path: root/Gem/develop/include/Gem/Base/CPPExtern.h

/*-----------------------------------------------------------------
LOG
    GEM - Graphics Environment for Multimedia

    The base class for all externs written in C++

    Copyright (c) 1997-1999 Mark Danks. mark@danks.org
    For information on usage and redistribution, and for a DISCLAIMER OF ALL
    WARRANTIES, see the file, "GEM.LICENSE.TERMS" in this distribution.

-----------------------------------------------------------------*/

#ifndef _INCLUDE__GEM_BASE_CPPEXTERN_H_
#define _INCLUDE__GEM_BASE_CPPEXTERN_H_

#include "Gem/ExportDef.h"

#include "Gem/RTE.h"
#include "Gem/Version.h"

#include <new>
#include <string>

class CPPExtern;

/* forward declaration of a generic exception handler for GemExceptions */
namespace gem
{
GEM_EXTERN void catchGemException(const char*objname, const t_object*obj);
};

/*-----------------------------------------------------------------
-------------------------------------------------------------------
CLASS
    Obj_header

    The obligatory object header

DESCRIPTION

    This is in a separate struct to assure that when PD uses the
    class, the t_object is the very first thing.  If it were the
    first thing in CPPExtern, then there could be problems with
    the vtable.

-----------------------------------------------------------------*/
struct GEM_EXTERN Obj_header {
  //////////
  // The obligatory object header
  t_object            pd_obj;

  //////////
  // Our data structure
  CPPExtern           *data;

  // This has a dummy arg so that NT won't complain
  void *operator new(size_t, void *location, void *dummy);
};

/*-----------------------------------------------------------------
-------------------------------------------------------------------
CLASS
    CPPExtern

    The base class for all externs written in C++

DESCRIPTION

    Each extern which is written in C++ needs to use the #defines at the
    end of this header file.  Currently, the operator new(size_t) and
    operator delete(void *) are not overridden.  This will be a problem
    when PD expects everything to fit in its memory space and control
    all memory allocation.

    The define

        CPPEXTERN_HEADER(NEW_CLASS, PARENT_CLASS);

    should be somewhere in your header file.
    One of the defines like

    CPPEXTERN_NEW(NEW_CLASS);
    CPPEXTERN_NEW_WITH_TWO_ARGS(NEW_CLASS, t_floatarg, A_FLOAT, t_floatarg, A_FLOAT);

    should be the first thing in your implementation file.
    NEW_CLASS is the name of your class and PARENT_CLASS is the
    parent of your class.

-----------------------------------------------------------------*/
class GEM_EXTERN CPPExtern
{
public:

  //////////
  // Constructor
  CPPExtern(void);

  //////////
  // The Pd header
  t_object          *x_obj;

  //////////
  // Destructor
  virtual ~CPPExtern(void) = 0;

  //////////
  // Get the object's canvas
  const t_canvas            *getCanvas(void) const
  {
    return(m_canvas);
  }

  //////////
  // This is a holder - don't touch it
  static t_object     *m_holder;

  //////////
  // my name
  static const char    *m_holdname;
  t_symbol             *m_objectname;

protected:

  //////////
  // Creation callback
  static void     real_obj_setupCallback(t_class *) {}

  ///////////
  // called directly before the destructor
  // normally you should not override this (use the dtor!)
  // if you do override this, make sure that you call the parent as well
  virtual void beforeDeletion();

private:

  //////////
  // The canvas that the object is in
  t_canvas            *m_canvas;

public:
  // these call pd's print-functions, and eventually prepend the object's name
  void            startpost(const char*format, ...) const;
  void            post(const char*format, ...) const;
  void            endpost(void) const;
  void            verbose(const int level, const char*format, ...) const;
  void            error(const char*format,
                        ...) const; /* internally uses pd_error() */

