diff options
author | Brian Paul <[email protected]> | 2001-03-17 00:25:40 +0000 |
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committer | Brian Paul <[email protected]> | 2001-03-17 00:25:40 +0000 |
commit | 77cc447b96a75106354da02437c4e868265d27bb (patch) | |
tree | 06336e071d4786d72d681c72d68126191f0b2993 /src/glu/sgi/libnurbs/nurbtess/polyDBG.cc | |
parent | 24fab8e2507d9ccc45c1a94de0ad44088cfb8738 (diff) |
SGI SI GLU library
Diffstat (limited to 'src/glu/sgi/libnurbs/nurbtess/polyDBG.cc')
-rw-r--r-- | src/glu/sgi/libnurbs/nurbtess/polyDBG.cc | 730 |
1 files changed, 730 insertions, 0 deletions
diff --git a/src/glu/sgi/libnurbs/nurbtess/polyDBG.cc b/src/glu/sgi/libnurbs/nurbtess/polyDBG.cc new file mode 100644 index 00000000000..bdf16ef96ec --- /dev/null +++ b/src/glu/sgi/libnurbs/nurbtess/polyDBG.cc @@ -0,0 +1,730 @@ +/* +** 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/polyDBG.cc,v 1.1 2001/03/17 00:25:41 brianp Exp $ +*/ + +#include <stdlib.h> +#include <stdio.h> +#include <math.h> +#include "zlassert.h" +#include "polyDBG.h" + + +static Real area(Real A[2], Real B[2], Real C[2]) +{ + Real Bx, By, Cx, Cy; + Bx = B[0] - A[0]; + By = B[1] - A[1]; + Cx = C[0] - A[0]; + Cy = C[1] - A[1]; + return Bx*Cy - Cx*By; +} + +Int DBG_isConvex(directedLine *poly) +{ + directedLine* temp; + if(area(poly->head(), poly->tail(), poly->getNext()->tail()) < 0.00000) + return 0; + for(temp = poly->getNext(); temp != poly; temp = temp->getNext()) + { + if(area(temp->head(), temp->tail(), temp->getNext()->tail()) < 0.00000) + return 0; + } + return 1; +} + +Int DBG_is_U_monotone(directedLine* poly) +{ + Int n_changes = 0; + Int prev_sign; + Int cur_sign; + directedLine* temp; + cur_sign = compV2InX(poly->tail(), poly->head()); + + n_changes = (compV2InX(poly->getPrev()->tail(), poly->getPrev()->head()) + != cur_sign); + + for(temp = poly->getNext(); temp != poly; temp = temp->getNext()) + { + prev_sign = cur_sign; + cur_sign = compV2InX(temp->tail(), temp->head()); + + if(cur_sign != prev_sign) + n_changes++; + } + + if(n_changes ==2) return 1; + else return 0; +} + +/*if u-monotone, and there is a long horizontal edge*/ +Int DBG_is_U_direction(directedLine* poly) +{ +/* + if(! DBG_is_U_monotone(poly)) + return 0; +*/ + Int V_count = 0; + Int U_count = 0; + directedLine* temp; + if( fabs(poly->head()[0] - poly->tail()[0]) <= fabs(poly->head()[1]-poly->tail()[1])) + V_count += poly->get_npoints(); + else + U_count += poly->get_npoints(); + /* + else if(poly->head()[1] == poly->tail()[1]) + U_count += poly->get_npoints(); + */ + for(temp = poly->getNext(); temp != poly; temp = temp->getNext()) + { + if( fabs(temp->head()[0] - temp->tail()[0]) <= fabs(temp->head()[1]-temp->tail()[1])) + V_count += temp->get_npoints(); + else + U_count += temp->get_npoints(); + /* + if(temp->head()[0] == temp->tail()[0]) + V_count += temp->get_npoints(); + else if(temp->head()[1] == temp->tail()[1]) + U_count += temp->get_npoints(); + */ + } + + if(U_count > V_count) return 1; + else return 0; +} + +/*given two line segments, determine whether + *they intersect each other or not. + *return 1 if they do, + *return 0 otherwise + */ +Int DBG_edgesIntersect(directedLine* l1, directedLine* l2) +{ + if(l1->getNext() == l2) + { + if(area(l1->head(), l1->tail(), l2->tail()) == 0) //colinear + { + if( (l1->tail()[0] - l1->head()[0])*(l2->tail()[0]-l2->head()[0]) + + (l1->tail()[1] - l1->head()[1])*(l2->tail()[1]-l2->head()[1]) >=0) + return 