[u/mrichter/AliRoot.git] / STEER / AliStrLine.cxx

/**************************************************************************
 * Copyright(c) 1998-2003, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/

/* $Id$ */

///////////////////////////////////////////////////////////////////
//                                                               //
// A straight line is coded as a point (3 Double_t) and           //
// 3 direction cosines                                           //
//                                                               //
///////////////////////////////////////////////////////////////////

#include <Riostream.h>
#include <TTree.h>
#include <TMath.h>

#include "AliStrLine.h"

ClassImp(AliStrLine)

//________________________________________________________
AliStrLine::AliStrLine() :
  TObject(),
  fTpar(0),
  fDebug(0)
 {
  // Default constructor
  for(Int_t i=0;i<3;i++) {
    fP0[i] = 0.;
    fSigma2P0[i] = 0.;
    fCd[i] = 0.;
  }
}

//________________________________________________________
AliStrLine::AliStrLine(Double_t *point, Double_t *cd,Bool_t twopoints) :
  TObject(),
  fTpar(0),
  fDebug(0)
{
  // Standard constructor
  // if twopoints is true:  point and cd are the 3D coordinates of
  //                        two points defininig the straight line
  // if twopoint is false: point represents the 3D coordinates of a point
  //                       belonging to the straight line and cd is the
  //                       direction in space
  for(Int_t i=0;i<3;i++) fSigma2P0[i] = 0.;
  if(twopoints){
    InitTwoPoints(point,cd);
  }
  else {
    InitDirection(point,cd);
  }
}

//________________________________________________________
AliStrLine::AliStrLine(Float_t *pointf, Float_t *cdf,Bool_t twopoints) :
  TObject(),
  fTpar(0),
  fDebug(0)
{
  // Standard constructor - with float arguments
  // if twopoints is true:  point and cd are the 3D coordinates of
  //                        two points defininig the straight line
  // if twopoint is false: point represents the 3D coordinates of a point
  //                       belonging to the straight line and cd is the
  //                       direction in space
  Double_t point[3];
  Double_t cd[3];
  for(Int_t i=0;i<3;i++){
    point[i] = pointf[i];
    cd[i] = cdf[i];
    fSigma2P0[i] = 0.;
  }
  if(twopoints){
    InitTwoPoints(point,cd);
  }
  else {
    InitDirection(point,cd);
  }
}

//________________________________________________________
AliStrLine::AliStrLine(Double_t *point, Double_t *sig2point, Double_t *cd,Bool_t twopoints) :
  TObject(),
  fTpar(0),
  fDebug(0)
{
  // Standard constructor
  // if twopoints is true:  point and cd are the 3D coordinates of
  //                        two points defininig the straight line
  // if twopoint is false: point represents the 3D coordinates of a point
  //                       belonging to the straight line and cd is the
  //                       direction in space
  for(Int_t i=0;i<3;i++) fSigma2P0[i] = sig2point[i];
  if(twopoints){
    InitTwoPoints(point,cd);
  }
  else {
    InitDirection(point,cd);
  }
}

//________________________________________________________
AliStrLine::AliStrLine(Float_t *pointf, Float_t *sig2point, Float_t *cdf,Bool_t twopoints) :
  TObject(),
  fTpar(0),
  fDebug(0)
{
  // Standard constructor - with float arguments
  // if twopoints is true:  point and cd are the 3D coordinates of
  //                        two points defininig the straight line
  // if twopoint is false: point represents the 3D coordinates of a point
  //                       belonging to the straight line and cd is the
  //                       direction in space
  Double_t point[3];
  Double_t cd[3];
  for(Int_t i=0;i<3;i++){
    point[i] = pointf[i];
    cd[i] = cdf[i];
    fSigma2P0[i] = sig2point[i];
  }
  if(twopoints){
    InitTwoPoints(point,cd);
  }
  else {
    InitDirection(point,cd);
  }
}
//________________________________________________________
void AliStrLine::InitDirection(Double_t *point, Double_t *cd){
  // Initialization from a point and a direction
  Double_t norm = 0.;
  for(Int_t i=0;i<3;i++)norm+=cd[i]*cd[i];
  if(norm) {
    norm = TMath::Sqrt(norm);
    for(Int_t i=0;i<3;i++) cd[i]/=norm;
  }
  else {
    Error("AliStrLine","Null direction cosines!!!");
  }
  SetP0(point);
  SetCd(cd);
  fTpar = 0.;
  SetDebug();
}