  // searches for a file based on the parent abstraction's path
  // wraps open_via_path() and canvas_makefilename()
  // the full filename is returned
  // if the file does not exist, it is constructed
  std::string findFile(const std::string&filename,
                       const std::string&ext) const;
  std::string findFile(const std::string&filename) const;

private:
  mutable bool m_endpost; /* internal state for startpost/post/endpost */
  static bool checkGemVersion(const int major, const int minor);
  CPPExtern(const CPPExtern&);
  virtual CPPExtern&operator=(const CPPExtern&);
};

////////////////////////////////////////
// This should be used in the header
////////////////////////////////////////

#define CPPEXTERN_HEADER(NEW_CLASS, PARENT_CLASS)               \
public:                                                         \
static void obj_freeCallback(void *data)                        \
{ CPPExtern *mydata = ((Obj_header *)data)->data;               \
  GetMyClass(data)->beforeDeletion();                           \
  delete mydata;                                                \
  ((Obj_header *)data)->Obj_header::~Obj_header(); }            \
static void real_obj_setupCallback(t_class *classPtr)           \
{ PARENT_CLASS::real_obj_setupCallback(classPtr);               \
  NEW_CLASS::obj_setupCallback(classPtr); }                     \
private:                                                        \
static inline NEW_CLASS *GetMyClass(void *data) {return((NEW_CLASS *)((Obj_header *)data)->data);} \
static void obj_setupCallback(t_class *classPtr);


////////////////////////////////////////
// This should be the first thing in the implementation file
////////////////////////////////////////

//
// NO ARGUMENTS
/////////////////////////////////////////////////
#define CPPEXTERN_NEW(NEW_CLASS)                     \
  REAL_NEW__CLASS(NEW_CLASS);                    \
  static void* create_ ## NEW_CLASS (void)       \
    REAL_NEW__CREATE1(NEW_CLASS)                 \
    obj->data = new NEW_CLASS();                 \
    REAL_NEW__CREATE2(NEW_CLASS)                 \
    REAL_NEW__SETUP1(NEW_CLASS)                  \
    REAL_NEW__SETUP2(NEW_CLASS)

//
// ONE ARGUMENT
/////////////////////////////////////////////////
#define CPPEXTERN_NEW_WITH_ONE_ARG(NEW_CLASS, TYPE, PD_TYPE)    \
  REAL_NEW__CLASS(NEW_CLASS);                    \
  static void* create_ ## NEW_CLASS (TYPE arg)   \
    REAL_NEW__CREATE1(NEW_CLASS)                 \
    obj->data = new NEW_CLASS(arg);              \
    REAL_NEW__CREATE2(NEW_CLASS)                 \
    REAL_NEW__SETUP1(NEW_CLASS)                  \
         PD_TYPE,                                \
    REAL_NEW__SETUP2(NEW_CLASS)

//
// GIMME ARGUMENT
/////////////////////////////////////////////////
#define CPPEXTERN_NEW_WITH_GIMME(NEW_CLASS)                     \
  REAL_NEW__CLASS(NEW_CLASS);                    \
  static void* create_ ## NEW_CLASS (t_symbol*s, int argc, t_atom*argv) \
    REAL_NEW__CREATE1(NEW_CLASS)                 \
       obj->data = new NEW_CLASS(argc,argv);     \
    REAL_NEW__CREATE2(NEW_CLASS)                 \
    REAL_NEW__SETUP1(NEW_CLASS)                  \
         A_GIMME,              \
    REAL_NEW__SETUP2(NEW_CLASS)

//
// TWO ARGUMENTS
/////////////////////////////////////////////////
#define CPPEXTERN_NEW_WITH_TWO_ARGS(NEW_CLASS, TYPE, PD_TYPE, TTWO, PD_TWO)     \
  REAL_NEW__CLASS(NEW_CLASS);                     \
  static void* create_ ## NEW_CLASS (TYPE arg, TTWO arg2) \
    REAL_NEW__CREATE1(NEW_CLASS)           \
    obj->data = new NEW_CLASS(arg, arg2);  \
    REAL_NEW__CREATE2(NEW_CLASS)           \
    REAL_NEW__SETUP1(NEW_CLASS)            \
         PD_TYPE, PD_TWO,                  \
    REAL_NEW__SETUP2(NEW_CLASS)

