lumiera_/src/steam/engine/proc-node.hpp

/*
  PROC-NODE.hpp  -  Key abstraction of the Render Engine: a Processing Node

   Copyright (C)
     2008,            Hermann Vosseler <Ichthyostega@web.de>

  **Lumiera** 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. See the file COPYING for further details.

*/

/** @file proc-node.hpp
 ** Interface to the processing nodes and the render nodes network.
 **
 ** Actually, there are three different interfaces to consider
 ** - the ProcNode#pull is the invocation interface. It is function-call style
 ** - the builder interface, comprised by the NodeFactory and the WiringFactory.
 ** - the actual processing function is supposed to be a C function and will be
 **   hooked up within a thin wrapper.
 **
 ** By using the builder interface, concrete node and wiring descriptor classes are created,
 ** based on some templates. These concrete classes form the "glue" to tie the node network
 ** together and contain much of the operation behaviour in a hard wired fashion.
 ** 
 ** @todo WIP-WIP-WIP 2024 Node-Invocation is reworked from ground up for the »Playback Vertical Slice«
 ** 
 ** @see nodefactory.hpp
 ** @see operationpoint.hpp
 */

#ifndef STEAM_ENGINE_PROC_NODE_H
#define STEAM_ENGINE_PROC_NODE_H

#include "lib/error.hpp"
#include "lib/nocopy.hpp"
#include "lib/hash-value.h"
//#include "steam/asset/proc.hpp"
//#include "steam/mobject/parameter.hpp"
#include "steam/engine/buffhandle.hpp"
#include "steam/engine/turnout-system.hpp"
#include "lib/ref-array.hpp" /////////////////////OOO phase out
#include "lib/format-string.hpp"
#include "lib/several.hpp"

#include <string>
#include <vector>
#include <optional>



namespace steam {
namespace engine {
  namespace err = lumiera::error;

  using std::move;
  using std::string;
  using lib::HashVal;
  using util::_Fmt;
  
  class ProcID;
  class ProcNode;
  class ProcNodeDiagnostic;
  
  using ProcNodeRef = std::reference_wrapper<ProcNode>;
  using OptionalBuff = std::optional<BuffHandle>;
  
  
  class Port
//  : util::MoveOnly     //////////////////////////////////////////////////OOO not clear if necessary here, and requires us to declare the ctors!!! See Turnout
    : util::NonCopyable  //////////////////////////////////////////////////OOO this would be the perfect solution, if we manage to handle this within the builder
    {
    public:
      virtual ~Port();  ///< this is an interface
      Port (ProcID& id) : procID{id} { }
      
      virtual BuffHandle weave (TurnoutSystem&, OptionalBuff =std::nullopt)   =0;
      
//    // compiler does not generate a move-ctor automatically due to explicit dtor
//    Port()       = default;
//    Port(Port&&) = default;
      ProcID& procID;
    };
  
  using PortRef = std::reference_wrapper<Port>;
  
  /**
   * Interface: Description of the input and output ports,
   * processing function and predecessor nodes for a given ProcNode.
   * 
   * @todo the design of this part is messy in several respects.
   *       Basically, its left-over from a first prototypical implementation from 2008
   *       As of 1/2012, we're re-shaping that engine interface and invocation with a top-down approach,
   *       starting from the player. Anyhow, you can expect the basic setup to remain as-is: there will
   *       be a ProcNode and a Connectivity descriptor, telling how it's connected to its predecessors,
   *       and defining how the Node is supposed to operate
   * 
   * @todo WIP-WIP-WIP 2024 Node-Invocation is reworked from ground up for the »Playback Vertical Slice«
   */
  class Connectivity
    {
    public: /* === public information record describing the node graph === */
/////////////////////////////////////////////////////////////////////////////////////////////////////////////TICKET #1367 : Rebuild the Node Invocation
      using Ports = lib::Several<Port>;
      using Leads = lib::Several<ProcNodeRef>;
      
      Ports ports;
      Leads leads;
      
/////////////////////////////////////////////////////////////////////////////////////////////////////////////TICKET #1367 : Rebuild the Node Invocation
      
//  protected:
/////////////////////////////////////////////////////////////////////////////////////////////////////////////TICKET #1367 : Rebuild the Node Invocation
      Connectivity (Ports&& pr, Leads&& lr)
        : ports(move(pr))
        , leads(move(lr))
        { }
/////////////////////////////////////////////////////////////////////////////////////////////////////////////TICKET #1367 : Rebuild the Node Invocation
      
      
/////////////////////////////////////////////////////////////////////////////////////////////////////////////TICKET #1367 : Rebuild the Node Invocation
      /* ==== strategy API for configuring the node operation ==== */
      
      friend class ProcNode;                               /////////////////////////////////OOO who needs friendship?
      
