/*
 * QSceneTreeRenderer.h
 * $Id: QSceneTreeRenderer.cpp,v 1.13 2002/04/03 11:00:16 jhirche Exp $
 *
 * Copyright (C) 2001 Richard Guenther, Markus Janich
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * As a special exception to the GPL, the QGLViewer authors (Markus
 * Janich, Michael Meissner, Richard Guenther, Alexander Buck and Thomas
 * Woerner) give permission to link this program with Qt (non-)commercial
 * edition, and distribute the resulting executable, without including
 * the source code for the Qt (non-)commercial edition in the source
 * distribution.
 *
 */

// Qt
///////
#include <qtimer.h>

// Own
////////
#include "QSceneTreeRenderer.h"




QSceneTreeRenderer::QSceneTreeRenderer(QGLViewer *pViewer)
   : QObject(),
     QSceneTreeNode(),
     m_pViewer(pViewer)
/*************************************************************/
{
   m_fNeedUpdate = false;
   m_pTimer = NULL;
}

QSceneTreeRenderer::~QSceneTreeRenderer()
/*************************************************************/
{
   /* m_pTimer automagically gets destroyed after this */
}



void QSceneTreeRenderer::sltPollUpdate()
/*************************************************************/
{
   if (!m_fNeedUpdate)
      return;
   m_fNeedUpdate = false;

   /* somehow trigger an sltPaintGL() signal is the follwing ok? */
   m_pViewer->sltUpdateView();
}



void QSceneTreeRenderer::requestUpdate()
/*************************************************************/
{
   m_fNeedUpdate = true;
   if (m_pTimer)
      return;

   /* Install a timer routine that polls on this flag
    * and will issue an update and clear the flag. */
   m_pTimer = new QTimer(this);
   connect(m_pTimer, SIGNAL(timeout()), SLOT(sltPollUpdate()));
   m_pTimer->start(1000/20 /* 20 fps */, FALSE);
}



void QSceneTreeRenderer::sltInitializeGL()
/*************************************************************/
{
   /* Do we need this? -- At least we should provide a sane default. */
   m_pViewer->makeCurrent();
   glClearColor(0.0, 0.0, 0.0, 0.0);
   glShadeModel( GL_SMOOTH );          // enable smooth shading

   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();
   /* add other stuff */
}



void QSceneTreeRenderer::traverseTree(int &nId, QSceneTreeNode *node)
{
   /* Check, if this node is hidded. */
   if ((node->getViewingMode() == QSceneTreeNode::hidden)||(node->getViewingMode() == QSceneTreeNode::disabled))
      return;

   /* Apply matrix, if available. */
   if (node->getTransformation()) {
      glPushMatrix();
      glMultMatrixd(((CMat4D *)node->getTransformation())->getArray());
   }

   QSceneTreeDrawable *pObj;
   if ((pObj = dynamic_cast<QSceneTreeDrawable *>(node))) {
      glLoadName(nId++);
      pObj->draw();
   }

   const CList<CTreeNode> &children = node->getChildrenList();
   CListContainer<CTreeNode> *pContainer = children.getFirst();
   while (pContainer) {
      QSceneTreeNode *pNode;
      if ((pNode = dynamic_cast<QSceneTreeNode *>(pContainer->getObject())))
	 traverseTree(nId, pNode);
      pContainer = pContainer->getNext();
   }

   /* Redo matrix apply. */
   if (node->getTransformation())
      glPopMatrix();
}

void QSceneTreeRenderer::sltPaintGL()
/*************************************************************/
{
  m_pViewer->makeCurrent();
  glMatrixMode(GL_MODELVIEW);

   /* Traverse the scene tree, apply the matrices and call
    * draw() methods of QSceneTreeDrawable objects.
    */

  /* We cannot use generic traversors as they dont provide a
   * walk-up hook for popping the matrix.
   */

  int nId=1;
  traverseTree(nId, this);
}


// Function   : sltManageSelection
// Parameters :
// Purpose    :
// Comments   :
void QSceneTreeRenderer::sltManageSelection(QMouseEvent *pqEvent)
/**********************************************************************/
{
  GLuint selectBuf[SELECT_BUF_SIZE]; // HARD coded limit!!!
  GLint hits;
  GLint viewport[4];
  double ardVVolume[6];