//
// THREE ARGUMENTS
/////////////////////////////////////////////////
#define CPPEXTERN_NEW_WITH_THREE_ARGS(NEW_CLASS, TYPE, PD_TYPE, TTWO, PD_TWO, TTHREE, PD_THREE) \
  REAL_NEW__CLASS(NEW_CLASS);                        \
  static void* create_ ## NEW_CLASS (TYPE arg, TTWO arg2, TTHREE arg3)  \
    REAL_NEW__CREATE1(NEW_CLASS)                    \
       obj->data = new NEW_CLASS(arg, arg2, arg3);  \
    REAL_NEW__CREATE2(NEW_CLASS)                    \
    REAL_NEW__SETUP1(NEW_CLASS)                     \
         PD_TYPE, PD_TWO, PD_THREE,                 \
    REAL_NEW__SETUP2(NEW_CLASS)

//
// FOUR ARGUMENTS
/////////////////////////////////////////////////
#define CPPEXTERN_NEW_WITH_FOUR_ARGS(NEW_CLASS, TYPE, PD_TYPE, TTWO, PD_TWO, TTHREE, PD_THREE, TFOUR, PD_FOUR) \
  REAL_NEW__CLASS(NEW_CLASS);                             \
  static void* create_ ## NEW_CLASS (TYPE arg, TTWO arg2, TTHREE arg3, TFOUR arg4) \
    REAL_NEW__CREATE1(NEW_CLASS)                         \
       obj->data = new NEW_CLASS(arg, arg2, arg3, arg4); \
    REAL_NEW__CREATE2(NEW_CLASS)                         \
    REAL_NEW__SETUP1(NEW_CLASS)                          \
         PD_TYPE, PD_TWO, PD_THREE, PD_FOUR,             \
    REAL_NEW__SETUP2(NEW_CLASS)

//
// FIVE ARGUMENTS
/////////////////////////////////////////////////
#define CPPEXTERN_NEW_WITH_FIVE_ARGS(NEW_CLASS, TYPE, PD_TYPE, TTWO, PD_TWO, TTHREE, PD_THREE, TFOUR, PD_FOUR, TFIVE, PD_FIVE) \
  REAL_NEW__CLASS(NEW_CLASS);                                   \
  static void* create_ ## NEW_CLASS (TYPE arg, TTWO arg2, TTHREE arg3, TFOUR arg4, TFIVE arg5) \
    REAL_NEW__CREATE1(NEW_CLASS)                               \
       obj->data = new NEW_CLASS(arg, arg2, arg3, arg4, arg5); \
    REAL_NEW__CREATE2(NEW_CLASS)                               \
    REAL_NEW__SETUP1(NEW_CLASS)                                \
         PD_TYPE, PD_TWO, PD_THREE, PD_FOUR, PD_FIVE           \
    REAL_NEW__SETUP2(NEW_CLASS)


//////////////////////////////////////////////////////////////////////////////
// These should never be called or used directly!!!
//
//
///////////////////////////////////////////////////////////////////////////////

#define REAL_NEW__CLASS(NEW_CLASS)  STATIC_CLASS t_class * NEW_CLASS ## _class
#define REAL_NEW__CREATE1(NEW_CLASS)  {                                          \
   try{                                                                          \
    Obj_header *obj = new (pd_new(NEW_CLASS ## _class),(void *)NULL) Obj_header; \
    CPPExtern::m_holder = &obj->pd_obj;                                            \
    CPPExtern::m_holdname=(char*)#NEW_CLASS;

