vcglib/apps/nexus/nxsalgo.cpp

797 lines
23 KiB
C++

/****************************************************************************
* VCGLib o o *
* Visual and Computer Graphics Library o o *
* _ O _ *
* Copyright(C) 2004 \/)\/ *
* Visual Computing Lab /\/| *
* ISTI - Italian National Research Council | *
* \ *
* All rights reserved. *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License (http://www.gnu.org/licenses/gpl.txt) *
* for more details. *
* *
****************************************************************************/
/****************************************************************************
History
$Log: not supported by cvs2svn $
Revision 1.26 2005/03/02 10:40:18 ponchio
Extraction rewrittten (to fix recusive problems).
Revision 1.25 2005/03/01 11:21:20 ponchio
Added line intersection
Revision 1.24 2005/02/22 14:20:44 ponchio
debug and mostly vertex unifying across borders
(still not perfect... :P)
Revision 1.23 2005/02/22 10:38:10 ponchio
Debug, cleaning and optimization.
Revision 1.22 2005/02/21 17:55:36 ponchio
debug debug debug
Revision 1.21 2005/02/20 18:07:01 ponchio
cleaning.
Revision 1.20 2005/02/19 10:45:04 ponchio
Patch generalized and small fixes.
Revision 1.19 2005/02/18 13:04:12 ponchio
Added patch reordering.
Revision 1.18 2005/02/17 16:40:35 ponchio
Optimized BuildLevels.
Revision 1.17 2005/02/08 12:43:03 ponchio
Added copyright
****************************************************************************/
#include <vector>
#include <map>
#include <set>
#include <algorithm>
#include <iostream>
//#include <wrap/strip/tristrip.h>
#include "nxsalgo.h"
#include "extraction.h"
#include "vpartition.h"
#include "vfile.h"
#include "nexus.h"
#include "zcurve.h"
#include "watch.h"
#include <vcg/space/line3.h>
#include <vcg/space/intersection3.h>
using namespace std;
using namespace nxs;
using namespace vcg;
void nxs::Connect(Nexus &nexus, std::vector< set<unsigned int> > &close,
float threshold) {
VPartition grid;
float max_radius = 0;
for(unsigned int patch = 0; patch < nexus.size(); patch++) {
Sphere3f &sphere = nexus[patch].sphere;
grid.push_back(sphere.Center());
float r = sphere.Radius();
if(r > max_radius) max_radius = r;
}
grid.Init();
close.clear();
close.resize(nexus.size());
vector<int> targets;
vector<double> dists;
for(unsigned int patch = 0; patch < nexus.size(); patch++) {
float radius = nexus[patch].sphere.Radius();
float max_distance = radius + max_radius + threshold;
max_distance *= max_distance;
grid.Closest(grid[patch], targets, dists, max_distance);
for(unsigned int i = 0; i < targets.size(); i++) {
unsigned int target = targets[i];
if(target == patch) continue;
float dist = radius + nexus[target].sphere.Radius() + threshold;
dist *= dist;
if(dist >= dists[i]) {
close[patch].insert(target);
}
}
}
//DOUBLECROSS CHECK
for(unsigned int patch = 0; patch < nexus.size(); patch++) {
set<unsigned int>::iterator i;
for(i = close[patch].begin(); i != close[patch].end(); i++) {
if(!close[*i].count(patch)) {
cerr << "Some problem width sphere intersection. Have alook.\n";
cerr << "Meanwhile i fix it.\n";
close[*i].insert(patch);
}
}
}
}
void nxs::ComputeNormals(Nexus &nexus) {
assert(nexus.signature.vnorm);
assert(!nexus.borders.IsReadOnly());
//first calculate level 0 normals
//I load all patches in a fragment
//calculate normals
//fix external borders getting from level below
//first try naive approach just load neighborough get normals and
//fix border with lower level
vector<int> levels;
nexus.history.BuildLevels(levels);
Report report(nexus.size(), 15);
//TODO check level 0 is the finer one
int current_level = 0;
while(1) {
int count = 0;
for(unsigned int p = 0; p < nexus.size(); p++) {
if(levels[p] != current_level) continue;
count++;
report.Step(p);
Border &border = nexus.GetBorder(p);
map<unsigned int, vector<Point3f> > normals;
normals[p] = vector<Point3f>();
