2 // light.cxx -- lighting routines
4 // Written by Curtis Olson, started April 1998.
6 // Copyright (C) 1998 Curtis L. Olson - http://www.flightgear.org/~curt
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
29 #include <simgear/compiler.h>
33 #include <simgear/constants.h>
34 #include <simgear/debug/logstream.hxx>
35 #include <simgear/math/interpolater.hxx>
36 #include <simgear/misc/sg_path.hxx>
37 #include <simgear/scene/sky/sky.hxx>
38 #include <simgear/screen/colors.hxx>
39 #include <simgear/timing/sg_time.hxx>
40 #include <simgear/structure/event_mgr.hxx>
42 #include <Main/main.hxx>
43 #include <Main/globals.hxx>
44 #include <Main/fg_props.hxx>
45 #include <Main/renderer.hxx>
46 #include <Main/viewer.hxx>
49 #include "sunsolver.hxx"
53 : _ambient_tbl( NULL ),
55 _specular_tbl( NULL ),
62 _moon_vec(0, 0, 0, 0),
63 _sun_vec_inv(0, 0, 0, 0),
64 _moon_vec_inv(0, 0, 0, 0),
70 _scene_ambient(0, 0, 0, 0),
71 _scene_diffuse(0, 0, 0, 0),
72 _scene_specular(0, 0, 0, 0),
73 _scene_chrome(0, 0, 0, 0),
74 _sun_color(1, 1, 1, 0),
75 _sky_color(0, 0, 0, 0),
76 _fog_color(0, 0, 0, 0),
77 _cloud_color(0, 0, 0, 0),
78 _adj_fog_color(0, 0, 0, 0),
79 _adj_sky_color(0, 0, 0, 0),
97 // initialize lighting tables
98 void FGLight::init () {
99 SG_LOG( SG_EVENT, SG_INFO,
100 "Initializing Lighting interpolation tables." );
102 // build the path names of the lookup tables
103 SGPath path( globals->get_fg_root() );
105 // initialize ambient, diffuse and specular tables
106 SGPath ambient_path = path;
107 ambient_path.append( "Lighting/ambient" );
108 _ambient_tbl = new SGInterpTable( ambient_path.str() );
110 SGPath diffuse_path = path;
111 diffuse_path.append( "Lighting/diffuse" );
112 _diffuse_tbl = new SGInterpTable( diffuse_path.str() );
114 SGPath specular_path = path;
115 specular_path.append( "Lighting/specular" );
116 _specular_tbl = new SGInterpTable( specular_path.str() );
118 // initialize sky table
119 SGPath sky_path = path;
120 sky_path.append( "Lighting/sky" );
121 _sky_tbl = new SGInterpTable( sky_path.str() );
123 globals->get_event_mgr()->addTask("updateSunPos", this,
124 &FGLight::updateSunPos, 0.5 );
128 void FGLight::reinit () {
129 _prev_sun_angle = -9999.0;
134 delete _specular_tbl;
141 update_adj_fog_color();
144 void FGLight::bind () {
145 SGPropertyNode *prop = globals->get_props();
148 prop->tie("/rendering/scene/saturation",SGRawValuePointer<float>(&_saturation));
149 prop->tie("/rendering/scene/scattering",SGRawValuePointer<float>(&_scattering));
150 prop->tie("/rendering/scene/overcast",SGRawValuePointer<float>(&_overcast));
152 _sunAngleRad = prop->getNode("/sim/time/sun-angle-rad", true);
153 _sunAngleRad->setDoubleValue(_sun_angle);
156 prop->tie("/rendering/scene/ambient/red",SGRawValuePointer<float>(&_scene_ambient[0]));
157 prop->tie("/rendering/scene/ambient/green",SGRawValuePointer<float>(&_scene_ambient[1]));
158 prop->tie("/rendering/scene/ambient/blue",SGRawValuePointer<float>(&_scene_ambient[2]));
159 prop->tie("/rendering/scene/diffuse/red",SGRawValuePointer<float>(&_scene_diffuse[0]));
160 prop->tie("/rendering/scene/diffuse/green",SGRawValuePointer<float>(&_scene_diffuse[1]));
161 prop->tie("/rendering/scene/diffuse/blue",SGRawValuePointer<float>(&_scene_diffuse[2]));
162 prop->tie("/rendering/scene/specular/red",SGRawValuePointer<float>(&_scene_specular[0]));
163 prop->tie("/rendering/scene/specular/green",SGRawValuePointer<float>(&_scene_specular[1]));
164 prop->tie("/rendering/scene/specular/blue",SGRawValuePointer<float>(&_scene_specular[2]));
165 prop->tie("/rendering/dome/sun/red",SGRawValuePointer<float>(&_sun_color[0]));
