//----------------------------------------------------------------------------
//  EgalTech 2017-2017
//----------------------------------------------------------------------------
// File : SceneImage.cpp         Data : 11.02.17           Versione : 1.8b2
// Contenuto : Implementazione della gestione immagini della classe scena.
//
//
//
// Modifiche : 11.02.17 DS Creazione modulo.
//
//
//----------------------------------------------------------------------------

//--------------------------- Include ----------------------------------------
#include "stdafx.h"
#include "Scene.h"
#include "\EgtDev\Include\EgtStringConverter.h"
#include "\EgtDev\Extern\FreeImage\Include\FreeImage.h"

using namespace std ;

//----------------------------------------------------------------------------
bool
Scene::GetImage( int nShowMode, bool bShowGrid, bool bShowFrame, Color colBackTop, Color colBackBottom,
                 int nDestWidth, int nDestHeight, const string& sFile)
{
  // Cerco e verifico il formato del file da scrivere a partire dall'estensione
   FREE_IMAGE_FORMAT fif = FreeImage_GetFIFFromFilenameU( stringtoW( sFile)) ;
   if ( fif == FIF_UNKNOWN  ||  ! FreeImage_FIFSupportsWriting( fif))
      return false ;

  // Dimensioni della vista
   int nWidth = m_nViewportW ;
   int nHeight = m_nViewportH ;
   if ( nWidth == 0  ||  nHeight == 0)
      return false ;

  // Coefficienti di scalatura
   if ( nDestWidth == 0  ||  nDestHeight == 0)
      return false ;
   double dCoeffW = double( nDestWidth) / nWidth ;
   double dCoeffH = double( nDestHeight) / nHeight ;

  // Alloco il buffer di lettura dei pixel della vista OpenGL ( fattore 4 perché RGBA)
   BYTE* pBuffer = new BYTE[ 4 * nWidth * nHeight] ;
   if ( pBuffer == nullptr)
      return false ;

  // Imposto attributi di visualizzazione
   int nCurrShowMode = m_nShowMode ;
   m_nShowMode = nShowMode ;
   bool bCurrShowGrid = m_bShowGrid ;
   m_bShowGrid = bShowGrid ;
   bool bCurrShowFrame = m_bShowFrame ;
   m_bShowFrame = bShowFrame ;
   Color colCurrBackTop = m_colBackTop ;
   Color colCurrBackBottom = m_colBackBottom ;
   m_colBackTop = colBackTop ;
   m_colBackBottom = colBackBottom ;
  // Imposto zoom
   double dCurrHalfWidth = m_dHalfWidth ;
   double dCurrHalfHeight = m_dHalfHeight ;
   double dCoeff = max( dCoeffW, dCoeffH) / min( dCoeffW, dCoeffH) ;
   m_dHalfWidth *= dCoeff ;
   m_dHalfHeight *= dCoeff ;

  // Eseguo disegno sul back buffer
   if ( ! MyDraw( false))
      return false ;

  // Ripristino attributi di visualizzazione originali
   m_nShowMode = nCurrShowMode ;
   m_bShowGrid = bCurrShowGrid ;
   m_bShowFrame = bCurrShowFrame ;
   m_colBackBottom = colCurrBackBottom ;
   m_colBackTop = colCurrBackTop ;
  // Ripristino zoom
   m_dHalfWidth = dCurrHalfWidth ;
   m_dHalfHeight = dCurrHalfHeight ;

  // Leggo l'immagine nel buffer
   glReadBuffer( GL_BACK) ;
   glReadPixels( 0, 0, nWidth, nHeight, GL_BGRA, GL_UNSIGNED_BYTE, pBuffer) ;

  // Converto al formato di FreeImage
   FIBITMAP* pDib = FreeImage_ConvertFromRawBits( pBuffer, nWidth, nHeight, 4 * nWidth, 32,
                                                  0x0000FF00, 0xFF000000, 0x00FF0000, false) ;
  // converto l'immagine a 24 bit per pixel
   FIBITMAP* pTmpDib = pDib ;
   pDib = FreeImage_ConvertTo24Bits( pTmpDib) ;
   FreeImage_Unload( pTmpDib) ;

  // Eseguo scalatura della bitmap
   int nLeft ; int nTop ;
   int nRight ; int nBottom ;
   if ( dCoeffW >= dCoeffH) {
      nLeft = 0 ;
      nRight = nWidth - 1 ;
      int nDeltaH = nHeight - int( nDestHeight / dCoeffW) ;
      nTop = nDeltaH / 2 ;
      nBottom = nHeight - nTop ; 
   }
   else {
      nTop = 0 ;
      nBottom = nHeight ; 
      int nDeltaW = nWidth - int( nDestWidth / dCoeffH) ;
      nLeft = nDeltaW / 2 ;
      nRight = nWidth - nLeft ;
   }
   FIBITMAP* pTmp2Dib = pDib ;
   pDib = FreeImage_RescaleRect( pTmp2Dib, nDestWidth, nDestHeight, nLeft, nTop, nRight, nBottom, FILTER_BSPLINE) ;
   FreeImage_Unload( pTmp2Dib) ;

  // Salvataggio
   int nFlag = 0 ;
   bool bOk = ( FreeImage_SaveU( fif, pDib, stringtoW( sFile), nFlag) != FALSE) ;

  // Libero le risorse
   FreeImage_Unload( pDib) ;
   delete pBuffer ;

   return bOk ;
}