/****************************************************************************

 Copyright (C) 2002-2007 Gilles Debunne (Gilles.Debunne@imag.fr)

 This file is part of the QGLViewer library.
 Version 2.2.6-3, released on August 28, 2007.

 http://artis.imag.fr/Members/Gilles.Debunne/QGLViewer

 libQGLViewer 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.

 libQGLViewer 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 libQGLViewer; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*****************************************************************************/

#include "multiSelect.h"
#include "manipulatedFrameSetConstraint.h"

#if QT_VERSION >= 0x040000
# include <QMouseEvent>
#endif

using namespace qglviewer;

Viewer::Viewer()
{
  selectionMode_ = NONE;

  // Fill the scene with objects positionned on a regular grid.
  // Consider increasing selectBufferSize() if you use more objects.
  const int nb = 10;
  for (int i=-nb; i<=nb; ++i)
    for (int j=-nb; j<=nb; ++j)
      {
	Object* o = new Object();
	o->frame.setPosition(Vec(i/float(nb), j/float(nb), 0.0f));
#if QT_VERSION < 0x040000
	// How could they sell this ?
	objects_.resize(objects_.size()+1);
	objects_.insert(objects_.size()-1, o);
#else
	objects_.append(o);
#endif	
      }
}

void Viewer::init()
{
  // A ManipulatedFrameSetConstraint will apply displacements to the selection
  setManipulatedFrame(new ManipulatedFrame());
  manipulatedFrame()->setConstraint(new ManipulatedFrameSetConstraint());
  
  // Used to display semi-transparent relection rectangle
  glBlendFunc(GL_ONE, GL_ONE);
  
  restoreStateFromFile();
  help();
}

QString Viewer::helpString() const
{
  QString text("<h2>m u l t i S e l e c t </h2>");
  text += "This example illustrates an application of the <code>select()</code> function that ";
  text += "enables the selection of several objects.<br><br>";
  text += "Object selection is preformed using the left mouse button. Press <b>Shift</b> to add objects ";
  text += "to the selection, and <b>Alt</b> to remove objects from the selection.<br><br>";
  text += "Individual objects (click on them) as well as rectangular regions (click and drag mouse) can be selected. ";
  text += "To do this, the selection region size is modified and the <code>endSelection()</code> function ";
  text += "has been overloaded so that <i>all</i> the objects of the region are taken into account ";
  text += "(the default implementation only selects the closest object).<br><br>";
  text += "The selected objects can then be manipulated by pressing the <b>Control</b> key. ";
  text += "Other set operations (parameter edition, deletion...) can also easily be applied to the selected objects.";
  return text;
}


//  D r a w i n g   f u n c t i o n

void Viewer::draw()
{
  // Draws selected objects only.
  glColor3f(0.9, 0.3, 0.3);
#if QT_VERSION < 0x040000
  for (QValueList<int>::const_iterator it=selection_.begin(), end=selection_.end(); it != end; ++it)
#else
    for (QList<int>::const_iterator it=selection_.begin(), end=selection_.end(); it != end; ++it)
#endif
      objects_.at(*it)->draw();

  // Draws all the objects. Selected ones are not repainted because of GL depth test.
  glColor3f(0.8, 0.8, 0.8);
  for (int i=0; i<int(objects_.size()); i++)
    objects_.at(i)->draw();

  // Draws manipulatedFrame (the set's rotation center)
  if (manipulatedFrame()->isManipulated())
    {
      glPushMatrix();
      glMultMatrixd(manipulatedFrame()->matrix());
      drawAxis(0.5);
      glPopMatrix();
    }
  
  // Draws rectangular selection area. Could be done in postDraw() instead.
  if (selectionMode_ != NONE)
    drawSelectionRectangle();
}


//   C u s t o m i z e d   m o u s e   e v e n t s

void Viewer::mousePressEvent(QMouseEvent* e)
{
  // Start selection. Mode is ADD with Shift key and TOGGLE with Alt key.
  rectangle_ = QRect(e->pos(), e->pos());

#if QT_VERSION < 0x040000
  if ((e->button() == Qt::LeftButton) && (e->state() == Qt::ShiftButton))
    selectionMode_ = ADD;
  else
    if ((e->button() == Qt::LeftButton) && (e->state() == Qt::AltButton))
      selectionMode_ = REMOVE;
    else
      {
	if (e->state() == Qt::ControlButton)

