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.
37 # define exception c_exception
43 #include <Aircraft/aircraft.hxx>
44 #include <Debug/logstream.hxx>
45 #include <Include/fg_constants.h>
46 #include <Main/options.hxx>
47 #include <Main/views.hxx>
48 #include <Math/fg_geodesy.hxx>
49 #include <Math/interpolater.hxx>
50 #include <Math/mat3.h>
51 #include <Math/polar3d.hxx>
53 #include "fg_time.hxx"
58 fgLIGHT cur_light_params;
62 fgLIGHT::fgLIGHT( void ) {
66 // initialize lighting tables
67 void fgLIGHT::Init( void ) {
68 string path, ambient, diffuse, sky;
70 FG_LOG( FG_EVENT, FG_INFO,
71 "Initializing Lighting interpolation tables." );
73 // build the path name to the ambient lookup table
74 path = current_options.get_fg_root();
75 ambient = path + "/Lighting/ambient";
76 diffuse = path + "/Lighting/diffuse";
77 sky = path + "/Lighting/sky";
79 // initialize ambient table
80 ambient_tbl = new fgINTERPTABLE((char *)ambient.c_str());
82 // initialize diffuse table
83 diffuse_tbl = new fgINTERPTABLE((char *)diffuse.c_str());
85 // initialize sky table
86 sky_tbl = new fgINTERPTABLE((char *)sky.c_str());
90 // update lighting parameters based on current sun position
91 void fgLIGHT::Update( void ) {
95 // if the 4th field is 0.0, this specifies a direction ...
96 GLfloat white[4] = { 1.0, 1.0, 1.0, 1.0 };
98 GLfloat base_sky_color[4] = {0.60, 0.60, 0.90, 1.0};
100 GLfloat base_fog_color[4] = {0.90, 0.90, 1.00, 1.0};
101 double deg, ambient, diffuse, sky_brightness;
103 f = current_aircraft.fdm_state;
104 t = &cur_time_params;
107 FG_LOG( FG_EVENT, FG_INFO, "Updating light parameters." );
109 // calculate lighting parameters based on sun's relative angle to
112 deg = sun_angle * 180.0 / FG_PI;
113 FG_LOG( FG_EVENT, FG_INFO, " Sun angle = " << deg );
115 ambient = ambient_tbl->interpolate( deg );
116 diffuse = diffuse_tbl->interpolate( deg );
117 sky_brightness = sky_tbl->interpolate( deg );
119 FG_LOG( FG_EVENT, FG_INFO,
120 " ambient = " << ambient << " diffuse = " << diffuse
121 << " sky = " << sky_brightness );
123 // sky_brightness = 0.15; // used to force a dark sky (when testing)
125 // if ( ambient < 0.02 ) { ambient = 0.02; }
126 // if ( diffuse < 0.0 ) { diffuse = 0.0; }
127 // if ( sky_brightness < 0.1 ) { sky_brightness = 0.1; }
129 scene_ambient[0] = white[0] * ambient;
130 scene_ambient[1] = white[1] * ambient;
131 scene_ambient[2] = white[2] * ambient;
133 scene_diffuse[0] = white[0] * diffuse;
134 scene_diffuse[1] = white[1] * diffuse;
135 scene_diffuse[2] = white[2] * diffuse;
138 sky_color[0] = base_sky_color[0] * sky_brightness;
139 sky_color[1] = base_sky_color[1] * sky_brightness;
140 sky_color[2] = base_sky_color[2] * sky_brightness;
141 sky_color[3] = base_sky_color[3];
144 fog_color[0] = base_fog_color[0] * sky_brightness;
145 fog_color[1] = base_fog_color[1] * sky_brightness;
146 fog_color[2] = base_fog_color[2] * sky_brightness;
147 fog_color[3] = base_fog_color[3];
151 // calculate fog color adjusted for sunrise/sunset effects
152 void fgLIGHT::UpdateAdjFog( void ) {
155 double sun_angle_deg, rotation, param1[3], param2[3];
157 f = current_aircraft.fdm_state;
160 FG_LOG( FG_EVENT, FG_DEBUG, "Updating adjusted fog parameters." );
162 // set fog color (we'll try to match the sunset color in the
163 // direction we are looking
165 // first determine the difference between our view angle and local
166 // direction to the sun
167 rotation = -(sun_rotation + FG_PI) - (f->get_Psi() - v->view_offset) ;
168 while ( rotation < 0 ) {
171 while ( rotation > FG_2PI ) {
174 rotation *= RAD_TO_DEG;
175 // fgPrintf( FG_EVENT, FG_INFO,
176 // " View to sun difference in degrees = %.2f\n", rotation);
178 // next check if we are in a sunset/sunrise situation
179 sun_angle_deg = sun_angle * RAD_TO_DEG;
180 if ( (sun_angle_deg > 80.0) && (sun_angle_deg < 100.0) ) {
182 param1[0] = (10.0 - fabs(90.0 - sun_angle_deg)) / 20.0;
183 param1[1] = (10.0 - fabs(90.0 - sun_angle_deg)) / 40.0;
184 param2[2] = -(10.0 - fabs(90.0 - sun_angle)) / 30.0;
186 param1[0] = param1[1] = param1[2] = 0.0;
189 if ( rotation - 180.0 <= 0.0 ) {
190 param2[0] = param1[0] * (180.0 - rotation) / 180.0;
191 param2[1] = param1[1] * (180.0 - rotation) / 180.0;
192 param2[2] = param1[2] * (180.0 - rotation) / 180.0;
193 // printf("param1[0] = %.2f param2[0] = %.2f\n", param1[0], param2[0]);
195 param2[0] = param1[0] * (rotation - 180.0) / 180.0;
196 param2[1] = param1[1] * (rotation - 180.0) / 180.0;
197 param2[2] = param1[2] * (rotation - 180.0) / 180.0;
198 // printf("param1[0] = %.2f param2[0] = %.2f\n", param1[0], param2[0]);
201 adj_fog_color[0] = fog_color[0] + param2[0];
202 if ( adj_fog_color[0] > 1.0 ) { adj_fog_color[0] = 1.0; }
204 adj_fog_color[1] = fog_color[1] + param2[1];
205 if ( adj_fog_color[1] > 1.0 ) { adj_fog_color[1] = 1.0; }
207 adj_fog_color[2] = fog_color[2] + param2[2];
208 if ( adj_fog_color[2] > 1.0 ) { adj_fog_color[2] = 1.0; }
210 adj_fog_color[3] = fog_color[3];
215 fgLIGHT::~fgLIGHT( void ) {
220 // Revision 1.23 1998/12/05 15:54:30 curt
221 // Renamed class fgFLIGHT to class FGState as per request by JSB.
