source: HiSusy/trunk/Delphes-3.0.0/external/fastjet/Voronoi.cc @ 1

Last change on this file since 1 was 1, checked in by zerwas, 11 years ago

first import of structure, PYTHIA8 and DELPHES

File size: 32.7 KB
Line 
1//STARTHEADER
2// $Id: Voronoi.cc 859 2012-11-28 01:49:23Z pavel $
3//
4// Copyright (c) 1994 by AT&T Bell Laboratories (see below)
5//
6//
7//----------------------------------------------------------------------
8// This file is included as part of FastJet but was mostly written by
9// S. Fortune in C, put into C++ with memory management by S
10// O'Sullivan, and with further interface and memory management
11// modifications by Gregory Soyez.
12//
13// Permission to use, copy, modify, and distribute this software for
14// any purpose without fee is hereby granted, provided that this
15// entire notice is included in all copies of any software which is or
16// includes a copy or modification of this software and in all copies
17// of the supporting documentation for such software. THIS SOFTWARE IS
18// BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED WARRANTY.
19// IN PARTICULAR, NEITHER THE AUTHORS NOR AT&T MAKE ANY REPRESENTATION
20// OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY OF THIS
21// SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
22//
23//----------------------------------------------------------------------
24//ENDHEADER
25
26
27/*
28 * The author of this software is Steven Fortune. 
29 * Copyright (c) 1994 by AT&T Bell Laboratories.
30 * Permission to use, copy, modify, and distribute this software for any
31 * purpose without fee is hereby granted, provided that this entire notice
32 * is included in all copies of any software which is or includes a copy
33 * or modification of this software and in all copies of the supporting
34 * documentation for such software.
35 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
36 * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHORS NOR AT&T MAKE ANY
37 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
38 * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
39 */
40
41/*
42 * This code was originally written by Stephan Fortune in C code.  I,
43 * Shane O'Sullivan, have since modified it, encapsulating it in a C++
44 * class and, fixing memory leaks and adding accessors to the Voronoi
45 * Edges.  Permission to use, copy, modify, and distribute this
46 * software for any purpose without fee is hereby granted, provided
47 * that this entire notice is included in all copies of any software
48 * which is or includes a copy or modification of this software and in
49 * all copies of the supporting documentation for such software.  THIS
50 * SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
51 * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHORS NOR AT&T MAKE ANY
52 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
53 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
54 * PURPOSE.
55 */
56
57/*
58 * This code, included in the FastJet distribution, was originally
59 * written by Stephan Fortune in C and adapted to C++ by Shane
60 * O'Sullivan under the terms reported above.
61 *
62 * Below are the list of changes implemented by the FastJet authors:
63 *
64 * 2011-11-14  Gregory Soyez  <soyez@fastjet.fr>
65 *
66 *      * removed 'plot' and 'triangulate' (were always 0)
67 *      * removed unused plot functions (openpl, circle, range,
68 *        out_bisector, out_ep, out_vertex, out_site, out_triple)
69 *      * removed unused 'VPoint p' in 'intersect'
70 *
71 *
72 * 2011-07-22  Gregory Soyez  <soyez@fastjet.fr>
73 *
74 *      * replaced Point by VPoint (to avoid any potential conflict
75 *        with an already existing class Point in FastJet
76 *
77 *
78 * 2011-06-28  Gregory Soyez  <soyez@fastjet.fr>
79 *
80 *      * added support for situations with degenerate particles (we just
81 *        discard the particles degenerate wiht an already existing
82 *        one which is perfectly sufficient for our needs)
83 *      * in 'VoronoiDiagramGenerator::intersect', improved the numerical
84 *        precision in cases where the 2 parents are nearly degenerate
85 *
86 *
87 * 2011-06-14  Gregory Soyez  <soyez@fastjet.fr>
88 *
89 *      * fixed a potential overflow bug in VoronoiDiagramGenerator::PQbucket
90 *
91 *
92 * 2007-05-07  Gregory Soyez  <soyez@fastjet.fr>
93 *
94 *      * fied a few memory leaks
95 *
96 *      * put the code in the fastjet namespace
97 *
98 *      * replaced float by double
99 *
100 *      * generateVoronoi() takes a vector of Point instead of 2
101 *        pointers
102 *
103 *      * added info about the parent sites to GraphEdge (and clip_line)
104 *
105 *      * removed condition on minimal distance between sites
106 */
107
108#include <stdio.h>
109#include "fastjet/internal/Voronoi.hh"
110
111using namespace std;
112
113FASTJET_BEGIN_NAMESPACE
114
115LimitedWarning VoronoiDiagramGenerator::_warning_degeneracy;
116
117VoronoiDiagramGenerator::VoronoiDiagramGenerator(){
118  siteidx = 0;
119  sites = NULL;
120  parent_sites = NULL;
121
122  allMemoryList = new FreeNodeArrayList;
123  allMemoryList->memory = NULL;
124  allMemoryList->next = NULL;
125  currentMemoryBlock = allMemoryList;
126  allEdges = NULL;
127  iteratorEdges = 0;
128  minDistanceBetweenSites = 0;
129
130  ELhash = NULL;
131  PQhash = NULL;
132}
133
134VoronoiDiagramGenerator::~VoronoiDiagramGenerator(){
135  cleanup();
136  cleanupEdges();
137
138  if (allMemoryList != NULL)
139    delete allMemoryList;
140}
141
142
143
144bool VoronoiDiagramGenerator::generateVoronoi(vector<VPoint> *_parent_sites,
145                                              double minX, double maxX, 
146                                              double minY, double maxY, 
147                                              double minDist){
148  cleanup();
149  cleanupEdges();
150  int i;
151  double x, y;
152
153  minDistanceBetweenSites = minDist;
154
155  parent_sites = _parent_sites;
156
157  nsites = n_parent_sites = parent_sites->size();
158  debug = 1;
159  sorted = 0; 
160  freeinit(&sfl, sizeof (Site));
161               
162  //sites = (Site *) myalloc(nsites*sizeof( *sites));
163  sites = (Site *) myalloc(nsites*sizeof( Site));
164  //parent_sites = (Site *) myalloc(nsites*sizeof( Site));
165 
166  if (sites == 0)
167    return false;
168
169  xmax = xmin = (*parent_sites)[0].x;
170  ymax = ymin = (*parent_sites)[0].y;
171 
172  for(i=0;i<nsites;i++){
173    x = (*parent_sites)[i].x;
174    y = (*parent_sites)[i].y;
175    sites[i].coord.x = x;
176    sites[i].coord.y = y;
177    sites[i].sitenbr = i;
178    sites[i].refcnt  = 0;
179   
180    if (x<xmin)
181      xmin=x;
182    else if (x>xmax)
183      xmax=x;
184   
185    if (y<ymin)
186      ymin=y;
187    else if (y>ymax)
188      ymax=y;
189  }
190       
191  qsort(sites, nsites, sizeof (*sites), scomp);
192
193  // Gregory Soyez
194  //
195  // check if some of the particles are degenerate to avoid a crash.