//________________________________________________________
void AliStrLine::InitTwoPoints(Double_t *pA, Double_t *pB){
  // Initialization from the coordinates of two
  // points in the space
  Double_t cd[3];
  for(Int_t i=0;i<3;i++)cd[i] = pB[i]-pA[i];
  InitDirection(pA,cd);
}

//________________________________________________________
AliStrLine::~AliStrLine() {
  // destructor
}

//________________________________________________________
void AliStrLine::PrintStatus() const {
  // Print current status
  cout <<"=======================================================\n";
  cout <<"Direction cosines: ";
  for(Int_t i=0;i<3;i++)cout <<fCd[i]<<"; ";
  cout <<endl;
  cout <<"Known point: ";
  for(Int_t i=0;i<3;i++)cout <<fP0[i]<<"; ";
  cout <<endl;
  cout <<"Error on known point: ";
  for(Int_t i=0;i<3;i++)cout <<TMath::Sqrt(fSigma2P0[i])<<"; ";
  cout <<endl;
  cout <<"Current value for the parameter: "<<fTpar<<endl;
  cout <<" Debug flag: "<<fDebug<<endl;
}

//________________________________________________________
Int_t AliStrLine::IsParallelTo(AliStrLine *line) const {
  // returns 1 if lines are parallel, 0 if not paralel
  Double_t cd2[3];
  line->GetCd(cd2);
  Double_t vecpx=fCd[1]*cd2[2]-fCd[2]*cd2[1];
  if(vecpx!=0) return 0;
  Double_t vecpy=-fCd[0]*cd2[2]+fCd[2]*cd2[0];
  if(vecpy!=0) return 0;
  Double_t vecpz=fCd[0]*cd2[1]-fCd[1]*cd2[0];
  if(vecpz!=0) return 0;
  return 1;
}
//________________________________________________________
Int_t AliStrLine::Crossrphi(AliStrLine *line){
  // Cross 2 lines in the X-Y plane
  Double_t p2[3];
  Double_t cd2[3];
  line->GetP0(p2);
  line->GetCd(cd2);
  Double_t a=fCd[0];
  Double_t b=-cd2[0];
  Double_t c=p2[0]-fP0[0];
  Double_t d=fCd[1];
  Double_t e=-cd2[1];
  Double_t f=p2[1]-fP0[1];
  Double_t deno = a*e-b*d;
  Int_t retcode = 0;
  if(deno != 0.) {
    fTpar = (c*e-b*f)/deno;
  }
  else {
    retcode = -1;
  }
  return retcode;
}

//________________________________________________________
Int_t AliStrLine::CrossPoints(AliStrLine *line, Double_t *point1, Double_t *point2){
  // Looks for the crossing point estimated starting from the
  // DCA segment
  Double_t p2[3];
  Double_t cd2[3];
  line->GetP0(p2);
  line->GetCd(cd2);
  Int_t i;
  Double_t k1 = 0;
  for(i=0;i<3;i++)k1+=(fP0[i]-p2[i])*fCd[i];
  Double_t k2 = 0;
  for(i=0;i<3;i++)k2+=(fP0[i]-p2[i])*cd2[i];
  Double_t a11 = 0;
  for(i=0;i<3;i++)a11+=fCd[i]*cd2[i];
  Double_t a22 = -a11;
  Double_t a21 = 0;
  for(i=0;i<3;i++)a21+=cd2[i]*cd2[i];
  Double_t a12 = 0;
  for(i=0;i<3;i++)a12-=fCd[i]*fCd[i];
  Double_t deno = a11*a22-a21*a12;
  if(deno == 0.) return -1;
  fTpar = (a11*k2-a21*k1) / deno;
  Double_t par2 = (k1*a22-k2*a12) / deno;
  line->SetPar(par2);
  GetCurrentPoint(point1);
  line->GetCurrentPoint(point2);
  return 0;
}
//________________________________________________________________
Int_t AliStrLine::Cross(AliStrLine *line, Double_t *point){

