID_LINE +//see work/newtess/internal/test/problems + + +/*split a polygon so that each vertex correcpond to one edge + *the head of the first edge of the returned plygon must be the head of the first + *edge of the origianl polygon. This is crucial for the code in sampleMonoPoly function + */ + directedLine* polygonConvert(directedLine* polygon) +{ + int i; + directedLine* ret; + sampledLine* sline; + sline = new sampledLine(2); + sline->setPoint(0, polygon->getVertex(0)); + sline->setPoint(1, polygon->getVertex(1)); + ret=new directedLine(INCREASING, sline); + for(i=1; i<= polygon->get_npoints()-2; i++) + { + sline = new sampledLine(2); + sline->setPoint(0, polygon->getVertex(i)); + sline->setPoint(1, polygon->getVertex(i+1)); + ret->insert(new directedLine(INCREASING, sline)); + } + + for(directedLine *temp = polygon->getNext(); temp != polygon; temp = temp->getNext()) + { + for(i=0; i<= temp->get_npoints()-2; i++) + { + sline = new sampledLine(2); + sline->setPoint(0, temp->getVertex(i)); + sline->setPoint(1, temp->getVertex(i+1)); + ret->insert(new directedLine(INCREASING, sline)); + } + } + return ret; +} + +void triangulateConvexPolyVertical(directedLine* topV, directedLine* botV, primStream *pStream) +{ + Int i,j; + Int n_leftVerts; + Int n_rightVerts; + Real** leftVerts; + Real** rightVerts; + directedLine* tempV; + n_leftVerts = 0; + for(tempV = topV; tempV != botV; tempV = tempV->getNext()) + { + n_leftVerts += tempV->get_npoints(); + } + n_rightVerts=0; + for(tempV = botV; tempV != topV; tempV = tempV->getNext()) + { + n_rightVerts += tempV->get_npoints(); + } + + Real2* temp_leftVerts = (Real2 *) malloc(sizeof(Real2) * n_leftVerts); + assert(temp_leftVerts); + Real2* temp_rightVerts = (Real2 *) malloc(sizeof(Real2) * n_rightVerts); + assert(temp_rightVerts); + + leftVerts = (Real**) malloc(sizeof(Real2*) * n_leftVerts); + assert(leftVerts); + rightVerts = (Real**) malloc(sizeof(Real2*) * n_rightVerts); + assert(rightVerts); + for(i=0; i<n_leftVerts; i++) + leftVerts[i] = temp_leftVerts[i]; + for(i=0; i<n_rightVerts; i++) + rightVerts[i] = temp_rightVerts[i]; + + i=0; + for(tempV = topV; tempV != botV; tempV = tempV->getNext()) + { + for(j=1; j<tempV->get_npoints(); j++) + { + leftVerts[i][0] = tempV->getVertex(j)[0]; + leftVerts[i][1] = tempV->getVertex(j)[1]; + i++; + } + } + n_leftVerts = i; + i=0; + for(tempV = topV->getPrev(); tempV != botV->getPrev(); tempV = tempV->getPrev()) + { + for(j=tempV->get_npoints()-1; j>=1; j--) + { + rightVerts[i][0] = tempV->getVertex(j)[0]; + rightVerts[i][1] = tempV->getVertex(j)[1]; + i++; + } + } + n_rightVerts = i; + triangulateXYMonoTB(n_leftVerts, leftVerts, n_rightVerts, rightVerts, pStream); + free(leftVerts); + free(rightVerts); + free(temp_leftVerts); + free(temp_rightVerts); +} + +void triangulateConvexPolyHoriz(directedLine* leftV, directedLine* rightV, primStream *pStream) +{ + Int i,j; + Int n_lowerVerts; + Int n_upperVerts; + Real2 *lowerVerts; + Real2 *upperVerts; + directedLine* tempV; + n_lowerVerts=0; + for(tempV = leftV; tempV != rightV; tempV = tempV->getNext()) + { + n_lowerVerts += tempV->get_npoints(); + } + n_upperVerts=0; + for(tempV = rightV; tempV != leftV; tempV = tempV->getNext()) + { + n_upperVerts += tempV->get_npoints(); + } + lowerVerts = (Real2 *) malloc(sizeof(Real2) * n_lowerVerts); + assert(n_lowerVerts); + upperVerts = (Real2 *) malloc(sizeof(Real2) * n_upperVerts); + assert(n_upperVerts); + i=0; + for(tempV = leftV; tempV != rightV; tempV = tempV->getNext()) + { + for(j=0; j<tempV->get_npoints(); j++) + { + lowerVerts[i][0] = tempV->getVertex(j)[0]; + lowerVerts[i][1] = tempV->getVertex(j)[1]; + i++; + } + } + i=0; + for(tempV = leftV->getPrev(); tempV != rightV->getPrev(); tempV = tempV->getPrev()) + { + for(j=tempV->get_npoints()-1; j>=0; j--) + { + upperVerts[i][0] = tempV->getVertex(j)[0]; + upperVerts[i][1] = tempV->getVertex(j)[1]; + i++; + } + } + triangulateXYMono(n_upperVerts, upperVerts, n_lowerVerts, lowerVerts, pStream); + free(lowerVerts); + free(upperVerts); +} +void triangulateConvexPoly(directedLine* polygon, Int ulinear, Int vlinear, primStream* pStream) +{ + /*find left, right, top , bot + */ + directedLine* tempV; + directedLine* topV; + directedLine* botV; + directedLine* leftV; + directedLine* rightV; + topV = botV = polygon; + + for(tempV = polygon->getNext(); tempV != polygon; tempV = tempV->getNext()) + { + if(compV2InY(topV->head(), tempV->head())<0) { + + topV = tempV; + } + if(compV2InY(botV->head(), tempV->head())>0) { + + botV = tempV; + } + } + //find leftV + for(tempV = topV; tempV != botV; tempV = tempV->getNext()) + { + if(tempV->tail()[0] >= tempV->head()[0]) + break; + } + leftV = tempV; + //find rightV + for(tempV = botV; tempV != topV; tempV = tempV->getNext()) + { + if(tempV->tail()[0] <= tempV->head()[0]) + break; + } + rightV = tempV; + if(vlinear) + { + triangulateConvexPolyHoriz( leftV, rightV, pStream); + } + else if(ulinear) + { + triangulateConvexPolyVertical(topV, botV, pStream); + } + else + { + if(DBG_is_U_direction(polygon)) + { + triangulateConvexPolyHoriz( leftV, rightV, pStream); + } + else + triangulateConvexPolyVertical(topV, botV, pStream); + } +} + +/*for debug purpose*/ +void drawCorners( + Real* topV, Real* botV, + vertexArray* leftChain, + vertexArray* rightChain, + gridBoundaryChain* leftGridChain, + gridBoundaryChain* rightGridChain, + Int gridIndex1, + Int gridIndex2, + Int leftCornerWhere, + Int leftCornerIndex, + Int rightCornerWhere, + Int rightCornerIndex, + Int bot_leftCornerWhere, + Int bot_leftCornerIndex, + Int bot_rightCornerWhere, + Int bot_rightCornerIndex) +{ + Real* leftCornerV; + Real* rightCornerV; + Real* bot_leftCornerV; + Real* bot_rightCornerV; + + if(leftCornerWhere == 1) + leftCornerV = topV; + else if(leftCornerWhere == 0) + leftCornerV = leftChain->getVertex(leftCornerIndex); + else + leftCornerV = rightChain->getVertex(leftCornerIndex); + + if(rightCornerWhere == 1) + rightCornerV = topV; + else if(rightCornerWhere == 0) + rightCornerV = leftChain->getVertex(rightCornerIndex); + else + rightCornerV = rightChain->getVertex(rightCornerIndex); + + if(bot_leftCornerWhere == 1) + bot_leftCornerV = botV; + else if(bot_leftCornerWhere == 0) + bot_leftCornerV = leftChain->getVertex(bot_leftCornerIndex); + else + bot_leftCornerV = rightChain->getVertex(bot_leftCornerIndex); + + if(bot_rightCornerWhere == 1) + bot_rightCornerV = botV; + else if(bot_rightCornerWhere == 0) + bot_rightCornerV = leftChain->getVertex(bot_rightCornerIndex); + else + bot_rightCornerV = rightChain->getVertex(bot_rightCornerIndex); + + Real topGridV = leftGridChain->get_v_value(gridIndex1); + Real topGridU1 = leftGridChain->get_u_value(gridIndex1); + Real topGridU2 = rightGridChain->get_u_value(gridIndex1); + Real botGridV = leftGridChain->get_v_value(gridIndex2); + Real botGridU1 = leftGridChain->get_u_value(gridIndex2); + Real botGridU2 = rightGridChain->get_u_value(gridIndex2); + + glBegin(GL_LINE_STRIP); + glVertex2fv(leftCornerV); + glVertex2f(topGridU1, topGridV); + glEnd(); + + glBegin(GL_LINE_STRIP); + glVertex2fv(rightCornerV); + glVertex2f(topGridU2, topGridV); + glEnd(); + + glBegin(GL_LINE_STRIP); + glVertex2fv(bot_leftCornerV); + glVertex2f(botGridU1, botGridV); + glEnd(); + + glBegin(GL_LINE_STRIP); + glVertex2fv(bot_rightCornerV); + glVertex2f(botGridU2, botGridV); + glEnd(); + + +} + +void toVertexArrays(directedLine* topV, directedLine* botV, vertexArray& leftChain, vertexArray& rightChain) +{ + Int i; + directedLine* tempV; + for(i=1; i<=topV->get_npoints()-2; i++) { /*the first vertex is the top vertex which doesn't belong to inc_chain*/ + leftChain.appendVertex(topV->getVertex(i)); + } + for(tempV = topV->getNext(); tempV != botV; tempV = tempV->getNext()) + { + for(i=0; i<=tempV->get_npoints()-2; i++){ + leftChain.appendVertex(tempV->getVertex(i)); + } + } + + for(tempV = topV->getPrev(); tempV != botV; tempV = tempV->getPrev()) + { + for(i=tempV->get_npoints()-2; i>=0; i--){ + rightChain.appendVertex(tempV->getVertex(i)); + } + } + for(i=botV->get_npoints()-2; i>=1; i--){ + rightChain.appendVertex(tempV->getVertex(i)); + } +} + + +void findTopAndBot(directedLine* polygon, directedLine*& topV, directedLine*& botV) +{ + assert(polygon); + directedLine* tempV; + topV = botV = polygon; + for(tempV = polygon->getNext(); tempV != polygon; tempV = tempV->getNext()) + { + if(compV2InY(topV->head(), tempV->head())<0) { + topV = tempV; + } + if(compV2InY(botV->head(), tempV->head())>0) { + botV = tempV; + } + } +} + +void findGridChains(directedLine* topV, directedLine* botV, + gridWrap* grid, + gridBoundaryChain*& leftGridChain, + gridBoundaryChain*& rightGridChain) +{ + /*find the first(top) and the last (bottom) grid line which intersect the + *this polygon + */ + Int firstGridIndex; /*the index in the grid*/ + Int lastGridIndex; + + firstGridIndex = (Int) ((topV->head()[1] - grid->get_v_min()) / (grid->get_v_max() - grid->get_v_min()) * (grid->get_n_vlines()-1)); + + if(botV->head()[1] < grid->get_v_min()) + lastGridIndex = 0; + else + lastGridIndex = (Int) ((botV->head()[1] - grid->get_v_min()) / (grid->get_v_max() - grid->get_v_min()) * (grid->get_n_vlines()-1)) + 1; + + /*find the interval inside the polygon for each gridline*/ + Int *leftGridIndices = (Int*) malloc(sizeof(Int) * (firstGridIndex - lastGridIndex +1)); + assert(leftGridIndices); + Int *rightGridIndices = (Int*) malloc(sizeof(Int) * (firstGridIndex - lastGridIndex +1)); + assert(rightGridIndices); + Int *leftGridInnerIndices = (Int*) malloc(sizeof(Int) * (firstGridIndex - lastGridIndex +1)); + assert(leftGridInnerIndices); + Int *rightGridInnerIndices = (Int*) malloc(sizeof(Int) * (firstGridIndex - lastGridIndex +1)); + assert(rightGridInnerIndices); + + findLeftGridIndices(topV, firstGridIndex, lastGridIndex, grid, leftGridIndices, leftGridInnerIndices); + + findRightGridIndices(topV, firstGridIndex, lastGridIndex, grid, rightGridIndices, rightGridInnerIndices); + + leftGridChain = new gridBoundaryChain(grid, firstGridIndex, firstGridIndex-lastGridIndex+1, leftGridIndices, leftGridInnerIndices); + + rightGridChain = new gridBoundaryChain(grid, firstGridIndex, firstGridIndex-lastGridIndex+1, rightGridIndices, rightGridInnerIndices); + + free(leftGridIndices); + free(rightGridIndices); + free(leftGridInnerIndices); + free(rightGridInnerIndices); +} + +void findDownCorners(Real *botVertex, + vertexArray *leftChain, Int leftChainStartIndex, Int leftChainEndIndex, + vertexArray *rightChain, Int rightChainStartIndex, Int rightChainEndIndex, + Real v, + Real uleft, + Real uright, + Int& ret_leftCornerWhere, /*0: left chain, 1: topvertex, 2: rightchain*/ + Int& ret_leftCornerIndex, /*useful when ret_leftCornerWhere == 0 or 2*/ + Int& ret_rightCornerWhere, /*0: left chain, 1: topvertex, 2: rightchain*/ + Int& ret_rightCornerIndex /*useful when ret_leftCornerWhere == 0 or 2*/ + ) +{ +#ifdef MYDEBUG +printf("*************enter find donw corner\n"); +printf("finddownCorner: v=%f, uleft=%f, uright=%f\n", v, uleft, uright); +printf("(%i,%i,%i,%i)\n", leftChainStartIndex, leftChainEndIndex,rightChainStartIndex, rightChainEndIndex); +printf("left chain is\n"); +leftChain->print(); +printf("right chain is\n"); +rightChain->print(); +#endif + + assert(v > botVertex[1]); + Real leftGridPoint[2]; + leftGridPoint[0] = uleft; + leftGridPoint[1] = v; + Real rightGridPoint[2]; + rightGridPoint[0] = uright; + rightGridPoint[1] = v; + + Int i; + Int index1, index2; + + index1 = leftChain->findIndexBelowGen(v, leftChainStartIndex, leftChainEndIndex); + index2 = rightChain->findIndexBelowGen(v, rightChainStartIndex, rightChainEndIndex); + + if(index2 <= rightChainEndIndex) //index2 was found above + index2 = rightChain->skipEqualityFromStart(v, index2, rightChainEndIndex); + + if(index1>leftChainEndIndex && index2 > rightChainEndIndex) /*no point below v on left chain or right chain*/ + { + + /*the botVertex is the only vertex below v*/ + ret_leftCornerWhere = 1; + ret_rightCornerWhere = 1; + } + else if(index1>leftChainEndIndex ) /*index2 <= rightChainEndIndex*/ + { + + ret_rightCornerWhere = 2; /*on right chain*/ + ret_rightCornerIndex = index2; + + + Real tempMin = rightChain->getVertex(index2)[0]; + Real tempI = index2; + for(i=index2+1; i<= rightChainEndIndex; i++) + if(rightChain->getVertex(i)[0] < tempMin) + { + tempI = i; + tempMin = rightChain->getVertex(i)[0]; + } + + + //we consider whether we can use botVertex as left corner. First check + //if (leftGirdPoint, botVertex) interesects right chian or not. + if(DBG_intersectChain(rightChain, rightChainStartIndex,rightChainEndIndex, + leftGridPoint, botVertex)) + { + ret_leftCornerWhere = 2;//right + ret_leftCornerIndex = index2; //should use tempI??? + } + else if(botVertex[0] < tempMin) + ret_leftCornerWhere = 1; //bot + else + { + ret_leftCornerWhere = 2; //right + ret_leftCornerIndex = (int)tempI; + } + } + else if(index2> rightChainEndIndex) /*index1<=leftChainEndIndex*/ + { + ret_leftCornerWhere = 0; /*left chain*/ + ret_leftCornerIndex = index1; + + /*find the vertex on the left chain with the maximum u, + *either this vertex or the botvertex can be used as the right corner + */ + + Real tempI; + //skip those points which are equal to v. (avoid degeneratcy) + for(tempI = index1; tempI <= leftChainEndIndex; tempI++) + if(leftChain->getVertex(tempI)[1] < v) + break; + if(tempI > leftChainEndIndex) + ret_rightCornerWhere = 1; + else + { + Real tempMax = leftChain->getVertex(tempI)[0]; + for(i=(int)tempI; i<= leftChainEndIndex; i++) + if(leftChain->getVertex(i)[0] > tempMax) + { + tempI = i; + tempMax = leftChain->getVertex(i)[0]; + } + + + + //we consider whether we can use botVertex as a corner. So first we check + //whether (rightGridPoint, botVertex) interescts the left chain or not. + if(DBG_intersectChain(leftChain, leftChainStartIndex,leftChainEndIndex, + rightGridPoint, botVertex)) + { + ret_rightCornerWhere = 0; + ret_rightCornerIndex = index1; //should use tempI??? + } + else if(botVertex[0] > tempMax) + { + + ret_rightCornerWhere = 1; + } + else + { + ret_rightCornerWhere = 0; + ret_rightCornerIndex = (int)tempI; + } + } + + } + else /*index1<=leftChainEndIndex and index2 <=rightChainEndIndex*/ + { + if(leftChain->getVertex(index1)[1] >= rightChain->getVertex(index2)[1]) /*left point above right point*/ + { + ret_leftCornerWhere = 0; /*on left chain*/ + ret_leftCornerIndex = index1; + + Real tempMax; + Int tempI; + + tempI = index1; + tempMax = leftChain->getVertex(index1)[0]; + + /*find the maximum u for all the points on the left above the right point index2*/ + for(i=index1+1; i<= leftChainEndIndex; i++) + { + if(leftChain->getVertex(i)[1] < rightChain->getVertex(index2)[1]) + break; + + if(leftChain->getVertex(i)[0]>tempMax) + { + tempI = i; + tempMax = leftChain->getVertex(i)[0]; + } + } + //we consider if we can use rightChain(index2) as right corner + //we check if (rightChain(index2), rightGidPoint) intersecs left chain or not. + if(DBG_intersectChain(leftChain, leftChainStartIndex,leftChainEndIndex, rightGridPoint, rightChain->getVertex(index2))) + { + ret_rightCornerWhere = 0; + ret_rightCornerIndex = index1; //should use tempI??? + } + else if(tempMax >= rightChain->getVertex(index2)[0] || + tempMax >= uright + ) + { + + ret_rightCornerWhere = 0; /*on left Chain*/ + ret_rightCornerIndex = tempI; + } + else + { + ret_rightCornerWhere = 2; /*on right chain*/ + ret_rightCornerIndex = index2; + } + } + else /*left below right*/ + { + ret_rightCornerWhere = 2; /*on the right*/ + ret_rightCornerIndex = index2; + + Real tempMin; + Int tempI; + + tempI = index2; + tempMin = rightChain->getVertex(index2)[0]; + + /*find the minimum u for all the points on the right above the left poitn index1*/ + for(i=index2+1; i<= rightChainEndIndex; i++) + { + if( rightChain->getVertex(i)[1] < leftChain->getVertex(index1)[1]) + break; + if(rightChain->getVertex(i)[0] < tempMin) + { + tempI = i; + tempMin = rightChain->getVertex(i)[0]; + } + } + + //we consider if we can use leftchain(index1) as left corner. + //we check if (leftChain(index1) intersects right chian or not + if(DBG_intersectChain(rightChain, rightChainStartIndex, rightChainEndIndex, leftGridPoint, leftChain->getVertex(index1))) + { + ret_leftCornerWhere = 2; + ret_leftCornerIndex = index2; //should use tempI??? + } + else if(tempMin <= leftChain->getVertex(index1)[0] || + tempMin <= uleft) + { + ret_leftCornerWhere = 2; /* on right chain*/ + ret_leftCornerIndex = tempI; + } + else + { + ret_leftCornerWhere = 0; /*on left chain*/ + ret_leftCornerIndex = index1; + } + } + } + +} + + +void findUpCorners(Real *topVertex, + vertexArray *leftChain, Int leftChainStartIndex, Int leftChainEndIndex, + vertexArray *rightChain, Int rightChainStartIndex, Int rightChainEndIndex, + Real v, + Real uleft, + Real uright, + Int& ret_leftCornerWhere, /*0: left chain, 1: topvertex, 2: rightchain*/ + Int& ret_leftCornerIndex, /*useful when ret_leftCornerWhere == 0 or 2*/ + Int& ret_rightCornerWhere, /*0: left chain, 1: topvertex, 2: rightchain*/ + Int& ret_rightCornerIndex /*useful when ret_leftCornerWhere == 0 or 2*/ + ) +{ +#ifdef MYDEBUG +printf("***********enter findUpCorners\n"); +#endif + + assert(v < topVertex[1]); + Real leftGridPoint[2]; + leftGridPoint[0] = uleft; + leftGridPoint[1] = v; + Real rightGridPoint[2]; + rightGridPoint[0] = uright; + rightGridPoint[1] = v; + + Int i; + Int index1, index2; + + index1 = leftChain->findIndexFirstAboveEqualGen(v, leftChainStartIndex, leftChainEndIndex); + + + index2 = rightChain->findIndexFirstAboveEqualGen(v, rightChainStartIndex, rightChainEndIndex); + + if(index2>= leftChainStartIndex) //index2 was found above + index2 = rightChain->skipEqualityFromStart(v, index2, rightChainEndIndex); + + if(index1<leftChainStartIndex && index2 <rightChainStartIndex) /*no point above v on left chain or right chain*/ + { + /*the topVertex is the only vertex above v*/ + ret_leftCornerWhere = 1; + ret_rightCornerWhere = 1; + } + else if(index1<leftChainStartIndex ) /*index2 >= rightChainStartIndex*/ + { + ret_rightCornerWhere = 2; /*on right chain*/ + ret_rightCornerIndex = index2; + + //find the minimum u on right top, either that, or top, or right[index2] is the left corner + Real tempMin = rightChain->getVertex(index2)[0]; + Int tempI = index2; + for(i=index2-1; i>=rightChainStartIndex; i--) + if(rightChain->getVertex(i)[0] < tempMin) + { + tempMin = rightChain->getVertex(i)[0]; + tempI = i; + } + //chech whether (leftGridPoint, top) intersects rightchai, + //if yes, use right corner as left corner + //if not, use top or right[tempI] as left corner + if(DBG_intersectChain(rightChain, rightChainStartIndex, rightChainEndIndex, + leftGridPoint, topVertex)) + { + ret_leftCornerWhere = 2; //rightChain + ret_leftCornerIndex = index2; + } + else if(topVertex[0] < tempMin) + ret_leftCornerWhere = 1; /*topvertex*/ + else + { + ret_leftCornerWhere = 2; //right chain + ret_leftCornerIndex = tempI; + } + + } + else if(index2< rightChainStartIndex) /*index1>=leftChainStartIndex*/ + { + ret_leftCornerWhere = 0; /*left chain*/ + ret_leftCornerIndex = index1; + + //find the maximum u on the left top section. either that or topvertex, or left[index1] is the right corner + Real tempMax = leftChain->getVertex(index1)[0]; + Int tempI = index1; + + for(i=index1-1; i>=leftChainStartIndex; i--){ + + if(leftChain->getVertex(i)[0] > tempMax) + { + + tempMax = leftChain->getVertex(i)[0]; + tempI = i; + } + } + //check whether (rightGridPoint, top) intersects leftChain or not + //if yes, we use leftCorner as the right corner + //if not, we use either top or left[tempI] as the right corner + if(DBG_intersectChain(leftChain, leftChainStartIndex,leftChainEndIndex, + rightGridPoint, topVertex)) + { + ret_rightCornerWhere = 0; //left chan + ret_rightCornerIndex = index1; + } + else if(topVertex[0] > tempMax) + ret_rightCornerWhere = 1;//topVertex + else + { + ret_rightCornerWhere = 0;//left chain + ret_rightCornerIndex = tempI; + } + } + else /*index1>=leftChainStartIndex and index2 >=rightChainStartIndex*/ + { + if(leftChain->getVertex(index1)[1] <= rightChain->getVertex(index2)[1]) /*left point below right point*/ + { + ret_leftCornerWhere = 0; /*on left chain*/ + ret_leftCornerIndex = index1; + + Real tempMax; + Int tempI; + + tempI = index1; + tempMax = leftChain->getVertex(index1)[0]; + + /*find the maximum u for all the points on the left below the right point index2*/ + for(i=index1-1; i>= leftChainStartIndex; i--) + { + if(leftChain->getVertex(i)[1] > rightChain->getVertex(index2)[1]) + break; + + if(leftChain->getVertex(i)[0]>tempMax) + { + tempI = i; + tempMax = leftChain->getVertex(i)[0]; + } + } + //chek whether (rightChain(index2), rightGridPoint) intersects leftchian or not + if(DBG_intersectChain(leftChain, leftChainStartIndex, leftChainEndIndex, rightGridPoint, rightChain->getVertex(index2))) + { + ret_rightCornerWhere = 0; + ret_rightCornerIndex = index1; + } + else if(tempMax >= rightChain->getVertex(index2)[0] || + tempMax >= uright) + { + ret_rightCornerWhere = 0; /*on left Chain*/ + ret_rightCornerIndex = tempI; + } + else + { + ret_rightCornerWhere = 2; /*on right chain*/ + ret_rightCornerIndex = index2; + } + } + else /*left above right*/ + { + ret_rightCornerWhere = 2; /*on the right*/ + ret_rightCornerIndex = index2; + + Real tempMin; + Int tempI; + + tempI = index2; + tempMin = rightChain->getVertex(index2)[0]; + + /*find the minimum u for all the points on the right below the left poitn index1*/ + for(i=index2-1; i>= rightChainStartIndex; i--) + { + if( rightChain->getVertex(i)[1] > leftChain->getVertex(index1)[1]) + break; + if(rightChain->getVertex(i)[0] < tempMin) + { + tempI = i; + tempMin = rightChain->getVertex(i)[0]; + } + } + //check whether (leftGRidPoint,left(index1)) interesect right chain + if(DBG_intersectChain(rightChain, rightChainStartIndex, rightChainEndIndex, + leftGridPoint, leftChain->getVertex(index1))) + { + ret_leftCornerWhere = 2; //right + ret_leftCornerIndex = index2; + } + else if(tempMin <= leftChain->getVertex(index1)[0] || + tempMin <= uleft) + { + ret_leftCornerWhere = 2; /* on right chain*/ + ret_leftCornerIndex = tempI; + } + else + { + ret_leftCornerWhere = 0; /*on left chain*/ + ret_leftCornerIndex = index1; + } + } + } +#ifdef MYDEBUG +printf("***********leave findUpCorners\n"); +#endif +} + +//return 1 if neck exists, 0 othewise +Int findNeckF(vertexArray *leftChain, Int botLeftIndex, + vertexArray *rightChain, Int botRightIndex, + gridBoundaryChain* leftGridChain, + gridBoundaryChain* rightGridChain, + Int gridStartIndex, + Int& neckLeft, + Int& neckRight) +{ +/* +printf("enter findNeckF, botleft, botright=%i,%i,gstartindex=%i\n",botLeftIndex,botRightIndex,gridStartIndex); +printf("leftChain is\n"); +leftChain->print(); +printf("rightChain is\n"); +rightChain->print(); +*/ + + Int lowerGridIndex; //the grid below leftChain and rightChian vertices + Int i; + Int n_vlines = leftGridChain->get_nVlines(); + Real v; + if(botLeftIndex >= leftChain->getNumElements() || + botRightIndex >= rightChain->getNumElements()) + return 0; //no neck exists + + v=min(leftChain->getVertex(botLeftIndex)[1], rightChain->getVertex(botRightIndex)[1]); + + + + + for(i=gridStartIndex; i<n_vlines; i++) + if(leftGridChain->get_v_value(i) <= v && + leftGridChain->getUlineIndex(i)<= rightGridChain->getUlineIndex(i)) + break; + + lowerGridIndex = i; + + if(lowerGridIndex == n_vlines) //the two trm vertex are higher than all gridlines + return 0; + else + { + Int botLeft2, botRight2; +/* +printf("leftGridChain->get_v_)value=%f\n",leftGridChain->get_v_value(lowerGridIndex), botLeftIndex); +printf("leftChain->get_vertex(0)=(%f,%f)\n", leftChain->getVertex(0)[0],leftChain->getVertex(0)[1]); +printf("leftChain->get_vertex(1)=(%f,%f)\n", leftChain->getVertex(1)[0],leftChain->getVertex(1)[1]); +printf("leftChain->get_vertex(2)=(%f,%f)\n", leftChain->getVertex(2)[0],leftChain->getVertex(2)[1]); +*/ + botLeft2 = leftChain->findIndexFirstAboveEqualGen(leftGridChain->get_v_value(lowerGridIndex), botLeftIndex, leftChain->getNumElements()-1) -1 ; + +/* +printf("botLeft2=%i\n", botLeft2); +printf("leftChain->getNumElements=%i\n", leftChain->getNumElements()); +*/ + + botRight2 = rightChain->findIndexFirstAboveEqualGen(leftGridChain->get_v_value(lowerGridIndex), botRightIndex, rightChain->getNumElements()-1) -1; + if(botRight2 < botRightIndex) botRight2=botRightIndex; + + if(botLeft2 < botLeftIndex) botLeft2 = botLeftIndex; + + assert(botLeft2 >= botLeftIndex); + assert(botRight2 >= botRightIndex); + //find nectLeft so that it is th erightmost vertex on letChain + + Int tempI = botLeftIndex; + Real temp = leftChain->getVertex(tempI)[0]; + for(i=botLeftIndex+1; i<= botLeft2; i++) + if(leftChain->getVertex(i)[0] > temp) + { + temp = leftChain->getVertex(i)[0]; + tempI = i; + } + neckLeft = tempI; + + tempI = botRightIndex; + temp = rightChain->getVertex(tempI)[0]; + for(i=botRightIndex+1; i<= botRight2; i++) + if(rightChain->getVertex(i)[0] < temp) + { + temp = rightChain->getVertex(i)[0]; + tempI = i; + } + neckRight = tempI; + return 1; + } +} + + + +/*find i>=botLeftIndex,j>=botRightIndex so that + *(leftChain[i], rightChain[j]) is a neck. + */ +void findNeck(vertexArray *leftChain, Int botLeftIndex, + vertexArray *rightChain, Int botRightIndex, + Int& leftLastIndex, /*left point of the neck*/ + Int& rightLastIndex /*right point of the neck*/ + ) +{ + assert(botLeftIndex < leftChain->getNumElements() && + botRightIndex < rightChain->getNumElements()); + + /*now the neck exists for sure*/ + + if(leftChain->getVertex(botLeftIndex)[1] <= rightChain->getVertex(botRightIndex)[1]) //left below right + { + + leftLastIndex = botLeftIndex; + + /*find i so that rightChain[i][1] >= leftchainbotverte[1], and i+1< + */ + rightLastIndex=rightChain->findIndexAboveGen(leftChain->getVertex(botLeftIndex)[1], botRightIndex+1, rightChain->getNumElements()-1); + } + else //left above right + { + + rightLastIndex = botRightIndex; + + leftLastIndex = leftChain->findIndexAboveGen(rightChain->getVertex(botRightIndex)[1], + botLeftIndex+1, + leftChain->getNumElements()-1); + } +} + + + +void findLeftGridIndices(directedLine* topEdge, Int firstGridIndex, Int lastGridIndex, gridWrap* grid, Int* ret_indices, Int* ret_innerIndices) +{ + + Int i,k,isHoriz; + Int n_ulines = grid->get_n_ulines(); + Real uMin = grid->get_u_min(); + Real uMax = grid->get_u_max(); + Real vMin = grid->get_v_min(); + Real vMax = grid->get_v_max(); + Real slop, uinterc; + +#ifdef SHORTEN_GRID_LINE + //uintercBuf stores all the interction u value for each grid line + //notice that lastGridIndex<= firstGridIndex + Real *uintercBuf = (Real *) malloc (sizeof(Real) * (firstGridIndex-lastGridIndex+1)); + assert(uintercBuf); +#endif + + /*initialization to make vtail bigger than grid->...*/ + directedLine* dLine = topEdge; + Real vtail = grid->get_v_value(firstGridIndex) + 1.0; + Real tempMaxU = grid->get_u_min(); + + + /*for each grid line*/ + for(k=0, i=firstGridIndex; i>=lastGridIndex; i--, k++) + { + + Real grid_v_value = grid->get_v_value(i); + + /*check whether this grid line is below the current trim edge.*/ + if(vtail > grid_v_value) + { + /*since the grid line is below the trim edge, we + *find the trim edge which will contain the trim line + */ + while( (vtail=dLine->tail()[1]) > grid_v_value){ + + tempMaxU = max(tempMaxU, dLine->tail()[0]); + dLine = dLine -> getNext(); + } + + if( fabs(dLine->head()[1] - vtail) < ZERO) + isHoriz = 1; + else + { + isHoriz = 0; + slop = (dLine->head()[0] - dLine->tail()[0]) / (dLine->head()[1]-vtail); + } + } + + if(isHoriz) + { + uinterc = max(dLine->head()[0], dLine->tail()[0]); + } + else + { + uinterc = slop * (grid_v_value - vtail) + dLine->tail()[0]; + } + + tempMaxU = max(tempMaxU, uinterc); + + if(uinterc < uMin && uinterc >= uMin - ZERO) + uinterc = uMin; + if(uinterc > uMax && uinterc <= uMax + ZERO) + uinterc = uMax; + +#ifdef SHORTEN_GRID_LINE + uintercBuf[k] = uinterc; +#endif + + assert(uinterc >= uMin && uinterc <= uMax); + if(uinterc == uMax) + ret_indices[k] = n_ulines-1; + else + ret_indices[k] = (Int)(((uinterc-uMin)/(uMax - uMin)) * (n_ulines-1)) + 1; + if(ret_indices[k] >= n_ulines) + ret_indices[k] = n_ulines-1; + + + ret_innerIndices[k] = (Int)(((tempMaxU-uMin)/(uMax - uMin)) * (n_ulines-1)) + 1; + + /*reinitialize tempMaxU for next grdiLine*/ + tempMaxU = uinterc; + } +#ifdef SHORTEN_GRID_LINE + //for each grid line, compare the left grid point with the + //intersection point. If the two points are too close, then + //we should move the grid point one grid to the right + //and accordingly we should update the inner index. + for(k=0, i=firstGridIndex; i>=lastGridIndex; i--, k++) + { + //check gridLine i + //check ret_indices[k] + Real a = grid->get_u_value(ret_indices[k]-1); + Real b = grid->get_u_value(ret_indices[k]); + assert(uintercBuf[k] >= a && uintercBuf < b); + if( (b-uintercBuf[k]) <= 0.2 * (b-a)) //interc is very close to b + { + ret_indices[k]++; + } + + //check ret_innerIndices[k] + if(k>0) + { + if(ret_innerIndices[k] < ret_indices[k-1]) + ret_innerIndices[k] = ret_indices[k-1]; + if(ret_innerIndices[k] < ret_indices[k]) + ret_innerIndices[k] = ret_indices[k]; + } + } + //clean up + free(uintercBuf); +#endif +} + +void findRightGridIndices(directedLine* topEdge, Int firstGridIndex, Int lastGridIndex, gridWrap* grid, Int* ret_indices, Int* ret_innerIndices) +{ + + Int i,k; + Int n_ulines = grid->get_n_ulines(); + Real uMin = grid->get_u_min(); + Real uMax = grid->get_u_max(); + Real vMin = grid->get_v_min(); + Real vMax = grid->get_v_max(); + Real slop, uinterc; + +#ifdef SHORTEN_GRID_LINE + //uintercBuf stores all the interction u value for each grid line + //notice that firstGridIndex >= lastGridIndex + Real *uintercBuf = (Real *) malloc (sizeof(Real) * (firstGridIndex-lastGridIndex+1)); + assert(uintercBuf); +#endif + + /*initialization to make vhead bigger than grid->v_value...*/ + directedLine* dLine = topEdge->getPrev(); + Real vhead = dLine->tail()[1]; + Real tempMinU = grid->get_u_max(); + + /*for each grid line*/ + for(k=0, i=firstGridIndex; i>=lastGridIndex; i--, k++) + { + + Real grid_v_value = grid->get_v_value(i); + + + /*check whether this grid line is below the current trim edge.*/ + if(vhead >= grid_v_value) + { + /*since the grid line is below the tail of the trim edge, we + *find the trim edge which will contain the trim line + */ + while( (vhead=dLine->head()[1]) > grid_v_value){ + tempMinU = min(tempMinU, dLine->head()[0]); + dLine = dLine -> getPrev(); + } + + /*skip the equality in the case of degenerat case: horizontal */ + while(dLine->head()[1] == grid_v_value) + dLine = dLine->getPrev(); + + assert( dLine->tail()[1] != dLine->head()[1]); + slop = (dLine->tail()[0] - dLine->head()[0]) / (dLine->tail()[1]-dLine->head()[1]); + /* + if(dLine->tail()[1] == vhead) + isHoriz = 1; + else + { + isHoriz = 0; + slop = (dLine->tail()[0] - dLine->head()[0]) / (dLine->tail()[1]-vhead); + } + */ + } + uinterc = slop * (grid_v_value - dLine->head()[1]) + dLine->head()[0]; + + //in case unterc is outside of the grid due to floating point + if(uinterc < uMin) + uinterc = uMin; + else if(uinterc > uMax) + uinterc = uMax; + +#ifdef SHORTEN_GRID_LINE + uintercBuf[k] = uinterc; +#endif + + tempMinU = min(tempMinU, uinterc); + + assert(uinterc >= uMin && uinterc <= uMax); + + if(uinterc == uMin) + ret_indices[k] = 0; + else + ret_indices[k] = (int)ceil((((uinterc-uMin)/(uMax - uMin)) * (n_ulines-1))) -1; +/* +if(ret_indices[k] >= grid->get_n_ulines()) + { + printf("ERROR3\n"); + exit(0); +} +if(ret_indices[k] < 0) + { + printf("ERROR4\n"); + exit(0); +} +*/ + ret_innerIndices[k] = (int)ceil ((((tempMinU-uMin)/(uMax - uMin)) * (n_ulines-1))) -1; + + tempMinU = uinterc; + } +#ifdef SHORTEN_GRID_LINE + //for each grid line, compare the left grid point with the + //intersection point. If the two points are too close, then + //we should move the grid point one grid to the right + //and accordingly we should update the inner index. + for(k=0, i=firstGridIndex; i>=lastGridIndex; i--, k++) + { + //check gridLine i + //check ret_indices[k] + Real a = grid->get_u_value(ret_indices[k]); + Real b = grid->get_u_value(ret_indices[k]+1); + assert(uintercBuf[k] > a && uintercBuf <= b); + if( (uintercBuf[k]-a) <= 0.2 * (b-a)) //interc is very close to a + { + ret_indices[k]--; + } + + //check ret_innerIndices[k] + if(k>0) + { + if(ret_innerIndices[k] > ret_indices[k-1]) + ret_innerIndices[k] = ret_indices[k-1]; + if(ret_innerIndices[k] > ret_indices[k]) + ret_innerIndices[k] = ret_indices[k]; + } + } + //clean up + free(uintercBuf); +#endif +} + + +void sampleMonoPoly(directedLine* polygon, gridWrap* grid, Int ulinear, Int vlinear, primStream* pStream, rectBlockArray* rbArray) +{ +/* +{ +grid->print(); +polygon->writeAllPolygons("zloutputFile"); +exit(0); +} +*/ + +if(grid->get_n_ulines() == 2 || + grid->get_n_vlines() == 2) +{ + if(ulinear && grid->get_n_ulines() == 2) + { + monoTriangulationFun(polygon, compV2InY, pStream); + return; + } + else if(DBG_isConvex(polygon) && polygon->numEdges() >=4) + { + triangulateConvexPoly(polygon, ulinear, vlinear, pStream); + return; + } + else if(vlinear || DBG_is_U_direction(polygon)) + { + Int n_cusps;//num interior cusps + Int n_edges = polygon->numEdges(); + directedLine** cusps = (directedLine**) malloc(sizeof(directedLine*) * n_edges); + assert(cusps); + findInteriorCuspsX(polygon, n_cusps, cusps); + + if(n_cusps == 0) //u_monotone + { + + monoTriangulationFun(polygon, compV2InX, pStream); + + free(cusps); + return; + } + else if(n_cusps == 1) //one interior cusp + { + + directedLine* new_polygon = polygonConvert(cusps[0]); + + directedLine* other = findDiagonal_singleCuspX( new_polygon); + + + + //<other> should NOT be null unless there are self-intersecting + //trim curves. In that case, we don't want to core dump, instead, + //we triangulate anyway, and print out error message. + if(other == NULL) + { + monoTriangulationFun(polygon, compV2InX, pStream); + free(cusps); + return; + } + + directedLine* ret_p1; + directedLine* ret_p2; + + new_polygon->connectDiagonal_2slines(new_polygon, other, + &ret_p1, + &ret_p2, + new_polygon); + + monoTriangulationFun(ret_p1, compV2InX, pStream); + monoTriangulationFun(ret_p2, compV2InX, pStream); + + ret_p1->deleteSinglePolygonWithSline(); + ret_p2->deleteSinglePolygonWithSline(); + + free(cusps); + return; + } + free(cusps); + } +} + + /*find the top and bottom of the polygon. It is supposed to be + *a V-monotone polygon + */ + + directedLine* tempV; + directedLine* topV; + directedLine* botV; + topV = botV = polygon; + + for(tempV = polygon->getNext(); tempV != polygon; tempV = tempV->getNext()) + { + if(compV2InY(topV->head(), tempV->head())<0) { + + topV = tempV; + } + if(compV2InY(botV->head(), tempV->head())>0) { + + botV = tempV; + } + } + + /*find the first(top) and the last (bottom) grid line which intersect the + *this polygon + */ + Int firstGridIndex; /*the index in the grid*/ + Int lastGridIndex; + firstGridIndex = (Int) ((topV->head()[1] - grid->get_v_min()) / (grid->get_v_max() - grid->get_v_min()) * (grid->get_n_vlines()-1)); + lastGridIndex = (Int) ((botV->head()[1] - grid->get_v_min()) / (grid->get_v_max() - grid->get_v_min()) * (grid->get_n_vlines()-1)) + 1; + + + /*find the interval inside the polygon for each gridline*/ + Int *leftGridIndices = (Int*) malloc(sizeof(Int) * (firstGridIndex - lastGridIndex +1)); + assert(leftGridIndices); + Int *rightGridIndices = (Int*) malloc(sizeof(Int) * (firstGridIndex - lastGridIndex +1)); + assert(rightGridIndices); + Int *leftGridInnerIndices = (Int*) malloc(sizeof(Int) * (firstGridIndex - lastGridIndex +1)); + assert(leftGridInnerIndices); + Int *rightGridInnerIndices = (Int*) malloc(sizeof(Int) * (firstGridIndex - lastGridIndex +1)); + assert(rightGridInnerIndices); + + findLeftGridIndices(topV, firstGridIndex, lastGridIndex, grid, leftGridIndices, leftGridInnerIndices); + + findRightGridIndices(topV, firstGridIndex, lastGridIndex, grid, rightGridIndices, rightGridInnerIndices); + + gridBoundaryChain leftGridChain(grid, firstGridIndex, firstGridIndex-lastGridIndex+1, leftGridIndices, leftGridInnerIndices); + + gridBoundaryChain rightGridChain(grid, firstGridIndex, firstGridIndex-lastGridIndex+1, rightGridIndices, rightGridInnerIndices); + + + +// leftGridChain.draw(); +// leftGridChain.drawInner(); +// rightGridChain.draw(); +// rightGridChain.drawInner(); + /*(1) determine the grid boundaries (left and right). + *(2) process polygon into two monotone chaines: use vertexArray + *(3) call sampleMonoPolyRec + */ + + /*copy the two chains into vertexArray datastructure*/ + Int i; + vertexArray leftChain(20); /*this is a dynamic array*/ + for(i=1; i<=topV->get_npoints()-2; i++) { /*the first vertex is the top vertex which doesn't belong to inc_chain*/ + leftChain.appendVertex(topV->getVertex(i)); + } + for(tempV = topV->getNext(); tempV != botV; tempV = tempV->getNext()) + { + for(i=0; i<=tempV->get_npoints()-2; i++){ + leftChain.appendVertex(tempV->getVertex(i)); + } + } + + vertexArray rightChain(20); + for(tempV = topV->getPrev(); tempV != botV; tempV = tempV->getPrev()) + { + for(i=tempV->get_npoints()-2; i>=0; i--){ + rightChain.appendVertex(tempV->getVertex(i)); + } + } + for(i=botV->get_npoints()-2; i>=1; i--){ + rightChain.appendVertex(tempV->getVertex(i)); + } + + sampleMonoPolyRec(topV->head(), + botV->head(), + &leftChain, + 0, + &rightChain, + 0, + &leftGridChain, + &rightGridChain, + 0, + pStream, + rbArray); + + + /*cleanup space*/ + free(leftGridIndices); + free(rightGridIndices); + free(leftGridInnerIndices); + free(rightGridInnerIndices); +} + +void sampleMonoPolyRec( + Real* topVertex, + Real* botVertex, + vertexArray* leftChain, + Int leftStartIndex, + vertexArray* rightChain, + Int rightStartIndex, + gridBoundaryChain* leftGridChain, + gridBoundaryChain* rightGridChain, + Int gridStartIndex, + primStream* pStream, + rectBlockArray* rbArray) +{ + + /*find the first connected component, and the four corners. + */ + Int index1, index2; /*the first and last grid line of the first connected component*/ + + if(topVertex[1] <= botVertex[1]) + return; + + /*find i so that the grid line is below the top vertex*/ + Int i=gridStartIndex; + while (i < leftGridChain->get_nVlines()) + { + if(leftGridChain->get_v_value(i) < topVertex[1]) + break; + i++; + } + + /*find the first connected component starting with i*/ + /*find index1 so that left_uline_index <= right_uline_index, that is, this + *grid line contains at least one inner grid point + */ + index1=i; + int num_skipped_grid_lines=0; + while(index1 < leftGridChain->get_nVlines()) + { + if(leftGridChain->getUlineIndex(index1) <= rightGridChain->getUlineIndex(index1)) + break; + num_skipped_grid_lines++; + index1++; + } + + + + if(index1 >= leftGridChain->get_nVlines()) /*no grid line exists which has inner point*/ + { + /*stop recursion, ...*/ + /*monotone triangulate it...*/ +// printf("no grid line exists\n"); +/* + monoTriangulationRecOpt(topVertex, botVertex, leftChain, leftStartIndex, + rightChain, rightStartIndex, pStream); +*/ + +if(num_skipped_grid_lines <2) + { + monoTriangulationRecGenOpt(topVertex, botVertex, leftChain, leftStartIndex, + leftChain->getNumElements()-1, + rightChain, rightStartIndex, + rightChain->getNumElements()-1, + pStream); + } +else + { + //the optimum way to triangulate is top-down since this polygon + //is narrow-long. + monoTriangulationRec(topVertex, botVertex, leftChain, leftStartIndex, + rightChain, rightStartIndex, pStream); + } + +/* + monoTriangulationRec(topVertex, botVertex, leftChain, leftStartIndex, + rightChain, rightStartIndex, pStream); +*/ + +/* monoTriangulationRecGenTBOpt(topVertex, botVertex, + leftChain, leftStartIndex, leftChain->getNumElements()-1, + rightChain, rightStartIndex, rightChain->getNumElements()-1, + pStream);*/ + + + + } + else + { + + /*find index2 so that left_inner_index <= right_inner_index holds until index2*/ + index2=index1+1; + if(index2 < leftGridChain->get_nVlines()) + while(leftGridChain->getInnerIndex(index2) <= rightGridChain->getInnerIndex(index2)) + { + index2++; + if(index2 >= leftGridChain->get_nVlines()) + break; + } + + index2--; + + + + /*the neck*/ + Int neckLeftIndex; + Int neckRightIndex; + + /*the four corners*/ + Int up_leftCornerWhere; + Int up_leftCornerIndex; + Int up_rightCornerWhere; + Int up_rightCornerIndex; + Int down_leftCornerWhere; + Int down_leftCornerIndex; + Int down_rightCornerWhere; + Int down_rightCornerIndex; + + Real* tempBotVertex; /*the bottom vertex for this component*/ + Real* nextTopVertex=NULL; /*for the recursion*/ + Int nextLeftStartIndex=0; + Int nextRightStartIndex=0; + + /*find the points below the grid line index2 on both chains*/ + Int botLeftIndex = leftChain->findIndexStrictBelowGen( + leftGridChain->get_v_value(index2), + leftStartIndex, + leftChain->getNumElements()-1); + Int botRightIndex = rightChain->findIndexStrictBelowGen( + rightGridChain->get_v_value(index2), + rightStartIndex, + rightChain->getNumElements()-1); + /*if either botLeftIndex>= numelements, + * or botRightIndex >= numelemnet, + *then there is no neck exists. the bottom vertex is botVertex, + */ + if(! findNeckF(leftChain, botLeftIndex, rightChain, botRightIndex, + leftGridChain, rightGridChain, index2, neckLeftIndex, neckRightIndex)) + /* + if(botLeftIndex == leftChain->getNumElements() || + botRightIndex == rightChain->getNumElements()) + */ + { +#ifdef MYDEBUG + printf("neck NOT exists, botRightIndex=%i\n", botRightIndex); +#endif + + tempBotVertex = botVertex; + nextTopVertex = botVertex; + botLeftIndex = leftChain->getNumElements()-1; + botRightIndex = rightChain->getNumElements()-1; + } + else /*neck exists*/ + { +#ifdef MYDEBUG + printf("neck exists\n"); +#endif + + /* + findNeck(leftChain, botLeftIndex, + rightChain, botRightIndex, + neckLeftIndex, + neckRightIndex); + */ +#ifdef MYDEBUG +printf("neck is found, neckLeftIndex=%i, neckRightIndex=%i\n", neckLeftIndex, neckRightIndex); +glBegin(GL_LINES); +glVertex2fv(leftChain->getVertex(neckLeftIndex)); +glVertex2fv(rightChain->getVertex(neckRightIndex)); +glEnd(); +#endif + + if(leftChain->getVertex(neckLeftIndex)[1] <= rightChain->getVertex(neckRightIndex)[1]) + { + tempBotVertex = leftChain->getVertex(neckLeftIndex); + botLeftIndex = neckLeftIndex-1; + botRightIndex = neckRightIndex; + nextTopVertex = rightChain->getVertex(neckRightIndex); + nextLeftStartIndex = neckLeftIndex; + nextRightStartIndex = neckRightIndex+1; + } + else + { + tempBotVertex = rightChain->getVertex(neckRightIndex); + botLeftIndex = neckLeftIndex; + botRightIndex = neckRightIndex-1; + nextTopVertex = leftChain->getVertex(neckLeftIndex); + nextLeftStartIndex = neckLeftIndex+1; + nextRightStartIndex = neckRightIndex; + } + } + + findUpCorners(topVertex, + leftChain, + leftStartIndex, botLeftIndex, + rightChain, + rightStartIndex, botRightIndex, + leftGridChain->get_v_value(index1), + leftGridChain->get_u_value(index1), + rightGridChain->get_u_value(index1), + up_leftCornerWhere, + up_leftCornerIndex, + up_rightCornerWhere, + up_rightCornerIndex); + + findDownCorners(tempBotVertex, + leftChain, + leftStartIndex, botLeftIndex, + rightChain, + rightStartIndex, botRightIndex, + leftGridChain->get_v_value(index2), + leftGridChain->get_u_value(index2), + rightGridChain->get_u_value(index2), + down_leftCornerWhere, + down_leftCornerIndex, + down_rightCornerWhere, + down_rightCornerIndex); +#ifdef MYDEBUG + printf("find corners done, down_leftwhere=%i, down_righwhere=%i,\n",down_leftCornerWhere, down_rightCornerWhere ); + printf("find corners done, up_leftwhere=%i, up_righwhere=%i,\n",up_leftCornerWhere, up_rightCornerWhere ); + printf("find corners done, up_leftindex=%i, up_righindex=%i,\n",up_leftCornerIndex, up_rightCornerIndex ); + printf("find corners done, down_leftindex=%i, down_righindex=%i,\n",down_leftCornerIndex, down_rightCornerIndex ); +#endif + +/* + drawCorners(topVertex, + tempBotVertex, + leftChain, + rightChain, + leftGridChain, + rightGridChain, + index1, + index2, + up_leftCornerWhere, + up_leftCornerIndex, + up_rightCornerWhere, + up_rightCornerIndex, + down_leftCornerWhere, + down_leftCornerIndex, + down_rightCornerWhere, + down_rightCornerIndex); +*/ + + + sampleConnectedComp(topVertex, tempBotVertex, + leftChain, + leftStartIndex, botLeftIndex, + rightChain, + rightStartIndex, botRightIndex, + leftGridChain, + rightGridChain, + index1, index2, + up_leftCornerWhere, + up_leftCornerIndex, + up_rightCornerWhere, + up_rightCornerIndex, + down_leftCornerWhere, + down_leftCornerIndex, + down_rightCornerWhere, + down_rightCornerIndex, + pStream, + rbArray + ); + + /*recursion*/ + + sampleMonoPolyRec( + nextTopVertex, + botVertex, + leftChain, + nextLeftStartIndex, + rightChain, + nextRightStartIndex, + leftGridChain, + rightGridChain, + index2+1, + pStream, rbArray); + + + } + +} + +void sampleLeftStrip(vertexArray* leftChain, + Int topLeftIndex, + Int botLeftIndex, + gridBoundaryChain* leftGridChain, + Int leftGridChainStartIndex, + Int leftGridChainEndIndex, + primStream* pStream + ) +{ + assert(leftChain->getVertex(topLeftIndex)[1] > leftGridChain->get_v_value(leftGridChainStartIndex)); + assert(leftChain->getVertex(topLeftIndex+1)[1] <= leftGridChain->get_v_value(leftGridChainStartIndex)); + assert(leftChain->getVertex(botLeftIndex)[1] <= leftGridChain->get_v_value(leftGridChainEndIndex)); + assert(leftChain->getVertex(botLeftIndex-1)[1] > leftGridChain->get_v_value(leftGridChainEndIndex)); + + /* + *(1)find the last grid line which doesn'; pass below + * this first edge, sample this region: one trim edge and + * possily multiple grid lines. + */ + Real *upperVert, *lowerVert; /*the end points of the first trim edge*/ + upperVert = leftChain->getVertex(topLeftIndex); + lowerVert = leftChain->getVertex(topLeftIndex+1); + + Int index = leftGridChainStartIndex; + while(leftGridChain->get_v_value(index) >= lowerVert[1]){ + index++; + if(index > leftGridChainEndIndex) + break; + } + index--; + + sampleLeftSingleTrimEdgeRegion(upperVert, lowerVert, + leftGridChain, + leftGridChainStartIndex, + index, + pStream); + sampleLeftStripRec(leftChain, topLeftIndex+1, botLeftIndex, + leftGridChain, index, leftGridChainEndIndex, + pStream); + +} + +void sampleLeftStripRec(vertexArray* leftChain, + Int topLeftIndex, + Int botLeftIndex, + gridBoundaryChain* leftGridChain, + Int leftGridChainStartIndex, + Int leftGridChainEndIndex, + primStream* pStream + ) +{ + /*now top left trim vertex is below the top grid line. + */ + /*stop condition: if topLeftIndex >= botLeftIndex, then stop. + */ + if(topLeftIndex >= botLeftIndex) + return; + + /*find the last trim vertex which is above the second top grid line: + * index1. + *and sampleLeftOneGridStep(leftchain, topLeftIndex, index1, leftGridChain, + * leftGridChainStartIndex). + * index1 could be equal to topLeftIndex. + */ + Real secondGridChainV = leftGridChain->get_v_value(leftGridChainStartIndex+1); + assert(leftGridChainStartIndex < leftGridChainEndIndex); + Int index1 = topLeftIndex; + while(leftChain->getVertex(index1)[1] > secondGridChainV) + index1++; + index1--; + + sampleLeftOneGridStep(leftChain, topLeftIndex, index1, leftGridChain, leftGridChainStartIndex, pStream); + + + /* + * Let the next trim vertex be nextTrimVertIndex (which should be + * below the second grid line). + * Find the last grid line index2 which is above nextTrimVert. + * sampleLeftSingleTrimEdgeRegion(uppervert[2], lowervert[2], + * leftGridChain, leftGridChainStartIndex+1, index2). + */ + Real *uppervert, *lowervert; + uppervert = leftChain->getVertex(index1); + lowervert = leftChain->getVertex(index1+1); + Int index2 = leftGridChainStartIndex+1; + + while(leftGridChain->get_v_value(index2) >= lowervert[1]) + { + index2++; + if(index2 > leftGridChainEndIndex) + break; + } + index2--; + sampleLeftSingleTrimEdgeRegion(uppervert, lowervert, leftGridChain, leftGridChainStartIndex+1, index2, pStream); + + /* sampleLeftStripRec(leftChain, + nextTrimVertIndex, + botLeftIndex, + leftGridChain, + index2, + leftGridChainEndIndex + ) + * + */ + sampleLeftStripRec(leftChain, index1+1, botLeftIndex, leftGridChain, index2, leftGridChainEndIndex, pStream); + +} + + +/***************begin RecF***********************/ +/* the gridlines from leftGridChainStartIndex to + * leftGridChainEndIndex are assumed to form a + * connected component. + * the trim vertex of topLeftIndex is assumed to + * be below the first gridline, and the tim vertex + * of botLeftIndex is assumed to be above the last + * grid line. + * If botLeftIndex < topLeftIndex, then no connected componeent exists, and this funcion returns without + * outputing any triangles. + * Otherwise botLeftIndex >= topLeftIndex, there is at least one triangle to output. + */ +void sampleLeftStripRecF(vertexArray* leftChain, + Int topLeftIndex, + Int botLeftIndex, + gridBoundaryChain* leftGridChain, + Int leftGridChainStartIndex, + Int leftGridChainEndIndex, + primStream* pStream + ) +{ + /*now top left trim vertex is below the top grid line. + */ + /*stop condition: if topLeftIndex > botLeftIndex, then stop. + */ + if(topLeftIndex > botLeftIndex) + return; + + /*if there is only one grid Line, return.