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>
40 #include <Main/main.hxx>
41 #include <Main/globals.hxx>
42 #include <Main/fg_props.hxx>
43 #include <Main/renderer.hxx>
44 #include <Main/viewer.hxx>
52 : _ambient_tbl( NULL ),
54 _specular_tbl( NULL ),
61 _moon_vec(0, 0, 0, 0),
62 _sun_vec_inv(0, 0, 0, 0),
63 _moon_vec_inv(0, 0, 0, 0),
69 _scene_ambient(0, 0, 0, 0),
70 _scene_diffuse(0, 0, 0, 0),
71 _scene_specular(0, 0, 0, 0),
72 _scene_chrome(0, 0, 0, 0),
73 _sky_color(0, 0, 0, 0),
74 _fog_color(0, 0, 0, 0),
75 _cloud_color(0, 0, 0, 0),
76 _adj_fog_color(0, 0, 0, 0),
77 _adj_sky_color(0, 0, 0, 0),
92 // initialize lighting tables
93 void FGLight::init () {
94 SG_LOG( SG_EVENT, SG_INFO,
95 "Initializing Lighting interpolation tables." );
97 // build the path names of the lookup tables
98 SGPath path( globals->get_fg_root() );
100 // initialize ambient, diffuse and specular tables
101 SGPath ambient_path = path;
102 ambient_path.append( "Lighting/ambient" );
103 _ambient_tbl = new SGInterpTable( ambient_path.str() );
105 SGPath diffuse_path = path;
106 diffuse_path.append( "Lighting/diffuse" );
107 _diffuse_tbl = new SGInterpTable( diffuse_path.str() );
109 SGPath specular_path = path;
110 specular_path.append( "Lighting/specular" );
111 _specular_tbl = new SGInterpTable( specular_path.str() );
113 // initialize sky table
114 SGPath sky_path = path;
115 sky_path.append( "Lighting/sky" );
116 _sky_tbl = new SGInterpTable( sky_path.str() );
120 void FGLight::reinit () {
121 _prev_sun_angle = -9999.0;
126 delete _specular_tbl;
134 update_adj_fog_color();
137 void FGLight::bind () {
138 SGPropertyNode *prop = globals->get_props();
139 prop->tie("/sim/time/sun-angle-rad",SGRawValuePointer<double>(&_sun_angle));
140 prop->tie("/rendering/scene/ambient/red",SGRawValuePointer<float>(&_scene_ambient[0]));
141 prop->tie("/rendering/scene/ambient/green",SGRawValuePointer<float>(&_scene_ambient[1]));
142 prop->tie("/rendering/scene/ambient/blue",SGRawValuePointer<float>(&_scene_ambient[2]));
143 prop->tie("/rendering/scene/diffuse/red",SGRawValuePointer<float>(&_scene_diffuse[0]));
144 prop->tie("/rendering/scene/diffuse/green",SGRawValuePointer<float>(&_scene_diffuse[1]));
145 prop->tie("/rendering/scene/diffuse/blue",SGRawValuePointer<float>(&_scene_diffuse[2]));
146 prop->tie("/rendering/scene/specular/red",SGRawValuePointer<float>(&_scene_specular[0]));
147 prop->tie("/rendering/scene/specular/green",SGRawValuePointer<float>(&_scene_specular[1]));
148 prop->tie("/rendering/scene/specular/blue",SGRawValuePointer<float>(&_scene_specular[2]));
149 prop->tie("/rendering/dome/sky/red",SGRawValuePointer<float>(&_sky_color[0]));
150 prop->tie("/rendering/dome/sky/green",SGRawValuePointer<float>(&_sky_color[1]));
151 prop->tie("/rendering/dome/sky/blue",SGRawValuePointer<float>(&_sky_color[2]));
152 prop->tie("/rendering/dome/fog/red",SGRawValuePointer<float>(&_fog_color[0]));
153 prop->tie("/rendering/dome/fog/green",SGRawValuePointer<float>(&_fog_color[1]));
154 prop->tie("/rendering/dome/fog/blue",SGRawValuePointer<float>(&_fog_color[2]));
155 // Properties used directly by effects
156 _chromeProps[0] = prop->getNode("/rendering/scene/chrome-light/red", true);
157 _chromeProps[1] = prop->getNode("/rendering/scene/chrome-light/green",
159 _chromeProps[2] = prop->getNode("/rendering/scene/chrome-light/blue", true);
160 _chromeProps[3] = prop->getNode("/rendering/scene/chrome-light/alpha",
162 for (int i = 0; i < 4; ++i)
163 _chromeProps[i]->setValue(0.0);
166 void FGLight::unbind () {
167 SGPropertyNode *prop = globals->get_props();
168 prop->untie("/sim/time/sun-angle-rad");
