1 // light.hxx -- lighting routines
3 // Written by Curtis Olson, started April 1998.
5 // Copyright (C) 1998 Curtis L. Olson - http://www.flightgear.org/~curt
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
29 # error This library requires C++
37 #include <simgear/compiler.h>
39 #include <simgear/props/props.hxx>
40 #include <simgear/structure/subsystem_mgr.hxx>
41 #include <simgear/math/interpolater.hxx>
44 // Define a structure containing the global lighting parameters
45 class FGLight : public SGSubsystem
51 * Lighting look up tables (based on sun angle with local horizon)
53 SGInterpTable *_ambient_tbl, *_diffuse_tbl, *_specular_tbl;
54 SGInterpTable *_sky_tbl;
57 * position of the sun and moon in various forms
60 // in geocentric coordinates
61 double _sun_lon, _sun_lat;
62 double _moon_lon, _moon_gc_lat;
64 // (in view coordinates)
65 SGVec4f _sun_vec, _moon_vec;
67 // inverse (in view coordinates)
68 SGVec4f _sun_vec_inv, _moon_vec_inv;
70 // the angle between the celestial object and the local horizontal
72 double _sun_angle, _moon_angle;
73 double _prev_sun_angle;
75 // the rotation around our vertical axis of the sun (relative to
76 // due south with positive numbers going in the counter clockwise
77 // direction.) This is the direction we'd need to face if we
78 // wanted to travel towards celestial object.
79 double _sun_rotation, _moon_rotation;
82 * Derived lighting values
85 // ambient, diffuse and specular component
86 SGVec4f _scene_ambient;
87 SGVec4f _scene_diffuse;
88 SGVec4f _scene_specular;
89 SGVec4f _scene_chrome;
91 // clear sky, fog and cloud color
96 // clear sky and fog color adjusted for sunset effects
97 SGVec4f _adj_fog_color;
98 SGVec4f _adj_sky_color;
100 // input parameters affected by the weather system
107 void update_sky_color ();
108 void update_adj_fog_color ();
112 // properties for chrome light; not a tie because I want to fire
113 // property listeners when the values change.
114 SGPropertyNode_ptr _chromeProps[4];
120 virtual void init ();
121 virtual void reinit ();
122 virtual void bind ();
123 virtual void unbind ();
124 virtual void update ( double dt );
127 // Color related functions
129 inline const SGVec4f& scene_ambient () const { return _scene_ambient; }
130 inline const SGVec4f& scene_diffuse () const { return _scene_diffuse; }
131 inline const SGVec4f& scene_specular () const { return _scene_specular; }
132 inline const SGVec4f& scene_chrome () const { return _scene_chrome; }
134 inline const SGVec4f& sky_color () const { return _sky_color; }
135 inline const SGVec4f& cloud_color () const { return _cloud_color; }
136 inline const SGVec4f& adj_fog_color () const { return _adj_fog_color; }
137 inline const SGVec4f& adj_sky_color () const { return _adj_sky_color; }
139 // Sun related functions
141 inline double get_sun_angle () const { return _sun_angle; }
142 inline void set_sun_angle (double a) { _sun_angle = a; }
144 inline double get_sun_rotation () const { return _sun_rotation; }
145 inline void set_sun_rotation (double r) { _sun_rotation = r; }
147 inline double get_sun_lon () const { return _sun_lon; }
148 inline void set_sun_lon (double l) { _sun_lon = l; }
150 inline double get_sun_lat () const { return _sun_lat; }
151 inline void set_sun_lat (double l) { _sun_lat = l; }
153 inline SGVec4f& sun_vec () { return _sun_vec; }
154 inline SGVec4f& sun_vec_inv () { return _sun_vec_inv; }
157 // Moon related functions
159 inline double get_moon_angle () const { return _moon_angle; }
160 inline void set_moon_angle (double a) { _moon_angle = a; }
162 inline double get_moon_rotation () const { return _moon_rotation; }
163 inline void set_moon_rotation (double r) { _moon_rotation = r; }
165 inline double get_moon_lon () const { return _moon_lon; }
166 inline void set_moon_lon (double l) { _moon_lon = l; }
168 inline double get_moon_gc_lat () const { return _moon_gc_lat; }
169 inline void set_moon_gc_lat (double l) { _moon_gc_lat = l; }
171 inline const SGVec4f& moon_vec () const { return _moon_vec; }
172 inline const SGVec4f& moon_vec_inv () const { return _moon_vec_inv; }