// fragment.hxx -- routines to handle "atomic" display objects
//
// Written by Curtis Olson, started August 1998.
//
// Copyright (C) 1998  Curtis L. Olson  - curt@me.umn.edu
//
// 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.
//
// $Id$
// (Log is kept at end of this file)


#ifndef _FRAGMENT_HXX
#define _FRAGMENT_HXX


#ifndef __cplusplus                                                          
# error This library requires C++
#endif                                   

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

#ifdef HAVE_WINDOWS_H
#  include <windows.h>
#endif

#include <GL/glut.h>
#include <XGL/xgl.h>

#include <Include/compiler.h>

#include <vector>

#include <Include/fg_constants.h>
#include <Math/mat3.h>
#include <Math/point3d.hxx>

FG_USING_STD(vector);


struct fgFACE {
    int n1, n2, n3;

    fgFACE( int a = 0, int b =0, int c =0 )
	: n1(a), n2(b), n3(c) {}

    fgFACE( const fgFACE & image )
	: n1(image.n1), n2(image.n2), n3(image.n3) {}

    fgFACE& operator= ( const fgFACE & image ) {
	n1 = image.n1; n2 = image.n2; n3 = image.n3; return *this;
    }

    ~fgFACE() {}
};

inline bool
operator== ( const fgFACE& lhs, const fgFACE& rhs )
{
    return (lhs.n1 == rhs.n1) && (lhs.n2 == rhs.n2) && (lhs.n3 == rhs.n3);
}

// Forward declarations
class fgTILE;
class fgMATERIAL;

// Object fragment data class
class fgFRAGMENT {

private:

public:
    // culling data for this object fragment (fine grain culling)
    Point3D center;
    double bounding_radius;

    // variable offset data for this object fragment for this frame
    // fgCartesianPoint3d tile_offset;

    // saved transformation matrix for this fragment (used by renderer)
    // GLfloat matrix[16];
    
    // tile_ptr & material_ptr are set so that when we traverse the
    // list of fragments we can quickly reference back the tile or
    // material property this fragment is assigned to.

    // material property pointer
    fgMATERIAL *material_ptr;

    // tile pointer
    fgTILE *tile_ptr;

    // OpenGL display list for fragment data
    GLint display_list;

    // face list (this indexes into the master tile vertex list)
    typedef vector < fgFACE > container;
    typedef container::iterator iterator;
    typedef container::const_iterator const_iterator;

    container faces;

public:

    // number of faces in this fragment
    int num_faces() {
	return faces.size();
    }

    // Add a face to the face list
    void add_face(int n1, int n2, int n3) {
	faces.push_back( fgFACE(n1,n2,n3) );
    }

    // test if line intesects with this fragment.  p0 and p1 are the
    // two line end points of the line.  If side_flag is true, check
    // to see that end points are on opposite sides of face.  Returns
    // 1 if it intersection found, 0 otherwise.  If it intesects,
    // result is the point of intersection
    int intersect( const Point3D& end0,
		   const Point3D& end1,
		   int side_flag,
		   Point3D& result) const;

    // Constructors
    fgFRAGMENT () { /*faces.reserve(512);*/}
    fgFRAGMENT ( const fgFRAGMENT &image );

    // Destructor
    ~fgFRAGMENT() { faces.erase( faces.begin(), faces.end() ); }

    // operators
    fgFRAGMENT & operator = ( const fgFRAGMENT & rhs );

    bool operator <  ( const fgFRAGMENT & rhs ) const {
	// This is completely arbitrary. It satisfies RW's STL implementation
	return bounding_radius < rhs.bounding_radius;
    }

    void init() {
	faces.erase( faces.begin(), faces.end() );
    }

    int deleteDisplayList() {
	xglDeleteLists( display_list, 1 ); return 0;
    }

    friend bool operator== ( const fgFRAGMENT & lhs, const fgFRAGMENT & rhs );
};

inline bool
operator == ( const fgFRAGMENT & lhs, const fgFRAGMENT & rhs ) {
    return lhs.center == rhs.center;
}