0; //not intersect + else + return 1; + } + //else we use the normal code + } + else if(l1->getPrev() == l2) + { + if(area(l2->head(), l2->tail(), l1->tail()) == 0) //colinear + { + if( (l2->tail()[0] - l2->head()[0])*(l1->tail()[0]-l1->head()[0]) + + (l2->tail()[1] - l2->head()[1])*(l1->tail()[1]-l1->head()[1]) >=0) + return 0; //not intersect + else + return 1; + } + //else we use the normal code + } + else //the two edges are not connected + { + if((l1->head()[0] == l2->head()[0] && + l1->head()[1] == l2->head()[1]) || + (l1->tail()[0] == l2->tail()[0] && + l1->tail()[1] == l2->tail()[1])) + return 1; + + } + + + if( + ( + area(l1->head(), l1->tail(), l2->head()) + * + area(l1->head(), l1->tail(), l2->tail()) + < 0 + ) + && + ( + area(l2->head(), l2->tail(), l1->head()) + *area(l2->head(), l2->tail(), l1->tail()) + < 0 + ) + ) + return 1; + else + return 0; +} + +/*whether AB and CD intersect + *return 1 if they do + *retur 0 otheriwse + */ +Int DBG_edgesIntersectGen(Real A[2], Real B[2], Real C[2], Real D[2]) +{ + if( + ( + area(A, B, C) * area(A,B,D) <0 + ) + && + ( + area(C,D,A) * area(C,D,B) < 0 + ) + ) + return 1; + else + return 0; +} + +/*determien whether (A,B) interesect chain[start] to [end] + */ +Int DBG_intersectChain(vertexArray* chain, Int start, Int end, Real A[2], Real B[2]) +{ + Int i; + for(i=start; i<=end-2; i++) + if(DBG_edgesIntersectGen(chain->getVertex(i), chain->getVertex(i+1), A, B)) + return 1; + + return 0; +} + +/*determine whether a polygon intersect itself or not + *return 1 is it does, + * 0 otherwise + */ +Int DBG_polygonSelfIntersect(directedLine* poly) +{ + directedLine* temp1; + directedLine* temp2; + temp1=poly; + for(temp2=temp1->getNext(); temp2 != temp1; temp2=temp2->getNext()) + { + if(DBG_edgesIntersect(temp1, temp2)) + { + return 1; + } + + } + + for(temp1=poly->getNext(); temp1 != poly; temp1 = temp1->getNext()) + for(temp2=temp1->getNext(); temp2 != temp1; temp2=temp2->getNext()) + { + if(DBG_edgesIntersect(temp1, temp2)) + { + return 1; + } + } + return 0; +} + +/*check whether a line segment intersects a polygon + */ +Int DBG_edgeIntersectPoly(directedLine* edge, directedLine* poly) +{ + directedLine* temp; + if(DBG_edgesIntersect(edge, poly)) + return 1; + for(temp=poly->getNext(); temp != poly; temp=temp->getNext()) + if(DBG_edgesIntersect(edge, temp)) + return 1; + return 0; +} + +/*check whether two polygons intersect + */ +Int DBG_polygonsIntersect(directedLine* p1, directedLine* p2) +{ + directedLine* temp; + if(DBG_edgeIntersectPoly(p1, p2)) + return 1; + for(temp=p1->getNext(); temp!= p1; temp = temp->getNext()) + if(DBG_edgeIntersectPoly(temp, p2)) + return 1; + return 0; +} + +/*check whether there are polygons intersecting each other in + *a list of polygons + */ +Int DBG_polygonListIntersect(directedLine* pList) +{ + directedLine *temp; + for(temp=pList; temp != NULL; temp = temp->getNextPolygon()) + if(DBG_polygonSelfIntersect(temp)) + return 1; + directedLine* temp2; + for(temp=pList; temp!