166 prop->tie("/rendering/dome/sun/green",SGRawValuePointer<float>(&_sun_color[1]));
167 prop->tie("/rendering/dome/sun/blue",SGRawValuePointer<float>(&_sun_color[2]));
168 prop->tie("/rendering/dome/sky/red",SGRawValuePointer<float>(&_sky_color[0]));
169 prop->tie("/rendering/dome/sky/green",SGRawValuePointer<float>(&_sky_color[1]));
170 prop->tie("/rendering/dome/sky/blue",SGRawValuePointer<float>(&_sky_color[2]));
171 prop->tie("/rendering/dome/cloud/red",SGRawValuePointer<float>(&_cloud_color[0]));
172 prop->tie("/rendering/dome/cloud/green",SGRawValuePointer<float>(&_cloud_color[1]));
173 prop->tie("/rendering/dome/cloud/blue",SGRawValuePointer<float>(&_cloud_color[2]));
174 prop->tie("/rendering/dome/fog/red",SGRawValuePointer<float>(&_fog_color[0]));
175 prop->tie("/rendering/dome/fog/green",SGRawValuePointer<float>(&_fog_color[1]));
176 prop->tie("/rendering/dome/fog/blue",SGRawValuePointer<float>(&_fog_color[2]));
177 // Properties used directly by effects
178 _chromeProps[0] = prop->getNode("/rendering/scene/chrome-light/red", true);
179 _chromeProps[1] = prop->getNode("/rendering/scene/chrome-light/green",
181 _chromeProps[2] = prop->getNode("/rendering/scene/chrome-light/blue", true);
182 _chromeProps[3] = prop->getNode("/rendering/scene/chrome-light/alpha",
184 for (int i = 0; i < 4; ++i)
185 _chromeProps[i]->setValue(0.0);
188 void FGLight::unbind () {
189 SGPropertyNode *prop = globals->get_props();
190 prop->untie("/rendering/scene/saturation");
191 prop->untie("/rendering/scene/scattering");
192 prop->untie("/rendering/scene/overcast");
193 prop->untie("/rendering/scene/ambient/red");
194 prop->untie("/rendering/scene/ambient/green");
195 prop->untie("/rendering/scene/ambient/blue");
196 prop->untie("/rendering/scene/diffuse/red");
197 prop->untie("/rendering/scene/diffuse/green");
198 prop->untie("/rendering/scene/diffuse/blue");
199 prop->untie("/rendering/scene/specular/red");
200 prop->untie("/rendering/scene/specular/green");
201 prop->untie("/rendering/scene/specular/blue");
202 prop->untie("/rendering/dome/sun/red");
203 prop->untie("/rendering/dome/sun/green");
204 prop->untie("/rendering/dome/sun/blue");
205 prop->untie("/rendering/dome/sky/red");
206 prop->untie("/rendering/dome/sky/green");
207 prop->untie("/rendering/dome/sky/blue");
208 prop->untie("/rendering/dome/cloud/red");
209 prop->untie("/rendering/dome/cloud/green");
210 prop->untie("/rendering/dome/cloud/blue");
211 prop->untie("/rendering/dome/fog/red");
212 prop->untie("/rendering/dome/fog/green");
213 prop->untie("/rendering/dome/fog/blue");
217 // update lighting parameters based on current sun position
218 void FGLight::update( double dt )
220 update_adj_fog_color();
222 if (_prev_sun_angle != _sun_angle) {
223 _prev_sun_angle = _sun_angle;
228 void FGLight::update_sky_color () {
229 const SGVec4f base_sky_color( 0.31, 0.43, 0.69, 1.0 );
230 const SGVec4f base_fog_color( 0.63, 0.72, 0.88, 1.0 );
232 SG_LOG( SG_EVENT, SG_DEBUG, "Updating light parameters." );
234 // calculate lighting parameters based on sun's relative angle to
236 static SGConstPropertyNode_ptr humidity = fgGetNode("/environment/relative-humidity");
237 float av = humidity->getFloatValue() * 45;
238 float visibility_log = log(av)/11.0;
239 float visibility_inv = (45000.0 - av)/45000.0;
241 float deg = _sun_angle * SGD_RADIANS_TO_DEGREES;
242 SG_LOG( SG_EVENT, SG_DEBUG, " Sun angle = " << deg );
244 if (_saturation < 0.0) _saturation = 0.0;
245 else if (_saturation > 1.0) _saturation = 1.0;
246 if (_scattering < 0.0) _scattering = 0.0;