  // Save state of mouse buttons
  ////////////////////////////////
  if ( pqEvent->button() == LeftButton ) {
    m_fLeftButtonPressed = true;
  }
  if ( pqEvent->button() == MidButton ) {
    m_fMiddleButtonPressed = true;
  }
  if ( pqEvent->button() == RightButton ) {
    m_fRightButtonPressed = true;
  }

  // save mouse position
  ////////////////////////
  m_nMousePosX = pqEvent->x();
  m_nMousePosY = pqEvent->y();

  // get camera data
  ////////////////////
  m_pViewer->getCameraPtr()->getVVolume(ardVVolume);
  m_pViewer->makeCurrent();

  glGetIntegerv(GL_VIEWPORT, viewport);

  glSelectBuffer(SELECT_BUF_SIZE, selectBuf);
  glRenderMode(GL_SELECT);

  glInitNames();
  glPushName(0);

  glPushMatrix();
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();

  // create 10x10 pixel picking region near cursor location.
  ////////////////////////////////////////////////////////////
  gluPickMatrix((GLdouble) m_nMousePosX,
		(GLdouble) (viewport[3] - m_nMousePosY), 
		5.0, 5.0, viewport);
  if (m_pViewer->getProjectionMode() == QGLViewer::perspective)
    glFrustum(ardVVolume[0], ardVVolume[1], ardVVolume[2], 
	      ardVVolume[3], ardVVolume[4], ardVVolume[5]);
  else
    glOrtho(ardVVolume[0], ardVVolume[1], ardVVolume[2], 
	    ardVVolume[3], ardVVolume[4], ardVVolume[5]);

  glMatrixMode(GL_MODELVIEW);

  sltPaintGL();  // render scene in selection mode

  glPopMatrix();
  glFlush();

  hits = glRenderMode(GL_RENDER);
  m_nChosen = processHits(hits, selectBuf);

  m_pViewer->sltUpdateView();

  return;
}



// Function   : sltManageRelease
// Parameters :
// Purpose    :
// Comments   :
void QSceneTreeRenderer::sltManageRelease(QMouseEvent *pqEvent)
/**********************************************************************/
{
  // Save state of mouse buttons
  ////////////////////////////////
  if ( pqEvent->button() == LeftButton ) {
    m_fLeftButtonPressed = false;
  }
  if ( pqEvent->button() == MidButton ) {
    m_fMiddleButtonPressed = false;
  }
  if ( pqEvent->button() == RightButton ) {
    m_fRightButtonPressed = false;
  }
}



// Function   : sltManageMove
// Parameters :
// Purpose    :
// Comments   :
void QSceneTreeRenderer::sltManageMove(QMouseEvent *pqEvent)
/**********************************************************************/
{
}



// Function   : processHits
// Parameters :
// Purpose    : processHits prints out the contents of the selection array
// Comments   :
GLuint QSceneTreeRenderer::processHits(GLint hits, GLuint buffer[])
  /********************************************************************/
{
  unsigned int i, j;
  GLuint names, nChosen, *ptr;
  float rfZValue, rfZ1;


  if(hits != 0) {
    nChosen = 1;
    rfZValue = (float)*(buffer+1)/0x7fffffff;

    cout << "Number of hits is = " << hits << endl;
    cout << "Now show all hits!" << endl;
    ptr = (GLuint *) buffer;

    for (i=0; i<hits; i++) { // for each hit
      names = *ptr;
      cout << "Number of names for this hit: " << ptr;
      ptr++;
      rfZ1 = (float) *ptr/0x7fffffff;
      cout << " z1 = " << rfZ1;
      ptr++;
      cout << " z2 = " << (float) *ptr/0x7fffffff << endl;
      ptr++;
      cout << " ..... and the names are: ";

      if(rfZValue >= rfZ1) {
        rfZValue = rfZ1;
        nChosen = *ptr;
      }

      for (j=0; j<names; j++) { // for each name
        cout << *ptr << " ";
        ptr++;
      }
      cout << endl;
    }
  }
  else {
    nChosen = 0;
  }

  cout << "Chosen node: " <<nChosen << endl;

  return nChosen;
}