  //Finds intersection between lines
  Double_t point1[3];
  Double_t point2[3];
  Int_t retcod=CrossPoints(line,point1,point2);
  if(retcod==0){
    for(Int_t i=0;i<3;i++)point[i]=(point1[i]+point2[i])/2.;
    return 0;
  }else{
    return -1;
  }
}

//___________________________________________________________
Double_t AliStrLine::GetDCA(AliStrLine *line) const{
  //Returns the distance of closest approach between two lines
  Double_t p2[3];
  Double_t cd2[3];
  line->GetP0(p2);
  line->GetCd(cd2);
  Int_t i;
  Int_t ispar=IsParallelTo(line);
  if(ispar){
    Double_t dist1q=0,dist2=0,mod=0;
    for(i=0;i<3;i++){
      dist1q+=(fP0[i]-p2[i])*(fP0[i]-p2[i]);
      dist2+=(fP0[i]-p2[i])*fCd[i];
      mod+=fCd[i]*fCd[i];
    }
    if(mod!=0){
      dist2/=mod;
      return TMath::Sqrt(dist1q-dist2*dist2);
    }else{return -1;}
  }else{
     Double_t perp[3];
     perp[0]=fCd[1]*cd2[2]-fCd[2]*cd2[1];
     perp[1]=-fCd[0]*cd2[2]+fCd[2]*cd2[0];
     perp[2]=fCd[0]*cd2[1]-fCd[1]*cd2[0];
     Double_t mod=0,dist=0;
     for(i=0;i<3;i++){
       mod+=perp[i]*perp[i];
       dist+=(fP0[i]-p2[i])*perp[i];
     }
     mod=sqrt(mod);
     if(mod!=0){
       dist/=mod;
       return TMath::Abs(dist);
     }else{return -1;}
  }
}
//________________________________________________________
void AliStrLine::GetCurrentPoint(Double_t *point) const {
  // Fills the array point with the current value on the line
  for(Int_t i=0;i<3;i++)point[i]=fP0[i]+fCd[i]*fTpar;
}

