/**************************************************************************
 * scenery.hxx -- data structures and routines for managing scenery.
 *
 * Written by Curtis Olson, started May 1997.
 *
 * Copyright (C) 1997  Curtis L. Olson  - curt@infoplane.com
 *
 * 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 _SCENERY_HXX
#define _SCENERY_HXX


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


#include <Include/fg_types.h>


/* Define a structure containing global scenery parameters */
struct fgSCENERY {
    /* center of current scenery chunk */
    fgPoint3d center;

    /* next center of current scenery chunk */
    fgPoint3d next_center;

    /* angle of sun relative to current local horizontal */
    double sun_angle;

    // elevation of terrain at our current lat/lon (based on the
    // actual drawn polygons)
    double cur_elev;
};

extern struct fgSCENERY scenery;


/* Initialize the Scenery Management system */
int fgSceneryInit( void );


/* Tell the scenery manager where we are so it can load the proper data, and
 * build the proper structures. */
void fgSceneryUpdate(double lon, double lat, double elev);


/* Render out the current scene */
void fgSceneryRender( void );


#endif /* _SCENERY_HXX */


/* $Log$
/* Revision 1.4  1998/07/12 03:18:28  curt
/* Added ground collision detection.  This involved:
/* - saving the entire vertex list for each tile with the tile records.
/* - saving the face list for each fragment with the fragment records.
/* - code to intersect the current vertical line with the proper face in
/*   an efficient manner as possible.
/* Fixed a bug where the tiles weren't being shifted to "near" (0,0,0)
/*
 * Revision 1.3  1998/07/08 14:47:22  curt
 * Fix GL_MODULATE vs. GL_DECAL problem introduced by splash screen.
 * polare3d.h renamed to polar3d.hxx
 * fg{Cartesian,Polar}Point3d consolodated.
 * Added some initial support for calculating local current ground elevation.
 *
 * Revision 1.2  1998/05/02 01:52:16  curt
 * Playing around with texture coordinates.
 *
 * Revision 1.1  1998/04/30 12:35:31  curt
 * Added a command line rendering option specify smooth/flat shading.
 *
 * Revision 1.21  1998/04/25 22:06:31  curt
 * Edited cvs log messages in source files ... bad bad bad!
 *
 * Revision 1.20  1998/04/22 13:22:45  curt
 * C++ - ifing the code a bit.
 *
 * Revision 1.19  1998/04/21 17:02:43  curt
 * Prepairing for C++ integration.
 *
 * Revision 1.18  1998/03/14 00:30:51  curt
 * Beginning initial terrain texturing experiments.
 *
 * Revision 1.17  1998/02/20 00:16:24  curt
 * Thursday's tweaks.
 *
 * Revision 1.16  1998/01/27 00:48:03  curt
 * Incorporated Paul Bleisch's <pbleisch@acm.org> new debug message
 * system and commandline/config file processing code.
 *
 * Revision 1.15  1998/01/22 02:59:41  curt
 * Changed #ifdef FILE_H to #ifdef _FILE_H
 *
 * Revision 1.14  1998/01/19 19:27:17  curt
 * Merged in make system changes from Bob Kuehne <rpk@sgi.com>
 * This should simplify things tremendously.
 *
 * Revision 1.13  1998/01/19 18:40:38  curt
 * Tons of little changes to clean up the code and to remove fatal errors
 * when building with the c++ compiler.
 *
 * Revision 1.12  1997/12/15 23:55:03  curt
 * Add xgl wrappers for debugging.
 * Generate terrain normals on the fly.
 *
 * Revision 1.11  1997/12/10 22:37:52  curt
 * Prepended "fg" on the name of all global structures that didn't have it yet.
 * i.e. "struct WEATHER {}" became "struct fgWEATHER {}"
 *
 * Revision 1.10  1997/09/04 02:17:37  curt
 * Shufflin' stuff.
 *
 * Revision 1.9  1997/08/27 03:30:33  curt
 * Changed naming scheme of basic shared structures.
 *
 * Revision 1.8  1997/08/06 00:24:30  curt
 * Working on correct real time sun lighting.
 *
 * Revision 1.7  1997/07/23 21:52:27  curt
 * Put comments around the text after an #endif for increased portability.
 *
 * Revision 1.6  1997/07/11 01:30:03  curt
 * More tweaking of terrian floor.
 *
 * Revision 1.5  1997/06/26 22:14:57  curt
 * Beginning work on a scenery management system.
 *
 * Revision 1.4  1997/06/21 17:57:21  curt
 * directory shuffling ...
 *
 * Revision 1.2  1997/05/23 15:40:43  curt
 * Added GNU copyright headers.
 *
 * Revision 1.1  1997/05/16 16:07:07  curt
 * Initial revision.
 *
 */