#else
	
  if ((e->button() == Qt::LeftButton) && (e->modifiers() == Qt::ShiftModifier))
    selectionMode_ = ADD;
  else
    if ((e->button() == Qt::LeftButton) && (e->modifiers() == Qt::AltModifier))
      selectionMode_ = REMOVE;
    else
      {
	if (e->modifiers() == Qt::ControlModifier)      
#endif
	  startManipulation();
        QGLViewer::mousePressEvent(e);
      }
}

void Viewer::mouseMoveEvent(QMouseEvent* e)
{
  if (selectionMode_ != NONE)
    {
      // Updates rectangle_ coordinates and redraws rectangle
#if QT_VERSION < 0x030000
      rectangle_.setX(e->x());
      rectangle_.setY(e->y());
#else
      rectangle_.setBottomRight(e->pos());
#endif
      updateGL();
    }
  else
    QGLViewer::mouseMoveEvent(e);
}

void Viewer::mouseReleaseEvent(QMouseEvent* e)
{
  if (selectionMode_ != NONE)
    {
      // Actual selection on the rectangular area.
      // Possibly swap left/right and top/bottom to make rectangle_ valid.
#if QT_VERSION < 0x040000
      rectangle_ = rectangle_.normalize();
#else
      rectangle_ = rectangle_.normalized();
#endif
      // Define selection window dimensions
      setSelectRegionWidth(rectangle_.width());
      setSelectRegionHeight(rectangle_.height());
      // Compute rectangle center and perform selection
      select(rectangle_.center());
      // Update display to show new selected objects
      updateGL();
    }
  else
    QGLViewer::mouseReleaseEvent(e);
}


//   C u s t o m i z e d   s e l e c t i o n   p r o c e s s

void Viewer::drawWithNames()
{
  for (int i=0; i<int(objects_.size()); i++)
    {
      glPushName(i);
      objects_.at(i)->draw();
      glPopName();
    }
}

void Viewer::endSelection(const QPoint&)
{
  // Flush GL buffers
  glFlush();

  // Get the number of objects that were seen through the pick matrix frustum. Reset GL_RENDER mode.
  GLint nbHits = glRenderMode(GL_RENDER);

  if (nbHits > 0)
    {
      // Interpret results : each object created 4 values in the selectBuffer().
      // (selectBuffer())[4*i+3] is the id pushed on the stack.
      for (int i=0; i<nbHits; ++i)
	switch (selectionMode_)
	  {
	  case ADD    : addIdToSelection((selectBuffer())[4*i+3]); break;
	  case REMOVE : removeIdFromSelection((selectBuffer())[4*i+3]);  break;
	  default : break;
	  }
    }
  selectionMode_ = NONE;
}

void Viewer::startManipulation()
{
  Vec averagePosition;
  ManipulatedFrameSetConstraint* mfsc = (ManipulatedFrameSetConstraint*)(manipulatedFrame()->constraint());
  mfsc->clearSet();

#if QT_VERSION < 0x040000
  for (QValueList<int>::const_iterator it=selection_.begin(), end=selection_.end(); it != end; ++it)
#else
  for (QList<int>::const_iterator it=selection_.begin(), end=selection_.end(); it != end; ++it)
#endif
    {
      mfsc->addObjectToSet(objects_[*it]);
      averagePosition += objects_[*it]->frame.position();
    }

  if (selection_.size() > 0)
    manipulatedFrame()->setPosition(averagePosition / selection_.size());
}


//   S e l e c t i o n   t o o l s

void Viewer::addIdToSelection(int id)
{
  if (!selection_.contains(id))
    selection_.push_back(id);
}

void Viewer::removeIdFromSelection(int id)
{
#if QT_VERSION < 0x040000
  selection_.remove(id);
#else
  selection_.removeAll(id);
#endif
}

void Viewer::drawSelectionRectangle() const
{
  startScreenCoordinatesSystem();
  glDisable(GL_LIGHTING);
  glEnable(GL_BLEND);

  glColor4f(0.0, 0.0, 0.3, 0.3);
  glBegin(GL_QUADS);
  glVertex2i(rectangle_.left(),  rectangle_.top());
  glVertex2i(rectangle_.right(), rectangle_.top());
  glVertex2i(rectangle_.right(), rectangle_.bottom());
  glVertex2i(rectangle_.left(),  rectangle_.bottom());
  glEnd();

  glLineWidth(2.0);
  glColor4f(0.4, 0.4, 0.5, 0.5);
  glBegin(GL_LINE_LOOP);
  glVertex2i(rectangle_.left(),  rectangle_.top());
  glVertex2i(rectangle_.right(), rectangle_.top());
  glVertex2i(rectangle_.right(), rectangle_.bottom());
  glVertex2i(rectangle_.left(),  rectangle_.bottom());
  glEnd();

  glDisable(GL_BLEND);
  glEnable(GL_LIGHTING);
  stopScreenCoordinatesSystem();
}