196  //
197  // At the moment, we work under the assumption that they will be
198  // "clustered" later on, so we just keep the 1st one and discard the
199  // others
200  unsigned int offset=0;
201  for (int is=1;is<nsites;is++){
202    if (sites[is].coord.y==sites[is-1].coord.y && sites[is].coord.x==sites[is-1].coord.x){
203      offset++;
204    } else if (offset>0){
205      sites[is-offset] = sites[is];
206    }
207  }
208
209  if (offset>0){
210    nsites-=offset;
211    _warning_degeneracy.warn("VoronoiDiagramGenerator: two (or more) particles are degenerate in rapidity and azimuth, Voronoi cell assigned to the first of each set of degenerate particles.");
212  }
213
214  siteidx = 0;
215  geominit();
216  double temp = 0;
217  if(minX > maxX){
218    temp = minX;
219    minX = maxX;
220    maxX = temp;
221  }
222  if(minY > maxY){
223    temp = minY;
224    minY = maxY;
225    maxY = temp;
226  }
227  borderMinX = minX;
228  borderMinY = minY;
229  borderMaxX = maxX;
230  borderMaxY = maxY;
231       
232  siteidx = 0;
233  voronoi();
234
235  return true;
236}
237
238bool VoronoiDiagramGenerator::ELinitialize(){
239  int i;
240  freeinit(&hfl, sizeof(Halfedge));
241  ELhashsize = 2 * sqrt_nsites;
242  //ELhash = (Halfedge **) myalloc ( sizeof *ELhash * ELhashsize);
243  ELhash = (Halfedge **) myalloc ( sizeof(Halfedge*)*ELhashsize);
244 
245  if(ELhash == 0)
246    return false;
247 
248  for(i=0; i<ELhashsize; i +=1) ELhash[i] = (Halfedge *)NULL;
249  ELleftend = HEcreate((Edge*) NULL, 0);
250  ELrightend = HEcreate((Edge*) NULL, 0);
251  ELleftend->ELleft = (Halfedge*) NULL;
252  ELleftend->ELright = ELrightend;
253  ELrightend->ELleft = ELleftend;
254  ELrightend->ELright = (Halfedge*) NULL;
255  ELhash[0] = ELleftend;
256  ELhash[ELhashsize-1] = ELrightend;
257
258  return true;
259}
260
261
262Halfedge* VoronoiDiagramGenerator::HEcreate(Edge *e,int pm){
263  Halfedge *answer;
264  answer = (Halfedge*) getfree(&hfl);
265  answer->ELedge = e;
266  answer->ELpm = pm;
267  answer->PQnext = (Halfedge*) NULL;
268  answer->vertex = (Site*) NULL;
269  answer->ELrefcnt = 0;
270  return answer;
271}
272
273
274void VoronoiDiagramGenerator::ELinsert(Halfedge *lb, Halfedge *newHe)
275{
276  newHe->ELleft = lb;
277  newHe->ELright = lb->ELright;
278  (lb->ELright)->ELleft = newHe;
279  lb->ELright = newHe;
280}
281
282
283/* Get entry from hash table, pruning any deleted nodes */
284Halfedge* VoronoiDiagramGenerator::ELgethash(int b){
285  Halfedge *he;
286       
287  if ((b<0) || (b>=ELhashsize)) 
288    return (Halfedge *) NULL;
289
290  he = ELhash[b]; 
291  if ((he==(Halfedge*) NULL) || (he->ELedge!=(Edge*) DELETED)) 
292    return he;
293       
294  /* Hash table points to deleted half edge.  Patch as necessary. */
295  ELhash[b] = (Halfedge*) NULL;
296  if ((he->ELrefcnt -= 1) == 0) 
297    makefree((Freenode*)he, &hfl);
298  return (Halfedge*) NULL;
299}       
300
301Halfedge * VoronoiDiagramGenerator::ELleftbnd(VPoint *p){
302  int i, bucket;
303  Halfedge *he;
304       
305  /* Use hash table to get close to desired halfedge */
306  // use the hash function to find the place in the hash map that this
307  // HalfEdge should be
308  // Gregory Soyez: the original code was
309  //
310  //   bucket = (int)((p->x - xmin)/deltax * ELhashsize);       
311  //   // make sure that the bucket position in within the range of the
312  //   //hash array
313  //   if (bucket<0) bucket =0;
314  //   if (bucket>=ELhashsize) bucket = ELhashsize - 1;
315  //
316  // but this runs the risk of having a overflow which would
317  // cause bucket to be truncated at 0 instead of ELhashsize - 1
318  // (or vice-versa)
319  // We fix this by performing the test immediately on the double
320  // We put in a extra bit of margin to be sure the conversion does
321  // not play dirty tricks on us
322
323  //const double &px = p->x;
324  if (p->x < xmin){ bucket=0;}
325  else if (p->x >= xmax){ bucket = ELhashsize - 1;}
326  else{
327    bucket= (int)((p->x - xmin)/deltax * ELhashsize);
328    if (bucket>=ELhashsize) bucket = ELhashsize - 1;  // the lower cut should be robust