for(unsigned int i = 0; i < border.Size(); i++) {
Link &link = border[i];
if(levels[link.end_patch] == current_level)
normals[link.end_patch] = vector<Point3f>();
}
map<unsigned int, vector<Point3f> >::iterator k;
for(k = normals.begin(); k != normals.end(); k++) {
Patch &patch = nexus.GetPatch((*k).first);
vector<Point3f> &normal = (*k).second;
normal.resize(patch.nv, Point3f(0, 0, 0));
if(nexus.signature.face == Signature::TRIANGLES) {
for(unsigned int i = 0; i < patch.nf; i++) {
unsigned short *f = patch.Face(i);
Point3f &v0 = patch.Vert3f(f[0]);
Point3f &v1 = patch.Vert3f(f[1]);
Point3f &v2 = patch.Vert3f(f[2]);
Point3f a = (v1 - v0);
Point3f b = (v2 - v0);
float n = a.Norm() * b.Norm();
if(n == 0) continue;
Point3f norm = a^b;
float rn = norm.Norm();
norm *= asin(rn/n)/n;
normal[f[0]] += norm;
normal[f[1]] += norm;
normal[f[2]] += norm;
}
} else if(nexus.signature.face == Signature::STRIPS) {
for(int i = 0; i < patch.nf - 2; i++) {
unsigned short *f = patch.FaceBegin() + i;
Point3f &v0 = patch.Vert3f(f[0]);
Point3f &v1 = patch.Vert3f(f[1]);
Point3f &v2 = patch.Vert3f(f[2]);
Point3f a = (v1 - v0);
Point3f b = (v2 - v0);
float n = a.Norm() * b.Norm();
if(n == 0) continue;
Point3f norm = a^b;
float rn = norm.Norm();
norm *= asin(rn/n)/n;
if(i%2) norm = -norm;
normal[f[0]] += norm;
normal[f[1]] += norm;
normal[f[2]] += norm;
}
} else
assert(0);
}
//now fix borders
map<unsigned int, vector<Link> > lowers;
for(unsigned int i = 0; i < border.Size(); i++) {
Link &link = border[i];
if(levels[link.end_patch] == current_level) {
//TODO remove these asserts
assert(normals[p].size() > link.start_vert);
assert(normals.count(link.end_patch));
assert(normals[link.end_patch].size() > link.end_vert);
normals[p][link.start_vert] += normals[link.end_patch][link.end_vert];
} else if (levels[link.end_patch] < current_level) {
lowers[link.end_patch].push_back(link);
}
}
map<unsigned int, vector<Link> >::iterator s;
for(s = lowers.begin(); s != lowers.end(); s++) {
Patch &patch = nexus.GetPatch((*s).first);
for(unsigned int i = 0; i < (*s).second.size(); i++) {
Link &link = (*s).second[i];
if(nexus.signature.vnorm == Encodings::FLOAT3)
normals[p][link.start_vert] =
((Point3f *)patch.VNormBegin())[link.end_vert];
else if(nexus.signature.vnorm == Encodings::SHORT4) {
Point3f &nor = normals[p][link.start_vert];
short *n = ((short *)patch.VNormBegin()) + 4*link.end_vert;
nor[0] = n[0];
nor[1] = n[1];
nor[2] = n[2];
}
}
}
//copy and normalize
Patch &patch = nexus.GetPatch(p);
Entry &entry = nexus[p];
Point3f *norm = (Point3f *)patch.VNormBegin();
vector<Point3f> &newnormals = normals[p];
assert(newnormals.size() == patch.nv);
for(unsigned int i = 0; i < patch.nv; i++) {
newnormals[i].Normalize();
if(nexus.signature.vnorm == Encodings::SHORT4) {
newnormals[i] *= 32766;
short *np = ((short *)norm) + 4 * i;
np[0] = (short)newnormals[i][0];
np[1] = (short)newnormals[i][1];
np[2] = (short)newnormals[i][2];
np[3] = 0;
} else if(nexus.signature.vnorm == Encodings::FLOAT3)
norm[i] = newnormals[i];
}
}
if(count == 0) break;
current_level++;
}
}
/*void nxs::ComputeNormals(Nexus &nexus) {
assert(nexus.signature.vnorm);
//setting borders readonly:
assert(!nexus.borders.IsReadOnly());
nexus.borders.SetReadOnly(true);
//TODO use a temporary file to store border normals
unsigned int tmpb_offset = 0;
vector<unsigned int> tmpb_start;
VFile<Point3f> tmpb;
if(!tmpb.Create("tmpb.tmp")) {
cerr << "Could not create temporary border file\n";
exit(0);
}
for(unsigned int p = 0; p < nexus.size(); p++) {
Border &border = nexus.borders[p];
tmpb_start.push_back(tmpb_offset);
tmpb_offset += border.Size();
}
Point3f zero(0.0f, 0.0f, 0.0f);
tmpb.Resize(tmpb_offset);
for(unsigned int i = 0; i < tmpb.Size(); i++)
tmpb[i] = zero;
tmpb.Flush();
vector<int> levels;
nexus.history.BuildLevels(levels);
//first step normals in the same patch.
