1 // light.hxx -- lighting routines
3 // Written by Curtis Olson, started April 1998.
5 // Copyright (C) 1998 Curtis L. Olson - curt@me.umn.edu
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
29 # error This library requires C++
44 // #include <Include/fg_types.h>
45 #include <Math/interpolater.hxx>
46 #include <Math/point3d.hxx>
49 // Define a structure containing the global lighting parameters
52 // Lighting look up tables (based on sun angle with local horizon)
53 fgINTERPTABLE *ambient_tbl;
54 fgINTERPTABLE *diffuse_tbl;
55 fgINTERPTABLE *sky_tbl;
59 ///////////////////////////////////////////////////////////
60 // position of the sun in various forms
62 // in geocentric coordinates
63 double sun_lon, sun_gc_lat;
65 // in cartesian coordiantes
68 // (in view coordinates)
71 // inverse (in view coordinates)
72 GLfloat sun_vec_inv[4];
74 // the angle between the sun and the local horizontal (in radians)
77 // the rotation around our vertical axis of the sun (relative to
78 // due south with positive numbers going in the counter clockwise
79 // direction.) This is the direction we'd need to face if we
80 // wanted to travel towards the sun.
83 ///////////////////////////////////////////////////////////
84 // Have the same for the moon. Useful for having some light at night
85 // and stuff. I (Durk) also want to use this for adding similar
86 // coloring effects to the moon as I did to the sun.
87 ///////////////////////////////////////////////////////////
88 // position of the moon in various forms
90 // in geocentric coordinates
91 double moon_lon, moon_gc_lat;
93 // in cartesian coordiantes
96 // (in view coordinates)
99 // inverse (in view coordinates)
100 GLfloat moon_vec_inv[4];
102 // the angle between the moon and the local horizontal (in radians)
105 // the rotation around our vertical axis of the moon (relative to
106 // due south with positive numbers going in the counter clockwise
107 // direction.) This is the direction we'd need to face if we
108 // wanted to travel towards the sun.
109 double moon_rotation;
111 ///////////////////////////////////////////////////////////
112 // Derived lighting values
115 GLfloat scene_ambient[3];
118 GLfloat scene_diffuse[3];
121 GLfloat fog_color[4];
123 // fog color adjusted for sunset effects
124 GLfloat adj_fog_color[4];
126 // clear screen color
127 GLfloat sky_color[4];
132 // initialize lighting tables
135 // update lighting parameters based on current sun position
138 // calculate fog color adjusted for sunrise/sunset effects
139 void UpdateAdjFog( void );
146 // Global shared light parameter structure
147 extern fgLIGHT cur_light_params;
154 // Revision 1.9 1999/03/22 02:08:17 curt
155 // Changes contributed by Durk Talsma:
157 // Here's a few changes I made to fg-0.58 this weekend. Included are the
158 // following features:
159 // - Sun and moon have a halo
160 // - The moon has a light vector, moon_angle, etc. etc. so that we can have
161 // some moonlight during the night.
162 // - Lot's of small changes tweakes, including some stuff Norman Vine sent
165 // Revision 1.8 1998/10/16 00:56:10 curt
166 // Converted to Point3D class.
168 // Revision 1.7 1998/08/29 13:11:33 curt
169 // Bernie Bright writes:
170 // I've created some new classes to enable pointers-to-functions and
171 // pointers-to-class-methods to be treated like objects. These objects
172 // can be registered with fgEVENT_MGR.
174 // File "Include/fg_callback.hxx" contains the callback class defns.
176 // Modified fgEVENT and fgEVENT_MGR to use the callback classes. Also
177 // some minor tweaks to STL usage.
179 // Added file "Include/fg_stl_config.h" to deal with STL portability
180 // issues. I've added an initial config for egcs (and probably gcc-2.8.x).
181 // I don't have access to Visual C++ so I've left that for someone else.
182 // This file is influenced by the stl_config.h file delivered with egcs.
184 // Added "Include/auto_ptr.hxx" which contains an implementation of the
185 // STL auto_ptr class which is not provided in all STL implementations
186 // and is needed to use the callback classes.
188 // Deleted fgLightUpdate() which was just a wrapper to call
189 // fgLIGHT::Update().
191 // Modified fg_init.cxx to register two method callbacks in place of the
192 // old wrapper functions.
194 // Revision 1.6 1998/07/22 21:45:39 curt
195 // fg_time.cxx: Removed call to ctime() in a printf() which should be harmless
196 // but seems to be triggering a bug.
197 // light.cxx: Added code to adjust fog color based on sunrise/sunset effects
198 // and view orientation. This is an attempt to match the fog color to the
199 // sky color in the center of the screen. You see discrepancies at the
200 // edges, but what else can be done?
201 // sunpos.cxx: Caculate local direction to sun here. (what compass direction
202 // do we need to face to point directly at sun)
204 // Revision 1.5 1998/07/08 14:48:39 curt
205 // polar3d.h renamed to polar3d.hxx
207 // Revision 1.4 1998/05/20 20:54:17 curt
208 // Converted fgLIGHT to a C++ class.
210 // Revision 1.3 1998/05/02 01:53:18 curt
211 // Fine tuning mktime() support because of varying behavior on different
214 // Revision 1.2 1998/04/24 00:52:31 curt
215 // Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
217 // Separated out lighting calcs into their own file.
219 // Revision 1.1 1998/04/22 13:24:06 curt
220 // C++ - ifiing the code a bit.
221 // Starting to reorginize some of the lighting calcs to use a table lookup.