/**************************************************************************\
 *
 *  This file is part of the Coin 3D visualization library.
 *  Copyright (C) 1998-2007 by Systems in Motion.  All rights reserved.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  ("GPL") version 2 as published by the Free Software Foundation.
 *  See the file LICENSE.GPL at the root directory of this source
 *  distribution for additional information about the GNU GPL.
 *
 *  For using Coin with software that can not be combined with the GNU
 *  GPL, and for taking advantage of the additional benefits of our
 *  support services, please contact Systems in Motion about acquiring
 *  a Coin Professional Edition License.
 *
 *  See http://www.coin3d.org/ for more information.
 *
 *  Systems in Motion, Postboks 1283, Pirsenteret, 7462 Trondheim, NORWAY.
 *  http://www.sim.no/  sales@sim.no  coin-support@coin3d.org
 *
\**************************************************************************/

#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#include <Inventor/C/glue/cg.h>

#include <Inventor/C/basic.h>
#include <Inventor/C/threads/threadsutilp.h>
#include <Inventor/C/glue/dl.h>
#include <Inventor/C/tidbitsp.h>
#include <Inventor/C/errors/debugerror.h>
#include <Inventor/C/tidbits.h>

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

typedef CGcontext (*glue_cgCreateContext_t)(void);
typedef void (*glue_cgDestroyContext_t)(CGcontext);
typedef CGbool (*glue_cgIsContext_t)(CGcontext);
typedef const char * (*glue_cgGetLastListing_t)(CGcontext);
typedef CGprogram (*glue_cgCreateProgram_t)(CGcontext, CGenum, const char *, CGprofile, const char *, const char **);
typedef void (*glue_cgDestroyProgram_t)(CGprogram);
typedef CGbool (*glue_cgIsProgram_t)(CGprogram);
typedef const char * (*glue_cgGetProfileString_t)(CGprofile);
typedef CGerror (*glue_cgGetError_t)(void);
typedef const char * (*glue_cgGetErrorString_t)(CGerror);
typedef void (*glue_cgSetErrorCallback_t)(CGerrorCallbackFunc);
typedef CGbool (*glue_cgIsParameter_t)(CGparameter);
typedef CGtype (*glue_cgGetParameterType_t)(CGparameter);
typedef CGparameter (*glue_cgGetNamedParameter_t)(CGprogram, const char *);
typedef const char * (*glue_cgGetTypeString_t)(CGtype);
typedef CGbool (*glue_cgGLIsProfileSupported_t)(CGprofile);
typedef void (*glue_cgGLEnableProfile_t)(CGprofile);
typedef void (*glue_cgGLDisableProfile_t)(CGprofile);
typedef CGprofile (*glue_cgGLGetLatestProfile_t)(CGGLenum);
typedef void (*glue_cgGLLoadProgram_t)(CGprogram);
typedef void (*glue_cgGLBindProgram_t)(CGprogram);
typedef void (*glue_cgGLSetParameter1f_t)(CGparameter, float);
typedef void (*glue_cgGLSetParameter2f_t)(CGparameter, float, float);
typedef void (*glue_cgGLSetParameter3f_t)(CGparameter, float, float, float);
typedef void (*glue_cgGLSetParameter4f_t)(CGparameter, float, float, float, float);
typedef void (*glue_cgGLSetStateMatrixParameter_t)(CGparameter, CGGLenum, CGGLenum);
typedef void (*glue_cgGLSetParameterArray1f_t)(CGparameter, long, long, const float *);
typedef void (*glue_cgGLSetParameterArray2f_t)(CGparameter, long, long, const float *);
typedef void (*glue_cgGLSetParameterArray3f_t)(CGparameter, long, long, const float *);
typedef void (*glue_cgGLSetParameterArray4f_t)(CGparameter, long, long, const float *);
typedef void (*glue_cgGLSetMatrixParameterfc_t)(CGparameter, const float *);
typedef void (*glue_cgGLSetMatrixParameterArrayfc_t)(CGparameter, long, long, const float *);
typedef int (*glue_cgGetArrayDimension_t)(CGparameter);
typedef int (*glue_cgGetArraySize_t)(CGparameter, int);