cerr << "First Step\n";
Report report(nexus.size(), 5);
vector<Point3f> normals;
for(unsigned int p = 0; p < nexus.size(); p++) {
int current_level = levels[p];
report.Step(p);
Patch &patch = nexus.GetPatch(p);
normals.clear();
normals.resize(patch.nv, Point3f(0, 0, 0));
if(nexus.signature.face == Signature::TRIANGLES)
for(unsigned int i = 0; i < patch.nf; i++) {
unsigned short *f = patch.Face(i);
Point3f &v0 = patch.Vert3f(f[0]);
Point3f &v1 = patch.Vert3f(f[1]);
Point3f &v2 = patch.Vert3f(f[2]);
Point3f norm = (v1 - v0) ^ (v2 - v0);
normals[f[0]] += norm;
normals[f[1]] += norm;
normals[f[2]] += norm;
}
if(nexus.signature.face == Signature::STRIPS)
for(int i = 0; i < patch.nf - 2; i++) {
unsigned short *f = patch.FaceBegin() + i;
Point3f &v0 = patch.Vert3f(f[0]);
Point3f &v1 = patch.Vert3f(f[1]);
Point3f &v2 = patch.Vert3f(f[2]);
Point3f norm = (v1 - v0) ^ (v2 - v0);
if(i%2) norm = -norm;
normals[f[0]] += norm;
normals[f[1]] += norm;
normals[f[2]] += norm;
}
if(nexus.signature.vnorm == Encodings::SHORT4) {
short *n = (short *)patch.VNormBegin();
for(unsigned int i = 0; i < patch.nv; i++, n += 4) {
Point3f &norm = normals[i];
norm.Normalize();
for(int k = 0; k < 3; k++)
n[k] = (short)(norm[k] * 32766);
n[3] = 0;
}
} else if(nexus.signature.vnorm == Encodings::FLOAT3) {
Point3f *n = (Point3f *)patch.VNormBegin();
for(unsigned int i = 0; i < patch.nv; i++) {
n[i] = normals[i];
n[i].Normalize();
}
}
Border &border = nexus.GetBorder(p);
map<unsigned int, map<unsigned short, Point3f> > bnorm;
map<unsigned int, Link> bcopy;
unsigned int poff = tmpb_start[p];
for(unsigned int i = 0; i < border.Size(); i++) {
Link &link = border[i];
if(link.IsNull()) continue; //this should never happen now.
Point3f pt = normals[link.start_vert];
if(levels[link.end_patch] == current_level) {
bnorm[link.end_patch][link.end_vert] = pt;
tmpb[poff + i] += pt;
} else if(levels[link.end_patch] > current_level) {
bcopy[i] = link;
}
}
map<unsigned int, map<unsigned short, Point3f> >::iterator k;
for(k = bnorm.begin(); k != bnorm.end(); k++) {
unsigned int patch = (*k).first;
Border &rborder = nexus.GetBorder(patch);
unsigned int offset = tmpb_start[patch];
for(unsigned int i = 0; i < rborder.Size(); i++) {
Link &link = rborder[i];
//assert(!link.IsNull());
//TODO not accurate
if(link.end_patch != p) continue;
if((*k).second.count(link.start_vert))
tmpb[offset + i] += (*k).second[link.start_vert];
}
}
//Uncomment this only when links are ok!