329  }
330
331  he = ELgethash(bucket);
332
333  // if the HE isn't found, search backwards and forwards in the hash
334  // map for the first non-null entry
335  if (he == (Halfedge*) NULL){   
336    for(i=1;1;i++){     
337      if ((he=ELgethash(bucket-i)) != (Halfedge*) NULL) 
338        break;
339      if ((he=ELgethash(bucket+i)) != (Halfedge*) NULL) 
340        break;
341    };
342    totalsearch += i;
343  };
344  ntry += 1;
345  /* Now search linear list of halfedges for the correct one */
346  if ((he==ELleftend)  || (he != ELrightend && right_of(he,p))){
347    do{
348      he = he->ELright;
349    } while (he!=ELrightend && right_of(he,p));
350      // keep going right on the list until either the end is reached,
351      // or you find the 1st edge which the point
352      he = he->ELleft;  //isn't to the right of
353  } else 
354    // if the point is to the left of the HalfEdge, then search left
355    // for the HE just to the left of the point
356    do{
357      he = he->ELleft;
358    } while ((he!=ELleftend )&& (!right_of(he,p)));
359               
360  /* Update hash table and reference counts */
361  if ((bucket > 0) && (bucket <ELhashsize-1)){ 
362    if(ELhash[bucket] != (Halfedge *) NULL){
363      ELhash[bucket]->ELrefcnt -= 1;
364    }
365    ELhash[bucket] = he;
366    ELhash[bucket]->ELrefcnt += 1;
367  };
368
369  return he;
370}
371
372
373/* This delete routine can't reclaim node, since pointers from hash
374   table may be present.   */
375void VoronoiDiagramGenerator::ELdelete(Halfedge *he){
376  (he->ELleft)->ELright = he->ELright;
377  (he->ELright)->ELleft = he->ELleft;
378  he->ELedge = (Edge*) DELETED;
379}
380
381
382Halfedge* VoronoiDiagramGenerator::ELright(Halfedge *he){
383  return he->ELright;
384}
385
386
387Halfedge* VoronoiDiagramGenerator::ELleft(Halfedge *he){
388  return he->ELleft;
389}
390
391
392Site * VoronoiDiagramGenerator::leftreg(Halfedge *he){
393  if (he->ELedge == (Edge*) NULL) 
394    return(bottomsite);
395  return (he->ELpm == le) 
396    ? he->ELedge->reg[le] 
397    : he->ELedge->reg[re];
398}
399
400Site * VoronoiDiagramGenerator::rightreg(Halfedge *he){
401  if (he->ELedge == (Edge*) NULL)
402    // if this halfedge has no edge, return the bottom site (whatever
403    // that is)
404    return bottomsite;
405 
406  // if the ELpm field is zero, return the site 0 that this edge
407  // bisects, otherwise return site number 1
408  return (he->ELpm == le)
409    ? he->ELedge->reg[re] 
410    : he->ELedge->reg[le];
411}
412
413void VoronoiDiagramGenerator::geominit(){
414  double sn;
415 
416  freeinit(&efl, sizeof(Edge));
417  nvertices = 0;
418  nedges = 0;
419  sn = (double)nsites+4;
420  sqrt_nsites = (int)sqrt(sn);
421  deltay = ymax - ymin;
422  deltax = xmax - xmin;
423}
424
425
426Edge * VoronoiDiagramGenerator::bisect(Site *s1, Site *s2){
427  double dx,dy,adx,ady;
428  Edge *newedge;       
429
430  newedge = (Edge*) getfree(&efl);
431       
432  newedge->reg[0] = s1; //store the sites that this edge is bisecting
433  newedge->reg[1] = s2;
434  ref(s1); 
435  ref(s2);
436
437  // to begin with, there are no endpoints on the bisector - it goes
438  // to infinity
439  newedge->ep[0] = (Site*) NULL;
440  newedge->ep[1] = (Site*) NULL;
441 
442  // get the difference in x dist between the sites
443  dx = s2->coord.x - s1->coord.x;
444  dy = s2->coord.y - s1->coord.y;
445
446  // make sure that the difference is positive
447  adx = dx>0 ? dx : -dx;
448  ady = dy>0 ? dy : -dy;
449
450  // get the slope of the line
451  newedge->c = (double)(s1->coord.x * dx + s1->coord.y * dy
452                        + (dx*dx + dy*dy)*0.5);
453
454  if (adx>ady){ 
455    //set formula of line, with x fixed to 1
456    newedge->a = 1.0; newedge->b = dy/dx; newedge->c /= dx;
457  } else {     
458    //set formula of line, with y fixed to 1
459    newedge->b = 1.0; newedge->a = dx/dy; newedge->c /= dy;
460  }
461       
462  newedge->edgenbr = nedges;
463  nedges++;
464
465  return newedge;
466}
467
468
469// create a new site where the HalfEdges el1 and el2 intersect - note
