//----------------------------------------------------------------------------
//  EgalTech 2014-2014
//----------------------------------------------------------------------------
// File : SceneGrid.cpp       Data : 25.10.14          Versione : 1.5j6
// Contenuto : Implementazione gestione e disegno griglia.
//
//
//
// Modifiche : 25.10.14 DS Creazione modulo.
//
//
//----------------------------------------------------------------------------

//--------------------------- Include ----------------------------------------
#include "stdafx.h"
#include "Scene.h"
#include "EGrUtils.h"
#include <algorithm>
                    
using namespace std ;

//----------------------------------------------------------------------------
bool
Scene::SetGridShow( bool bShowGrid, bool bShowFrame)
{
   m_bShowGrid = bShowGrid ;
   m_bShowFrame = bShowFrame ;
   return true ;
}

//----------------------------------------------------------------------------
bool
Scene::SetGridGeo( double dSnapStep, int nMinLineSstep, int nMajLineSstep, int nExtSstep)
{
   const double MIN_SNAP_STEP = 0.1 ;
   m_dSnapStep = std::max( fabs( dSnapStep), MIN_SNAP_STEP) ;
   m_nMinLineSstep = abs( nMinLineSstep) ;
   m_nMajLineSstep = abs( nMajLineSstep) ;
   m_nExtSstep = abs( nExtSstep) ;
   return true ;
}

//----------------------------------------------------------------------------
bool
Scene::SetGridColor( Color colMinLine, Color colMajLine)
{
   m_colMinLine = colMinLine ;
   m_colMajLine = colMajLine ;
   return true ;
}

//----------------------------------------------------------------------------
bool
Scene::DrawGrid( void)
{
  // se non devo disegnare, esco subito
   if ( ! m_bShowGrid  &&  ! m_bShowFrame)
      return true ;

  // imposto il riferimento
   glPushMatrix() ;
   double Matrix[OGLMAT_DIM] ;
   if ( FrameToOpenGlMatrix( GetGridFrame(), Matrix))
      glMultMatrixd( Matrix) ;

  // semi-estensione della griglia
   float dExt = float( m_nExtSstep * m_dSnapStep) ;
  // abbassamento in Z per evitare sovrapposizioni con geometria
   const float Z_DOWN = float( - 0.01) ;

  // se richiesto, disegno la griglia
   if ( m_bShowGrid) {
     // disegno linee minori (a trattini)
      glLineStipple( 2, 0xAAAA) ;
      glEnable( GL_LINE_STIPPLE) ;
      glBegin( GL_LINES) ;
      glColor3f( m_colMinLine.GetRed(), m_colMinLine.GetGreen(), m_colMinLine.GetBlue()) ;
      for ( int i = m_nMinLineSstep ; i <= m_nExtSstep ; i += m_nMinLineSstep) {
        // se non si sovrappongono alle maggiori
         if ( ( i % m_nMajLineSstep) != 0) {
            float dPos = float( i * m_dSnapStep) ;
            // X +
            glVertex3f( dPos, - dExt, Z_DOWN) ;
            glVertex3f( dPos, dExt, Z_DOWN) ;
            // X -
            glVertex3f( - dPos, - dExt, Z_DOWN) ;
            glVertex3f( - dPos, dExt, Z_DOWN) ;
            // Y +
            glVertex3f( - dExt, dPos, Z_DOWN) ;
            glVertex3f( dExt, dPos, Z_DOWN) ;
            // Y -
            glVertex3f( - dExt, - dPos, Z_DOWN) ;
            glVertex3f( dExt, - dPos, Z_DOWN) ;
         }
      }
      glEnd() ;
      glDisable( GL_LINE_STIPPLE) ;
     // disegno linee maggiori
      glBegin( GL_LINES) ;
      glColor3f( m_colMajLine.GetRed(), m_colMajLine.GetGreen(), m_colMajLine.GetBlue()) ;
      for ( int i = m_nMajLineSstep ; i <= m_nExtSstep ; i += m_nMajLineSstep) {
         float dPos = float( i * m_dSnapStep) ;
         // X +
         glVertex3f( dPos, - dExt, Z_DOWN) ;
         glVertex3f( dPos, dExt, Z_DOWN) ;
         // X -
         glVertex3f( - dPos, - dExt, Z_DOWN) ;
         glVertex3f( - dPos, dExt, Z_DOWN) ;
         // Y +
         glVertex3f( - dExt, dPos, Z_DOWN) ;
         glVertex3f( dExt, dPos, Z_DOWN) ;
         // Y -
         glVertex3f( - dExt, - dPos, Z_DOWN) ;
         glVertex3f( dExt, - dPos, Z_DOWN) ;
      }
      glEnd() ;
   }

  // se richiesto, disegno assi del frame
   if ( m_bShowFrame) {
      glBegin( GL_LINES) ;
      // asse X+
      glColor3f( RED.GetRed(), RED.GetGreen(), RED.GetBlue()) ;
      glVertex3f( 0, 0, Z_DOWN) ;
      glVertex3f( dExt, 0, Z_DOWN) ;
      // asse Y+
      glColor3f( LIME.GetRed(), LIME.GetGreen(), LIME.GetBlue()) ;
      glVertex3f( 0, 0, Z_DOWN) ;
      glVertex3f( 0, dExt, Z_DOWN) ;
      // se richiesta griglia, assi X- e Y-
      if ( m_bShowGrid) {
         glColor3f( m_colMajLine.GetRed(), m_colMajLine.GetGreen(), m_colMajLine.GetBlue()) ;
         glVertex3f( 0, 0, Z_DOWN) ;
         glVertex3f( -dExt, 0, Z_DOWN) ;
         glVertex3f( 0, 0, Z_DOWN) ;
         glVertex3f( 0, -dExt, Z_DOWN) ;
      }
      glEnd() ;
   }
  // altrimenti, se richiesta sola griglia li disegno come linee principali
   else if ( m_bShowGrid) {
      glBegin( GL_LINES) ;
      glColor3f( m_colMajLine.GetRed(), m_colMajLine.GetGreen(), m_colMajLine.GetBlue()) ;
      // asse X
      glVertex3f( - dExt, 0, Z_DOWN) ;
      glVertex3f( dExt, 0, Z_DOWN) ;
      // asse Y
      glVertex3f( 0, - dExt, Z_DOWN) ;
      glVertex3f( 0, dExt, Z_DOWN) ;
      glEnd() ;
   }

  // ripristino lo stack delle matrici
   glPopMatrix() ;

   return true ;
}