typedef struct {
  int available;

  glue_cgCreateContext_t cgCreateContext;
  glue_cgDestroyContext_t cgDestroyContext;
  glue_cgIsContext_t cgIsContext;
  glue_cgGetLastListing_t cgGetLastListing;
  glue_cgCreateProgram_t cgCreateProgram;
  glue_cgDestroyProgram_t cgDestroyProgram;
  glue_cgIsProgram_t cgIsProgram;
  glue_cgGetProfileString_t cgGetProfileString;
  glue_cgGetError_t cgGetError;
  glue_cgGetErrorString_t cgGetErrorString;
  glue_cgSetErrorCallback_t cgSetErrorCallback;
  glue_cgIsParameter_t cgIsParameter;
  glue_cgGetParameterType_t cgGetParameterType;
  glue_cgGetNamedParameter_t cgGetNamedParameter;
  glue_cgGetTypeString_t cgGetTypeString;
  glue_cgGLIsProfileSupported_t cgGLIsProfileSupported;
  glue_cgGLEnableProfile_t cgGLEnableProfile;
  glue_cgGLDisableProfile_t cgGLDisableProfile;
  glue_cgGLGetLatestProfile_t cgGLGetLatestProfile;
  glue_cgGLLoadProgram_t cgGLLoadProgram;
  glue_cgGLBindProgram_t cgGLBindProgram;
  glue_cgGLSetParameter1f_t cgGLSetParameter1f;
  glue_cgGLSetParameter2f_t cgGLSetParameter2f;
  glue_cgGLSetParameter3f_t cgGLSetParameter3f;
  glue_cgGLSetParameter4f_t cgGLSetParameter4f;
  glue_cgGLSetStateMatrixParameter_t cgGLSetStateMatrixParameter;
  glue_cgGLSetParameterArray1f_t cgGLSetParameterArray1f;
  glue_cgGLSetParameterArray2f_t cgGLSetParameterArray2f;
  glue_cgGLSetParameterArray3f_t cgGLSetParameterArray3f;      
  glue_cgGLSetParameterArray4f_t cgGLSetParameterArray4f;
  glue_cgGLSetMatrixParameterfc_t cgGLSetMatrixParameterfc;
  glue_cgGLSetMatrixParameterArrayfc_t cgGLSetMatrixParameterArrayfc;
  glue_cgGetArrayDimension_t cgGetArrayDimension;
  glue_cgGetArraySize_t cgGetArraySize;
} cc_cgglue_t;

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

static cc_cgglue_t * cg_instance = NULL;
/* Cg is split into two dll's under Windows. Need two libhandles */
static cc_libhandle cg_libhandle = NULL;
static cc_libhandle cg_libhandle2 = NULL;
static int cg_failed_to_load = 0;

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

/* Cleans up at exit. */
static void
cgglue_cleanup(void)
{
#ifdef CGLIB_RUNTIME_LINKING
  if (cg_libhandle) { cc_dl_close(cg_libhandle); }
  if (cg_libhandle2) { cc_dl_close(cg_libhandle2); }
#endif /* CGLIB_RUNTIME_LINKING */
  assert(cg_instance);
  free(cg_instance);

  /* restore variables to initial value */
  cg_instance = NULL;
  cg_libhandle = NULL;
  cg_libhandle2 = NULL;
  cg_failed_to_load = 0;
}

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

static const cc_cgglue_t *
cgglue_init(void)
{
  CC_SYNC_BEGIN(cgglue_init);
    
  if (!cg_instance && !cg_failed_to_load) {
    /* First invocation, do initializations. */
    cc_cgglue_t * zi = (cc_cgglue_t *)malloc(sizeof(cc_cgglue_t));
    (void)coin_atexit((coin_atexit_f *)cgglue_cleanup, CC_ATEXIT_DYNLIBS);