#endif // _FRAGMENT_HXX 


// $Log$
// Revision 1.1  1999/04/05 21:32:49  curt
// Initial revision
//
// Revision 1.12  1999/04/05 02:14:21  curt
// Moved max node per tile definition to fg_constants.h
//
// Revision 1.11  1999/03/25 19:02:53  curt
// Removed an unneeded include.
//
// Revision 1.10  1999/03/15 17:59:12  curt
// MSVC++ portability tweaks contributed by Bernie Bright.
//   Un-nested struct fgFace.
//   Made fgFragment::deleteDisplayList() a non-const member.
//
// Revision 1.9  1999/03/02 01:03:23  curt
// Tweaks for building with native SGI compilers.
//
// Revision 1.8  1999/02/26 22:09:57  curt
// Added initial support for native SGI compilers.
//
// Revision 1.7  1998/11/02 18:29:00  curt
// Portability changes for the Borland compiler.
//
// Revision 1.6  1998/10/16 00:54:38  curt
// Converted to Point3D class.
//
// Revision 1.5  1998/09/15 01:35:04  curt
// cleaned up my fragment.num_faces hack :-) to use the STL (no need in
// duplicating work.)
// Tweaked fgTileMgrRender() do not calc tile matrix unless necessary.
// removed some unneeded stuff from fgTileMgrCurElev()
//
// Revision 1.4  1998/09/10 19:07:09  curt
// /Simulator/Objects/fragment.hxx
//   Nested fgFACE inside fgFRAGMENT since its not used anywhere else.
//
// ./Simulator/Objects/material.cxx
// ./Simulator/Objects/material.hxx
//   Made fgMATERIAL and fgMATERIAL_MGR bona fide classes with private
//   data members - that should keep the rabble happy :)
//
// ./Simulator/Scenery/tilemgr.cxx
//   In viewable() delay evaluation of eye[0] and eye[1] in until they're
//   actually needed.
//   Change to fgTileMgrRender() to call fgMATERIAL_MGR::render_fragments()
//   method.
//
// ./Include/fg_stl_config.h
// ./Include/auto_ptr.hxx
//   Added support for g++ 2.7.
//   Further changes to other files are forthcoming.
//
// Brief summary of changes required for g++ 2.7.
//   operator->() not supported by iterators: use (*i).x instead of i->x
//   default template arguments not supported,
//   <functional> doesn't have mem_fun_ref() needed by callbacks.
//   some std include files have different names.
//   template member functions not supported.
//
// Revision 1.3  1998/09/08 21:40:44  curt
// Updates from Bernie Bright.
//
// Revision 1.2  1998/09/01 19:03:08  curt
// Changes contributed by Bernie Bright <bbright@c031.aone.net.au>
//  - The new classes in libmisc.tgz define a stream interface into zlib.
//    I've put these in a new directory, Lib/Misc.  Feel free to rename it
//    to something more appropriate.  However you'll have to change the
//    include directives in all the other files.  Additionally you'll have
//    add the library to Lib/Makefile.am and Simulator/Main/Makefile.am.
//
//    The StopWatch class in Lib/Misc requires a HAVE_GETRUSAGE autoconf
//    test so I've included the required changes in config.tgz.
//
//    There are a fair few changes to Simulator/Objects as I've moved
//    things around.  Loading tiles is quicker but thats not where the delay
//    is.  Tile loading takes a few tenths of a second per file on a P200
//    but it seems to be the post-processing that leads to a noticeable
//    blip in framerate.  I suppose its time to start profiling to see where
//    the delays are.
//
//    I've included a brief description of each archives contents.
//
// Lib/Misc/
//   zfstream.cxx
//   zfstream.hxx
//     C++ stream interface into zlib.
//     Taken from zlib-1.1.3/contrib/iostream/.
//     Minor mods for STL compatibility.
//     There's no copyright associated with these so I assume they're
//     covered by zlib's.
//
//   fgstream.cxx
//   fgstream.hxx
//     FlightGear input stream using gz_ifstream.  Tries to open the
//     given filename.  If that fails then filename is examined and a
//     ".gz" suffix is removed or appended and that file is opened.
//
//   stopwatch.hxx
//     A simple timer for benchmarking.  Not used in production code.
//     Taken from the Blitz++ project.  Covered by GPL.
//
//   strutils.cxx
//   strutils.hxx
//     Some simple string manipulation routines.
//
// Simulator/Airports/
//   Load airports database using fgstream.
//   Changed fgAIRPORTS to use set<> instead of map<>.
//   Added bool fgAIRPORTS::search() as a neater way doing the lookup.
//   Returns true if found.
//
// Simulator/Astro/
//   Modified fgStarsInit() to load stars database using fgstream.
//
// Simulator/Objects/
//   Modified fgObjLoad() to use fgstream.
//   Modified fgMATERIAL_MGR::load_lib() to use fgstream.
//   Many changes to fgMATERIAL.
//   Some changes to fgFRAGMENT but I forget what!
//
// Revision 1.1  1998/08/25 16:51:23  curt
// Moved from ../Scenery
//
//