src/Environment/fgclouds.cxx

   1 // Build a cloud layer based on metar
   2 //
   3 // Written by Harald JOHNSEN, started April 2005.
   4 //
   5 // Copyright (C) 2005  Harald JOHNSEN - hjohnsen@evc.net
   6 //
   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.
  11 //
  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.
  16 //
  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, 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA
  20 //
  21 //
  22
  23 #include <Main/fg_props.hxx>
  24
  25 #include <simgear/constants.h>
  26 #include <simgear/sound/soundmgr_openal.hxx>
  27 #include <simgear/scene/sky/sky.hxx>
  28 #include <simgear/environment/visual_enviro.hxx>
  29 #include <simgear/scene/sky/cloudfield.hxx>
  30 #include <simgear/scene/sky/newcloud.hxx>
  31 #include <simgear/math/sg_random.h>
  32 #include <Main/globals.hxx>
  33 #include <Airports/simple.hxx>
  34 #include <Main/util.hxx>
  35
  36 #include "environment_mgr.hxx"
  37 #include "fgmetar.hxx"
  38 #include "fgclouds.hxx"
  39
  40 extern SGSky *thesky;
  41
  42
  43 FGClouds::FGClouds() :
  44         station_elevation_ft(0.0),
  45         snd_lightning(NULL)
  46 {
  47         update_event = 0;
  48         fgSetString("/environment/weather-scenario", "METAR");
  49 }
  50 FGClouds::~FGClouds() {
  51 }
  52
  53 int FGClouds::get_update_event(void) const {
  54         return update_event;
  55 }
  56 void FGClouds::set_update_event(int count) {
  57         update_event = count;
  58         build();
  59 }
  60
  61 void FGClouds::init(void) {
  62         if( snd_lightning == NULL ) {
  63                 snd_lightning = new SGSoundSample(globals->get_fg_root().c_str(), "Sounds/thunder.wav", true);
  64                 snd_lightning->set_max_dist(7000.0f);
  65                 snd_lightning->set_reference_dist(3000.0f);
  66                 SGSoundMgr *soundMgr = globals->get_soundmgr();
  67                 soundMgr->add( snd_lightning, "thunder" );
  68                 sgEnviro.set_soundMgr( soundMgr );
  69         }
  70 }
  71
  72 SGNewCloud *FGClouds::buildCloud(SGPropertyNode *cloud_def_root, string name) {
  73         SGPropertyNode *cld_def=NULL;
  74
  75         cld_def = cloud_def_root->getChild(name.c_str());
  76         string base_name = name.substr(0,2);
  77         if( !cld_def ) {
  78                 if( name[2] == '-' ) {
  79                         cld_def = cloud_def_root->getChild(base_name.c_str());
  80                 }
  81                 if( !cld_def )
  82                         return NULL;
  83         }
  84         string familly = cld_def->getStringValue("familly", base_name.c_str());
  85         SGNewCloud *cld = new SGNewCloud(familly);
  86         for(int i = 0; i < cld_def->nChildren() ; i++) {
  87                 SGPropertyNode *abox = cld_def->getChild(i);
  88                 if( strcmp(abox->getName(), "box") == 0) {
  89                         double x = abox->getDoubleValue("x");
  90                         double y = abox->getDoubleValue("y");
  91                         double z = abox->getDoubleValue("z");
  92                         double size = abox->getDoubleValue("size");
  93                         int type = abox->getIntValue("type", SGNewCloud::CLbox_standard);
  94                         cld->addContainer(x, y, z, size, (SGNewCloud::CLbox_type) type);
  95                 }
  96         }
  97         cld->genSprites();
  98         return cld;
  99 }
 100
 101 void FGClouds::buildLayer(SGCloudField *layer, string name, double alt, double coverage) {
 102         struct {
 103                 string name;
 104                 double count;
 105         } tCloudVariety[20];
 106         int CloudVarietyCount = 0;
 107         double totalCount = 0.0;
 108
 109         SGPropertyNode *cloud_def_root = fgGetNode("/environment/config/cloudlayers/clouds", false);