470// that the VPoint in the argument list is not used, don't know why
471// it's there
472//
473// Gregory Soyez: removed the uinused point p
474Site* VoronoiDiagramGenerator::intersect(Halfedge *el1, Halfedge *el2
475                                         /*, VPoint *p*/){
476  Edge *e1,*e2, *e;
477  Halfedge *el;
478  double d, xint, yint;
479  int right_of_site;
480  Site *v;
481       
482  e1 = el1->ELedge;
483  e2 = el2->ELedge;
484  if ((e1==(Edge*)NULL) || (e2==(Edge*)NULL)) 
485    return ((Site*) NULL);
486
487  // if the two edges bisect the same parent, return null
488  if (e1->reg[1] == e2->reg[1]) 
489    return (Site*) NULL;
490
491  // Gregory Soyez:
492  //   
493  // if the 2 parents are too close, the intersection is going to be
494  // computed from the "long edges" of the triangle which could causes
495  // large rounding errors. In this case, use the bisector of the 2
496  // parents to find the interaction point
497  //
498  // The following replaces
499  //   d = e1->a * e2->b - e1->b * e2->a;
500  //   if (-1.0e-10<d && d<1.0e-10)
501  //     return (Site*) NULL;
502  //   
503  //   xint = (e1->c*e2->b - e2->c*e1->b)/d;
504  //   yint = (e2->c*e1->a - e1->c*e2->a)/d;
505
506  double dx = e2->reg[1]->coord.x - e1->reg[1]->coord.x;
507  double dy = e2->reg[1]->coord.y - e1->reg[1]->coord.y;
508  double dxref = e1->reg[1]->coord.x - e1->reg[0]->coord.x;
509  double dyref = e1->reg[1]->coord.y - e1->reg[0]->coord.y;
510
511  if (dx*dx + dy*dy < 1e-14*(dxref*dxref+dyref*dyref)){
512    // make sure that the difference is positive
513    double adx = dx>0 ? dx : -dx;
514    double ady = dy>0 ? dy : -dy;
515   
516    // get the slope of the line
517    double a,b;
518    double c = (double)(e1->reg[1]->coord.x * dx + e1->reg[1]->coord.y * dy
519                        + (dx*dx + dy*dy)*0.5);
520   
521    if (adx>ady){
522      a = 1.0; b = dy/dx; c /= dx;
523    } else {
524      b = 1.0; a = dx/dy; c /= dy;
525    }
526
527    d = e1->a * b - e1->b * a;
528    if (-1.0e-10<d && d<1.0e-10) {
529      return (Site*) NULL;
530    }
531       
532    xint = (e1->c*b - c*e1->b)/d;
533    yint = (c*e1->a - e1->c*a)/d;
534   
535  } else {     
536    d = e1->a * e2->b - e1->b * e2->a;
537    if (-1.0e-10<d && d<1.0e-10) {
538      return (Site*) NULL;
539    }
540       
541    xint = (e1->c*e2->b - e2->c*e1->b)/d;
542    yint = (e2->c*e1->a - e1->c*e2->a)/d;
543  }
544  // end of Gregory Soyez's modifications
545
546  volatile double local_y1 = e1->reg[1]->coord.y;
547  volatile double local_y2 = e2->reg[1]->coord.y;
548       
549  if( (local_y1 < local_y2) ||
550      ((local_y1 == local_y2) &&
551       (e1->reg[1]->coord.x <  e2->reg[1]->coord.x)) ){ 
552    el = el1; 
553    e = e1;
554  } else {     
555    el = el2; 
556    e = e2;
557  }
558       
559  right_of_site = xint >= e->reg[1]->coord.x;
560  if ((right_of_site && el->ELpm == le) || (!right_of_site && el->ELpm == re)) 
561    return (Site*) NULL;
562       
563  // create a new site at the point of intersection - this is a new
564  // vector event waiting to happen
565  v = (Site*) getfree(&sfl);
566  v->refcnt = 0;
567  v->coord.x = xint;
568  v->coord.y = yint;
569  return v;
570}
571
572//HERE
573
574/* returns 1 if p is to right of halfedge e */
575int VoronoiDiagramGenerator::right_of(Halfedge *el,VPoint *p)
576{
577  Edge *e;
578  Site *topsite;
579  int right_of_site, above, fast;
580  double dxp, dyp, dxs, t1, t2, t3, yl;
581       
582  e = el->ELedge;
583  topsite = e->reg[1];
584  right_of_site = p->x > topsite->coord.x;
585  if(right_of_site && el->ELpm == le) return(1);
586  if(!right_of_site && el->ELpm == re) return (0);
587       
588  if (e->a == 1.0)
589    {   dyp = p->y - topsite->coord.y;
590    dxp = p->x - topsite->coord.x;
591    fast = 0;
592    if ((!right_of_site & (e->b<0.0)) | (right_of_site & (e->b>=0.0)) )
593      { above = dyp>= e->b*dxp; 
594      fast = above;
595      }
596    else 
597      { above = p->x + p->y*e->b > e-> c;
598      if(e->b<0.0) above = !above;
599      if (!above) fast = 1;
600      };
601    if (!fast)
602      { dxs = topsite->coord.x - (e->reg[0])->coord.x;
