2 // light.hxx -- lighting routines
4 // Written by Curtis Olson, started April 1998.
6 // Copyright (C) 1998 Curtis L. Olson - curt@me.umn.edu
8 // This program is free software; you can redistribute it and/or
9 // modify it under the terms of the GNU General Public License as
10 // published by the Free Software Foundation; either version 2 of the
11 // License, or (at your option) any later version.
13 // This program is distributed in the hope that it will be useful, but
14 // WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 // General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
38 #include <Aircraft/aircraft.hxx>
39 #include <Debug/logstream.hxx>
40 #include <Include/fg_constants.h>
41 #include <Main/options.hxx>
42 #include <Main/views.hxx>
43 #include <Math/fg_geodesy.hxx>
44 #include <Math/interpolater.hxx>
45 #include <Math/mat3.h>
46 #include <Math/polar3d.hxx>
48 #include "fg_time.hxx"
53 fgLIGHT cur_light_params;
57 fgLIGHT::fgLIGHT( void ) {
61 // initialize lighting tables
62 void fgLIGHT::Init( void ) {
63 string path, ambient, diffuse, sky;
65 FG_LOG( FG_EVENT, FG_INFO,
66 "Initializing Lighting interpolation tables." );
68 // build the path name to the ambient lookup table
69 path = current_options.get_fg_root();
70 ambient = path + "/Lighting/ambient";
71 diffuse = path + "/Lighting/diffuse";
72 sky = path + "/Lighting/sky";
74 // initialize ambient table
75 ambient_tbl = new fgINTERPTABLE((char *)ambient.c_str());
77 // initialize diffuse table
78 diffuse_tbl = new fgINTERPTABLE((char *)diffuse.c_str());
80 // initialize sky table
81 sky_tbl = new fgINTERPTABLE((char *)sky.c_str());
85 // update lighting parameters based on current sun position
86 void fgLIGHT::Update( void ) {
90 // if the 4th field is 0.0, this specifies a direction ...
91 GLfloat white[4] = { 1.0, 1.0, 1.0, 1.0 };
93 GLfloat base_sky_color[4] = {0.60, 0.60, 0.90, 1.0};
95 GLfloat base_fog_color[4] = {0.90, 0.90, 1.00, 1.0};
96 double deg, ambient, diffuse, sky_brightness;
98 f = current_aircraft.flight;
102 FG_LOG( FG_EVENT, FG_INFO, "Updating light parameters." );
104 // calculate lighting parameters based on sun's relative angle to
107 deg = sun_angle * 180.0 / FG_PI;
108 FG_LOG( FG_EVENT, FG_INFO, " Sun angle = " << deg );
110 ambient = ambient_tbl->interpolate( deg );
111 diffuse = diffuse_tbl->interpolate( deg );
112 sky_brightness = sky_tbl->interpolate( deg );
114 FG_LOG( FG_EVENT, FG_INFO,
115 " ambient = " << ambient << " diffuse = " << diffuse
116 << " sky = " << sky_brightness );
118 // sky_brightness = 0.15; // used to force a dark sky (when testing)
120 // if ( ambient < 0.02 ) { ambient = 0.02; }
121 // if ( diffuse < 0.0 ) { diffuse = 0.0; }
122 // if ( sky_brightness < 0.1 ) { sky_brightness = 0.1; }
124 scene_ambient[0] = white[0] * ambient;
125 scene_ambient[1] = white[1] * ambient;
126 scene_ambient[2] = white[2] * ambient;
128 scene_diffuse[0] = white[0] * diffuse;
129 scene_diffuse[1] = white[1] * diffuse;
130 scene_diffuse[2] = white[2] * diffuse;
133 sky_color[0] = base_sky_color[0] * sky_brightness;
134 sky_color[1] = base_sky_color[1] * sky_brightness;
135 sky_color[2] = base_sky_color[2] * sky_brightness;
136 sky_color[3] = base_sky_color[3];
139 fog_color[0] = base_fog_color[0] * sky_brightness;
140 fog_color[1] = base_fog_color[1] * sky_brightness;
141 fog_color[2] = base_fog_color[2] * sky_brightness;
142 fog_color[3] = base_fog_color[3];
146 // calculate fog color adjusted for sunrise/sunset effects
147 void fgLIGHT::UpdateAdjFog( void ) {
150 double sun_angle_deg, rotation, param1[3], param2[3];
152 f = current_aircraft.flight;
155 FG_LOG( FG_EVENT, FG_DEBUG, "Updating adjusted fog parameters." );
157 // set fog color (we'll try to match the sunset color in the
158 // direction we are looking
160 // first determine the difference between our view angle and local
161 // direction to the sun
162 rotation = -(sun_rotation + FG_PI) - (FG_Psi - v->view_offset) ;
163 while ( rotation < 0 ) {
166 while ( rotation > FG_2PI ) {
169 rotation *= RAD_TO_DEG;
170 // fgPrintf( FG_EVENT, FG_INFO,
171 // " View to sun difference in degrees = %.2f\n", rotation);
173 // next check if we are in a sunset/sunrise situation
174 sun_angle_deg = sun_angle * RAD_TO_DEG;
175 if ( (sun_angle_deg > 80.0) && (sun_angle_deg < 100.0) ) {
177 param1[0] = (10.0 - fabs(90.0 - sun_angle_deg)) / 20.0;
178 param1[1] = (10.0 - fabs(90.0 - sun_angle_deg)) / 40.0;
179 param2[2] = -(10.0 - fabs(90.0 - sun_angle)) / 30.0;
181 param1[0] = param1[1] = param1[2] = 0.0;
184 if ( rotation - 180.0 <= 0.0 ) {
185 param2[0] = param1[0] * (180.0 - rotation) / 180.0;
186 param2[1] = param1[1] * (180.0 - rotation) / 180.0;
187 param2[2] = param1[2] * (180.0 - rotation) / 180.0;
188 // printf("param1[0] = %.2f param2[0] = %.2f\n", param1[0], param2[0]);
190 param2[0] = param1[0] * (rotation - 180.0) / 180.0;
191 param2[1] = param1[1] * (rotation - 180.0) / 180.0;
192 param2[2] = param1[2] * (rotation - 180.0) / 180.0;
193 // printf("param1[0] = %.2f param2[0] = %.2f\n", param1[0], param2[0]);
196 adj_fog_color[0] = fog_color[0] + param2[0];
197 if ( adj_fog_color[0] > 1.0 ) { adj_fog_color[0] = 1.0; }
199 adj_fog_color[1] = fog_color[1] + param2[1];
200 if ( adj_fog_color[1] > 1.0 ) { adj_fog_color[1] = 1.0; }
202 adj_fog_color[2] = fog_color[2] + param2[2];
203 if ( adj_fog_color[2] > 1.0 ) { adj_fog_color[2] = 1.0; }
205 adj_fog_color[3] = fog_color[3];
210 fgLIGHT::~fgLIGHT( void ) {
215 // Revision 1.20 1998/11/06 21:18:27 curt
216 // Converted to new logstream debugging facility. This allows release
217 // builds with no messages at all (and no performance impact) by using
218 // the -DFG_NDEBUG flag.
