SceneGraph.hh

/*===========================================================================*\
 *                                                                           *
 *                              OpenFlipper                                  *
 *      Copyright (C) 2001-2009 by Computer Graphics Group, RWTH Aachen      *
 *                           www.openflipper.org                             *
 *                                                                           *
 *---------------------------------------------------------------------------*
 *  This file is part of OpenFlipper.                                        *
 *                                                                           *
 *  OpenFlipper is free software: you can redistribute it and/or modify      *
 *  it under the terms of the GNU Lesser General Public License as           *
 *  published by the Free Software Foundation, either version 3 of           *
 *  the License, or (at your option) any later version with the              *
 *  following exceptions:                                                    *
 *                                                                           *
 *  If other files instantiate templates or use macros                       *
 *  or inline functions from this file, or you compile this file and         *
 *  link it with other files to produce an executable, this file does        *
 *  not by itself cause the resulting executable to be covered by the        *
 *  GNU Lesser General Public License. This exception does not however       *
 *  invalidate any other reasons why the executable file might be            *
 *  covered by the GNU Lesser General Public License.                        *
 *                                                                           *
 *  OpenFlipper 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 Lesser General Public License for more details.                      *
 *                                                                           *
 *  You should have received a copy of the GNU LesserGeneral Public          *
 *  License along with OpenFlipper. If not,                                  *
 *  see <http://www.gnu.org/licenses/>.                                      *
 *                                                                           *
\*===========================================================================*/

/*===========================================================================*\
 *                                                                           *
 *   $Revision: 6743 $                                                       *
 *   $Author: moebius $                                                      *
 *   $Date: 2009-08-05 11:03:10 +0200 (Mi, 05. Aug 2009) $                   *
 *                                                                           *
\*===========================================================================*/




//=============================================================================
//
//  CLASS SceneGraph
//
//=============================================================================

#ifndef ACG_SCENEGRAPH_HH
#define ACG_SCENEGRAPH_HH


//== INCLUDES =================================================================

#include "BaseNode.hh"
#include "DrawModes.hh"
#include "../GL/gl.hh"
#include "../Math/VectorT.hh"
#include <float.h>

#include <QMouseEvent>

//== NAMESPACES ===============================================================

namespace ACG {
namespace SceneGraph {


//== CLASS DEFINITION =========================================================

template<bool C, typename T = void>
struct enable_if {
  typedef T type;
};

template<typename T>
struct enable_if<false, T> { };

#define HAS_MEM_FUNC(func) \
    template<typename T, typename Sign>                                               \
    struct has_##func {                                                               \
        template <typename U, U> struct type_check;                                   \
        template <typename _1> static char (& chk(type_check<Sign, &_1::func> *))[1]; \
        template <typename   > static char (& chk(...))[2];                           \
        static bool const value = sizeof(chk<T>(0)) == 1;                             \
    };

HAS_MEM_FUNC(enter)

// if the enter function is implemented
template<typename Action> 
typename enable_if<has_enter <Action, void (Action::*) (BaseNode *) >::value, void>::type
if_has_enter(Action &_action, BaseNode *_node) {
  _action.enter (_node);
}

// if the enter function isn't implemented
template<typename Action> 
typename enable_if<!has_enter <Action, void (Action::*) (BaseNode *) >::value, void>::type
if_has_enter(Action &, BaseNode *) {
}

HAS_MEM_FUNC(leave)

// if the enter function is implemented
template<typename Action> 
typename enable_if<has_leave <Action, void (Action::*) (BaseNode *) >::value, void>::type
if_has_leave(Action &_action, BaseNode *_node) {
  _action.leave (_node);
}

// if the enter function isn't implemented
template<typename Action> 
typename enable_if<!has_enter <Action, void (Action::*) (BaseNode *) >::value, void>::type
if_has_leave(Action &, BaseNode *) {
}