 110         SGPropertyNode *layer_def_root = fgGetNode("/environment/config/cloudlayers/layers", false);
 111
 112         layer->clear();
 113         // when we don't generate clouds the layer is rendered in 2D
 114         if( coverage == 0.0 )
 115                 return;
 116         if( layer_def_root == NULL || cloud_def_root == NULL)
 117                 return;
 118         if( name == "ci" || name == "sc" || name == "st")
 119                 return;
 120
 121         SGPropertyNode *layer_def=NULL;
 122
 123         layer_def = layer_def_root->getChild(name.c_str());
 124         if( !layer_def ) {
 125                 if( name[2] == '-' ) {
 126                         string base_name = name.substr(0,2);
 127                         layer_def = layer_def_root->getChild(base_name.c_str());
 128                 }
 129                 if( !layer_def )
 130                         return;
 131         }
 132
 133         double grid_x_size = layer_def->getDoubleValue("grid-x-size", 1000.0);
 134         double grid_y_size = layer_def->getDoubleValue("grid-y-size", 1000.0);
 135         double grid_x_rand = layer_def->getDoubleValue("grid-x-rand", grid_x_size);
 136         double grid_y_rand = layer_def->getDoubleValue("grid-y-rand", grid_y_size);
 137         double grid_z_rand = layer_def->getDoubleValue("grid-z-rand");
 138
 139         for(int i = 0; i < layer_def->nChildren() ; i++) {
 140                 SGPropertyNode *acloud = layer_def->getChild(i);
 141                 if( strcmp(acloud->getName(), "cloud") == 0) {
 142                         string cloud_name = acloud->getStringValue("name");
 143                         tCloudVariety[CloudVarietyCount].name = cloud_name;
 144                         double count = acloud->getDoubleValue("count", 1.0);
 145                         tCloudVariety[CloudVarietyCount].count = count;
 146                         int variety = 0;
 147                         cloud_name = cloud_name + "-%d";
 148                         char variety_name[50];
 149                         do {
 150                                 variety++;
 151                                 snprintf(variety_name, sizeof(variety_name), cloud_name.c_str(), variety);
 152                         } while( cloud_def_root->getChild(variety_name, 0, false) );
 153
 154                         totalCount += count;
 155                         if( CloudVarietyCount < 20 )
 156                                 CloudVarietyCount++;
 157                 }
 158         }
 159         totalCount = 1.0 / totalCount;
 160         double currCoverage = 0.0;
 161
 162         for(double px = 0.0; px < SGCloudField::fieldSize; px += grid_x_size) {
 163                 for(double py = 0.0; py < SGCloudField::fieldSize; py += grid_y_size) {
 164                         double x = px + grid_x_rand * (sg_random() - 0.5);
 165                         double y = py + grid_y_rand * (sg_random() - 0.5);
 166                         double z = alt + grid_z_rand * (sg_random() - 0.5);
 167                         double choice = sg_random();
 168                         currCoverage += coverage;
 169                         if( currCoverage < 1.0 )
 170                                 continue;
 171                         currCoverage -= 1.0;
 172
 173                         for(int i = 0; i < CloudVarietyCount ; i ++) {
 174                                 choice -= tCloudVariety[i].count * totalCount;
 175                                 if( choice <= 0.0 ) {
 176                                         SGNewCloud *cld = buildCloud(cloud_def_root, tCloudVariety[i].name);
 177                                         sgVec3 pos={x,z,y};
 178                                         if( cld )
 179                                                 layer->addCloud(pos, cld);
 180