//________________________________________________________
Double_t AliStrLine::GetDistFromPoint(Double_t *point) const {
  // computes distance from point 
  AliStrLine tmp(point,(Double_t *)fCd,kFALSE);
  return this->GetDCA(&tmp);
}
Commit	Line	Data
edc97986	1	/**************************************************************************
	2	* Copyright(c) 1998-2003, ALICE Experiment at CERN, All rights reserved. *
	3	* *
	4	* Author: The ALICE Off-line Project. *
	5	* Contributors are mentioned in the code where appropriate. *
	6	* *
	7	* Permission to use, copy, modify and distribute this software and its *
	8	* documentation strictly for non-commercial purposes is hereby granted *
	9	* without fee, provided that the above copyright notice appears in all *
	10	* copies and that both the copyright notice and this permission notice *
	11	* appear in the supporting documentation. The authors make no claims *
	12	* about the suitability of this software for any purpose. It is *
	13	* provided "as is" without express or implied warranty. *
	14	**************************************************************************/
090026bf	15
	16	/* $Id$ */
	17
edc97986	18	///////////////////////////////////////////////////////////////////
	19	// //
	20	// A straight line is coded as a point (3 Double_t) and //
	21	// 3 direction cosines //
	22	// //
	23	///////////////////////////////////////////////////////////////////
090026bf	24
edc97986	25	#include <Riostream.h>
edc97986	26	#include <TTree.h>
090026bf	27	#include <TMath.h>
090026bf	28
edc97986	29	#include "AliStrLine.h"
	30
	31	ClassImp(AliStrLine)
	32
	33	//________________________________________________________
fe12e09c	34	AliStrLine::AliStrLine() :
	35	TObject(),
	36	fTpar(0),
	37	fDebug(0)
	38	{
edc97986	39	// Default constructor
	40	for(Int_t i=0;i<3;i++) {
	41	fP0[i] = 0.;
28dc94e2	42	fSigma2P0[i] = 0.;
edc97986	43	fCd[i] = 0.;
edc97986	44	}
edc97986	45	}
	46
	47	//________________________________________________________
fe12e09c	48	AliStrLine::AliStrLine(Double_t point, Double_t cd,Bool_t twopoints) :
	49	TObject(),
	50	fTpar(0),
	51	fDebug(0)
	52	{
edc97986	53	// Standard constructor
24a0c65f	54	// if twopoints is true: point and cd are the 3D coordinates of
	55	// two points defininig the straight line
	56	// if twopoint is false: point represents the 3D coordinates of a point
	57	// belonging to the straight line and cd is the
	58	// direction in space
28dc94e2	59	for(Int_t i=0;i<3;i++) fSigma2P0[i] = 0.;
24a0c65f	60	if(twopoints){
	61	InitTwoPoints(point,cd);
	62	}
	63	else {
	64	InitDirection(point,cd);
	65	}
	66	}
	67
2c9641ee	68	//________________________________________________________
	69	AliStrLine::AliStrLine(Float_t pointf, Float_t cdf,Bool_t twopoints) :
	70	TObject(),
	71	fTpar(0),
	72	fDebug(0)
	73	{
	74	// Standard constructor - with float arguments
	75	// if twopoints is true: point and cd are the 3D coordinates of
	76	// two points defininig the straight line
	77	// if twopoint is false: point represents the 3D coordinates of a point
	78	// belonging to the straight line and cd is the
	79	// direction in space
	80	Double_t point[3];
	81	Double_t cd[3];
	82	for(Int_t i=0;i<3;i++){
	83	point[i] = pointf[i];
	84	cd[i] = cdf[i];
28dc94e2	85	fSigma2P0[i] = 0.;
2c9641ee	86	}
	87	if(twopoints){
	88	InitTwoPoints(point,cd);
	89	}
	90	else {
	91	InitDirection(point,cd);
	92	}
	93	}
24a0c65f	94
28dc94e2	95	//________________________________________________________