603      above = e->b * (dxp*dxp - dyp*dyp) <
604        dxs*dyp*(1.0+2.0*dxp/dxs + e->b*e->b);
605      if(e->b<0.0) above = !above;
606      };
607    }
608  else  /*e->b==1.0 */
609    {   yl = e->c - e->a*p->x;
610    t1 = p->y - yl;
611    t2 = p->x - topsite->coord.x;
612    t3 = yl - topsite->coord.y;
613    above = t1*t1 > t2*t2 + t3*t3;
614    };
615  return (el->ELpm==le ? above : !above);
616}
617
618
619void VoronoiDiagramGenerator::endpoint(Edge *e,int lr,Site * s)
620{
621  e->ep[lr] = s;
622  ref(s);
623  if(e->ep[re-lr]== (Site *) NULL) 
624    return;
625
626  clip_line(e);
627
628  deref(e->reg[le]);
629  deref(e->reg[re]);
630  makefree((Freenode*)e, &efl);
631}
632
633
634double VoronoiDiagramGenerator::dist(Site *s,Site *t)
635{
636  double dx,dy;
637  dx = s->coord.x - t->coord.x;
638  dy = s->coord.y - t->coord.y;
639  return (double)(sqrt(dx*dx + dy*dy));
640}
641
642
643void VoronoiDiagramGenerator::makevertex(Site *v)
644{
645  v->sitenbr = nvertices;
646  nvertices += 1;
647  //GS unused plot: out_vertex(v);
648}
649
650
651void VoronoiDiagramGenerator::deref(Site *v)
652{
653  v->refcnt -= 1;
654  if (v->refcnt == 0 ) 
655    makefree((Freenode*)v, &sfl);
656}
657
658void VoronoiDiagramGenerator::ref(Site *v)
659{
660  v->refcnt += 1;
661}
662
663//push the HalfEdge into the ordered linked list of vertices
664void VoronoiDiagramGenerator::PQinsert(Halfedge *he,Site * v, double offset)
665{
666  Halfedge *last, *next;
667       
668  he->vertex = v;
669  ref(v);
670  he->ystar = (double)(v->coord.y + offset);
671  last = &PQhash[PQbucket(he)];
672  while ((next = last->PQnext) != (Halfedge *) NULL &&
673         (he->ystar  > next->ystar  ||
674          (he->ystar == next->ystar && v->coord.x > next->vertex->coord.x)))
675    {   
676      last = next;
677    };
678  he->PQnext = last->PQnext; 
679  last->PQnext = he;
680  PQcount += 1;
681}
682
683//remove the HalfEdge from the list of vertices
684void VoronoiDiagramGenerator::PQdelete(Halfedge *he)
685{
686  Halfedge *last;
687       
688  if(he->vertex != (Site *) NULL)
689    {   
690      last = &PQhash[PQbucket(he)];
691      while (last->PQnext != he) 
692        last = last->PQnext;
693
694      last->PQnext = he->PQnext;
695      PQcount -= 1;
696      deref(he->vertex);
697      he->vertex = (Site *) NULL;
698    };
699}
700
701int VoronoiDiagramGenerator::PQbucket(Halfedge *he)
702{
703  // Gregory Soyez: the original code was
704  //
705  //   bucket = (int)((he->ystar - ymin)/deltay * PQhashsize);
706  //   if (bucket<0) bucket = 0;
707  //   if (bucket>=PQhashsize) bucket = PQhashsize-1 ;
708  //   if (bucket < PQmin) PQmin = bucket;
709  //   return(bucket);
710  //
711  // but this runs the risk of having a overflow which would
712  // cause bucket to be truncated at 0 instead of PQhashsize-1
713  // (or vice-versa)
714  // We fix this by performing the test immediately on the double
715  // We put in a extra bit of margin to be sure the conversion does
716  // not play dirty tricks on us
717
718  int bucket;
719       
720  double hey = he->ystar;
721  if (hey < ymin){ bucket = 0;}
722  else if (hey >= ymax){ bucket = PQhashsize-1;}
723  else {
724    bucket = (int)((hey - ymin)/deltay * PQhashsize);
725    if (bucket>=PQhashsize) bucket = PQhashsize-1 ;
726  }
727
728  if (bucket < PQmin) PQmin = bucket;
729  return(bucket);
730}
731
732
733
734int VoronoiDiagramGenerator::PQempty()
735{
736  return(PQcount==0);
737}
738
739
740VPoint VoronoiDiagramGenerator::PQ_min()
741{
742  VPoint answer;
743       
744  while(PQhash[PQmin].PQnext == (Halfedge *)NULL) {PQmin += 1;};
745  answer.x = PQhash[PQmin].PQnext->vertex->coord.x;
746  answer.y = PQhash[PQmin].PQnext->ystar;
747  return (answer);
748}
749
750Halfedge * VoronoiDiagramGenerator::PQextractmin()
751{
752  Halfedge *curr;
753       
754  curr = PQhash[PQmin].PQnext;
755  PQhash[PQmin].PQnext = curr->PQnext;
756  PQcount -= 1;
757  return(curr);
758}
759
760
761bool VoronoiDiagramGenerator::PQinitialize()
762{
763  int i; 
764       
765  PQcount = 0;
766  PQmin = 0;