map<unsigned int, Link>::iterator j;
for(j = bcopy.begin(); j != bcopy.end(); j++) {
unsigned int b = (*j).first;
Link link = (*j).second;
Border &rborder = nexus.GetBorder(link.end_patch, false);
unsigned int offset = tmpb_start[link.end_patch];
for(unsigned int i = 0; i < rborder.Size(); i++) {
Link &rlink = rborder[i];
if(rlink.end_patch == p && rlink.start_vert == link.end_vert) {
assert(rlink.end_vert == link.start_vert);
tmpb[poff + b] = tmpb[offset + i];
}
}
}
}
//Second step unify normals across borders
cerr << "Second step\n";
report.Init(nexus.size());
for(unsigned int p = 0; p < nexus.size(); p++) {
report.Step(p);
Patch &patch = nexus.GetPatch(p);
Border &border = nexus.GetBorder(p);
Point3f *normf = (Point3f *)patch.VNormBegin();
short *norms = (short *)patch.VNormBegin();
for(unsigned int i = 0; i < border.Size(); i++) {
Link &link = border[i];
if(link.IsNull()) continue;
unsigned int off = tmpb_start[p];
// Point3f &n = tmpb[off + i];
Point3f n = tmpb[off + i];
if(n == Point3f(0.0f,0.0f,0.0f)) continue;
n.Normalize();
if(nexus.signature.vnorm == Encodings::SHORT4) {
n *= 32766;
short *np = norms + 4 * link.start_vert;
np[0] = (short)n[0];
np[1] = (short)n[1];
np[2] = (short)n[2];
np[3] = 0;
} else if(nexus.signature.vnorm == Encodings::FLOAT3) {
normf[link.start_vert] = n;
}
}
}
tmpb.Close();
tmpb.Delete();
//TODO remove temporary file.
nexus.borders.SetReadOnly(false);
}*/
/*
//TODO why i created this function? wonder...void nxs::Reorder(Signature &signature, Patch &patch) {
vector<unsigned> remap;
remap.resize(patch.nv, 0xffff);
int nf = patch.nf;
if(signature.face == Signature::TRIANGLES)
nf *= 3;
else if(signature.face != Signature::STRIPS) {
assert(0); //mah...
}
//building remap
unsigned short *f = patch.FaceBegin();
unsigned int count = 0;
for(int i = 0; i < nf; i++) {
assert(f[i] < remap.size());
if(remap[f[i]] == 0xffff) {
remap[f[i]] = count++;
}
}
//test no unreferenced vertices
for(int i = 0; i < patch.nv; i++)
if(remap[i] == 0xffff)
remap[i] = i;
//converting faces
for(int i = 0; i < nf; i++)
f[i] = remap[f[i]];
vector<Point3f> vert;
vert.resize(patch.nv);
memcpy(&*vert.begin(), patch.Vert3fBegin(), patch.nv * sizeof(Point3f));
for(int i = 0; i < patch.nv; i++)
patch.Vert3f(remap[i]) = vert[i];
}*/
//TODO actually use threshold
void nxs::Unify(vector<Point3f> &points, vector<unsigned short> &faces,
vector<unsigned int> &remap, float threshold) {
vector<unsigned short> newfaces = faces;
VPartition grid;
for(unsigned int i = 0; i < points.size(); i++)
grid.push_back(points[i]);
grid.Init();
remap.resize(points.size());
vector<int> targets;
vector<double> dists;
points.clear();
unsigned int count = 0;
for(unsigned int i = 0; i < grid.size(); i++) {
grid.Closest(grid[i], targets, dists, threshold);
if(targets.size() > 1) {
unsigned int p;
for(p = 0; p < targets.size(); p++) {
if(targets[p] < i) {
remap[i] = remap[targets[p]];
break;
}
}
if(p < targets.size()) continue;
}
remap[i] = count++;
points.push_back(grid[i]);
}
//fixing faces now
faces.clear();
for(unsigned int i = 0; i < newfaces.size(); i += 3) {
unsigned short f[3];
f[0] = remap[newfaces[i]];
f[1] = remap[newfaces[i+1]];
f[2] = remap[newfaces[i+2]];
if(f[0] == f[1] || f[0] == f[2] || f[1] == f[2])
continue;
for(int k = 0; k < 3; k++)
faces.push_back(f[k]);
}
}
/*void nxs::Unify(Nexus &nexus, float threshold) {
threshold = 0.00001;
unsigned int duplicated = 0;
unsigned int degenerate = 0;
for(unsigned int p = 0; p < nexus.size(); p++) {
if(levels[p] != current_level) continue;
count++;
report.Step(p);
Border &border = nexus.GetBorder(p);
map<unsigned int, vector<Point3f> > normals;
normals[p] = vector<Point3f>();
for(unsigned int i = 0; i < border.Size(); i++) {
Link &link = border[i];
if(levels[link.end_patch] == current_level)
normals[link.end_patch] = vector<Point3f>();
}
map<unsigned int, vector<Point3f> >::iterator k;
for(k = normals.begin(); k != normals.end(); k++) {
Patch &patch = nexus.GetPatch((*k).first);
}
}
}*/
/*
void nxs::Unify(Nexus &nexus, float threshold) {
threshold = 0.001;
//TODO what if colors or normals or strips?