247 else if (_scattering > 1.0) _scattering = 1.0;
248 if (_overcast < 0.0) _overcast = 0.0;
249 else if (_overcast > 1.0) _overcast = 1.0;
251 float ambient = _ambient_tbl->interpolate( deg ) + visibility_inv/10;
252 float diffuse = _diffuse_tbl->interpolate( deg );
253 float specular = _specular_tbl->interpolate( deg ) * visibility_log;
254 float sky_brightness = _sky_tbl->interpolate( deg );
256 ambient *= _saturation;
257 diffuse *= _saturation;
258 specular *= _saturation;
259 sky_brightness *= _saturation;
261 SG_LOG( SG_EVENT, SG_DEBUG,
262 " ambient = " << ambient << " diffuse = " << diffuse
263 << " specular = " << specular << " sky = " << sky_brightness );
265 // sky_brightness = 0.15; // used to force a dark sky (when testing)
268 float sqr_sky_brightness = sky_brightness * sky_brightness * _scattering;
269 _fog_color = base_fog_color * sqr_sky_brightness;
270 gamma_correct_rgb( _fog_color.data() );
273 static const SGVec4f one_vec( 1.0f, 1.0f, 1.0f, 1.0f);
274 SGVec4f overcast_color = (one_vec - base_sky_color) * _overcast;
275 _sky_color = (base_sky_color + overcast_color) * sky_brightness;
276 gamma_correct_rgb( _sky_color.data() );
279 _cloud_color = base_fog_color * sky_brightness;
281 /** adjust the cloud colors for sunrise/sunset effects (darken them) */
282 if (_sun_angle > 1.0) {
283 float sun2 = 1.0 / sqrt(_sun_angle);
284 _cloud_color *= sun2;
286 gamma_correct_rgb( _cloud_color.data() );
289 _scene_ambient = _fog_color * ambient;
290 gamma_correct_rgb( _scene_ambient.data() );
293 SGSky* thesky = globals->get_renderer()->getSky();
294 SGVec4f color = thesky->get_scene_color();
295 _scene_diffuse = color * diffuse;
296 gamma_correct_rgb( _scene_diffuse.data() );
298 SGVec4f chrome = _scene_ambient * .4f + _scene_diffuse;
300 if (chrome != _scene_chrome) {
301 _scene_chrome = chrome;
302 for (int i = 0; i < 4; ++i)
303 _chromeProps[i]->setValue(static_cast<double>(_scene_chrome[i]));
306 /** specular light */
307 _sun_color = thesky->get_sun_color();
308 _scene_specular = _sun_color * specular;
309 gamma_correct_rgb( _scene_specular.data() );
313 // calculate fog color adjusted for sunrise/sunset effects
314 void FGLight::update_adj_fog_color () {
316 // double pitch = globals->get_current_view()->getPitch_deg()
317 // * SGD_DEGREES_TO_RADIANS;
318 // double pitch_offset = globals->get_current_view()-> getPitchOffset_deg()
319 // * SGD_DEGREES_TO_RADIANS;
320 double heading = globals->get_current_view()->getHeading_deg()
321 * SGD_DEGREES_TO_RADIANS;
322 double heading_offset = globals->get_current_view()->getHeadingOffset_deg()
323 * SGD_DEGREES_TO_RADIANS;
325 SG_LOG( SG_EVENT, SG_DEBUG, "Updating adjusted fog parameters." );
327 // set fog color (we'll try to match the sunset color in the
328 // direction we are looking
330 // Do some sanity checking ...
331 if ( _sun_rotation < -2.0 * SGD_2PI || _sun_rotation > 2.0 * SGD_2PI ) {
332 SG_LOG( SG_EVENT, SG_ALERT, "Sun rotation bad = " << _sun_rotation );
336 if ( heading < -2.0 * SGD_2PI || heading > 2.0 * SGD_2PI ) {
337 SG_LOG( SG_EVENT, SG_ALERT, "Heading rotation bad = " << heading );
341 if ( heading_offset < -2.0 * SGD_2PI || heading_offset > 2.0 * SGD_2PI ) {
342 SG_LOG( SG_EVENT, SG_ALERT, "Heading offset bad = " << heading_offset );
346 static float gamma = system_gamma;
348 // first determine the difference between our view angle and local
349 // direction to the sun
350 //double vert_rotation = pitch + pitch_offset;
352 double hor_rotation = -_sun_rotation + SGD_PI - heading + heading_offset;
354 // revert to unmodified values before using them.
