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/structure/subsystem_mgr.hxx>
40 #include <simgear/math/interpolater.hxx>
43 // Define a structure containing the global lighting parameters
44 class FGLight : public SGSubsystem
50 * Lighting look up tables (based on sun angle with local horizon)
52 SGInterpTable *_ambient_tbl, *_diffuse_tbl, *_specular_tbl;
53 SGInterpTable *_sky_tbl;
56 * position of the sun and moon in various forms
59 // in geocentric coordinates
60 double _sun_lon, _sun_lat;
61 double _moon_lon, _moon_gc_lat;
63 // (in view coordinates)
64 SGVec4f _sun_vec, _moon_vec;
66 // inverse (in view coordinates)
67 SGVec4f _sun_vec_inv, _moon_vec_inv;
69 // the angle between the celestial object and the local horizontal
71 double _sun_angle, _moon_angle;
72 double _prev_sun_angle;
74 // the rotation around our vertical axis of the sun (relative to
75 // due south with positive numbers going in the counter clockwise
76 // direction.) This is the direction we'd need to face if we
77 // wanted to travel towards celestial object.
78 double _sun_rotation, _moon_rotation;
81 * Derived lighting values
84 // ambient, diffuse and specular component
85 SGVec4f _scene_ambient;
86 SGVec4f _scene_diffuse;
87 SGVec4f _scene_specular;
89 // clear sky, fog and cloud color
94 // clear sky and fog color adjusted for sunset effects
95 SGVec4f _adj_fog_color;
96 SGVec4f _adj_sky_color;
100 void update_sky_color ();
101 void update_adj_fog_color ();
108 virtual void init ();
109 virtual void reinit ();
110 virtual void bind ();
111 virtual void unbind ();
112 virtual void update ( double dt );
115 // Color related functions
117 inline const SGVec4f& scene_ambient () const { return _scene_ambient; }
118 inline const SGVec4f& scene_diffuse () const { return _scene_diffuse; }
119 inline const SGVec4f& scene_specular () const { return _scene_specular; }
121 inline const SGVec4f& sky_color () const { return _sky_color; }
122 inline const SGVec4f& cloud_color () const { return _cloud_color; }
123 inline const SGVec4f& adj_fog_color () const { return _adj_fog_color; }
124 inline const SGVec4f& adj_sky_color () const { return _adj_sky_color; }
127 // Sun related functions
129 inline double get_sun_angle () const { return _sun_angle; }
130 inline void set_sun_angle (double a) { _sun_angle = a; }
132 inline double get_sun_rotation () const { return _sun_rotation; }
133 inline void set_sun_rotation (double r) { _sun_rotation = r; }
135 inline double get_sun_lon () const { return _sun_lon; }
136 inline void set_sun_lon (double l) { _sun_lon = l; }
138 inline double get_sun_lat () const { return _sun_lat; }
139 inline void set_sun_lat (double l) { _sun_lat = l; }
141 inline SGVec4f& sun_vec () { return _sun_vec; }
142 inline SGVec4f& sun_vec_inv () { return _sun_vec_inv; }
145 // Moon related functions
147 inline double get_moon_angle () const { return _moon_angle; }
148 inline void set_moon_angle (double a) { _moon_angle = a; }
150 inline double get_moon_rotation () const { return _moon_rotation; }
151 inline void set_moon_rotation (double r) { _moon_rotation = r; }
153 inline double get_moon_lon () const { return _moon_lon; }
154 inline void set_moon_lon (double l) { _moon_lon = l; }
156 inline double get_moon_gc_lat () const { return _moon_gc_lat; }
157 inline void set_moon_gc_lat (double l) { _moon_gc_lat = l; }
159 inline const SGVec4f& moon_vec () const { return _moon_vec; }
160 inline const SGVec4f& moon_vec_inv () const { return _moon_vec_inv; }