767  PQhashsize = 4 * sqrt_nsites;
768  //PQhash = (Halfedge *) myalloc(PQhashsize * sizeof *PQhash);
769  PQhash = (Halfedge *) myalloc(PQhashsize * sizeof(Halfedge));
770
771  if(PQhash == 0)
772    return false;
773
774  for(i=0; i<PQhashsize; i+=1) PQhash[i].PQnext = (Halfedge *)NULL;
775
776  return true;
777}
778
779
780void VoronoiDiagramGenerator::freeinit(Freelist *fl,int size)
781{
782  fl->head = (Freenode *) NULL;
783  fl->nodesize = size;
784}
785
786char * VoronoiDiagramGenerator::getfree(Freelist *fl)
787{
788  int i; 
789  Freenode *t;
790
791  if(fl->head == (Freenode *) NULL)
792    {   
793      t =  (Freenode *) myalloc(sqrt_nsites * fl->nodesize);
794
795      if(t == 0)
796        return 0;
797               
798      currentMemoryBlock->next = new FreeNodeArrayList;
799      currentMemoryBlock = currentMemoryBlock->next;
800      currentMemoryBlock->memory = t;
801      currentMemoryBlock->next = 0;
802
803      for(i=0; i<sqrt_nsites; i+=1)     
804        makefree((Freenode *)((char *)t+i*fl->nodesize), fl);           
805    };
806  t = fl->head;
807  fl->head = (fl->head)->nextfree;
808  return((char *)t);
809}
810
811
812
813void VoronoiDiagramGenerator::makefree(Freenode *curr,Freelist *fl)
814{
815  curr->nextfree = fl->head;
816  fl->head = curr;
817}
818
819void VoronoiDiagramGenerator::cleanup()
820{
821  if(sites != NULL){
822    free(sites);
823    sites = 0;
824  }
825
826  FreeNodeArrayList* current=NULL, *prev=NULL;
827
828  current = prev = allMemoryList;
829
830  while(current->next!=NULL){
831    prev = current;
832    current = current->next;
833    free(prev->memory);
834    delete prev;
835    prev = NULL;
836  }
837
838  if(current!=NULL){
839    if (current->memory!=NULL){
840      free(current->memory);
841    }
842    delete current;
843  }
844
845  allMemoryList = new FreeNodeArrayList;
846  allMemoryList->next = NULL;
847  allMemoryList->memory = NULL;
848  currentMemoryBlock = allMemoryList;
849
850  if (ELhash!=NULL)
851    free(ELhash);
852
853  if (PQhash!=NULL)
854    free(PQhash);
855}
856
857void VoronoiDiagramGenerator::cleanupEdges()
858{
859  GraphEdge* geCurrent = NULL, *gePrev = NULL;
860  geCurrent = gePrev = allEdges;
861
862  while(geCurrent!=NULL){
863    gePrev = geCurrent;
864    geCurrent = geCurrent->next;
865    delete gePrev;
866  }
867
868  allEdges = 0;
869
870}
871
872void VoronoiDiagramGenerator::pushGraphEdge(double x1, double y1, double x2, double y2,
873                                            Site *s1, Site *s2)
874{
875  GraphEdge* newEdge = new GraphEdge;
876  newEdge->next = allEdges;
877  allEdges = newEdge;
878  newEdge->x1 = x1;
879  newEdge->y1 = y1;
880  newEdge->x2 = x2;
881  newEdge->y2 = y2;
882
883  newEdge->point1 = s1->sitenbr;
884  newEdge->point2 = s2->sitenbr;
885}
886
887
888char * VoronoiDiagramGenerator::myalloc(unsigned n)
889{
890  char *t=0;   
891  t=(char*)malloc(n);
892  total_alloc += n;
893  return(t);
894}
895
896
897// unused plot functions
898//
899// /* for those who don't have Cherry's plot */
900// /* #include <plot.h> */
901// void VoronoiDiagramGenerator::openpl(){}
902// void VoronoiDiagramGenerator::circle(double x, double y, double radius){}
903// void VoronoiDiagramGenerator::range(double minX, double minY, double maxX, double maxY){}
904//
905//
906//
907// void VoronoiDiagramGenerator::out_bisector(Edge *e)
908// {
909//     
910//
911// }
912//
913//
914// void VoronoiDiagramGenerator::out_ep(Edge *e)
915// {
916//     
917//     
918// }
919//
920// void VoronoiDiagramGenerator::out_vertex(Site *v)
921// {
922//     
923// }
924//
925//
926// void VoronoiDiagramGenerator::out_site(Site *s)
927// {
928//   // Gregory Soyez:
929//   //   plot was always 0 so the expression below was always false
930//   //   and even if it was not, 'circle' does nothing!
931//   //
932//   // if(!triangulate & plot & !debug)
933//   //   circle (s->coord.x, s->coord.y, cradius);
934//     
935// }
936//
937//
938// void VoronoiDiagramGenerator::out_triple(Site *s1, Site *s2,Site * s3)
939// {
940//     
941// }
942
943
944
945void VoronoiDiagramGenerator::plotinit()
