// newmat.cxx -- class to handle material properties
//
// Written by Curtis Olson, started May 1998.
//
// Copyright (C) 1998 - 2000  Curtis L. Olson  - curt@flightgear.org
//
// 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.
//
// $Id$


#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include <simgear/compiler.h>

#include <map>
SG_USING_STD(map);

#include <simgear/compiler.h>

#ifdef SG_MATH_EXCEPTION_CLASH
#  include <math.h>
#endif

#include <simgear/debug/logstream.hxx>
#include <simgear/math/sg_random.h>
#include <simgear/misc/sg_path.hxx>
#include <simgear/misc/sgstream.hxx>

#include <Main/globals.hxx>
#include <Main/fg_props.hxx>

#include "newmat.hxx"


////////////////////////////////////////////////////////////////////////
// Local static variables.
// FIXME: write a proper manager.
////////////////////////////////////////////////////////////////////////

// Objects already loaded (that can be reused).
map<string,ssgEntity *> object_map;



////////////////////////////////////////////////////////////////////////
// Local static functions.
////////////////////////////////////////////////////////////////////////

// FIXME: this is totally evil and non-robust: it assumes that
// entities will never be refcounted to 0 (which is safe for now).
static ssgEntity *
load_object (char * path)
{
  ssgEntity * object = object_map[path];
  if (object == 0) {
    object = ssgLoad(path);
    object_map[path] = object;
  }
  return object;
}

/**
 * Internal method to test whether a file exists.
 *
 * TODO: this should be moved to a SimGear library of local file
 * functions.
 */
static inline bool
local_file_exists( const string& path ) {
    sg_gzifstream in( path );
    if ( ! in.is_open() ) {
	return false;
    } else {
	return true;
    }
}



////////////////////////////////////////////////////////////////////////
// Implementation of FGNewMat::Object.
////////////////////////////////////////////////////////////////////////

FGNewMat::Object::Object (const SGPropertyNode * node, double range_m)
  : _models_loaded(false),
    _coverage_m2(node->getDoubleValue("coverage-m2", 1000000)),
    _range_m(range_m)
{
				// Sanity check
  if (_coverage_m2 < 1000) {
    SG_LOG(SG_INPUT, SG_ALERT, "Random object coverage " << _coverage_m2
	   << " is too small, forcing, to 1000");
    _coverage_m2 = 1000;
  }

				// Note all the model paths
  vector <SGPropertyNode_ptr> path_nodes = node->getChildren("path");
  for (unsigned int i = 0; i < path_nodes.size(); i++)
    _paths.push_back(path_nodes[i]->getStringValue());

				// Note the heading type
  string hdg = node->getStringValue("heading-type", "fixed");
  if (hdg == "fixed") {
    _heading_type = HEADING_FIXED;
  } else if (hdg == "billboard") {
    _heading_type = HEADING_BILLBOARD;
  } else if (hdg == "random") {
    _heading_type = HEADING_RANDOM;
  } else {
    _heading_type = HEADING_FIXED;
    SG_LOG(SG_INPUT, SG_ALERT, "Unknown heading type: " << hdg
	   << "; using 'fixed' instead.");
  }

  // uncomment to preload models
  // load_models();
}

FGNewMat::Object::~Object ()
{
  for (unsigned int i = 0; i < _models.size(); i++) {
    if (_models[i] != 0) {
      _models[i]->deRef();
      _models[i] = 0;
    }
  }
}

int
FGNewMat::Object::get_model_count () const
{
  return _models.size();
}

inline void
FGNewMat::Object::load_models () const
{
				// Load model only on demand
  if (!_models_loaded) {
    for (unsigned int i = 0; i < _paths.size(); i++) {
      SGPath path = globals->get_fg_root();
      path.append(_paths[i]);
      ssgTexturePath((char *)path.dir().c_str());
      ssgEntity * entity = load_object((char *)path.c_str());
      if (entity != 0) {
	float ranges[] = {0, _range_m};
	ssgRangeSelector * lod = new ssgRangeSelector;
	lod->setRanges(ranges, 2);
	if (_heading_type == HEADING_BILLBOARD) {
	  ssgCutout * cutout = new ssgCutout(false);
	  cutout->addKid(entity);
	  lod->addKid(cutout);
	} else {
	  lod->addKid(entity);
	}
	lod->ref();
	_models.push_back(lod);
      } else {
	SG_LOG(SG_INPUT, SG_ALERT, "Failed to load object " << path.str());
      }
    }
  }
  _models_loaded = true;
}

ssgEntity *
FGNewMat::Object::get_model (int index) const
{
  load_models();                // comment this out if preloading models
  return _models[index];
}

ssgEntity *
FGNewMat::Object::get_random_model () const
{
  load_models();                // comment this out if preloading models
  int nModels = _models.size();
  int index = int(sg_random() * nModels);
  if (index >= nModels)
    index = 0;
  return _models[index];
}

double
FGNewMat::Object::get_coverage_m2 () const
{
  return _coverage_m2;
}

FGNewMat::Object::HeadingType
FGNewMat::Object::get_heading_type () const
{
  return _heading_type;
}