169 prop->untie("/rendering/scene/ambient/red");
170 prop->untie("/rendering/scene/ambient/green");
171 prop->untie("/rendering/scene/ambient/blue");
172 prop->untie("/rendering/scene/diffuse/red");
173 prop->untie("/rendering/scene/diffuse/green");
174 prop->untie("/rendering/scene/diffuse/blue");
175 prop->untie("/rendering/scene/specular/red");
176 prop->untie("/rendering/scene/specular/green");
177 prop->untie("/rendering/scene/specular/blue");
178 prop->untie("/rendering/dome/sun/red");
179 prop->untie("/rendering/dome/sun/green");
180 prop->untie("/rendering/dome/sun/blue");
181 prop->untie("/rendering/dome/sky/red");
182 prop->untie("/rendering/dome/sky/green");
183 prop->untie("/rendering/dome/sky/blue");
184 prop->untie("/rendering/dome/fog/red");
185 prop->untie("/rendering/dome/fog/green");
186 prop->untie("/rendering/dome/fog/blue");
190 // update lighting parameters based on current sun position
191 void FGLight::update( double dt ) {
194 if (_dt_total >= 0.5) {
199 update_adj_fog_color();
201 if (_prev_sun_angle != _sun_angle) {
202 _prev_sun_angle = _sun_angle;
207 void FGLight::update_sky_color () {
208 // if the 4th field is 0.0, this specifies a direction ...
209 // const GLfloat white[4] = { 1.0, 1.0, 1.0, 1.0 };
210 const GLfloat base_sky_color[4] = { 0.31, 0.43, 0.69, 1.0 };
211 const GLfloat base_fog_color[4] = { 0.63, 0.72, 0.88, 1.0 };
213 SG_LOG( SG_EVENT, SG_DEBUG, "Updating light parameters." );
215 // calculate lighting parameters based on sun's relative angle to
217 static SGConstPropertyNode_ptr humidity = fgGetNode("/environment/relative-humidity");
218 float av = humidity->getFloatValue() * 45;
219 float visibility_log = log(av)/11.0;
220 float visibility_inv = (45000.0 - av)/45000.0;
222 float deg = _sun_angle * SGD_RADIANS_TO_DEGREES;
223 SG_LOG( SG_EVENT, SG_DEBUG, " Sun angle = " << deg );
225 float ambient = _ambient_tbl->interpolate( deg ) + visibility_inv/10;
226 float diffuse = _diffuse_tbl->interpolate( deg );
227 float specular = _specular_tbl->interpolate( deg ) * visibility_log;
228 float sky_brightness = _sky_tbl->interpolate( deg );
230 SG_LOG( SG_EVENT, SG_DEBUG,
231 " ambient = " << ambient << " diffuse = " << diffuse
232 << " specular = " << specular << " sky = " << sky_brightness );
234 // sky_brightness = 0.15; // used to force a dark sky (when testing)
236 // set fog and cloud color
237 float sqrt_sky_brightness = 1.0 - sqrt(1.0 - sky_brightness);
238 _fog_color[0] = base_fog_color[0] * sqrt_sky_brightness;
239 _fog_color[1] = base_fog_color[1] * sqrt_sky_brightness;
240 _fog_color[2] = base_fog_color[2] * sqrt_sky_brightness;
241 _fog_color[3] = base_fog_color[3];
242 gamma_correct_rgb( _fog_color.data() );
245 _sky_color[0] = base_sky_color[0] * sky_brightness;
246 _sky_color[1] = base_sky_color[1] * sky_brightness;
247 _sky_color[2] = base_sky_color[2] * sky_brightness;
248 _sky_color[3] = base_sky_color[3];
249 gamma_correct_rgb( _sky_color.data() );
251 _cloud_color[0] = base_fog_color[0] * sky_brightness;
252 _cloud_color[1] = base_fog_color[1] * sky_brightness;
253 _cloud_color[2] = base_fog_color[2] * sky_brightness;
254 _cloud_color[3] = base_fog_color[3];
256 // adjust the cloud colors for sunrise/sunset effects (darken them)
257 if (_sun_angle > 1.0) {
258 float sun2 = sqrt(_sun_angle);
259 _cloud_color[0] /= sun2;
260 _cloud_color[1] /= sun2;
261 _cloud_color[2] /= sun2;
263 gamma_correct_rgb( _cloud_color.data() );
265 _scene_ambient[0] = _fog_color[0] * ambient;
266 _scene_ambient[1] = _fog_color[1] * ambient;
267 _scene_ambient[2] = _fog_color[2] * ambient;
268 _scene_ambient[3] = 1.0;