=NULL; temp=temp->getNextPolygon()) + { + for(temp2=temp->getNextPolygon(); temp2 != NULL; temp2=temp2->getNextPolygon()) + if(DBG_polygonsIntersect(temp, temp2)) + return 1; + } + + return 0; +} + + +Int DBG_isCounterclockwise(directedLine* poly) +{ + return (poly->polyArea() > 0); +} + +/*ray: v0 with direction (dx,dy). + *edge: v1-v2. + * the extra point v10[2] is given for the information at + *v1. Basically this edge is connectd to edge + * v10-v1. If v1 is on the ray, + * then we need v10 to determine whether this ray intersects + * the edge or not (that is, return 1 or return 0). + * If v1 is on the ray, then if v2 and v10 are on the same side of the ray, + * we return 0, otherwise return 1. + *For v2, if v2 is on the ray, we always return 0. + *Notice that v1 and v2 are not symmetric. So the edge is directed!!! + * The purpose for this convention is such that: a point is inside a polygon + * if and only if it intersets with odd number of edges. + */ +Int DBG_rayIntersectEdge(Real v0[2], Real dx, Real dy, Real v10[2], Real v1[2], Real v2[2]) +{ +/* +if( (v1[1] >= v0[1] && v2[1]<= v0[1] ) + ||(v2[1] >= v0[1] && v1[1]<= v0[1] ) + ) + printf("rayIntersectEdge, *********\n"); +*/ + + Real denom = (v2[0]-v1[0])*(-dy) - (v2[1]-v1[1]) * (-dx); + Real nomRay = (v2[0]-v1[0]) * (v0[1] - v1[1]) - (v2[1]-v1[1])*(v0[0]-v1[0]); + Real nomEdge = (v0[0]-v1[0]) * (-dy) - (v0[1]-v1[1])*(-dx); + + + /*if the ray is parallel to the edge, return 0: not intersect*/ + if(denom == 0.0) + return 0; + + /*if v0 is on the edge, return 0: not intersect*/ + if(nomRay == 0.0) + return 0; + + /*if v1 is on the positive ray, and the neighbor of v1 crosses the ray + *return 1: intersect + */ + if(nomEdge == 0) + { /*v1 is on the positive or negative ray*/ + +/* + printf("v1 is on the ray\n"); +*/ + + if(dx*(v1[0]-v0[0])>=0 && dy*(v1[1]-v0[1])>=0) /*v1 on positive ray*/ + { + if(area(v0, v1, v10) * area(v0, v1, v2) >0) + return 0; + else + return 1; + } + else /*v1 on negative ray*/ + return 0; + } + + /*if v2 is on the ray, always return 0: not intersect*/ + if(nomEdge == denom) { +/* printf("v2 is on the ray\n");*/ + return 0; + } + + /*finally */ + if(denom*nomRay>0 && denom*nomEdge>0 && nomEdge/denom <=1.0) + return 1; + return 0; +} + + +/*return the number of intersections*/ +Int DBG_rayIntersectPoly(Real v0[2], Real dx, Real dy, directedLine* poly) +{ + directedLine* temp; + Int count=0; + if(DBG_rayIntersectEdge(v0, dx, dy, poly->getPrev()->head(), poly->head(), poly->tail())) + count++; + + for(temp=poly->getNext(); temp != poly; temp = temp->getNext()) + if(DBG_rayIntersectEdge(v0, dx, dy, temp->getPrev()->head(), temp->head(), temp->tail())) + count++; +/*printf("ray intersect poly: count=%i\n", count);*/ + return count; +} + +Int DBG_pointInsidePoly(Real v[2], directedLine* poly) +{ +/* +printf("enter pointInsidePoly , v=(%f,%f)\n", v[0], v[1]); +printf("the polygon is\n"); +poly->printList(); +*/ + /*for debug purpose*/ + assert( (DBG_rayIntersectPoly(v,1,0,poly) % 2 ) + == (DBG_rayIntersectPoly(v,1,0.1234, poly) % 2 ) + ); + if(DBG_rayIntersectPoly(v, 1, 0, poly) % 2 == 1) + return 1; + else + return 0; +} + +/*return the number of polygons which contain thie polygon + * as a subset + */ +Int DBG_enclosingPolygons(directedLine* poly, directedLine* list) +{ + directedLine* temp; + Int count=0; +/* +printf("%i\n", DBG_pointInsidePoly(poly->head(), + list->getNextPolygon() + ->getNextPolygon() + ->getNextPolygon() + ->getNextPolygon() +)); +*/ + + for(temp = list; temp != NULL; temp = temp->getNextPolygon()) + { + if(poly != temp) + if(DBG_pointInsidePoly(poly->head(), temp)) + count++; +/* printf("count=%i\n", count);*/ + } + return count; +} + +void DBG_reverse(directedLine* poly) +{ + if(poly->getDirection() == INCREASING) + poly->putDirection(DECREASING); + else + poly->putDirection(INCREASING); + + directedLine* oldNext = poly->getNext(); + poly->putNext(poly->getPrev()); + poly->putPrev(oldNext); + + directedLine* temp; + for(temp=oldNext; temp!