unsigned int duplicated = 0;
unsigned int degenerate = 0;
for(unsigned int p = 0; p < nexus.size(); p++) {
Entry &entry = nexus[p];
Patch &patch = nexus.GetPatch(p);
VPartition part;
for(unsigned int i = 0; i < patch.nv; i++) {
Point3f &point = patch.Vert3f(i);
part.push_back(point);
}
part.Init();
unsigned int vcount = 0;
vector<unsigned short> remap;
remap.resize(patch.nv);
int targets[8];
double dists[8];
//TODO CRITICAL FIX this unifying routine.
for(unsigned int i = 0; i < patch.nv; i++) {
Point3f &point = patch.Vert3f(i);
part.Closest(point, 8, targets, dists);
int k = 0;
for(k = 0; k < 8; k++) {
if(dists[k] > threshold) {
remap[i] = vcount++;
break;
}
if(targets[k] < i) {
remap[i] = remap[targets[k]];
duplicated++;
break;
}
}
if(k == 8)
remap[i] = vcount++;
}
if(vcount == patch.nv) //no need to unify
continue;
vector<Point3f> newvert;
newvert.resize(vcount);
for(unsigned int i = 0; i < patch.nv; i++)
newvert[remap[i]] = patch.Vert3f(i);
vector<unsigned short> newface;
//check no degenerate faces get created.
for(unsigned int f = 0; f < entry.nface; f++) {
unsigned short *face = patch.Face(f);
if(face[0] != face[1] && face[1] != face[2] && face[0] != face[2] &&
newvert[remap[face[0]]] != newvert[remap[face[1]]] &&
newvert[remap[face[0]]] != newvert[remap[face[2]]] &&
newvert[remap[face[1]]] != newvert[remap[face[2]]]) {
newface.push_back(remap[face[0]]);
newface.push_back(remap[face[1]]);
newface.push_back(remap[face[2]]);
} else {
degenerate++;
}
}
//rewrite patch now.
entry.nvert = newvert.size();
entry.nface = newface.size()/3;
patch.Init(nexus.signature, entry.nvert, entry.nface);
memcpy(patch.Vert3fBegin(), &(newvert[0]), entry.nvert*sizeof(Point3f));
memcpy(patch.FaceBegin(), &(newface[0]), entry.nface*3*sizeof(short));
//testiamo il tutto... TODO remove this of course
#ifdef NDEBUG
for(unsigned int i =0; i < patch.nf; i++) {
for(int k =0 ; k < 3; k++)
if(patch.Face(i)[k] >= patch.nv) {
cerr <<" Unify has problems\n";
exit(0);
}
}
#endif
//TODO CRITICAL FIX unify vertices across borders..... HOW??????
//fix patch borders now
set<unsigned int> close; //bordering pathes
Border &border = nexus.GetBorder(p);
for(unsigned int b = 0; b < border.Size(); b++) {
if(border[b].IsNull()) continue;
close.insert(border[b].end_patch);
border[b].start_vert = remap[border[b].start_vert];
}
set<unsigned int>::iterator c;
for(c = close.begin(); c != close.end(); c++) {
Border &bord = nexus.GetBorder(*c);
for(unsigned int b = 0; b < bord.Size(); b++) {
if(bord[b].IsNull()) continue;
if(bord[b].end_patch == p) {
bord[b].end_vert = remap[bord[b].end_vert];
}
}
}
}
//better to compact directly borders than setting them null.