    /* The common case is that the library is either available from
       the linking process or we're successfully going to link it
       in. */
    zi->available = 1;

#ifdef CGLIB_RUNTIME_LINKING
    {
      int idx;
      /* FIXME: should we get the system shared library name from an
         Autoconf check? 20000930 mortene. */
      const char * possiblelibnames[] = {
        NULL, /* is set below */
        "CgGL", "libCgGL", "libCgGL.so",

        /* FIXME: not yet tested on Mac OS X. 20050125 mortene. */
        "libCgGL.dylib", 
        NULL
      };

      possiblelibnames[0] = coin_getenv("COIN_CG_LIBNAME");
      idx = possiblelibnames[0] ? 0 : 1;

      while (!cg_libhandle && possiblelibnames[idx]) {
        cg_libhandle = cc_dl_open(possiblelibnames[idx]);
        idx++;
      }

      if (!cg_libhandle) {
        zi->available = 0;
        cg_failed_to_load = 1;
      }
      /* Cg is split into two dll's under Windows */
      if (cg_libhandle) {
        /* FIXME: do a proper possiblenames while loop? pederb, 2005-11-28 */
        cg_libhandle2 = cc_dl_open("Cg");
      }
    }
    /* Define CGGLUE_REGISTER_FUNC macro. Casting the type is
       necessary for this file to be compatible with C++ compilers. */
#define CGGLUE_REGISTER_FUNC(_funcsig_, _funcname_) \
    do { \
      zi->_funcname_ = (_funcsig_)cc_dl_sym(cg_libhandle, SO__QUOTE(_funcname_)); \
      if (!zi->_funcname_ && cg_libhandle2) { \
        zi->_funcname_ = (_funcsig_)cc_dl_sym(cg_libhandle2, SO__QUOTE(_funcname_)); \
      } \
      if (zi->_funcname_ == NULL) zi->available = 0; \
    } while (0)

#elif defined(HAVE_CGLIB) /* no dynamic linking, but static linking possible */

    /* Define CGGLUE_REGISTER_FUNC macro. */
#define CGGLUE_REGISTER_FUNC(_funcsig_, _funcname_) \
    zi->_funcname_ = (_funcsig_)_funcname_

#else /* no dynamic linking, and Cg-lib not available for static linking */
    zi->available = 0;
    /* Define CGGLUE_REGISTER_FUNC macro. */
#define CGGLUE_REGISTER_FUNC(_funcsig_, _funcname_) \
    zi->_funcname_ = NULL

