/* * $RCSfile: BottleNeck.java,v $ * * Copyright (c) 2007 Sun Microsystems, Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistribution of source code must retain the above copyright *   notice, this list of conditions and the following disclaimer. * * - Redistribution in binary form must reproduce the above copyright *   notice, this list of conditions and the following disclaimer in *   the documentation and/or other materials provided with the *   distribution. * * Neither the name of Sun Microsystems, Inc. or the names of * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * This software is provided "AS IS," without a warranty of any * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY * EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL * NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF * USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR * ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, * CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND * REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR * INABILITY TO USE THIS SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE * POSSIBILITY OF SUCH DAMAGES. * * You acknowledge that this software is not designed, licensed or * intended for use in the design, construction, operation or * maintenance of any nuclear facility. * * $Revision: 1.4 $ * $Date: 2007/02/09 17:20:17 $ * $State: Exp $ */// ----------------------------------------------------------------------//// The reference to Fast Industrial Strength Triangulation (FIST) code// in this release by Sun Microsystems is related to Sun's rewrite of// an early version of FIST. FIST was originally created by Martin// Held and Joseph Mitchell at Stony Brook University and is// incorporated by Sun under an agreement with The Research Foundation// of SUNY (RFSUNY). The current version of FIST is available for// commercial use under a license agreement with RFSUNY on behalf of// the authors and Stony Brook University.  Please contact the Office// of Technology Licensing at Stony Brook, phone 631-632-9009, for// licensing information.//// ----------------------------------------------------------------------package com.sun.j3d.utils.geometry;import java.io.*;import java.util.*;import javax.vecmath.*;class BottleNeck {    static boolean checkArea(Triangulator triRef, int ind4, int ind5) {	int  ind1, ind2;	int i0, i1, i2;	double area = 0.0, area1 = 0, area2 = 0.0;	i0 = triRef.fetchData(ind4);	ind1 = triRef.fetchNextData(ind4);	i1 = triRef.fetchData(ind1);	while (ind1 != ind5) {	    ind2  = triRef.fetchNextData(ind1);	    i2 = triRef.fetchData(ind2);	    area =Numerics.stableDet2D(triRef, i0, i1, i2);	    area1 += area;	    ind1   = ind2;	    i1     = i2;	}	if (Numerics.le(area1, triRef.ZERO))  return false;	ind1 = triRef.fetchNextData(ind5);	i1 = triRef.fetchData(ind1);	while (ind1 != ind4) {	    ind2  = triRef.fetchNextData(ind1);	    i2 = triRef.fetchData(ind2);	    area = Numerics.stableDet2D(triRef, i0, i1, i2);	    area2 += area;	    ind1   = ind2;	    i1     = i2;	}	if (Numerics.le(area2, triRef.ZERO))  return false;	else                  return true;    }    // Yet another check needed in order to handle degenerate cases!    static boolean checkBottleNeck(Triangulator triRef,				   int i1, int i2, int i3, int ind4) {	int ind5;	int i4, i5;	boolean flag;	i4 = i1;	ind5 = triRef.fetchPrevData(ind4);	i5 = triRef.fetchData(ind5);	if ((i5 != i2)  &&  (i5 != i3)) {	    flag = Numerics.pntInTriangle(triRef, i1, i2, i3, i5);	    if (flag)  return true;	}	if (i2 <= i3) {	    if (i4 <= i5)      flag = Numerics.segIntersect(triRef, i2, i3, i4, i5, -1);	    else               flag = Numerics.segIntersect(triRef, i2, i3, i5, i4, -1);	}	else {	    if (i4 <= i5)      flag = Numerics.segIntersect(triRef, i3, i2, i4, i5, -1);	    else               flag = Numerics.segIntersect(triRef, i3, i2, i5, i4, -1);	}	if (flag)  return true;	ind5 = triRef.fetchNextData(ind4);	i5 = triRef.fetchData(ind5);	if ((i5 != i2)  &&  (i5 != i3)) {	    flag = Numerics.pntInTriangle(triRef, i1, i2, i3, i5);	    if (flag)  return true;	}	if (i2 <= i3) {	    if (i4 <= i5)     flag = Numerics.segIntersect(triRef, i2, i3, i4, i5, -1);	    else              flag = Numerics.segIntersect(triRef, i2, i3, i5, i4, -1);	}	else {	    if (i4 <= i5)     flag = Numerics.segIntersect(triRef, i3, i2, i4, i5, -1);	    else              flag = Numerics.segIntersect(triRef, i3, i2, i5, i4, -1);	}	if (flag)  return true;	ind5 = triRef.fetchNextData(ind4);	i5 = triRef.fetchData(ind5);	while (ind5 != ind4) {	    if (i4 == i5) {		if (checkArea(triRef, ind4, ind5))  return true;	    }	    ind5 = triRef.fetchNextData(ind5);	    i5 = triRef.fetchData(ind5);	}	return  false;    }}