 181                                         break;
 182                                 }
 183                         }
 184                 }
 185         }
 186
 187 }
 188
 189 // TODO:call this after real metar updates
 190 void FGClouds::buildMETAR(void) {
 191         SGPropertyNode *metar_root = fgGetNode("/environment", true);
 192
 193         double wind_speed_kt     = metar_root->getDoubleValue("wind-speed-kt");
 194         double temperature_degc  = metar_root->getDoubleValue("temperature-sea-level-degc");
 195         double dewpoint_degc     = metar_root->getDoubleValue("dewpoint-sea-level-degc");
 196         double pressure_mb              = metar_root->getDoubleValue("pressure-sea-level-inhg") * SG_INHG_TO_PA / 100.0;
 197
 198         double dewp = pow(10.0, 7.5 * dewpoint_degc / (237.7 + dewpoint_degc));
 199         double temp = pow(10.0, 7.5 * temperature_degc / (237.7 + temperature_degc));
 200         double rel_humidity = dewp * 100 / temp;
 201
 202         // formule d'Epsy, base d'un cumulus
 203         double cumulus_base = 122.0 * (temperature_degc - dewpoint_degc);
 204         double stratus_base = 100.0 * (100.0 - rel_humidity) * SG_FEET_TO_METER;
 205
 206         bool cu_seen = false;
 207
 208         for(int iLayer = 0 ; iLayer < thesky->get_cloud_layer_count(); iLayer++) {
 209                 SGPropertyNode *cloud_root = fgGetNode("/environment/clouds/layer", iLayer, true);
 210
 211                 double alt_ft = cloud_root->getDoubleValue("elevation-ft");
 212                 double alt_m = alt_ft * SG_FEET_TO_METER;
 213                 string coverage = cloud_root->getStringValue("coverage");
 214                 double coverage_norm = 0.0;
 215                 if( coverage == "few" )
 216                         coverage_norm = 2.0/8.0;        // <1-2
 217                 else if( coverage == "scattered" )
 218                         coverage_norm = 4.0/8.0;        // 3-4
 219                 else if( coverage == "broken" )
 220                         coverage_norm = 6.0/8.0;        // 5-7
 221                 else if( coverage == "overcast" )
 222                         coverage_norm = 8.0/8.0;        // 8
 223
 224                 string layer_type = "nn";
 225                 if( coverage == "cirrus" ) {
 226                         layer_type = "ci";
 227                 } else if( alt_ft > 16500 ) {
 228 //                      layer_type = "ci|cs|cc";
 229                         layer_type = "ci";
 230                 } else if( alt_ft > 6500 ) {
 231 //                      layer_type = "as|ac|ns";
 232                         layer_type = "ac";
 233                         if( pressure_mb < 1005.0 && coverage_norm >= 5.5 )
 234                                 layer_type = "ns";
 235                 } else {
 236 //                      layer_type = "st|cu|cb|sc";
 237                         // +/- 20% from stratus probable base
 238                         if( stratus_base * 0.80 < alt_m && stratus_base * 1.40 > alt_m )
 239                                 layer_type = "st";
 240                         // +/- 20% from cumulus probable base
 241                         else if( cumulus_base * 0.80 < alt_m && cumulus_base * 1.20 > alt_m )
 242                                 layer_type = "cu";
 243                         else {
 244                                 // above formulae is far from perfect
 245                                 if ( alt_ft < 2000 )
 246                                         layer_type = "st";
 247                                 else if( alt_ft < 4500 )
 248                                         layer_type = "cu";
 249                                 else
 250                                         layer_type = "sc";
 251                         }
 252                 }
 253
 254                 SGCloudField *layer3D = thesky->get_cloud_layer(iLayer)->get_layer3D();