220 // Revision 1.19 1998/10/20 18:41:53 curt
221 // Tweaked sunrise/sunset colors.
223 // Revision 1.18 1998/10/17 01:34:30 curt
226 // Revision 1.17 1998/08/29 13:11:33 curt
227 // Bernie Bright writes:
228 // I've created some new classes to enable pointers-to-functions and
229 // pointers-to-class-methods to be treated like objects. These objects
230 // can be registered with fgEVENT_MGR.
232 // File "Include/fg_callback.hxx" contains the callback class defns.
234 // Modified fgEVENT and fgEVENT_MGR to use the callback classes. Also
235 // some minor tweaks to STL usage.
237 // Added file "Include/fg_stl_config.h" to deal with STL portability
238 // issues. I've added an initial config for egcs (and probably gcc-2.8.x).
239 // I don't have access to Visual C++ so I've left that for someone else.
240 // This file is influenced by the stl_config.h file delivered with egcs.
242 // Added "Include/auto_ptr.hxx" which contains an implementation of the
243 // STL auto_ptr class which is not provided in all STL implementations
244 // and is needed to use the callback classes.
246 // Deleted fgLightUpdate() which was just a wrapper to call
247 // fgLIGHT::Update().
249 // Modified fg_init.cxx to register two method callbacks in place of the
250 // old wrapper functions.
252 // Revision 1.16 1998/08/27 17:02:11 curt
253 // Contributions from Bernie Bright <bbright@c031.aone.net.au>
254 // - use strings for fg_root and airport_id and added methods to return
256 // - inlined all access methods,
257 // - made the parsing functions private methods,
258 // - deleted some unused functions.
259 // - propogated some of these changes out a bit further.
261 // Revision 1.15 1998/08/25 20:53:33 curt
262 // Shuffled $FG_ROOT file layout.
264 // Revision 1.14 1998/08/06 12:47:22 curt
265 // Adjusted dusk/dawn lighting ...
267 // Revision 1.13 1998/07/24 21:42:26 curt
268 // Output message tweaks.
270 // Revision 1.12 1998/07/22 21:45:38 curt
271 // fg_time.cxx: Removed call to ctime() in a printf() which should be harmless
272 // but seems to be triggering a bug.
273 // light.cxx: Added code to adjust fog color based on sunrise/sunset effects
274 // and view orientation. This is an attempt to match the fog color to the
275 // sky color in the center of the screen. You see discrepancies at the
276 // edges, but what else can be done?
277 // sunpos.cxx: Caculate local direction to sun here. (what compass direction
278 // do we need to face to point directly at sun)
280 // Revision 1.11 1998/07/13 21:02:08 curt
281 // Wrote access functions for current fgOPTIONS.
283 // Revision 1.10 1998/07/08 14:48:38 curt
284 // polar3d.h renamed to polar3d.hxx
286 // Revision 1.9 1998/05/29 20:37:51 curt
287 // Renamed <Table>.table to be <Table> so we can add a .gz under DOS.
289 // Revision 1.8 1998/05/20 20:54:16 curt
290 // Converted fgLIGHT to a C++ class.
292 // Revision 1.7 1998/05/13 18:26:50 curt
293 // Root path info moved to fgOPTIONS.
295 // Revision 1.6 1998/05/11 18:18:51 curt
296 // Made fog color slightly bluish.
298 // Revision 1.5 1998/05/03 00:48:38 curt
299 // polar.h -> polar3d.h
301 // Revision 1.4 1998/04/28 01:22:18 curt
302 // Type-ified fgTIME and fgVIEW.
304 // Revision 1.3 1998/04/26 05:10:04 curt
305 // "struct fgLIGHT" -> "fgLIGHT" because fgLIGHT is typedef'd.
307 // Revision 1.2 1998/04/24 00:52:30 curt
308 // Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
310 // Separated out lighting calcs into their own file.
312 // Revision 1.1 1998/04/22 13:24:06 curt
313 // C++ - ifiing the code a bit.
314 // Starting to reorginize some of the lighting calcs to use a table lookup.