*/ + + if(leftGridChainStartIndex>=leftGridChainEndIndex) + return; + + + assert(leftChain->getVertex(topLeftIndex)[1] <= leftGridChain->get_v_value(leftGridChainStartIndex) && + leftChain->getVertex(botLeftIndex)[1] >= leftGridChain->get_v_value(leftGridChainEndIndex)); + + /*firs find the first trim vertex which is below or equal to the second top grid line: + * index1. + */ + Real secondGridChainV = leftGridChain->get_v_value(leftGridChainStartIndex+1); + + + Int index1 = topLeftIndex; + + while(leftChain->getVertex(index1)[1] > secondGridChainV){ + index1++; + if(index1>botLeftIndex) + break; + } + + /*now leftChain->getVertex(index-1)[1] > secondGridChainV and + * leftChain->getVertex(index)[1] <= secondGridChainV + *If equality holds, then we should include the vertex index1, otherwise we include only index1-1, to + *perform sampleOneGridStep. + */ + if(index1>botLeftIndex) + index1--; + else if(leftChain->getVertex(index1)[1] < secondGridChainV) + index1--; + + /*now we have leftChain->getVertex(index1)[1] >= secondGridChainV, and + * leftChain->getVertex(index1+1)[1] <= secondGridChainV + */ + + + sampleLeftOneGridStep(leftChain, topLeftIndex, index1, leftGridChain, leftGridChainStartIndex, pStream); + + + /*if leftChain->getVertex(index1)[1] == secondGridChainV, then we can recursively do the rest. + */ + if(leftChain->getVertex(index1)[1] == secondGridChainV) + { + + sampleLeftStripRecF(leftChain, index1, botLeftIndex,leftGridChain, leftGridChainStartIndex+1, leftGridChainEndIndex, pStream); + } + else if(index1 < botLeftIndex) + { + + /* Otherwise, we have leftChain->getVertex(index1)[1] > secondGridChainV, + * let the next trim vertex be nextTrimVertIndex (which should be strictly + * below the second grid line). + * Find the last grid line index2 which is above nextTrimVert. + * sampleLeftSingleTrimEdgeRegion(uppervert[2], lowervert[2], + * leftGridChain, leftGridChainStartIndex+1, index2). + */ + Real *uppervert, *lowervert; + uppervert = leftChain->getVertex(index1); + lowervert = leftChain->getVertex(index1+1); //okay since index1<botLeftIndex + Int index2 = leftGridChainStartIndex+1; + + + while(leftGridChain->get_v_value(index2) >= lowervert[1]) + { + index2++; + if(index2 > leftGridChainEndIndex) + break; + } + index2--; + + + sampleLeftSingleTrimEdgeRegion(uppervert, lowervert, leftGridChain, leftGridChainStartIndex+1, index2, pStream); + + /*recursion*/ + + sampleLeftStripRecF(leftChain, index1+1, botLeftIndex, leftGridChain, index2, leftGridChainEndIndex, pStream); + } + +} + +/***************End RecF***********************/ + +/*sample the left area in between one trim edge and multiple grid lines. + * all the grid lines should be in between the two end poins of the + *trim edge. + */ +void sampleLeftSingleTrimEdgeRegion(Real upperVert[2], Real lowerVert[2], + gridBoundaryChain* gridChain, + Int beginIndex, + Int endIndex, + primStream* pStream) +{ + Int i,j,k; + + vertexArray vArray(endIndex-beginIndex+1); + vArray.appendVertex(gridChain->get_vertex(beginIndex)); + + for(k=1, i=beginIndex+1; i<=endIndex; i++, k++) + { + vArray.appendVertex(gridChain->get_vertex(i)); + + /*output the fan of the grid points of the (i)th and (i-1)th grid line. + */ + if(gridChain->getUlineIndex(i) < gridChain->getUlineIndex(i-1)) + { + pStream->begin(); + pStream->insert(gridChain->get_vertex(i-1)); + for(j=gridChain->getUlineIndex(i); j<= gridChain->getUlineIndex(i-1); j++) + pStream->insert(gridChain->getGrid()->get_u_value(j), gridChain->get_v_value(i)); + pStream->end(PRIMITIVE_STREAM_FAN); + } + else if(gridChain->getUlineIndex(i) > gridChain->getUlineIndex(i-1)) + { + pStream->begin(); + pStream->insert(gridChain->get_vertex(i)); + for(j=gridChain->getUlineIndex(i); j>= gridChain->getUlineIndex(i-1); j--) + pStream->insert(gridChain->getGrid()->get_u_value(j), gridChain->get_v_value(i-1)); + pStream->end(PRIMITIVE_STREAM_FAN); + } + /*otherwisem, the two are equal, so there is no fan to outout*/ + } + + monoTriangulation2(upperVert, lowerVert, &vArray, 0, endIndex-beginIndex, + 0, /*decreasing chain*/ + pStream); +} + +/*return i, such that from begin to i-1 the chain is strictly u-monotone. + */ +Int findIncreaseChainFromBegin(vertexArray* chain, Int begin ,Int end) +{ + Int i=begin; + Real prevU = chain->getVertex(i)[0]; + Real thisU; + for(i=begin+1; i<=end; i++){ + thisU = chain->getVertex(i)[0]; + + if(prevU < thisU){ + prevU = thisU; + } + else + break; + } + return i; +} + +/*check whether there is a vertex whose v value is strictly + *inbetween vup vbelow + *if no middle exists return -1, else return the idnex. + */ +Int checkMiddle(vertexArray* chain, Int begin, Int end, + Real vup, Real vbelow) +{ + Int i; + for(i=begin; i<=end; i++) + { + if(chain->getVertex(i)[1] < vup && chain->getVertex(i)[1]>vbelow) + return i; + } + return -1; +} + +/*the degenerat case of sampleLeftOneGridStep*/ +void sampleLeftOneGridStepNoMiddle(vertexArray* leftChain, + Int beginLeftIndex, + Int endLeftIndex, + gridBoundaryChain* leftGridChain, + Int leftGridChainStartIndex, + primStream* pStream) +{ + /*since there is no middle, there is at most one point which is on the + *second grid line, there could be multiple points on the first (top) + *grid line. + */ + + leftGridChain->leftEndFan(leftGridChainStartIndex+1, pStream); + + monoTriangulation2(leftGridChain->get_vertex(leftGridChainStartIndex), + leftGridChain->get_vertex(leftGridChainStartIndex+1), + leftChain, + beginLeftIndex, + endLeftIndex, + 1, //is increase chain. + pStream); +} + + + +/*sampling the left area in between two grid lines. + */ +void sampleLeftOneGridStep(vertexArray* leftChain, + Int beginLeftIndex, + Int endLeftIndex, + gridBoundaryChain* leftGridChain, + Int leftGridChainStartIndex, + primStream* pStream + ) +{ + if(checkMiddle(leftChain, beginLeftIndex, endLeftIndex, + leftGridChain->get_v_value(leftGridChainStartIndex), + leftGridChain->get_v_value(leftGridChainStartIndex+1))<0) + + { + + sampleLeftOneGridStepNoMiddle(leftChain, beginLeftIndex, endLeftIndex, leftGridChain, leftGridChainStartIndex, pStream); + return; + } + + //copy into a polygon + { + directedLine* poly = NULL; + sampledLine* sline; + directedLine* dline; + gridWrap* grid = leftGridChain->getGrid(); + Real vert1[2]; + Real vert2[2]; + Int i; + + Int innerInd = leftGridChain->getInnerIndex(leftGridChainStartIndex+1); + Int upperInd = leftGridChain->getUlineIndex(leftGridChainStartIndex); + Int lowerInd = leftGridChain->getUlineIndex(leftGridChainStartIndex+1); + Real upperV = leftGridChain->get_v_value(leftGridChainStartIndex); + Real lowerV = leftGridChain->get_v_value(leftGridChainStartIndex+1); + + //the upper gridline + vert1[1] = vert2[1] = upperV; + for(i=innerInd; i>upperInd; i--) + { + vert1[0]=grid->get_u_value(i); + vert2[0]=grid->get_u_value(i-1); + sline = new sampledLine(vert1, vert2); + dline = new directedLine(INCREASING, sline); + if(poly == NULL) + poly = dline; + else + poly->insert(dline); + } + + //the edge connecting upper grid with left chain + vert1[0] = grid->get_u_value(upperInd); + vert1[1] = upperV; + sline = new sampledLine(vert1, leftChain->getVertex(beginLeftIndex)); + dline = new directedLine(INCREASING, sline); + if(poly == NULL) + poly = dline; + else + poly->insert(dline); + + //the left chain + for(i=beginLeftIndex; i<endLeftIndex; i++) + { + sline = new sampledLine(leftChain->getVertex(i), leftChain->getVertex(i+1)); + dline = new directedLine(INCREASING, sline); + poly->insert(dline); + } + + //the edge connecting left chain with lower gridline + vert2[0] = grid->get_u_value(lowerInd); + vert2[1] = lowerV; + sline = new sampledLine(leftChain->getVertex(endLeftIndex), vert2); + dline = new directedLine(INCREASING, sline); + poly->insert(dline); + + //the lower grid line + vert1[1] = vert2[1] = lowerV; + for(i=lowerInd; i<innerInd; i++) + { + vert1[0] = grid->get_u_value(i); + vert2[0] = grid->get_u_value(i+1); + sline = new sampledLine(vert1, vert2); + dline = new directedLine(INCREASING, sline); + poly->insert(dline); + } + + //the vertical grid line segement + vert1[0]=vert2[0] = grid->get_u_value(innerInd); + vert2[1]=upperV; + vert1[1]=lowerV; + sline=new