//----------------------------------------------------------------------------
//  EgalTech 2014-2014
//----------------------------------------------------------------------------
// File : ObjNewGraphics.cpp       Data : 10.02.14          Versione : 1.5b1
// Contenuto : Implementazione della classe grafica di un oggetto geometrico.
//
//
//
// Modifiche : 10.02.14 DS Creazione modulo.
//
//
//----------------------------------------------------------------------------

//--------------------------- Include ----------------------------------------
#include "stdafx.h"
#include "ObjNewGraphics.h"
#include "Scene.h"

#define glewGetContext()    (( m_pScene != nullptr) ? m_pScene->glewGetContext() : nullptr)


//----------------------------------------------------------------------------
ObjNewGraphics::~ObjNewGraphics( void)
{
  // cancello eventuali vecchi vertici
   DeleteVaoVbo() ;
}

//----------------------------------------------------------------------------
void
ObjNewGraphics::Reset( void)
{
   m_bValid = false ;
}

//----------------------------------------------------------------------------
bool
ObjNewGraphics::AddPolyLine( const PolyLine& PL)
{
   if ( m_pScene == nullptr  ||  ! m_pScene->MakeCurrent())
      return false ;

  // cancello eventuali vecchi vertici
   DeleteVaoVbo() ;
  // imposto il nuovo stato
   m_bValid = true ;
   m_nMode = GL_LINE_STRIP ;
  // inserisco i nuovi vertici
   glGenVertexArrays( 1, &m_nVaoId) ;
   if ( m_nVaoId == 0)
      return false ;
   glBindVertexArray( m_nVaoId) ;
   glGenBuffers( 1, &m_nVboId) ;
   glBindBuffer( GL_ARRAY_BUFFER, m_nVboId) ;
   glBufferData( GL_ARRAY_BUFFER, PL.GetPointNbr() * SIZEV3F, NULL, GL_STATIC_DRAW) ;
   Point3d ptP ;
   Vert3f  v3V ;
   m_nCount = 0 ;
   for ( bool bFound = PL.GetFirstPoint( ptP) ; bFound ; bFound = PL.GetNextPoint( ptP)) {
      v3V.Set( ptP.x, ptP.y, ptP.z) ;
      glBufferSubData( GL_ARRAY_BUFFER, m_nCount * SIZEV3F, SIZEV3F, &v3V) ;
      ++ m_nCount ;
   }
   glVertexAttribPointer( (GLuint)0, 3, GL_FLOAT, GL_FALSE, 0, 0) ;
   glEnableVertexAttribArray( 0) ;
   glBindVertexArray( 0) ;

   return true ;
}

//----------------------------------------------------------------------------
bool
ObjNewGraphics::Draw( void)
{
   if ( m_pScene == nullptr  ||  ! m_pScene->MakeCurrent())
      return false ;

  // se vuoto non faccio alcunché
   if ( m_nCount == 0)
      return true ;

   if ( m_nVaoId != 0) {
      glBindVertexArray( m_nVaoId) ; 
      glDrawArrays( m_nMode, 0, m_nCount) ;
   }

   return true ;
}

//----------------------------------------------------------------------------
bool
ObjNewGraphics::DeleteVaoVbo( void)
{
   if ( m_pScene == nullptr  ||  ! m_pScene->MakeCurrent())
      return false ;

  // cancellazione VAO/VBO
   if ( m_nCount > 0) {
      glBindBuffer( GL_ARRAY_BUFFER, 0) ;
      glDeleteBuffers( 1, &m_nVboId) ;
      glBindVertexArray( 0) ;
      glDeleteVertexArrays( 1, &m_nVaoId) ;
      m_nCount = 0 ;
   }

   return true ;
}