//----------------------------------------------------------------------------


template <class Action>
void
traverse( BaseNode* _node, Action& _action )
{
  if (_node)
  {
    BaseNode::StatusMode status(_node->status());
    bool process_children(status != BaseNode::HideChildren);

    if (status != BaseNode::HideSubtree)
    {

      if (_node->status() != BaseNode::HideNode)
      {
        if_has_enter (_action, _node);
        if (_node->traverseMode() & BaseNode::NodeFirst)
          process_children &= _action(_node);
      }

      if (process_children)
      {
        BaseNode::ChildIter cIt, cEnd(_node->childrenEnd());
        for (cIt = _node->childrenBegin(); cIt != cEnd; ++cIt)
          if (~(*cIt)->traverseMode() & BaseNode::SecondPass)
            traverse(*cIt, _action);
        for (cIt = _node->childrenBegin(); cIt != cEnd; ++cIt)
          if ((*cIt)->traverseMode() & BaseNode::SecondPass)
            traverse(*cIt, _action);
      }

      if (_node->status() != BaseNode::HideNode)
      {
        if (_node->traverseMode() & BaseNode::ChildrenFirst)
          _action(_node);
        if_has_leave (_action, _node);
      }
    }
  }
}

//----------------------------------------------------------------------------

template <class Action>
class MetaAction
{
  public:
    MetaAction (Action & _action, GLState& _state, unsigned int _drawmode) :
      action_(_action),
      state_(_state),
      drawmode_(_drawmode)
    {
    }

    bool operator()(BaseNode* _node)
    {
      return action_(_node, state_);
    }

    void enter (BaseNode *_node)
    {
      unsigned int drawmode = ((_node->drawMode() == DrawModes::DEFAULT) ?
                               drawmode_ : _node->drawMode());
      _node->enter(state_, drawmode);
    }

    void leave (BaseNode *_node)
    {
      unsigned int drawmode = ((_node->drawMode() == DrawModes::DEFAULT) ?
                               drawmode_ : _node->drawMode());
      _node->leave(state_, drawmode);
    }

  private:
    Action  &action_;
    GLState &state_;
    unsigned int drawmode_;

};

//----------------------------------------------------------------------------

template <class Action>
void
traverse( BaseNode*     _node,
          Action&       _action,
          GLState&      _state,
          unsigned int  _drawmode=DrawModes::DEFAULT)
{
  MetaAction<Action> action (_action, _state, _drawmode);
  traverse (_node, action);
}

//----------------------------------------------------------------------------


class BoundingBoxAction
{
public:

  BoundingBoxAction() :
    bbMin_( FLT_MAX,  FLT_MAX,  FLT_MAX),
    bbMax_(-FLT_MAX, -FLT_MAX, -FLT_MAX),
    state_(false)
  { }

  bool operator()(BaseNode* _node)
  {
    Vec3f bbMin( FLT_MAX,  FLT_MAX,  FLT_MAX);
    Vec3f bbMax(-FLT_MAX, -FLT_MAX, -FLT_MAX);
    _node->boundingBox(bbMin, bbMax);

    if ((bbMin[0] > bbMax[0]) ||
        (bbMin[1] > bbMax[1]) ||
        (bbMin[2] > bbMax[2]))
      return true;

    bbMin_.minimize(state_.modelview().transform_point (bbMin));
    bbMin_.minimize(state_.modelview().transform_point (bbMax));
    bbMax_.maximize(state_.modelview().transform_point (bbMin));
    bbMax_.maximize(state_.modelview().transform_point (bbMax));
    return true;
  }

  void enter (BaseNode *_node)
  {
    _node->enter(state_, DrawModes::DEFAULT);
  }

  void leave (BaseNode *_node)
  {
    _node->leave(state_, DrawModes::DEFAULT);
  }

  const Vec3f& bbMin() const { return bbMin_; }
  const Vec3f& bbMax() const { return bbMax_; }

private:

  Vec3f        bbMin_, bbMax_;
  GLState      state_;
};


//----------------------------------------------------------------------------


class FindNodeAction
{
public:

  FindNodeAction(unsigned int _node_id) :
    node_id_(_node_id), node_ptr_(0)  {}

  bool operator()(BaseNode* _node)
  {
    if (_node->id() == node_id_)
    {
      node_ptr_ = _node;
      return false;
    }
    return true;
  }