#endif /* no linking */

    if (zi->available) {
      CGGLUE_REGISTER_FUNC(glue_cgCreateContext_t, cgCreateContext);
      CGGLUE_REGISTER_FUNC(glue_cgDestroyContext_t, cgDestroyContext);
      CGGLUE_REGISTER_FUNC(glue_cgIsContext_t, cgIsContext);
      CGGLUE_REGISTER_FUNC(glue_cgGetLastListing_t, cgGetLastListing);
      CGGLUE_REGISTER_FUNC(glue_cgCreateProgram_t, cgCreateProgram);
      CGGLUE_REGISTER_FUNC(glue_cgDestroyProgram_t, cgDestroyProgram);
      CGGLUE_REGISTER_FUNC(glue_cgIsProgram_t, cgIsProgram);
      CGGLUE_REGISTER_FUNC(glue_cgGetProfileString_t, cgGetProfileString);
      CGGLUE_REGISTER_FUNC(glue_cgGetError_t, cgGetError);
      CGGLUE_REGISTER_FUNC(glue_cgGetErrorString_t, cgGetErrorString);
      CGGLUE_REGISTER_FUNC(glue_cgSetErrorCallback_t, cgSetErrorCallback);
      CGGLUE_REGISTER_FUNC(glue_cgIsParameter_t, cgIsParameter);
      CGGLUE_REGISTER_FUNC(glue_cgGetParameterType_t, cgGetParameterType);
      CGGLUE_REGISTER_FUNC(glue_cgGetNamedParameter_t, cgGetNamedParameter);
      CGGLUE_REGISTER_FUNC(glue_cgGetTypeString_t, cgGetTypeString);
      CGGLUE_REGISTER_FUNC(glue_cgGLIsProfileSupported_t, cgGLIsProfileSupported);
      CGGLUE_REGISTER_FUNC(glue_cgGLEnableProfile_t, cgGLEnableProfile);
      CGGLUE_REGISTER_FUNC(glue_cgGLDisableProfile_t, cgGLDisableProfile);
      CGGLUE_REGISTER_FUNC(glue_cgGLGetLatestProfile_t, cgGLGetLatestProfile);
      CGGLUE_REGISTER_FUNC(glue_cgGLLoadProgram_t, cgGLLoadProgram);
      CGGLUE_REGISTER_FUNC(glue_cgGLBindProgram_t, cgGLBindProgram);
      CGGLUE_REGISTER_FUNC(glue_cgGLSetParameter1f_t, cgGLSetParameter1f);
      CGGLUE_REGISTER_FUNC(glue_cgGLSetParameter2f_t, cgGLSetParameter2f);
      CGGLUE_REGISTER_FUNC(glue_cgGLSetParameter3f_t, cgGLSetParameter3f);
      CGGLUE_REGISTER_FUNC(glue_cgGLSetParameter4f_t, cgGLSetParameter4f);
      CGGLUE_REGISTER_FUNC(glue_cgGLSetStateMatrixParameter_t, cgGLSetStateMatrixParameter);
      CGGLUE_REGISTER_FUNC(glue_cgGLSetParameterArray1f_t, cgGLSetParameterArray1f);
      CGGLUE_REGISTER_FUNC(glue_cgGLSetParameterArray2f_t, cgGLSetParameterArray2f);
      CGGLUE_REGISTER_FUNC(glue_cgGLSetParameterArray3f_t, cgGLSetParameterArray3f);      
      CGGLUE_REGISTER_FUNC(glue_cgGLSetParameterArray4f_t, cgGLSetParameterArray4f);
      CGGLUE_REGISTER_FUNC(glue_cgGLSetMatrixParameterfc_t, cgGLSetMatrixParameterfc);
      CGGLUE_REGISTER_FUNC(glue_cgGLSetMatrixParameterArrayfc_t, cgGLSetMatrixParameterArrayfc);
      CGGLUE_REGISTER_FUNC(glue_cgGetArrayDimension_t, cgGetArrayDimension);
      CGGLUE_REGISTER_FUNC(glue_cgGetArraySize_t, cgGetArraySize);
    }
    /* Do this late, so we can detect recursive calls to this function. */
    cg_instance = zi;
  }
  CC_SYNC_END(cgglue_init);
  return cg_instance;
}

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

int 
cc_cgglue_available(void)
{
  if (cg_instance && cg_instance->available) { return 1; }
  else { cgglue_init(); }
  return (cg_instance && cg_instance->available);
}

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

CGcontext
glue_cgCreateContext(void)
{
  return cg_instance->cgCreateContext();
}

void
glue_cgDestroyContext(CGcontext c)
{
  cg_instance->cgDestroyContext(c);
}

CGbool
glue_cgIsContext(CGcontext c)
{
  return cg_instance->cgIsContext(c);
}

const char *
glue_cgGetLastListing(CGcontext c)
{
  return cg_instance->cgGetLastListing(c);
}

CGprogram
glue_cgCreateProgram(CGcontext c, CGenum e, const char * cp0, CGprofile p,
                     const char * cp1, const char ** cpp)
{
  return cg_instance->cgCreateProgram(c, e, cp0, p, cp1, cpp);
}

void
glue_cgDestroyProgram(CGprogram p)
{
  cg_instance->cgDestroyProgram(p);
}

CGbool
glue_cgIsProgram(CGprogram p)
{
  return cg_instance->cgIsProgram(p);
}

const char *
glue_cgGetProfileString(CGprofile p)
{
  return cg_instance->cgGetProfileString(p);
}