      /** the wiring-dependent part of the node operation.
       *  Includes the creation of a one-way state object on the stack
       *  holding the actual buffer pointers and issuing the recursive pull() calls
       *  @see NodeWiring#callDown default implementation
       */
#if false /////////////////////////////////////////////////////////////////////////////////////////////////////////////UNIMPLEMENTED :: TICKET #1367 : Rebuild the Node Invocation
      virtual BuffHandle
      callDown (StateClosure_OBSOLETE& currentProcess, uint requiredOutputNr)  const =0;
#endif    /////////////////////////////////////////////////////////////////////////////////////////////////////////////UNIMPLEMENTED :: TICKET #1367 : Rebuild the Node Invocation
/////////////////////////////////////////////////////////////////////////////////////////////////////////////TICKET #1367 : Rebuild the Node Invocation
      
    };
  
  
  
  
  /**
   * Key abstraction of the Render Engine: A Data processing Node
   * 
   * @todo it's not clear as of 9/09 if ProcNode shall be an ABC/Interface
   *       It might be used as ABC (as was the original intention) when implementing
   *       several query/information functions. In that case, the ctor will become protected.
   *       The alternative would be to push down these information-retrieval part into a
   *       configurable element within Connectivity, in which case we even might drop
   *       ProcNode as a frontend entirely.
   * @todo WIP-WIP-WIP 2024 Node-Invocation is reworked from ground up for the »Playback Vertical Slice«
   */
  class ProcNode
    : util::NonCopyable
    {
      
      Connectivity wiring_;
      
    public:
/////////////////////////////////////////////////////////////////////////////////////////////////////////////TICKET #1367 : Rebuild the Node Invocation
      ProcNode (Connectivity&& con)
        : wiring_(move(con))
        { }
      
/////////////////////////////////////////////////////////////////////////////////////////////////////////////TICKET #1367 : Rebuild the Node Invocation
      
      
    public:
/////////////////////////////////////////////////////////////////////////////////////////////////////////////TICKET #1367 : Rebuild the Node Invocation
      
      Port&
      getPort (uint portIdx)
        {
          if (portIdx >= wiring_.ports.size())
            throw err::Logic{_Fmt{"Accessing node-port #%d, while only %d ports are defined."}
                     % portIdx % wiring_.ports.size()
                ,LERR_(INDEX_BOUNDS)
                };
          return wiring_.ports[portIdx];
        }
      
      /** Engine Core operation: render and pull output from this node.
       *  On return, currentProcess will hold onto output buffer(s)
       *  containing the calculated result frames. In case this node
       *  calculates a multichannel output, only one channel can be
       *  retrieved by such a \c pull() call, but you can expect data
       *  of the other channels to be processed and fed to cache.
       *  @param currentProcess the current processing state for
       *         managing buffers and accessing current parameter values
       *  @param requestedOutputNr the output channel requested
       *         (in case this node delivers more than one output channel)
       *  @return handle to the buffer containing the calculated result.
       */
#if false /////////////////////////////////////////////////////////////////////////////////////////////////////////////UNIMPLEMENTED :: TICKET #1367 : Rebuild the Node Invocation
      BuffHandle
      pull (StateClosure_OBSOLETE& currentProcess, uint requestedOutputNr=0)  const
        {
          return this->wiringConfig_.callDown (currentProcess, requestedOutputNr);
        }
#endif    /////////////////////////////////////////////////////////////////////////////////////////////////////////////UNIMPLEMENTED :: TICKET #1367 : Rebuild the Node Invocation
/////////////////////////////////////////////////////////////////////////////////////////////////////////////TICKET #1367 : Rebuild the Node Invocation
      
      /// „backdoor“ to watch internals from tests
      friend class ProcNodeDiagnostic;
    };
  
  
/////////////////////////////////////////////////////////////////////////////////////////////////////////////TICKET #1367 : Rebuild the Node Invocation
  class ProcNodeDiagnostic
    : util::MoveOnly
    {
      ProcNode& n_;
      
    public:
      ProcNodeDiagnostic (ProcNode& theNode)
        : n_{theNode}
        { }
      
      auto& leads() { return n_.wiring_.leads; }
      auto& ports() { return n_.wiring_.ports; }
      
      bool isSrc()  { return n_.wiring_.leads.empty(); }
      
      bool
      isValid()
        {
          return 0 < ports().size();
          ///////////////////////////////////////////////////TODO 10/2024 more to verify here
        }
      
      string getNodeSpec();   ///< generate a descriptive Spec of this ProcNode for diagnostics
      HashVal getNodeHash();  ///< calculate an unique hash-key to designate this node
      
      string getPortSpec  (uint portIdx);  ///< generate a descriptive diagnostic Spec for the designated Turnout
      HashVal getPortHash (uint portIdx);  ///< calculate an unique, stable and reproducible hash-key to identify the Turnout
    };
  
  inline ProcNodeDiagnostic
  watch (ProcNode& theNode)
  {
    return ProcNodeDiagnostic{theNode};
  }
  
  
}} // namespace steam::engine
#endif /*STEAM_ENGINE_PROC_NODE_H*/