946{
947  double dx,dy,d;
948       
949  dy = ymax - ymin;
950  dx = xmax - xmin;
951  d = (double)(( dx > dy ? dx : dy) * 1.1);
952  pxmin = (double)(xmin - (d-dx)/2.0);
953  pxmax = (double)(xmax + (d-dx)/2.0);
954  pymin = (double)(ymin - (d-dy)/2.0);
955  pymax = (double)(ymax + (d-dy)/2.0);
956  cradius = (double)((pxmax - pxmin)/350.0);
957  //GS unused: openpl();
958  //GS unused: range(pxmin, pymin, pxmax, pymax);
959}
960
961
962void VoronoiDiagramGenerator::clip_line(Edge *e)
963{
964  Site *s1, *s2;
965  double x1=0,x2=0,y1=0,y2=0; //, temp = 0;
966
967  x1 = e->reg[0]->coord.x;
968  x2 = e->reg[1]->coord.x;
969  y1 = e->reg[0]->coord.y;
970  y2 = e->reg[1]->coord.y;
971
972  //if the distance between the two points this line was created from is less than
973  //the square root of 2, then ignore it
974  //TODO improve/remove
975  //if(sqrt(((x2 - x1) * (x2 - x1)) + ((y2 - y1) * (y2 - y1))) < minDistanceBetweenSites)
976  //  {
977  //    return;
978  //  }
979  pxmin = borderMinX;
980  pxmax = borderMaxX;
981  pymin = borderMinY;
982  pymax = borderMaxY;
983
984  if(e->a == 1.0 && e ->b >= 0.0)
985    {   
986      s1 = e->ep[1];
987      s2 = e->ep[0];
988    }
989  else 
990    {
991      s1 = e->ep[0];
992      s2 = e->ep[1];
993    };
994       
995  if(e->a == 1.0)
996    {
997      y1 = pymin;
998      if (s1!=(Site *)NULL && s1->coord.y > pymin)
999        {
1000          y1 = s1->coord.y;
1001        }
1002      if(y1>pymax) 
1003        {
1004          //    printf("\nClipped (1) y1 = %f to %f",y1,pymax);
1005          y1 = pymax;
1006          //return;
1007        }
1008      x1 = e->c - e->b * y1;
1009      y2 = pymax;
1010      if (s2!=(Site *)NULL && s2->coord.y < pymax) 
1011        y2 = s2->coord.y;
1012
1013      if(y2<pymin) 
1014        {
1015          //printf("\nClipped (2) y2 = %f to %f",y2,pymin);
1016          y2 = pymin;
1017          //return;
1018        }
1019      x2 = (e->c) - (e->b) * y2;
1020      if (((x1> pxmax) & (x2>pxmax)) | ((x1<pxmin)&(x2<pxmin))) 
1021        {
1022          //printf("\nClipLine jumping out(3), x1 = %f, pxmin = %f, pxmax = %f",x1,pxmin,pxmax);
1023          return;
1024        }
1025      if(x1> pxmax)
1026        {       x1 = pxmax; y1 = (e->c - x1)/e->b;};
1027      if(x1<pxmin)
1028        {       x1 = pxmin; y1 = (e->c - x1)/e->b;};
1029      if(x2>pxmax)
1030        {       x2 = pxmax; y2 = (e->c - x2)/e->b;};
1031      if(x2<pxmin)
1032        {       x2 = pxmin; y2 = (e->c - x2)/e->b;};
1033    }
1034  else
1035    {
1036      x1 = pxmin;
1037      if (s1!=(Site *)NULL && s1->coord.x > pxmin) 
1038        x1 = s1->coord.x;
1039      if(x1>pxmax) 
1040        {
1041          //printf("\nClipped (3) x1 = %f to %f",x1,pxmin);
1042          //return;
1043          x1 = pxmax;
1044        }
1045      y1 = e->c - e->a * x1;
1046      x2 = pxmax;
1047      if (s2!=(Site *)NULL && s2->coord.x < pxmax) 
1048        x2 = s2->coord.x;
1049      if(x2<pxmin) 
1050        {
1051          //printf("\nClipped (4) x2 = %f to %f",x2,pxmin);
1052          //return;
1053          x2 = pxmin;
1054        }
1055      y2 = e->c - e->a * x2;
1056      if (((y1> pymax) & (y2>pymax)) | ((y1<pymin)&(y2<pymin))) 
1057        {
1058          //printf("\nClipLine jumping out(6), y1 = %f, pymin = %f, pymax = %f",y2,pymin,pymax);
1059          return;
1060        }
1061      if(y1> pymax)
1062        {       y1 = pymax; x1 = (e->c - y1)/e->a;};
1063      if(y1<pymin)
1064        {       y1 = pymin; x1 = (e->c - y1)/e->a;};
1065      if(y2>pymax)
1066        {       y2 = pymax; x2 = (e->c - y2)/e->a;};
1067      if(y2<pymin)
1068        {       y2 = pymin; x2 = (e->c - y2)/e->a;};
1069    };
1070       
1071  //printf("\nPushing line (%f,%f,%f,%f)",x1,y1,x2,y2);
1072  //fprintf(stdout, "Line with vertices (%f,%f) and (%f,%f)\n",
1073  //    e->reg[0]->coord.x, e->reg[1]->coord.x, e->reg[0]->coord.y, e->reg[1]->coord.y);
1074  pushGraphEdge(x1,y1,x2,y2,e->reg[0],e->reg[1]);
1075}
1076
1077
1078/* implicit parameters: nsites, sqrt_nsites, xmin, xmax, ymin, ymax,
1079   deltax, deltay (can all be estimates).