 255                 buildLayer(layer3D, layer_type, alt_m, coverage_norm);
 256         }
 257 }
 258
 259 // copy from FGMetarEnvironmentCtrl until better
 260 void
 261 FGClouds::update_metar_properties( FGMetar *m )
 262 {
 263     int i;
 264     double d;
 265     char s[128];
 266
 267     fgSetString("/environment/metar/station-id", m->getId());
 268     fgSetDouble("/environment/metar/min-visibility-m",
 269                 m->getMinVisibility().getVisibility_m() );
 270     fgSetDouble("/environment/metar/max-visibility-m",
 271                 m->getMaxVisibility().getVisibility_m() );
 272
 273     SGMetarVisibility *dirvis = m->getDirVisibility();
 274     for (i = 0; i < 8; i++, dirvis++) {
 275         const char *min = "/environment/metar/visibility[%d]/min-m";
 276         const char *max = "/environment/metar/visibility[%d]/max-m";
 277
 278         d = dirvis->getVisibility_m();
 279
 280         snprintf(s, 128, min, i);
 281         fgSetDouble(s, d);
 282         snprintf(s, 128, max, i);
 283         fgSetDouble(s, d);
 284     }
 285
 286     fgSetInt("/environment/metar/base-wind-range-from",
 287              m->getWindRangeFrom() );
 288     fgSetInt("/environment/metar/base-wind-range-to",
 289              m->getWindRangeTo() );
 290     fgSetDouble("/environment/metar/base-wind-speed-kt",
 291                 m->getWindSpeed_kt() );
 292     fgSetDouble("/environment/metar/gust-wind-speed-kt",
 293                 m->getGustSpeed_kt() );
 294     fgSetDouble("/environment/metar/temperature-degc",
 295                 m->getTemperature_C() );
 296     fgSetDouble("/environment/metar/dewpoint-degc",
 297                 m->getDewpoint_C() );
 298     fgSetDouble("/environment/metar/rel-humidity-norm",
 299                 m->getRelHumidity() );
 300     fgSetDouble("/environment/metar/pressure-inhg",
 301                 m->getPressure_inHg() );
 302
 303     vector<SGMetarCloud> cv = m->getClouds();
 304     vector<SGMetarCloud>::iterator cloud;
 305
 306     const char *cl = "/environment/clouds/layer[%i]";
 307     for (i = 0, cloud = cv.begin(); cloud != cv.end(); cloud++, i++) {
 308         const char *coverage_string[5] =
 309             { "clear", "few", "scattered", "broken", "overcast" };
 310         const double thickness[5] = { 0, 65, 600,750, 1000};
 311         int q;
 312
 313         snprintf(s, 128, cl, i);
 314         strncat(s, "/coverage", 128);
 315         q = cloud->getCoverage();
 316         fgSetString(s, coverage_string[q] );
 317
 318         snprintf(s, 128, cl, i);
 319         strncat(s, "/elevation-ft", 128);
 320         fgSetDouble(s, cloud->getAltitude_ft() + station_elevation_ft);
 321
 322         snprintf(s, 128, cl, i);
 323         strncat(s, "/thickness-ft", 128);
 324         fgSetDouble(s, thickness[q]);
 325
 326         snprintf(s, 128, cl, i);
 327         strncat(s, "/span-m", 128);
 328         fgSetDouble(s, 40000.0);
 329     }
 330
 331     for (; i < FGEnvironmentMgr::MAX_CLOUD_LAYERS; i++) {
 332         snprintf(s, 128, cl, i);
 333         strncat(s, "/coverage", 128);
 334         fgSetString(s, "clear");
 335
 336         snprintf(s, 128, cl, i);
 337         strncat(s, "/elevation-ft", 128);
 338         fgSetDouble(s, -9999);
 339
 340         snprintf(s, 128, cl, i);
 341         strncat(s, "/thickness-ft", 128);
 342         fgSetDouble(s, 0);
 343
 344         snprintf(s, 128, cl, i);
 345         strncat(s, "/span-m", 128);
 346         fgSetDouble(s, 40000.0);
 347     }
 348
 349     fgSetDouble("/environment/metar/rain-norm", m->getRain());
 350     fgSetDouble("/environment/metar/hail-norm", m->getHail());
 351     fgSetDouble("/environment/metar/snow-norm", m->getSnow());
 352     fgSetBool("/environment/metar/snow-cover", m->getSnowCover());
 353 }
 354
 355 void
 356 FGClouds::update_env_config ()
 357 {