=poly; temp = oldNext) + { + if(temp->getDirection() == INCREASING) + temp->putDirection(DECREASING); + else + temp->putDirection(INCREASING); + + oldNext = temp->getNext(); + temp->putNext(temp->getPrev()); + temp->putPrev(oldNext); + } + printf("reverse done\n"); +} + +Int DBG_checkConnectivity(directedLine *polygon) +{ + if(polygon == NULL) return 1; + directedLine* temp; + if(polygon->head()[0] != polygon->getPrev()->tail()[0] || + polygon->head()[1] != polygon->getPrev()->tail()[1]) + return 0; + for(temp=polygon->getNext(); temp != polygon; temp=temp->getNext()) + { + if(temp->head()[0] != temp->getPrev()->tail()[0] || + temp->head()[1] != temp->getPrev()->tail()[1]) + return 0; + } + return 1; +} + +/*print out error message. + *If it cannot modify the polygon list to make it satify the + *requirements, return 1. + *otherwise modify the polygon list, and return 0 + */ +Int DBG_check(directedLine *polyList) +{ + directedLine* temp; + if(polyList == NULL) return 0; + + /*if there are intersections, print out error message + */ + if(DBG_polygonListIntersect(polyList)) + { + fprintf(stderr, "DBG_check: there are self intersections, don't know to modify the polygons\n"); + return 1; + } + + /*check the connectivity of each polygon*/ + for(temp = polyList; temp!= NULL; temp = temp ->getNextPolygon()) + { + if(! DBG_checkConnectivity(temp)) + { + fprintf(stderr, "DBG_check, polygon not connected\n"); + return 1; + } + } + + /*check the orientation of each polygon*/ + for(temp = polyList; temp!= NULL; temp = temp ->getNextPolygon()) + { + + + Int correctDir; + + if( DBG_enclosingPolygons(temp, polyList) % 2 == 0) + correctDir = 1; /*counterclockwise*/ + else + correctDir = 0; /*clockwise*/ + + Int actualDir = DBG_isCounterclockwise(temp); + + if(correctDir != actualDir) + { + fprintf(stderr, "DBG_check: polygon with incorrect orientations. reversed\n"); + + DBG_reverse(temp); + } + + } + return 0; +} + +/**************handle self intersections*****************/ +//determine whether e interects [begin, end] or not +static directedLine* DBG_edgeIntersectChainD(directedLine *e, + directedLine *begin, directedLine *end) +{ + directedLine *temp; + for(temp=begin; temp != end; temp = temp->getNext()) + { + if(DBG_edgesIntersect(e, temp)) + return temp; + } + if(DBG_edgesIntersect(e, end)) + return end; + return NULL; +} + +//given a polygon, cut the edges off and finally obtain a +//a polygon without intersections. The cut-off edges are +//dealloated. The new polygon is returned. +directedLine* DBG_cutIntersectionPoly(directedLine *polygon, int& cutOccur) +{ + directedLine *begin, *end, *next; + begin = polygon; + end = polygon; + cutOccur = 0; + while( (next = end->getNext()) != begin) + { + directedLine *interc = NULL; + if( (interc = DBG_edgeIntersectChainD(next, begin, end))) + { + int fixed = 0; + if(DBG_edgesIntersect(next, interc->getNext())) + { + //trying to fix it + Real buf[2]; + int i; + Int n=5; + buf[0] = interc->tail()[0]; + buf[1] = interc->tail()[1]; + + for(i=1; i<n; i++) + { + Real r = ((Real)i) / ((Real) n); + Real u = (1-r) * interc->head()[0] + r * interc->tail()[0]; + Real v = (1-r) * interc->head()[1] + r * interc->tail()[1]; + interc->tail()[0] = interc->getNext()->head()[0] = u; + interc->tail()[1] = interc->getNext()->head()[1] = v; + if( (! DBG_edgesIntersect(next, interc)) && + (! DBG_edgesIntersect(next, interc->getNext()))) + break; //we