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flightgear/Time/light.hxx
1998-05-20 20:54:16 +00:00

133 lines
3.2 KiB
C++

// light.hxx -- lighting routines
//
// Written by Curtis Olson, started April 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.
//
// $Id$
#ifndef _LIGHT_HXX
#define _LIGHT_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/fg_types.h>
#include <Math/interpolater.hxx>
// Define a structure containing the global lighting parameters
class fgLIGHT {
// Lighting look up tables (based on sun angle with local horizon)
fgINTERPTABLE *ambient_tbl;
fgINTERPTABLE *diffuse_tbl;
fgINTERPTABLE *sky_tbl;
public:
///////////////////////////////////////////////////////////
// position of the sun in various forms
// in geocentric coordinates
double sun_lon, sun_gc_lat;
// in cartesian coordiantes
fgCartesianPoint3d fg_sunpos;
// (in view coordinates)
GLfloat sun_vec[4];
// inverse (in view coordinates)
GLfloat sun_vec_inv[4];
// the angle between the sun and the local horizontal
double sun_angle;
///////////////////////////////////////////////////////////
// Derived lighting values
// ambient component
GLfloat scene_ambient[3];
// diffuse component
GLfloat scene_diffuse[3];
// fog color
GLfloat fog_color[4];
// clear screen color
GLfloat sky_color[4];
// Constructor
fgLIGHT( void );
// initialize lighting tables
void Init( void );
// update lighting parameters based on current sun position
void Update( void);
// Destructor
~fgLIGHT( void );
};
// Global shared light parameter structure
extern fgLIGHT cur_light_params;
// wrapper function for updating light parameters via the event scheduler
void fgLightUpdate ( void );
#endif // _LIGHT_HXX
// $Log$
// Revision 1.4 1998/05/20 20:54:17 curt
// Converted fgLIGHT to a C++ class.
//
// Revision 1.3 1998/05/02 01:53:18 curt
// Fine tuning mktime() support because of varying behavior on different
// platforms.
//
// Revision 1.2 1998/04/24 00:52:31 curt
// Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
// Fog color fixes.
// Separated out lighting calcs into their own file.
//
// Revision 1.1 1998/04/22 13:24:06 curt
// C++ - ifiing the code a bit.
// Starting to reorginize some of the lighting calcs to use a table lookup.
//
//