356 SGSky* thesky = globals->get_renderer()->getSky();
357 SGVec4f color = thesky->get_scene_color();
359 gamma_restore_rgb( _fog_color.data(), gamma );
360 gamma_restore_rgb( _sky_color.data(), gamma );
362 // Calculate the fog color in the direction of the sun for
363 // sunrise/sunset effects.
365 _sun_color[0] = color[0]*color[0]*color[0];
366 _sun_color[1] = color[1]*color[1]*color[1];
367 _sun_color[2] = color[2]*color[2];
369 // interpolate between the sunrise/sunset color and the color
370 // at the opposite direction of this effect. Take in account
371 // the current visibility.
373 float av = thesky->get_visibility();
374 if (av > 45000) av = 45000;
376 float avf = 0.87 - (45000 - av) / 83333.33;
377 float sif = 0.5 - cos(_sun_angle*2)/2;
382 float rf1 = fabs(fmod(hor_rotation, SGD_2PI) - SGD_PI) / SGD_PI;
383 float rf2 = avf * pow(rf1*rf1, 1/sif) * 1.0639 * _saturation * _scattering;
384 float rf3 = 1.0 - rf2;
386 gamma = system_gamma * (0.9 - sif*avf);
387 _adj_fog_color = rf3 * _fog_color + rf2 * _sun_color;;
388 gamma_correct_rgb( _adj_fog_color.data(), gamma);
390 // make sure the colors have their original value before they are being
391 // used by the rest of the program.
393 gamma_correct_rgb( _fog_color.data(), gamma );
394 gamma_correct_rgb( _sky_color.data(), gamma );
397 // update the cur_time_params structure with the current sun position
398 void FGLight::updateSunPos()
400 SGTime *t = globals->get_time_params();
401 SG_LOG( SG_EVENT, SG_DEBUG, " Updating Sun position" );
402 SG_LOG( SG_EVENT, SG_DEBUG, " Gst = " << t->getGst() );
404 fgSunPositionGST(t->getGst(), &_sun_lon, &_sun_lat);
406 // It might seem that sun_gc_lat needs to be converted to geodetic
407 // latitude here, but it doesn't. The sun latitude is the latitude
408 // of the point on the earth where the up vector has the same
409 // angle from geocentric Z as the sun direction. But geodetic
410 // latitude is defined as 90 - angle of up vector from Z!
411 SGVec3d sunpos = SGVec3d::fromGeoc(SGGeoc::fromRadM(_sun_lon, _sun_lat,
414 SG_LOG( SG_EVENT, SG_DEBUG, " t->cur_time = " << t->get_cur_time() );
415 SG_LOG( SG_EVENT, SG_DEBUG,
416 " Sun Geocentric lat = " << _sun_lat
417 << " Geodcentric lat = " << _sun_lat );
419 // update the sun light vector
420 _sun_vec = SGVec4f(toVec3f(normalize(sunpos)), 0);
421 _sun_vec_inv = - _sun_vec;
423 // calculate the sun's relative angle to local up
424 FGViewer *v = globals->get_current_view();
425 SGQuatd hlOr = SGQuatd::fromLonLat( v->getPosition() );
426 SGVec3d world_up = hlOr.backTransform( -SGVec3d::e3() );
427 // cout << "nup = " << nup[0] << "," << nup[1] << ","
428 // << nup[2] << endl;
429 // cout << "nsun = " << nsun[0] << "," << nsun[1] << ","
430 // << nsun[2] << endl;
432 SGVec3d nsun = normalize(sunpos);
433 SGVec3d nup = normalize(world_up);
434 _sun_angle = acos( dot( nup, nsun ) );
436 double signnedPI = (_sun_angle < 0.0) ? -SGD_PI : SGD_PI;
437 _sun_angle = fmod(_sun_angle+signnedPI, SGD_2PI) - signnedPI;
439 SG_LOG( SG_EVENT, SG_DEBUG, "sun angle relative to current location = "
440 << get_sun_angle() );
442 // Get direction to the sun in the local frame.
443 SGVec3d local_sun_vec = hlOr.transform(nsun);
446 _sun_rotation = 2.0 * atan2(local_sun_vec.x(), -local_sun_vec.y());
448 // cout << " Sky needs to rotate = " << _sun_rotation << " rads = "
449 // << _sun_rotation * SGD_RADIANS_TO_DEGREES << " degrees." << endl;
451 _sunAngleRad->setDoubleValue(_sun_angle);