 358     fgSetupWind( fgGetDouble("/environment/metar/base-wind-range-from"),
 359                  fgGetDouble("/environment/metar/base-wind-range-to"),
 360                  fgGetDouble("/environment/metar/base-wind-speed-kt"),
 361                  fgGetDouble("/environment/metar/gust-wind-speed-kt") );
 362
 363     fgDefaultWeatherValue( "visibility-m",
 364                            fgGetDouble("/environment/metar/min-visibility-m") );
 365 #if 0
 366     set_temp_at_altitude( fgGetDouble("/environment/metar/temperature-degc"),
 367                           station_elevation_ft );
 368     set_dewpoint_at_altitude( fgGetDouble("/environment/metar/dewpoint-degc"),
 369                               station_elevation_ft );
 370 #endif
 371     fgDefaultWeatherValue( "pressure-sea-level-inhg",
 372                            fgGetDouble("/environment/metar/pressure-inhg") );
 373 }
 374
 375
 376 void FGClouds::setLayer( int iLayer, float alt_ft, string coverage, string layer_type ) {
 377         double coverage_norm = 0.0;
 378         if( coverage == "few" )
 379                 coverage_norm = 2.0/8.0;        // <1-2
 380         else if( coverage == "scattered" )
 381                 coverage_norm = 4.0/8.0;        // 3-4
 382         else if( coverage == "broken" )
 383                 coverage_norm = 6.0/8.0;        // 5-7
 384         else if( coverage == "overcast" )
 385                 coverage_norm = 8.0/8.0;        // 8
 386
 387         SGCloudField *layer3D = thesky->get_cloud_layer(iLayer)->get_layer3D();
 388         buildLayer(layer3D, layer_type, station_elevation_ft + alt_ft * SG_FEET_TO_METER, coverage_norm);
 389 }
 390
 391 void FGClouds::buildScenario( string scenario ) {
 392         string fakeMetar="";
 393         string station = fgGetString("/environment/metar/station-id", "XXXX");
 394
 395         // fetch station elevation if exists
 396     FGAirport a = globals->get_airports()->search( station );
 397     station_elevation_ft = a.getElevation();
 398
 399         for(int iLayer = 0 ; iLayer < thesky->get_cloud_layer_count(); iLayer++) {
 400                 thesky->get_cloud_layer(iLayer)->get_layer3D()->clear();
 401         }
 402
 403         station += " 011000Z ";
 404         if( scenario == "Fair weather" ) {
 405                 fakeMetar = "15003KT 12SM SCT033 FEW200 20/08 Q1015 NOSIG";
 406                 setLayer(0, 3300.0, "scattered", "cu");
 407         } else if( scenario == "Thunderstorm" ) {
 408                 fakeMetar = "15012KT 08SM TSRA SCT040 BKN070 20/12 Q0995";
 409                 setLayer(0, 4000.0, "scattered", "cb");
 410                 setLayer(1, 7000.0, "scattered", "ns");
 411         } else
 412                 return;
 413         FGMetar *m = new FGMetar( station + fakeMetar );
 414         update_metar_properties( m );
 415         update_env_config();
 416         fgSetString("/environment/metar/last-metar", m->getData());
 417         // TODO:desactivate real metar updates
 418         if( scenario == "Fair weather" ) {
 419                 fgSetString("/environment/clouds/layer[1]/coverage", "cirrus");
 420         }
 421 }
 422
 423
 424 void FGClouds::build(void) {
 425         string scenario = fgGetString("/environment/weather-scenario", "METAR");
 426
 427         if( scenario == "METAR" ) {
 428                 string realMetar = fgGetString("/environment/metar/last-metar", "");
 429                 if( realMetar != "" ) {
 430                         FGMetar *m = new FGMetar( realMetar );
 431                         update_metar_properties( m );
 432                         update_env_config();
 433                 }
 434                 buildMETAR();
 435         }
 436         else
 437                 buildScenario( scenario );
 438
 439         // ...
 440         if( snd_lightning == NULL )
 441                 init();
 442 }