	96	AliStrLine::AliStrLine(Double_t point, Double_t sig2point, Double_t *cd,Bool_t twopoints) :
	97	TObject(),
	98	fTpar(0),
	99	fDebug(0)
	100	{
	101	// Standard constructor
	102	// if twopoints is true: point and cd are the 3D coordinates of
	103	// two points defininig the straight line
	104	// if twopoint is false: point represents the 3D coordinates of a point
	105	// belonging to the straight line and cd is the
	106	// direction in space
	107	for(Int_t i=0;i<3;i++) fSigma2P0[i] = sig2point[i];
	108	if(twopoints){
	109	InitTwoPoints(point,cd);
	110	}
	111	else {
	112	InitDirection(point,cd);
	113	}
	114	}
	115
	116	//________________________________________________________
	117	AliStrLine::AliStrLine(Float_t pointf, Float_t sig2point, Float_t *cdf,Bool_t twopoints) :
	118	TObject(),
	119	fTpar(0),
	120	fDebug(0)
	121	{
	122	// Standard constructor - with float arguments
	123	// if twopoints is true: point and cd are the 3D coordinates of
	124	// two points defininig the straight line
	125	// if twopoint is false: point represents the 3D coordinates of a point
	126	// belonging to the straight line and cd is the
	127	// direction in space
	128	Double_t point[3];
	129	Double_t cd[3];
	130	for(Int_t i=0;i<3;i++){
	131	point[i] = pointf[i];
	132	cd[i] = cdf[i];
	133	fSigma2P0[i] = sig2point[i];
	134	}
	135	if(twopoints){
	136	InitTwoPoints(point,cd);
	137	}
	138	else {
	139	InitDirection(point,cd);
	140	}
	141	}
24a0c65f	142	//________________________________________________________
	143	void AliStrLine::InitDirection(Double_t point, Double_t cd){
	144	// Initialization from a point and a direction
edc97986	145	Double_t norm = 0.;
	146	for(Int_t i=0;i<3;i++)norm+=cd[i]*cd[i];
	147	if(norm) {
	148	norm = TMath::Sqrt(norm);
	149	for(Int_t i=0;i<3;i++) cd[i]/=norm;
	150	}
	151	else {
	152	Error("AliStrLine","Null direction cosines!!!");
	153	}
	154	SetP0(point);
	155	SetCd(cd);
	156	fTpar = 0.;
	157	SetDebug();
	158	}
	159
24a0c65f	160	//________________________________________________________
	161	void AliStrLine::InitTwoPoints(Double_t pA, Double_t pB){
	162	// Initialization from the coordinates of two
	163	// points in the space
	164	Double_t cd[3];
	165	for(Int_t i=0;i<3;i++)cd[i] = pB[i]-pA[i];
	166	InitDirection(pA,cd);
	167	}
	168
edc97986	169	//________________________________________________________
	170	AliStrLine::~AliStrLine() {
	171	// destructor
	172	}
	173
	174	//________________________________________________________
	175	void AliStrLine::PrintStatus() const {
	176	// Print current status
	177	cout <<"=======================================================\n";
	178	cout <<"Direction cosines: ";
	179	for(Int_t i=0;i<3;i++)cout <<fCd[i]<<"; ";
	180	cout <<endl;
	181	cout <<"Known point: ";
	182	for(Int_t i=0;i<3;i++)cout <<fP0[i]<<"; ";
	183	cout <<endl;
28dc94e2	184	cout <<"Error on known point: ";
	185	for(Int_t i=0;i<3;i++)cout <<TMath::Sqrt(fSigma2P0[i])<<"; ";
	186	cout <<endl;
edc97986	187	cout <<"Current value for the parameter: "<<fTpar<<endl;
	188	cout <<" Debug flag: "<<fDebug<<endl;
	189	}
	190
	191	//________________________________________________________
	192	Int_t AliStrLine::IsParallelTo(AliStrLine *line) const {
	193	// returns 1 if lines are parallel, 0 if not paralel
	194	Double_t cd2[3];
	195	line->GetCd(cd2);
	196	Double_t vecpx=fCd[1]cd2[2]-fCd[2]cd2[1];
	197	if(vecpx!=0) return 0;
	198	Double_t vecpy=-fCd[0]cd2[2]+fCd[2]cd2[0];
	199	if(vecpy!=0) return 0;
	200	Double_t vecpz=fCd[0]cd2[1]-fCd[1]cd2[0];
	201	if(vecpz!=0) return 0;
	202	return 1;