223 // Revision 1.22 1998/12/03 01:18:42 curt
224 // Converted fgFLIGHT to a class.
226 // Revision 1.21 1998/11/23 21:49:09 curt
227 // Borland portability tweaks.
229 // Revision 1.20 1998/11/06 21:18:27 curt
230 // Converted to new logstream debugging facility. This allows release
231 // builds with no messages at all (and no performance impact) by using
232 // the -DFG_NDEBUG flag.
234 // Revision 1.19 1998/10/20 18:41:53 curt
235 // Tweaked sunrise/sunset colors.
237 // Revision 1.18 1998/10/17 01:34:30 curt
240 // Revision 1.17 1998/08/29 13:11:33 curt
241 // Bernie Bright writes:
242 // I've created some new classes to enable pointers-to-functions and
243 // pointers-to-class-methods to be treated like objects. These objects
244 // can be registered with fgEVENT_MGR.
246 // File "Include/fg_callback.hxx" contains the callback class defns.
248 // Modified fgEVENT and fgEVENT_MGR to use the callback classes. Also
249 // some minor tweaks to STL usage.
251 // Added file "Include/fg_stl_config.h" to deal with STL portability
252 // issues. I've added an initial config for egcs (and probably gcc-2.8.x).
253 // I don't have access to Visual C++ so I've left that for someone else.
254 // This file is influenced by the stl_config.h file delivered with egcs.
256 // Added "Include/auto_ptr.hxx" which contains an implementation of the
257 // STL auto_ptr class which is not provided in all STL implementations
258 // and is needed to use the callback classes.
260 // Deleted fgLightUpdate() which was just a wrapper to call
261 // fgLIGHT::Update().
263 // Modified fg_init.cxx to register two method callbacks in place of the
264 // old wrapper functions.
266 // Revision 1.16 1998/08/27 17:02:11 curt
267 // Contributions from Bernie Bright <bbright@c031.aone.net.au>
268 // - use strings for fg_root and airport_id and added methods to return
270 // - inlined all access methods,
271 // - made the parsing functions private methods,
272 // - deleted some unused functions.
273 // - propogated some of these changes out a bit further.
275 // Revision 1.15 1998/08/25 20:53:33 curt
276 // Shuffled $FG_ROOT file layout.
278 // Revision 1.14 1998/08/06 12:47:22 curt
279 // Adjusted dusk/dawn lighting ...
281 // Revision 1.13 1998/07/24 21:42:26 curt
282 // Output message tweaks.
284 // Revision 1.12 1998/07/22 21:45:38 curt
285 // fg_time.cxx: Removed call to ctime() in a printf() which should be harmless
286 // but seems to be triggering a bug.
287 // light.cxx: Added code to adjust fog color based on sunrise/sunset effects
288 // and view orientation. This is an attempt to match the fog color to the
289 // sky color in the center of the screen. You see discrepancies at the
290 // edges, but what else can be done?
291 // sunpos.cxx: Caculate local direction to sun here. (what compass direction
292 // do we need to face to point directly at sun)
294 // Revision 1.11 1998/07/13 21:02:08 curt
295 // Wrote access functions for current fgOPTIONS.
297 // Revision 1.10 1998/07/08 14:48:38 curt
298 // polar3d.h renamed to polar3d.hxx
300 // Revision 1.9 1998/05/29 20:37:51 curt
301 // Renamed <Table>.table to be <Table> so we can add a .gz under DOS.
303 // Revision 1.8 1998/05/20 20:54:16 curt
304 // Converted fgLIGHT to a C++ class.
306 // Revision 1.7 1998/05/13 18:26:50 curt
307 // Root path info moved to fgOPTIONS.
309 // Revision 1.6 1998/05/11 18:18:51 curt
310 // Made fog color slightly bluish.
312 // Revision 1.5 1998/05/03 00:48:38 curt
313 // polar.h -> polar3d.h
315 // Revision 1.4 1998/04/28 01:22:18 curt
316 // Type-ified fgTIME and fgVIEW.
318 // Revision 1.3 1998/04/26 05:10:04 curt
319 // "struct fgLIGHT" -> "fgLIGHT" because fgLIGHT is typedef'd.
321 // Revision 1.2 1998/04/24 00:52:30 curt
322 // Wrapped "#include <config.h>" in "#ifdef HAVE_CONFIG_H"
324 // Separated out lighting calcs into their own file.
326 // Revision 1.1 1998/04/22 13:24:06 curt
327 // C++ - ifiing the code a bit.
328 // Starting to reorginize some of the lighting calcs to use a table lookup.