CGerror
glue_cgGetError(void)
{
  return cg_instance->cgGetError();
}

const char *
glue_cgGetErrorString(CGerror e)
{
  return cg_instance->cgGetErrorString(e);
}

void
glue_cgSetErrorCallback(CGerrorCallbackFunc f)
{
  cg_instance->cgSetErrorCallback(f);
}

CGbool
glue_cgIsParameter(CGparameter p)
{
  return cg_instance->cgIsParameter(p);
}

CGtype
glue_cgGetParameterType(CGparameter p)
{
  return cg_instance->cgGetParameterType(p);
}

CGparameter
glue_cgGetNamedParameter(CGprogram p, const char * c)
{
  return cg_instance->cgGetNamedParameter(p, c);
}

const char *
glue_cgGetTypeString(CGtype t)
{
  return cg_instance->cgGetTypeString(t);
}

CGbool
glue_cgGLIsProfileSupported(CGprofile p)
{
  return cg_instance->cgGLIsProfileSupported(p);
}

void
glue_cgGLEnableProfile(CGprofile p)
{
  cg_instance->cgGLEnableProfile(p);
}

void
glue_cgGLDisableProfile(CGprofile p)
{
  cg_instance->cgGLDisableProfile(p);
}

CGprofile
glue_cgGLGetLatestProfile(CGGLenum e)
{
  return cg_instance->cgGLGetLatestProfile(e);
}

void
glue_cgGLLoadProgram(CGprogram p)
{
  cg_instance->cgGLLoadProgram(p);
}

void
glue_cgGLBindProgram(CGprogram p)
{
  cg_instance->cgGLBindProgram(p);
}

void
glue_cgGLSetParameter1f(CGparameter p, float f)
{
  cg_instance->cgGLSetParameter1f(p, f);
}

void
glue_cgGLSetParameter2f(CGparameter p, float f0, float f1)
{
  cg_instance->cgGLSetParameter2f(p, f0, f1);
}

void
glue_cgGLSetParameter3f(CGparameter p, float f0, float f1, float f2)
{
  cg_instance->cgGLSetParameter3f(p, f0, f1, f2);
}

void
glue_cgGLSetParameter4f(CGparameter p, float f0, float f1, float f2, float f3)
{
  cg_instance->cgGLSetParameter4f(p, f0, f1, f2, f3);
}

void
glue_cgGLSetStateMatrixParameter(CGparameter p, CGGLenum e0, CGGLenum e1)
{
  cg_instance->cgGLSetStateMatrixParameter(p, e0, e1);
}

void
glue_cgGLSetParameterArray1f(CGparameter p, long o, long n, const float *v)
{
  cg_instance->cgGLSetParameterArray1f(p, o, n, v);
}

void
glue_cgGLSetParameterArray2f(CGparameter p, long o, long n, const float *v)
{
  cg_instance->cgGLSetParameterArray2f(p, o, n, v);
}

void
glue_cgGLSetParameterArray3f(CGparameter p, long o, long n, const float *v)
{
  cg_instance->cgGLSetParameterArray3f(p, o, n, v);
}

void
glue_cgGLSetParameterArray4f(CGparameter p, long o, long n, const float *v)
{
  cg_instance->cgGLSetParameterArray4f(p, o, n, v);
}

void
glue_cgGLSetMatrixParameterfc(CGparameter p, const float *v)
{
  cg_instance->cgGLSetMatrixParameterfc(p, v);
}

void
glue_cgGLSetMatrixParameterArrayfc(CGparameter p, long o, long n, const float *v)
{
  cg_instance->cgGLSetMatrixParameterArrayfc(p, o, n, v);
}

int
glue_cgGetArrayDimension(CGparameter p)
{
  return cg_instance->cgGetArrayDimension(p);
}

int
glue_cgGetArraySize(CGparameter p, int dim)
{
  return cg_instance->cgGetArraySize(p, dim);
}

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