1080   Performance suffers if they are wrong; better to make nsites,
1081   deltax, and deltay too big than too small.  (?) */
1082
1083bool VoronoiDiagramGenerator::voronoi()
1084{
1085  Site *newsite, *bot, *top, *temp, *p;
1086  Site *v;
1087  VPoint newintstar;
1088  int pm;
1089  Halfedge *lbnd, *rbnd, *llbnd, *rrbnd, *bisector;
1090  Edge *e;
1091       
1092  PQinitialize();
1093  bottomsite = nextone();
1094  //GS unused plot: out_site(bottomsite);
1095  bool retval = ELinitialize();
1096
1097  if(!retval)
1098    return false;
1099       
1100  newsite = nextone();
1101  while(1)
1102    {
1103
1104      if(!PQempty()) 
1105        newintstar = PQ_min();
1106               
1107      //if the lowest site has a smaller y value than the lowest vector intersection, process the site
1108      //otherwise process the vector intersection               
1109      if (newsite != (Site *)NULL  && (PQempty() || newsite->coord.y < newintstar.y
1110                                       || (newsite->coord.y == newintstar.y && newsite->coord.x < newintstar.x)))
1111        {/* new site is smallest - this is a site event*/
1112          //GS unused plot: out_site(newsite);                                          //output the site
1113          lbnd = ELleftbnd(&(newsite->coord));                          //get the first HalfEdge to the LEFT of the new site
1114          rbnd = ELright(lbnd);                                         //get the first HalfEdge to the RIGHT of the new site
1115          bot = rightreg(lbnd);                                         //if this halfedge has no edge, , bot = bottom site (whatever that is)
1116          e = bisect(bot, newsite);                                     //create a new edge that bisects
1117          bisector = HEcreate(e, le);                                   //create a new HalfEdge, setting its ELpm field to 0                   
1118          ELinsert(lbnd, bisector);                                     //insert this new bisector edge between the left and right vectors in a linked list     
1119           
1120          if ((p = intersect(lbnd, bisector)) != (Site *) NULL)         //if the new bisector intersects with the left edge, remove the left edge's vertex, and put in the new one
1121            {   
1122              PQdelete(lbnd);
1123              PQinsert(lbnd, p, dist(p,newsite));
1124            };
1125          lbnd = bisector;                                             
1126          bisector = HEcreate(e, re);                                   //create a new HalfEdge, setting its ELpm field to 1
1127          ELinsert(lbnd, bisector);                                     //insert the new HE to the right of the original bisector earlier in the IF stmt
1128           
1129          if ((p = intersect(bisector, rbnd)) != (Site *) NULL) //if this new bisector intersects with the
1130            {   
1131              PQinsert(bisector, p, dist(p,newsite));                   //push the HE into the ordered linked list of vertices
1132            };
1133          newsite = nextone(); 
1134        }
1135      else if (!PQempty()) /* intersection is smallest - this is a vector event */                     
1136        {       
1137          lbnd = PQextractmin();                                                //pop the HalfEdge with the lowest vector off the ordered list of vectors                               
1138          llbnd = ELleft(lbnd);                                         //get the HalfEdge to the left of the above HE
1139          rbnd = ELright(lbnd);                                         //get the HalfEdge to the right of the above HE
1140          rrbnd = ELright(rbnd);                                                //get the HalfEdge to the right of the HE to the right of the lowest HE
1141          bot = leftreg(lbnd);                                          //get the Site to the left of the left HE which it bisects
1142          top = rightreg(rbnd);                                         //get the Site to the right of the right HE which it bisects
1143           
1144          //GS unused plot: out_triple(bot, top, rightreg(lbnd));               //output the triple of sites, stating that a circle goes through them
1145           
1146          v = lbnd->vertex;                                             //get the vertex that caused this event
1147          makevertex(v);                                                        //set the vertex number - couldn't do this earlier since we didn't know when it would be processed
1148          endpoint(lbnd->ELedge,lbnd->ELpm,v);  //set the endpoint of the left HalfEdge to be this vector
1149          endpoint(rbnd->ELedge,rbnd->ELpm,v);  //set the endpoint of the right HalfEdge to be this vector
1150          ELdelete(lbnd);                                                       //mark the lowest HE for deletion - can't delete yet because there might be pointers to it in Hash Map 
1151          PQdelete(rbnd);                                                       //remove all vertex events to do with the  right HE
1152          ELdelete(rbnd);                                                       //mark the right HE for deletion - can't delete yet because there might be pointers to it in Hash Map   
1153          pm = le;                                                              //set the pm variable to zero
1154           
1155          if (bot->coord.y > top->coord.y)              //if the site to the left of the event is higher than the Site
1156            {                                                                           //to the right of it, then swap them and set the 'pm' variable to 1
1157              temp = bot; 
1158              bot = top; 
1159              top = temp; 
1160              pm = re;
1161            }
1162          e = bisect(bot, top);                                 //create an Edge (or line) that is between the two Sites. This creates
1163          //the formula of the line, and assigns a line number to it
1164          bisector = HEcreate(e, pm);                           //create a HE from the Edge 'e', and make it point to that edge with its ELedge field
1165          ELinsert(llbnd, bisector);                            //insert the new bisector to the right of the left HE
1166          endpoint(e, re-pm, v);                                        //set one endpoint to the new edge to be the vector point 'v'.
1167          //If the site to the left of this bisector is higher than the right
1168          //Site, then this endpoint is put in position 0; otherwise in pos 1
1169          deref(v);                                                             //delete the vector 'v'
1170           
1171          //if left HE and the new bisector don't intersect, then delete the left HE, and reinsert it
1172          if((p = intersect(llbnd, bisector)) != (Site *) NULL)
1173            {   
1174              PQdelete(llbnd);
1175              PQinsert(llbnd, p, dist(p,bot));
1176            };
1177           
1178          //if right HE and the new bisector don't intersect, then reinsert it
1179          if ((p = intersect(bisector, rrbnd)) != (Site *) NULL)
1180            {   
1181              PQinsert(bisector, p, dist(p,bot));
1182            };
1183        }
1184      else break;
1185    };
1186
1187       
1188
1189
1190  for(lbnd=ELright(ELleftend); lbnd != ELrightend; lbnd=ELright(lbnd))
1191    {   
1192      e = lbnd->ELedge;
1193
1194      clip_line(e);
1195    };
1196
1197  //cleanup();
1198
1199  return true;
1200       
1201}
1202
1203
1204int scomp(const void *p1,const void *p2)
1205{
1206  VPoint *s1 = (VPoint*)p1, *s2=(VPoint*)p2;
1207  if(s1->y < s2->y) return(-1);
1208  if(s1->y > s2->y) return(1);
1209  if(s1->x < s2->x) return(-1);
1210  if(s1->x > s2->x) return(1);
1211  return(0);
1212}
1213
1214/* return a single in-storage site */
1215Site * VoronoiDiagramGenerator::nextone()
1216{
1217  Site *s;
1218  if(siteidx < nsites)
1219    {   
1220      s = &sites[siteidx];
1221      siteidx += 1;
1222      return(s);
1223    }
1224  else 
1225    return( (Site *)NULL);
1226}
1227
1228FASTJET_END_NAMESPACE
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