sampledLine(vert1, vert2); + dline=new directedLine(INCREASING, sline); + poly->insert(dline); + monoTriangulationOpt(poly, pStream); + //cleanup + poly->deleteSinglePolygonWithSline(); + return; + } + + + + + + Int i; + if(1/*leftGridChain->getUlineIndex(leftGridChainStartIndex) >= + leftGridChain->getUlineIndex(leftGridChainStartIndex+1)*/ + ) /*the second grid line is beyond the first one to the left*/ + { + /*find the maximal U-monotone chain + * of endLeftIndex, endLeftIndex-1, ..., + */ + i=endLeftIndex; + Real prevU = leftChain->getVertex(i)[0]; + for(i=endLeftIndex-1; i>=beginLeftIndex; i--){ + Real thisU = leftChain->getVertex(i)[0]; + if( prevU < thisU){ + prevU = thisU; + } + else + break; + } + /*from endLeftIndex to i+1 is strictly U- monotone */ + /*if i+1==endLeftIndex and the vertex and leftchain is on the second gridline, then + *we should use 2 vertices on the leftchain. If we only use one (endLeftIndex), then we + *we would output degenerate triangles + */ + if(i+1 == endLeftIndex && leftChain->getVertex(endLeftIndex)[1] == leftGridChain->get_v_value(1+leftGridChainStartIndex)) + i--; + + Int j = beginLeftIndex/*endLeftIndex*/+1; + + + if(leftGridChain->getInnerIndex(leftGridChainStartIndex+1) > leftGridChain->getUlineIndex(leftGridChainStartIndex)) + { + j = findIncreaseChainFromBegin(leftChain, beginLeftIndex, i+1/*endLeftIndex*/); + + Int temp = beginLeftIndex; + /*now from begin to j-1 is strictly u-monotone*/ + /*if j-1 is on the first grid line, then we want to skip to the vertex which is strictly + *below the grid line. This vertexmust exist since there is a 'corner turn' inbetween the two grid lines + */ + if(j-1 == beginLeftIndex) + { + while(leftChain->getVertex(j-1)[1] == leftGridChain->get_v_value(leftGridChainStartIndex)) + j++; + + Real vert[2]; + vert[0] = leftGridChain->get_u_value(leftGridChainStartIndex); + vert[1] = leftGridChain->get_v_value(leftGridChainStartIndex); + + monoTriangulation2( + vert/*leftChain->getVertex(beginLeftIndex)*/, + leftChain->getVertex(j-1), + leftChain, + beginLeftIndex, + j-2, + 1, + pStream //increase chain + ); + + temp = j-1; + } + + stripOfFanLeft(leftChain, j-1, temp/*beginLeftIndex*/, leftGridChain->getGrid(), + leftGridChain->getVlineIndex(leftGridChainStartIndex), + leftGridChain->getUlineIndex(leftGridChainStartIndex), + leftGridChain->getInnerIndex(leftGridChainStartIndex+1), + pStream, + 1 /*the grid line is above the trim line*/ + ); + } + + stripOfFanLeft(leftChain, endLeftIndex, i+1, leftGridChain->getGrid(), + leftGridChain->getVlineIndex(leftGridChainStartIndex+1), + leftGridChain->getUlineIndex(leftGridChainStartIndex+1), + leftGridChain->getInnerIndex(leftGridChainStartIndex+1), + pStream, + 0 /*the grid line is below the trim lines*/ + ); + + /*monotone triangulate the remaining left chain togther with the + *two vertices on the two grid v-lines. + */ + Real vert[2][2]; + vert[0][0]=vert[1][0] = leftGridChain->getInner_u_value(leftGridChainStartIndex+1); + vert[0][1] = leftGridChain->get_v_value(leftGridChainStartIndex); + vert[1][1] = leftGridChain->get_v_value(leftGridChainStartIndex+1); + +// vertexArray right(vert, 2); + + monoTriangulation2( + &vert[0][0], /*top vertex */ + &vert[1][0], /*bottom vertex*/ + leftChain, + /*beginLeftIndex*/j-1, + i+1, + 1, /*an increasing chain*/ + pStream); + } + else /*the second one is shorter than the first one to the left*/ + { + /*find the maximal U-monotone chain of beginLeftIndex, beginLeftIndex+1,..., + */ + i=beginLeftIndex; + Real prevU = leftChain->getVertex(i)[0]; + for(i=beginLeftIndex+1; i<=endLeftIndex; i++){ + Real thisU = leftChain->getVertex(i)[0]; + + if(prevU < thisU){ + prevU = thisU; + } + else + break; + } + /*from beginLeftIndex to i-1 is strictly U-monotone*/ + + + stripOfFanLeft(leftChain, i-1, beginLeftIndex, leftGridChain->getGrid(), + leftGridChain->getVlineIndex(leftGridChainStartIndex), + leftGridChain->getUlineIndex(leftGridChainStartIndex), + leftGridChain->getUlineIndex(leftGridChainStartIndex+1), + pStream, + 1 /*the grid line is above the trim lines*/ + ); + /*monotone triangulate the remaining left chain together with the + *two vertices on the two grid v-lines. + */ + Real vert[2][2]; + vert[0][0]=vert[1][0] = leftGridChain->get_u_value(leftGridChainStartIndex+1); + vert[0][1] = leftGridChain->get_v_value(leftGridChainStartIndex); + vert[1][1] = leftGridChain->get_v_value(leftGridChainStartIndex+1); + + vertexArray right(vert, 2); + + monoTriangulation2( + &vert[0][0], //top vertex + &vert[1][0], //bottom vertex + leftChain, + i-1, + endLeftIndex, + 1, /*an increase chain*/ + pStream); + + } +} + +/*n_upper>=1 + *n_lower>=1 + */ +void triangulateXYMono(Int n_upper, Real upperVerts[][2], + Int n_lower, Real lowerVerts[][2], + primStream* pStream) +{ + Int i,j,k,l; + Real* leftMostV; + + assert(n_upper>=1 && n_lower>=1); + if(upperVerts[0][0] <= lowerVerts[0][0]) + { + i=1; + j=0; + leftMostV = upperVerts[0]; + } + else + { + i=0; + j=1; + leftMostV = lowerVerts[0]; + } + + while(1) + { + if(i >= n_upper) /*case1: no more in upper*/ + { + + if(j<n_lower-1) /*at least two vertices in lower*/ + { + pStream->begin(); + pStream->insert(leftMostV); + while(j<n_lower){ + pStream->insert(lowerVerts[j]); + j++; + } + pStream->end(PRIMITIVE_STREAM_FAN); + } + + break; + } + else if(j>= n_lower) /*case2: no more in lower*/ + { + + if(i<n_upper-1) /*at least two vertices in upper*/ + { + pStream->begin(); + pStream->insert(leftMostV); + + for(k=n_upper-1; k>=i; k--) + pStream->insert(upperVerts[k]); + + pStream->end(PRIMITIVE_STREAM_FAN); + } + + break; + } + else /* case3: neither is empty, plus the leftMostV, there is at least one triangle to output*/ + { + + if(upperVerts[i][0] <= lowerVerts[j][0]) + { + pStream->begin(); + pStream->insert(lowerVerts[j]); /*the origin of this fan*/ + + /*find the last k>=i such that + *upperverts[k][0] <= lowerverts[j][0] + */ + k=i; + while(k<n_upper) + { + if(upperVerts[k][0] > lowerVerts[j][0]) + break; + k++; + } + k--; + for(l=k; l>=i; l--)/*the reverse is for two-face lighting*/ + { + pStream->insert(upperVerts[l]); + } + pStream->insert(leftMostV); + + pStream->end(PRIMITIVE_STREAM_FAN); + //update i for next loop + i = k+1; + leftMostV = upperVerts[k]; + + } + else /*upperVerts[i][0] > lowerVerts[j][0]*/ + { + pStream->begin(); + pStream->insert(upperVerts[i]);/*the origion of this fan*/ + pStream->insert(leftMostV); + /*find the last k>=j such that + *lowerverts[k][0] < upperverts[i][0]*/ + k=j; + while(k< n_lower) + { + if(lowerVerts[k][0] >= upperVerts[i][0]) + break; + pStream->insert(lowerVerts[k]); + k++; + } + pStream->end(PRIMITIVE_STREAM_FAN); + j=k; + leftMostV = lowerVerts[j-1]; + } + } + } +} + + +void stripOfFanLeft(vertexArray* leftChain, + Int largeIndex, + Int smallIndex, + gridWrap* grid, + Int vlineIndex, + Int ulineSmallIndex, + Int ulineLargeIndex, + primStream* pStream, + Int gridLineUp /*1 if the grid line is above the trim lines*/ + ) +{ + assert(largeIndex >= smallIndex); + + Real grid_v_value; + grid_v_value = grid->get_v_value(vlineIndex); + + Real2* trimVerts=(Real2*) malloc(sizeof(Real2)* (largeIndex-smallIndex+1)); + assert(trimVerts); + + + Real2* gridVerts=(Real2*) malloc(sizeof(Real2)* (ulineLargeIndex-ulineSmallIndex+1)); + assert(gridVerts); + + Int k,i; + if(gridLineUp) /*trim line is below grid line, so trim vertices are going right when index increases*/ + for(k=0, i=smallIndex; i<=largeIndex; i++, k++) + { + trimVerts[k][0] = leftChain->getVertex(i)[0]; + trimVerts[k][1] = leftChain->getVertex(i)[1]; + } + else + for(k=0, i=largeIndex; i>=smallIndex; i--, k++) + { + trimVerts[k][0] = leftChain->getVertex(i)[0]; + trimVerts[k][1] = leftChain->getVertex(i)[1]; + } + + for(k=0, i=ulineSmallIndex; i<= ulineLargeIndex; i++, k++) + { + gridVerts[k][0] = grid->get_u_value(i); + gridVerts[k][1] = grid_v_value; + } + + if(gridLineUp) + triangulateXYMono( + ulineLargeIndex-ulineSmallIndex+1, gridVerts, + largeIndex-smallIndex+1, trimVerts, + pStream); + else + triangulateXYMono(largeIndex-smallIndex+1, trimVerts, + ulineLargeIndex-ulineSmallIndex+1, gridVerts, + pStream); + free(trimVerts); + free(gridVerts); +} + + + + + |