////////////////////////////////////////////////////////////////////////
// Implementation of FGNewMat::ObjectGroup.
////////////////////////////////////////////////////////////////////////

FGNewMat::ObjectGroup::ObjectGroup (SGPropertyNode * node)
  : _range_m(node->getDoubleValue("range-m", 2000))
{
				// Load the object subnodes
  vector<SGPropertyNode_ptr> object_nodes =
    ((SGPropertyNode *)node)->getChildren("object");
  for (unsigned int i = 0; i < object_nodes.size(); i++) {
    const SGPropertyNode * object_node = object_nodes[i];
    if (object_node->hasChild("path"))
      _objects.push_back(new Object(object_node, _range_m));
    else
      SG_LOG(SG_INPUT, SG_ALERT, "No path supplied for object");
  }
}

FGNewMat::ObjectGroup::~ObjectGroup ()
{
  for (unsigned int i = 0; i < _objects.size(); i++) {
    delete _objects[i];
    _objects[i] = 0;
  }
}

double
FGNewMat::ObjectGroup::get_range_m () const
{
  return _range_m;
}

int
FGNewMat::ObjectGroup::get_object_count () const
{
  return _objects.size();
}

FGNewMat::Object *
FGNewMat::ObjectGroup::get_object (int index) const
{
  return _objects[index];
}



////////////////////////////////////////////////////////////////////////
// Constructors and destructor.
////////////////////////////////////////////////////////////////////////


FGNewMat::FGNewMat (const SGPropertyNode * props)
{
    init();
    read_properties(props);
    build_ssg_state(false);
}

FGNewMat::FGNewMat (const string &texpath)
{
    init();
    texture_path = texpath;
    build_ssg_state(true);
}

FGNewMat::FGNewMat (ssgSimpleState * s)
{
    init();
    set_ssg_state(s);
}

FGNewMat::~FGNewMat (void)
{
  for (unsigned int i = 0; i < object_groups.size(); i++) {
    delete object_groups[i];
    object_groups[i] = 0;
  }
}



////////////////////////////////////////////////////////////////////////
// Public methods.
////////////////////////////////////////////////////////////////////////

void
FGNewMat::read_properties (const SGPropertyNode * props)
{
				// Get the path to the texture
  string tname = props->getStringValue("texture", "unknown.rgb");
  SGPath tpath(globals->get_fg_root());
  tpath.append("Textures.high");
  tpath.append(tname);
  if (!local_file_exists(tpath.str())) {
    tpath = SGPath(globals->get_fg_root());
    tpath.append("Textures");
    tpath.append(tname);
  }
  texture_path = tpath.str();

  xsize = props->getDoubleValue("xsize", 0.0);
  ysize = props->getDoubleValue("ysize", 0.0);
  wrapu = props->getBoolValue("wrapu", true);
  wrapv = props->getBoolValue("wrapv", true);
  mipmap = props->getBoolValue("mipmap", true);
  light_coverage = props->getDoubleValue("light-coverage", 0.0);

  ambient[0] = props->getDoubleValue("ambient/r", 0.0);
  ambient[1] = props->getDoubleValue("ambient/g", 0.0);
  ambient[2] = props->getDoubleValue("ambient/b", 0.0);
  ambient[3] = props->getDoubleValue("ambient/a", 0.0);

  diffuse[0] = props->getDoubleValue("diffuse/r", 0.0);
  diffuse[1] = props->getDoubleValue("diffuse/g", 0.0);
  diffuse[2] = props->getDoubleValue("diffuse/b", 0.0);
  diffuse[3] = props->getDoubleValue("diffuse/a", 0.0);

  specular[0] = props->getDoubleValue("specular/r", 0.0);
  specular[1] = props->getDoubleValue("specular/g", 0.0);
  specular[2] = props->getDoubleValue("specular/b", 0.0);
  specular[3] = props->getDoubleValue("specular/a", 0.0);

  emission[0] = props->getDoubleValue("emissive/r", 0.0);
  emission[1] = props->getDoubleValue("emissive/g", 0.0);
  emission[2] = props->getDoubleValue("emissive/b", 0.0);
  emission[3] = props->getDoubleValue("emissive/a", 0.0);

  vector<SGPropertyNode_ptr> object_group_nodes =
    ((SGPropertyNode *)props)->getChildren("object-group");
  for (unsigned int i = 0; i < object_group_nodes.size(); i++)
    object_groups.push_back(new ObjectGroup(object_group_nodes[i]));
}