//finally: there may be duplicated borders
for(unsigned int p = 0; p < nexus.size(); p++) {
Border &border = nexus.GetBorder(p);
set<Link> links;
for(unsigned int b = 0; b < border.Size(); b++) {
Link &link = border[b];
assert(!link.IsNull());
//if(border[b].IsNull()) continue;
links.insert(link);
}
int count = 0;
for(set<Link>::iterator k = links.begin(); k != links.end(); k++)
border[count++] = *k;
nexus.borders[p].used = links.size();
}
nexus.totvert -= duplicated;
if(duplicated)
cerr << "Found " << duplicated << " duplicated vertices" << endl;
if(degenerate)
cerr << "Found " << degenerate << " degenerate face while unmifying\n";
}
*/
void nxs::ZSort(Nexus &nexus, vector<unsigned int> &forward,
vector<unsigned int> &backward) {
//lets get a bounding box from the sphere:
ZCurve zcurve;
float r = nexus.sphere.Radius();
Point3f radius(r, r, r);
zcurve.Set(nexus.sphere.Center());
zcurve.Add(nexus.sphere.Center() - radius);
zcurve.Add(nexus.sphere.Center() + radius);
vector<int> levels;
nexus.history.BuildLevels(levels);
forward.clear();
vector< vector<ZEntry> > entries;
for(unsigned int i = 0; i < nexus.size(); i++) {
int level = levels[i];
while(level >= entries.size()) entries.push_back(vector<ZEntry>());
ZEntry e;
e.id = i;
e.pos = zcurve.Pos(nexus[i].sphere.Center());
entries[level].push_back(e);
}
for(unsigned int i = 0; i < entries.size(); i++) {
vector<ZEntry> &lev = entries[i];
std::sort(lev.begin(), lev.end());
for(unsigned int k = 0; k < lev.size(); k++)
forward.push_back(lev[k].id);
}
backward.resize(forward.size());
for(unsigned int i = 0; i < backward.size(); i++)
backward[forward[i]] = i;
}
bool nxs::LineIntersect(Nexus &nexus, Extraction &extraction,
Line3f line, Point3f &hit) {
//seguiamo la history;
Point3f tmp;
if(!Intersection(nexus.sphere, line, hit, tmp))
return false;
bool found = false;
float min_dist = -1;
float bar1, bar2, dist;
for(unsigned int i = 0; i < extraction.draw_size; i++) {
unsigned int p = extraction.selected[i].id;
if(!Intersection(nexus[p].sphere, line, hit, tmp))
continue;
Patch &patch = nexus.GetPatch(p);
if(nexus.signature.face == Signature::TRIANGLES) {
for(unsigned int i = 0; i < patch.nf; i++) {
unsigned short *f = patch.Face(i);
Point3f &v0 = patch.Vert3f(f[0]);
Point3f &v1 = patch.Vert3f(f[1]);
Point3f &v2 = patch.Vert3f(f[2]);
if(Intersection(line, v0, v1, v2, bar1, bar2, dist) &&
dist > 0 &&
(min_dist == -1 || min_dist > dist)) {
hit = v0*(1-bar1-bar2) + v1*bar1 + v2*bar2;
min_dist = dist;
found = true;
}
}
} else if(nexus.signature.face == Signature::STRIPS) {
for(int i = 0; i < patch.nf - 2; i++) {
unsigned short *f = patch.FaceBegin() + i;
Point3f &v0 = patch.Vert3f(f[0]);
Point3f &v1 = patch.Vert3f(f[1]);
Point3f &v2 = patch.Vert3f(f[2]);
if(Intersection(line, v0, v1, v2, bar1, bar2, dist) &&
dist > 0 &&
(min_dist == -1 || min_dist > dist)) {
hit = v0*(1-bar1-bar2) + v1*bar1 + v2*bar2;
min_dist = dist;
found = true;
}
}
} else
assert(0);
}
return found;
}