/*
  NODEWIRING.hpp  -  Implementation of the node network and operation control
 
  Copyright (C)         Lumiera.org
    2008,               Hermann Vosseler <Ichthyostega@web.de>
 
  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., 675 Mass Ave, Cambridge, MA 02139, USA.
 
*/


#ifndef ENGINE_NODEWIRING_H
#define ENGINE_NODEWIRING_H


#include "proc/engine/procnode.hpp"

#include <boost/noncopyable.hpp>
#include <boost/scoped_ptr.hpp>
#include <cstddef>



namespace engine {


  class WiringFactory;
  
  namespace config { class WiringFactoryImpl; }
  
  using lib::RefArray;
  
  
  /**
   * Finding out about a concrete way of wiring up a
   * ProcNode about to be built. Such a (temporary) setup object
   * is used while building the low-level model. It is loaded with
   * information concerning the intended connections to be made
   * and then used to initialise the wiring descriptor, which
   * in turn allows us to setup the ProcNode.  
   */
  class WiringInstaller : boost::noncopyable
    {
    public:
      RefArray<ChannelDescriptor>& makeOutDescriptor() ;
      RefArray<InChanDescriptor>&  makeInDescriptor() ;
      WiringDescriptor::ProcFunc*  resolveProcessingFunction() ;
      lumiera::NodeID const&       createNodeID() ;
    };
  
  
  
  
  /**
   * Actual implementation of the link between nodes,
   * also acting as "track switch" for the execution path
   * chosen while operating the node network for rendering.
   * @param STATE Invocation state object controlling the
   *        behaviour of callDown() while rendering.
   * @see StateAdapter
   * @see NodeFactory 
   */
  template<class STATE>
  class NodeWiring
    : public WiringDescriptor
    {
      
      NodeWiring(WiringInstaller& setup)
        : WiringDescriptor(setup.makeOutDescriptor(), 
                           setup.makeInDescriptor(),
                           setup.resolveProcessingFunction(),
                           setup.createNodeID())
        {
          nrO = out.size();
          nrI = in.size();
        }
      
      friend class WiringFactory;
      
      
    protected:
      virtual BuffHandle
      callDown (State& currentProcess, uint requestedOutputNr)  const 
        {
          STATE thisStep (currentProcess, *this, requestedOutputNr);
          return thisStep.retrieve (); // fetch or calculate results
        }
      
    };

    
    
  class WiringFactory
    {
      boost::scoped_ptr<config::WiringFactoryImpl> pImpl_;
      
    public:
      WiringDescriptor&
      operator() (WiringInstaller& setup, bool cache);
    };
  
  
  
} // namespace engine
#endif