#define REAL_NEW__CREATE2(NEW_CLASS) \
  CPPExtern::m_holder = NULL;                                   \
  CPPExtern::m_holdname=NULL;                                   \
  return(obj);                                                  \
  } catch (...) {gem::catchGemException(CPPExtern::m_holdname, CPPExtern::m_holder); return NULL;} \
  }

#define REAL_NEW__SETUP1(NEW_CLASS) \
  extern "C" {                                                  \
    GEM_EXPORT void NEW_CLASS ## _setup(void)                                  \
    {                                                           \
    static int recalled=0; if(recalled)return; recalled=1;      \
    NEW_CLASS ## _class = class_new(                          \
                                      gensym(#NEW_CLASS),               \
                                      (t_newmethod)create_ ## NEW_CLASS, \
                                      (t_method)&NEW_CLASS::obj_freeCallback, \
                                      sizeof(Obj_header), GEM_CLASSFLAGS,
#define REAL_NEW__SETUP2(NEW_CLASS)                         \
  A_NULL);                                                  \
  SET_HELPSYMBOL(NEW_CLASS);                                \
  NEW_CLASS::real_obj_setupCallback(NEW_CLASS ## _class);   \
  }                                                         \
  }                                                         \
  AUTO_REGISTER_CLASS(NEW_CLASS);


///////////////////////////////////////////////////////////////////////////////
// static class:
//   by default classes are declared static
//   however, sometimes we need classes not-static, so we can refer to them
//   from other classes
///////////////////////////////////////////////////////////////////////////////
#ifdef NO_STATIC_CLASS
# define STATIC_CLASS
#else
# define STATIC_CLASS static
#endif

///////////////////////////////////////////////////////////////////////////////
// auto registering a class
// this creates a dummy class, whose constructor calls the setup-function
// (registering the class with pd)
// a static copy of this class is created at runtime, to actually do the setup-call
///////////////////////////////////////////////////////////////////////////////
typedef void (*t_class_setup)(void);
extern "C" { GEM_EXTERN void gem_register_class_setup(const char*name, t_class_setup); }

#ifdef NO_AUTO_REGISTER_CLASS
// if NO_AUTO_REGISTER_CLASS is defined, we will not register the class
# define AUTO_REGISTER_CLASS(NEW_CLASS) \
  static int NEW_CLASS ## _dummyinstance
#else
// for debugging we can show the which classes are auto-registering
# define AUTO_REGISTER_CLASS(NEW_CLASS)                                 \
  class NEW_CLASS ## _cppclass {                                        \
  public:                                                               \
  NEW_CLASS ## _cppclass(void) {gem_register_class_setup(#NEW_CLASS, & NEW_CLASS ## _setup); } \
};                                                                      \
  static NEW_CLASS ## _cppclass NEW_CLASS ## _instance
#endif

///////////////////////////////////////////////////////////////////////////////
// setting the help-symbol
///////////////////////////////////////////////////////////////////////////////
#if defined HELPSYMBOL_BASE || defined HELPSYMBOL
# ifndef HELPSYMBOL_BASE
#  define HELPSYMBOL_BASE ""
# endif

# ifndef HELPSYMBOL
#  define SET_HELPSYMBOL(NEW_CLASS)                                     \
  class_sethelpsymbol(NEW_CLASS ## _class, gensym(HELPSYMBOL_BASE #NEW_CLASS))
# else
#  define SET_HELPSYMBOL(NEW_CLASS)                             \
    class_sethelpsymbol(NEW_CLASS ## _class, gensym(HELPSYMBOL_BASE HELPSYMBOL))
# endif

#else
# define SET_HELPSYMBOL(NEW_CLASS)
#endif /* HELPSYMBOL */

///////////////////////////////////////////////////////////////////////////////
// setting the class-flags
///////////////////////////////////////////////////////////////////////////////
#ifndef GEM_CLASSFLAGS
# define GEM_CLASSFLAGS 0
#endif

// macros for boilerplate code to object messages
#include "RTE/MessageCallbacks.h"

#endif  // for header file