fixed it + } + if(i==n) // we didn't fix it + { + fixed = 0; + //back to original + interc->tail()[0] = interc->getNext()->head()[0] = buf[0]; + interc->tail()[1] = interc->getNext()->head()[1] = buf[1]; + } + else + { + fixed = 1; + } + } + if(fixed == 0) + { + cutOccur = 1; + begin->deleteSingleLine(next); + + if(begin != end) + { + if(DBG_polygonSelfIntersect(begin)) + { + directedLine* newEnd = end->getPrev(); + begin->deleteSingleLine(end); + end = newEnd; + } + } + } + else + { + end = end->getNext(); + } + } + else + { + end = end->getNext(); + } + } + return begin; +} + +//given a polygon, cut the edges off and finally obtain a +//a polygon without intersections. The cut-off edges are +//dealloated. The new polygon is returned. +static directedLine* DBG_cutIntersectionPoly_notwork(directedLine *polygon) +{ + directedLine *crt;//current polygon + directedLine *begin; + directedLine *end; + directedLine *temp; + crt = polygon; + int find=0; + while(1) + { +//printf("loop\n"); + //if there are less than 3 edges, we should stop + if(crt->getPrev()->getPrev() == crt) + return NULL; + + if(DBG_edgesIntersect(crt, crt->getNext()) || + (crt->head()[0] == crt->getNext()->tail()[0] && + crt->head()[1] == crt->getNext()->tail()[1]) + ) + { + find = 1; + crt=crt->deleteChain(crt, crt->getNext()); + } + else + { + //now we know crt and crt->getNext do not intersect + begin = crt; + end = crt->getNext(); +//printf("begin=(%f,%f)\n", begin->head()[0], begin->head()[1]); +//printf("end=(%f,%f)\n", end->head()[0], end->head()[1]); + for(temp=end->getNext(); temp!=begin; temp= temp->getNext()) + { +//printf("temp=(%f,%f)\n", temp->head()[0], temp->head()[1]); + directedLine *intersect = DBG_edgeIntersectChainD(temp, begin, end); + if(intersect != NULL) + { + crt = crt->deleteChain(intersect, temp); + find=1; + break; //the for loop + } + else + { + end = temp; + } + } + } + if(find == 0) + return crt; + else + find = 0; //go to next loop +} +} + +directedLine* DBG_cutIntersectionAllPoly(directedLine* list) +{ + directedLine* temp; + directedLine* tempNext=NULL; + directedLine* ret = NULL; + int cutOccur=0; + for(temp=list; temp != NULL; temp = tempNext) + { + directedLine *left; + tempNext = temp->getNextPolygon(); + + left = DBG_cutIntersectionPoly(temp, cutOccur); + if(left != NULL) + ret=left->insertPolygon(ret); + } + return ret; +} + +sampledLine* DBG_collectSampledLinesAllPoly(directedLine *polygonList) +{ + directedLine *temp; + sampledLine* tempHead = NULL; + sampledLine* tempTail = NULL; + sampledLine* cHead = NULL; + sampledLine* cTail = NULL; + + if(polygonList == NULL) + return NULL; + + DBG_collectSampledLinesPoly(polygonList, cHead, cTail); + + assert(cHead); + assert(cTail); + for(temp = polygonList->getNextPolygon(); temp != NULL; temp = temp->getNextPolygon()) + { + DBG_collectSampledLinesPoly(temp, tempHead, tempTail); + cTail->insert(tempHead); + cTail = tempTail; + } + return cHead; +} + +void DBG_collectSampledLinesPoly(directedLine *polygon, sampledLine*& retHead, sampledLine*& retTail) +{ + directedLine *temp; + sampledLine *ret = NULL; + retHead = NULL; + retTail = NULL; + if(polygon == NULL) + return; + + retHead = retTail = polygon->getSampledLine(); + for(temp = polygon->getNext(); temp != polygon; temp=temp->getNext()) + { + retHead = temp->getSampledLine()->insert(retHead); + } +} |