  BaseNode*  node_ptr() { return node_ptr_; }

private:

  unsigned int  node_id_;
  BaseNode*     node_ptr_;
};


ACGDLLEXPORT
BaseNode* find_node( BaseNode* _root, unsigned int _node_idx );


//----------------------------------------------------------------------------


class CollectDrawModesAction
{
public:

  CollectDrawModesAction() : drawModes_(0) {}

  bool operator()(BaseNode* _node)
  {
    drawModes_ |= _node->availableDrawModes();
    return true;
  }

  unsigned int drawModes() const { return drawModes_; }

private:

  unsigned int drawModes_;
};

//----------------------------------------------------------------------------


class CollectActiveDrawModesAction
{
public:

  CollectActiveDrawModesAction() : drawMode_(0) {}

  bool operator()(BaseNode* _node)
  {
    drawMode_ |= _node->drawMode();
    return true;
  }

  unsigned int drawMode() const { return drawMode_; }

private:

  unsigned int drawMode_;
};

//----------------------------------------------------------------------------


class SetDrawModesAction
{
public:

  SetDrawModesAction(unsigned int _mode) : newModes_(_mode) {}

  bool operator()(BaseNode* _node)
  {
    if ( newModes_ == DrawModes::DEFAULT )
      _node->drawMode( DrawModes::DEFAULT );

    unsigned int availableModes = _node->availableDrawModes();

    if ( availableModes & newModes_ )
      _node->drawMode( availableModes & newModes_ );
    else
      _node->drawMode( DrawModes::DEFAULT );

    return true;
  }

private:
  unsigned int newModes_;
};


//----------------------------------------------------------------------------


class DrawAction
{
public:

  DrawAction(unsigned int _drawMode, bool _blending)
    : drawMode_(_drawMode), blending_(_blending) {}

  bool operator()(BaseNode* _node, GLState& _state)
  {
    // draw only if Material status == DrawAction status
    if(_state.blending() == blending_)
    {
      _node->setDirty (false);
      if (_node->drawMode() == DrawModes::DEFAULT)
        _node->draw(_state, drawMode_);
      else
        _node->draw(_state, _node->drawMode());
    }
    return true;
  }

private:

  unsigned int drawMode_;
  bool         blending_;
};


//----------------------------------------------------------------------------


class ACGDLLEXPORT PickAction
{
public:

  PickAction(GLState &_state, PickTarget _target, unsigned int _drawmode) :
    state_(_state),
    pickTarget_(_target),
    drawmode_(_drawmode) {}

  bool operator()(BaseNode* _node);

  void enter(BaseNode* _node)
  {
    if (_node->drawMode() == DrawModes::DEFAULT)
        _node->enterPick(state_, pickTarget_, drawmode_);
      else
        _node->enterPick(state_, pickTarget_, _node->drawMode());    
  }

  void leave(BaseNode* _node)
  {
    if (_node->drawMode() == DrawModes::DEFAULT)
        _node->leavePick(state_, pickTarget_, drawmode_);
      else
        _node->leavePick(state_, pickTarget_, _node->drawMode());
  }

private:

  GLState      &state_;
  PickTarget   pickTarget_;
  unsigned int drawmode_;
};


//----------------------------------------------------------------------------


class MouseEventAction
{
public:


  MouseEventAction(QMouseEvent* _event) : event_(_event) {}

  bool operator()(BaseNode* _node, GLState& _state)
  {
    _node->mouseEvent(_state, event_);
    return true;
  }

private:

  QMouseEvent* event_;
};

//----------------------------------------------------------------------------


class CheckDirtyAction
{
public:


  CheckDirtyAction() : dirty_(false) {}

  bool operator()(BaseNode* _node)
  {
    dirty_ |= _node->isDirty();
    // don't traverse children if current node is _dirty
    return !dirty_;
  }

  bool isDirty() const { return dirty_; };

private:

  bool dirty_;
};


//=============================================================================
} // namespace SceneGraph
} // namespace ACG
//=============================================================================
#endif // ACG_SCENEGRAPH_HH defined
//=============================================================================