////////////////////////////////////////////////////////////////////////
// Private methods.
////////////////////////////////////////////////////////////////////////

void 
FGNewMat::init ()
{
  texture_path = "";
  state = 0;
  textured = 0;
  nontextured = 0;
  xsize = 0;
  ysize = 0;
  wrapu = true;
  wrapv = true;
  mipmap = true;
  light_coverage = 0.0;
  texture_loaded = false;
  refcount = 0;
  for (int i = 0; i < 4; i++)
    ambient[i] = diffuse[i] = specular[i] = emission[i] = 0.0;
}

bool
FGNewMat::load_texture ()
{
  if (texture_loaded) {
    return false;
  } else {
    SG_LOG( SG_GENERAL, SG_INFO, "Loading deferred texture " << texture_path );
    textured->setTexture((char *)texture_path.c_str(), wrapu, wrapv, mipmap );
    texture_loaded = true;
    return true;
  }
}


void 
FGNewMat::build_ssg_state (bool defer_tex_load)
{
    GLenum shade_model =
      (fgGetBool("/sim/rendering/shading") ? GL_SMOOTH : GL_FLAT);
    bool texture_default = fgGetBool("/sim/rendering/textures");

    state = new ssgStateSelector(2);
    state->ref();

    textured = new ssgSimpleState();
    textured->ref();

    nontextured = new ssgSimpleState();
    nontextured->ref();

    // Set up the textured state
    textured->setShadeModel( shade_model );
    textured->enable( GL_LIGHTING );
    textured->enable ( GL_CULL_FACE ) ;
    textured->enable( GL_TEXTURE_2D );
    textured->disable( GL_BLEND );
    textured->disable( GL_ALPHA_TEST );
#if 0
#  ifdef GL_EXT_texture_filter_anisotropic
    float max_anisotropy;
    glGetFloatv( GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &max_anisotropy );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT,
		     max_anisotropy );
    cout << "Max anisotropy = " << max_anisotropy << endl;
#  endif
#endif
    if ( !defer_tex_load ) {
	textured->setTexture( (char *)texture_path.c_str(), wrapu, wrapv );
	texture_loaded = true;
    } else {
	texture_loaded = false;
    }
    textured->enable( GL_COLOR_MATERIAL );
    textured->setColourMaterial( GL_AMBIENT_AND_DIFFUSE );
    textured->setMaterial( GL_EMISSION, 0, 0, 0, 1 );
    textured->setMaterial( GL_SPECULAR, 0, 0, 0, 1 );

    // Set up the coloured state
    nontextured->enable( GL_LIGHTING );
    nontextured->setShadeModel( shade_model );
    nontextured->enable ( GL_CULL_FACE      ) ;
    nontextured->disable( GL_TEXTURE_2D );
    nontextured->disable( GL_BLEND );
    nontextured->disable( GL_ALPHA_TEST );
    nontextured->disable( GL_COLOR_MATERIAL );

    nontextured->setMaterial ( GL_AMBIENT, 
			       ambient[0], ambient[1], 
			       ambient[2], ambient[3] ) ;
    nontextured->setMaterial ( GL_DIFFUSE, 
			       diffuse[0], diffuse[1], 
			       diffuse[2], diffuse[3] ) ;
    nontextured->setMaterial ( GL_SPECULAR, 
			       specular[0], specular[1], 
			       specular[2], specular[3] ) ;
    nontextured->setMaterial ( GL_EMISSION, 
			       emission[0], emission[1], 
			       emission[2], emission[3] ) ;

    state->setStep( 0, textured );    // textured
    state->setStep( 1, nontextured ); // untextured

    // Choose the appropriate starting state.
    if ( texture_default ) {
	state->selectStep(0);
    } else {
	state->selectStep(1);
    }
}


void FGNewMat::set_ssg_state( ssgSimpleState *s )
{
    state = new ssgStateSelector(2);
    state->ref();

    textured = s;

    nontextured = new ssgSimpleState();
    nontextured->ref();

    // Set up the coloured state
    nontextured->enable( GL_LIGHTING );
    nontextured->setShadeModel( GL_FLAT );
    nontextured->enable ( GL_CULL_FACE      ) ;
    nontextured->disable( GL_TEXTURE_2D );
    nontextured->disable( GL_BLEND );
    nontextured->disable( GL_ALPHA_TEST );
    nontextured->disable( GL_COLOR_MATERIAL );

    /* cout << "ambient = " << ambient[0] << "," << ambient[1] 
       << "," << ambient[2] << endl; */
    nontextured->setMaterial ( GL_AMBIENT, 
			       ambient[0], ambient[1], 
			       ambient[2], ambient[3] ) ;
    nontextured->setMaterial ( GL_DIFFUSE, 
			       diffuse[0], diffuse[1], 
			       diffuse[2], diffuse[3] ) ;
    nontextured->setMaterial ( GL_SPECULAR, 
			       specular[0], specular[1], 
			       specular[2], specular[3] ) ;
    nontextured->setMaterial ( GL_EMISSION, 
			       emission[0], emission[1], 
			       emission[2], emission[3] ) ;

    state->setStep( 0, textured );    // textured
    state->setStep( 1, nontextured ); // untextured

    // Choose the appropriate starting state.
    state->selectStep(0);
}

// end of newmat.cxx