269 gamma_correct_rgb( _scene_ambient.data() );
271 SGVec4f color = thesky->get_scene_color();
272 _scene_diffuse[0] = color[0] * diffuse;
273 _scene_diffuse[1] = color[1] * diffuse;
274 _scene_diffuse[2] = color[2] * diffuse;
275 _scene_diffuse[3] = 1.0;
276 gamma_correct_rgb( _scene_diffuse.data() );
278 SGVec4f chrome = _scene_ambient * .4f + _scene_diffuse;
280 if (chrome != _scene_chrome) {
281 _scene_chrome = chrome;
282 for (int i = 0; i < 4; ++i)
283 _chromeProps[i]->setValue(static_cast<double>(_scene_chrome[i]));
286 color = thesky->get_sun_color();
287 _scene_specular[0] = color[0] * specular;
288 _scene_specular[1] = color[1] * specular;
289 _scene_specular[2] = color[2] * specular;
290 _scene_specular[3] = 1.0;
291 gamma_correct_rgb( _scene_specular.data() );
295 // calculate fog color adjusted for sunrise/sunset effects
296 void FGLight::update_adj_fog_color () {
298 double pitch = globals->get_current_view()->getPitch_deg()
299 * SGD_DEGREES_TO_RADIANS;
300 double pitch_offset = globals->get_current_view()-> getPitchOffset_deg()
301 * SGD_DEGREES_TO_RADIANS;
302 double heading = globals->get_current_view()->getHeading_deg()
303 * SGD_DEGREES_TO_RADIANS;
304 double heading_offset = globals->get_current_view()->getHeadingOffset_deg()
305 * SGD_DEGREES_TO_RADIANS;
307 SG_LOG( SG_EVENT, SG_DEBUG, "Updating adjusted fog parameters." );
309 // set fog color (we'll try to match the sunset color in the
310 // direction we are looking
312 // Do some sanity checking ...
313 if ( _sun_rotation < -2.0 * SGD_2PI || _sun_rotation > 2.0 * SGD_2PI ) {
314 SG_LOG( SG_EVENT, SG_ALERT, "Sun rotation bad = " << _sun_rotation );
318 if ( heading < -2.0 * SGD_2PI || heading > 2.0 * SGD_2PI ) {
319 SG_LOG( SG_EVENT, SG_ALERT, "Heading rotation bad = " << heading );
323 if ( heading_offset < -2.0 * SGD_2PI || heading_offset > 2.0 * SGD_2PI ) {
324 SG_LOG( SG_EVENT, SG_ALERT, "Heading offset bad = " << heading_offset );
328 double hor_rotation, vert_rotation;
330 // first determine the difference between our view angle and local
331 // direction to the sun
332 vert_rotation = pitch + pitch_offset;
333 hor_rotation = -(_sun_rotation + SGD_PI) - heading + heading_offset;
334 if (hor_rotation < 0 )
335 hor_rotation = fmod(hor_rotation, SGD_2PI) + SGD_2PI;
337 hor_rotation = fmod(hor_rotation, SGD_2PI);
339 // revert to unmodified values before usign them.
341 SGVec4f color = thesky->get_scene_color();
343 gamma_restore_rgb( _fog_color.data() );
344 gamma_restore_rgb( _sky_color.data() );
346 // Calculate the fog color in the direction of the sun for
347 // sunrise/sunset effects.
349 float s_red = color[0]*color[0]*color[0];
350 float s_green = color[1]*color[1]*color[1];
351 float s_blue = color[2]*color[2];
353 // interpolate beween the sunrise/sunset color and the color
354 // at the opposite direction of this effect. Take in account
355 // the current visibility.
357 float av = thesky->get_visibility();
358 if (av > 45000) av = 45000;
360 float avf = 0.87 - (45000 - av) / 83333.33;
361 float sif = 0.5 - cos(_sun_angle*2)/2;
366 float rf1 = fabs((hor_rotation - SGD_PI) / SGD_PI); // 0.0 .. 1.0
367 float rf2 = avf * pow(rf1*rf1, 1/sif) * 1.0639;
368 float rf3 = 1.0 - rf2;
370 _adj_fog_color[0] = rf3 * _fog_color[0] + rf2 * s_red;
371 _adj_fog_color[1] = rf3 * _fog_color[1] + rf2 * s_green;
372 _adj_fog_color[2] = rf3 * _fog_color[2] + rf2 * s_blue;
373 gamma_correct_rgb( _adj_fog_color.data() );
375 // make sure the colors have their original value before they are being
376 // used by the rest of the program.
378 gamma_correct_rgb( _fog_color.data() );
379 gamma_correct_rgb( _sky_color.data() );