//----------------------------------------------------------------------------
//  EgalTech 2017-2018
//----------------------------------------------------------------------------
// File : DistPointTria.cpp       Data : 14.12.18          Versione : 1.9l2
// Contenuto : Implementazione della classe distanza punto da triangolo.
//
//
//
// Modifiche : 19.10.17 DS Creazione modulo.
//
//
//----------------------------------------------------------------------------

//--------------------------- Include ----------------------------------------
#include "stdafx.h"
#include "ProjPlane.h"
#include "/EgtDev/Include/EGkDistPointLine.h"
#include "/EgtDev/Include/EGkDistPointTria.h"


//----------------------------------------------------------------------------
DistPointTriangle::DistPointTriangle( const Point3d& ptP, const Triangle3d& Tria)
{
   if ( &Tria == nullptr  ||  ! Tria.IsValid()) {
     // distanza non calcolabile
      m_dSqDist = - 1 ;
      return ;
   }

  // eseguo calcoli e determino il quadrato della distanza
   Calculate( ptP, Tria) ;

  // dichiaro distanza non ancora calcolata
   m_dDist = - 1 ;
}

//----------------------------------------------------------------------------
void
DistPointTriangle::Calculate( const Point3d& ptP, const Triangle3d& Tria)
{
  // Proiezione del punto sul piano del triangolo
   Point3d ptQ = ptP - (( ptP - Tria.GetCentroid()) * Tria.GetN()) * Tria.GetN() ;

  // Verifico se il punto proiettato sta nel triangolo
   if ( PointInTria( ptQ, Tria) != PTT_OUT) {
      m_dSqDist = SqDist( ptP, ptQ) ;
      m_ptMinDist = ptQ ;
      return ;
   }

  // Determino la minima distanza dai tre lati
   m_dSqDist = - 1 ;
   for ( int i = 0 ; i < 3 ; ++ i) {
      DistPointLine dstPL( ptP, Tria.GetP( i), Tria.GetP( ( i + 1) % 3)) ;
      double dSqDist ;
      if ( dstPL.GetSqDist( dSqDist)  &&  ( m_dSqDist < 0  ||  dSqDist < m_dSqDist)) {
         m_dSqDist = dSqDist ;
         dstPL.GetMinDistPoint( m_ptMinDist) ;
      }
   }
}

//----------------------------------------------------------------------------
bool
DistPointTriangle::GetSqDist( double& dSqDist)
{
   if ( m_dSqDist < 0)
      return false ;

   dSqDist = m_dSqDist ;
   return true ;
}

//----------------------------------------------------------------------------
bool
DistPointTriangle::GetDist( double& dDist)
{
   if ( m_dSqDist < 0)
      return false ;

   if ( m_dDist < 0)
      m_dDist = sqrt( m_dSqDist) ;
   dDist = m_dDist ;
   return true ;
}

//----------------------------------------------------------------------------
bool
DistPointTriangle::GetMinDistPoint( Point3d& ptMinDist)
{
   if ( m_dSqDist < 0)
      return false ;

   ptMinDist = m_ptMinDist ;
   return true ;
}