	203	}
	204	//________________________________________________________
	205	Int_t AliStrLine::Crossrphi(AliStrLine *line){
	206	// Cross 2 lines in the X-Y plane
	207	Double_t p2[3];
	208	Double_t cd2[3];
	209	line->GetP0(p2);
	210	line->GetCd(cd2);
	211	Double_t a=fCd[0];
	212	Double_t b=-cd2[0];
	213	Double_t c=p2[0]-fP0[0];
	214	Double_t d=fCd[1];
	215	Double_t e=-cd2[1];
	216	Double_t f=p2[1]-fP0[1];
	217	Double_t deno = ae-bd;
	218	Int_t retcode = 0;
	219	if(deno != 0.) {
	220	fTpar = (ce-bf)/deno;
	221	}
	222	else {
	223	retcode = -1;
	224	}
	225	return retcode;
	226	}
	227
	228	//________________________________________________________
	229	Int_t AliStrLine::CrossPoints(AliStrLine line, Double_t point1, Double_t *point2){
	230	// Looks for the crossing point estimated starting from the
	231	// DCA segment
	232	Double_t p2[3];
	233	Double_t cd2[3];
	234	line->GetP0(p2);
	235	line->GetCd(cd2);
	236	Int_t i;
	237	Double_t k1 = 0;
	238	for(i=0;i<3;i++)k1+=(fP0[i]-p2[i])*fCd[i];
	239	Double_t k2 = 0;
	240	for(i=0;i<3;i++)k2+=(fP0[i]-p2[i])*cd2[i];
	241	Double_t a11 = 0;
	242	for(i=0;i<3;i++)a11+=fCd[i]*cd2[i];
	243	Double_t a22 = -a11;
	244	Double_t a21 = 0;
	245	for(i=0;i<3;i++)a21+=cd2[i]*cd2[i];
	246	Double_t a12 = 0;
	247	for(i=0;i<3;i++)a12-=fCd[i]*fCd[i];
	248	Double_t deno = a11a22-a21a12;
	249	if(deno == 0.) return -1;
	250	fTpar = (a11k2-a21k1) / deno;
251	Double_t par2 = (k1a22-k2a12) / deno;
252	line->SetPar(par2);
253	GetCurrentPoint(point1);
254	line->GetCurrentPoint(point2);
255	return 0;
256	}
257	//________________________________________________________________
258	Int_t AliStrLine::Cross(AliStrLine line, Double_t point){
259
260	//Finds intersection between lines
261	Double_t point1[3];
262	Double_t point2[3];
263	Int_t retcod=CrossPoints(line,point1,point2);
264	if(retcod==0){
265	for(Int_t i=0;i<3;i++)point[i]=(point1[i]+point2[i])/2.;
266	return 0;
267	}else{
268	return -1;
269	}
270	}
271
272	//___________________________________________________________
2c9641ee	273	Double_t AliStrLine::GetDCA(AliStrLine *line) const{
edc97986	274	//Returns the distance of closest approach between two lines
	275	Double_t p2[3];
	276	Double_t cd2[3];
	277	line->GetP0(p2);
	278	line->GetCd(cd2);
	279	Int_t i;
	280	Int_t ispar=IsParallelTo(line);
	281	if(ispar){
	282	Double_t dist1q=0,dist2=0,mod=0;
	283	for(i=0;i<3;i++){
	284	dist1q+=(fP0[i]-p2[i])*(fP0[i]-p2[i]);
	285	dist2+=(fP0[i]-p2[i])*fCd[i];
	286	mod+=fCd[i]*fCd[i];
	287	}
	288	if(mod!=0){
	289	dist2/=mod;
	290	return TMath::Sqrt(dist1q-dist2*dist2);
	291	}else{return -1;}
	292	}else{
	293	Double_t perp[3];
	294	perp[0]=fCd[1]cd2[2]-fCd[2]cd2[1];
	295	perp[1]=-fCd[0]cd2[2]+fCd[2]cd2[0];
	296	perp[2]=fCd[0]cd2[1]-fCd[1]cd2[0];
	297	Double_t mod=0,dist=0;
	298	for(i=0;i<3;i++){
	299	mod+=perp[i]*perp[i];
	300	dist+=(fP0[i]-p2[i])*perp[i];
	301	}
	302	mod=sqrt(mod);
	303	if(mod!=0){
	304	dist/=mod;
	305	return TMath::Abs(dist);
	306	}else{return -1;}
	307	}
	308	}
	309	//________________________________________________________
	310	void AliStrLine::GetCurrentPoint(Double_t *point) const {
	311	// Fills the array point with the current value on the line
	312	for(Int_t i=0;i<3;i++)point[i]=fP0[i]+fCd[i]*fTpar;
	313	}
2c9641ee	314
	315	//________________________________________________________
	316	Double_t AliStrLine::GetDistFromPoint(Double_t *point) const {
	317	// computes distance from point
	318	AliStrLine tmp(point,(Double_t *)fCd,kFALSE);
	319	return this->GetDCA(&tmp);
	320	}