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, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20 //
  21 //
  22
  23 #ifdef HAVE_CONFIG_H
  24 #  include "config.h"
  25 #endif
  26
  27 #include <cstring>
  28 #include <Main/fg_props.hxx>
  29
  30 #include <simgear/constants.h>
  31 #include <simgear/sound/soundmgr_openal.hxx>
  32 #include <simgear/scene/sky/sky.hxx>
  33 //#include <simgear/environment/visual_enviro.hxx>
  34 #include <simgear/scene/sky/cloudfield.hxx>
  35 #include <simgear/scene/sky/newcloud.hxx>
  36 #include <simgear/structure/commands.hxx>
  37 #include <simgear/props/props_io.hxx>
  38
  39 #include <Main/globals.hxx>
  40 #include <Main/util.hxx>
  41 #include <Viewer/renderer.hxx>
  42 #include <Airports/simple.hxx>
  43
  44 #include "fgclouds.hxx"
  45
  46 static bool do_delete_3Dcloud (const SGPropertyNode *arg);
  47 static bool do_move_3Dcloud (const SGPropertyNode *arg);
  48 static bool do_add_3Dcloud (const SGPropertyNode *arg);
  49
  50 // RNG seed to ensure cloud synchronization across multi-process
  51 // deployments
  52 static mt seed;
  53
  54 FGClouds::FGClouds() :
  55 #if 0
  56     snd_lightning(0),
  57 #endif
  58     clouds_3d_enabled(false),
  59     index(0)
  60 {
  61         update_event = 0;
  62 }
  63
  64 FGClouds::~FGClouds()
  65 {
  66 }
  67
  68 int FGClouds::get_update_event(void) const {
  69         return update_event;
  70 }
  71
  72 void FGClouds::set_update_event(int count) {
  73         update_event = count;
  74         buildCloudLayers();
  75 }
  76
  77 void FGClouds::Init(void) {
  78 #if 0
  79         if( snd_lightning == NULL ) {
  80                 snd_lightning = new SGSoundSample("Sounds/thunder.wav", SGPath());
  81                 snd_lightning->set_max_dist(7000.0f);
  82                 snd_lightning->set_reference_dist(3000.0f);
  83                 SGSoundMgr *smgr = globals->get_soundmgr();
  84                 SGSampleGroup *sgr = smgr->find("weather", true);
  85                 sgr->add( snd_lightning, "thunder" );
  86         }
  87 #endif
  88
  89         mt_init_time_10(&seed);
  90
  91         globals->get_commands()->addCommand("add-cloud", do_add_3Dcloud);
  92         globals->get_commands()->addCommand("del-cloud", do_delete_3Dcloud);
  93         globals->get_commands()->addCommand("move-cloud", do_move_3Dcloud);
  94 }
  95
  96 // Build an invidual cloud. Returns the extents of the cloud for coverage calculations
  97 double FGClouds::buildCloud(SGPropertyNode *cloud_def_root, SGPropertyNode *box_def_root, const string& name, double grid_z_rand, SGCloudField *layer) {
  98         SGPropertyNode *box_def=NULL;
  99         SGPropertyNode *cld_def=NULL;
 100         double extent = 0.0;
 101
 102         SGPath texture_root = globals->get_fg_root();
 103         texture_root.append("Textures");
 104         texture_root.append("Sky");
 105
 106         box_def = box_def_root->getChild(name.c_str());
 107
 108         string base_name = name.substr(0,2);
 109         if( !box_def ) {
 110                 if( name[2] == '-' ) {
 111                         box_def = box_def_root->getChild(base_name.c_str());
 112                 }
 113                 if( !box_def )
 114                         return 0.0;
 115         }
 116
 117         double x = mt_rand(&seed) * SGCloudField::fieldSize - (SGCloudField::fieldSize / 2.0);
 118         double y = mt_rand(&seed) * SGCloudField::fieldSize - (SGCloudField::fieldSize / 2.0);
 119         double z = grid_z_rand * (mt_rand(&seed) - 0.5);
 120
 121         float lon = fgGetNode("/position/longitude-deg", false)->getFloatValue();
 122         float lat = fgGetNode("/position/latitude-deg", false)->getFloatValue();
 123
 124         SGVec3f pos(x,y,z);
 125
 126         for(int i = 0; i < box_def->nChildren() ; i++) {
 127                 SGPropertyNode *abox = box_def->getChild(i);
 128                 if( strcmp(abox->getName(), "box") == 0) {
 129
 130                         string type = abox->getStringValue("type", "cu-small");
 131                         cld_def = cloud_def_root->getChild(type.c_str());
 132                         if ( !cld_def ) return 0.0;
 133
 134                         double w = abox->getDoubleValue("width", 1000.0);
 135                         double h = abox->getDoubleValue("height", 1000.0);
 136                         int hdist = abox->getIntValue("hdist", 1);
 137                         int vdist = abox->getIntValue("vdist", 1);
 138
 139                         double c = abox->getDoubleValue("count", 5);
 140                         int count = (int) (c + (mt_rand(&seed) - 0.5) * c);
 141
 142                         extent = std::max(w*w, extent);
 143
 144                         for (int j = 0; j < count; j++) {
 145
 146                                 // Locate the clouds randomly in the defined space. The hdist and
 147                                 // vdist values control the horizontal and vertical distribution
 148                                 // by simply summing random components.
 149                                 double x = 0.0;
 150                                 double y = 0.0;
 151                                 double z = 0.0;
 152
 153                                 for (int k = 0; k < hdist; k++)
 154                                 {
 155                                         x += (mt_rand(&seed) / hdist);
 156                                         y += (mt_rand(&seed) / hdist);
 157                                 }
 158
 159                                 for (int k = 0; k < vdist; k++)
 160                                 {
 161                                         z += (mt_rand(&seed) / vdist);
 162                                 }
 163
 164                                 x = w * (x - 0.5) + pos[0]; // N/S
 165                                 y = w * (y - 0.5) + pos[1]; // E/W
 166                                 z = h * z + pos[2]; // Up/Down. pos[2] is the cloudbase
 167
 168                                 //SGVec3f newpos = SGVec3f(x, y, z);
 169                                 SGNewCloud cld(texture_root, cld_def, &seed);
 170
 171                                 //layer->addCloud(newpos, cld.genCloud());
 172                                 layer->addCloud(lon, lat, z, x, y, index++, cld.genCloud());
 173                         }
 174                 }
 175         }
 176
 177         // Return the maximum extent of the cloud
 178         return extent;
 179 }
 180
 181 void FGClouds::buildLayer(int iLayer, const string& name, double coverage) {
 182         struct {
 183                 string name;
 184                 double count;
 185         } tCloudVariety[20];
 186         int CloudVarietyCount = 0;
 187         double totalCount = 0.0;
 188
 189     SGSky* thesky = globals->get_renderer()->getSky();
 190
 191         SGPropertyNode *cloud_def_root = fgGetNode("/environment/cloudlayers/clouds", false);
 192         SGPropertyNode *box_def_root   = fgGetNode("/environment/cloudlayers/boxes", false);
 193         SGPropertyNode *layer_def_root = fgGetNode("/environment/cloudlayers/layers", false);
 194         SGCloudField *layer = thesky->get_cloud_layer(iLayer)->get_layer3D();
 195         layer->clear();
 196
 197         // If we don't have the required properties, then render the cloud in 2D
 198         if ((! clouds_3d_enabled) || coverage == 0.0 ||
 199                 layer_def_root == NULL || cloud_def_root == NULL || box_def_root == NULL) {
 200                         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(false);
 201                         return;
 202         }
 203
 204         // If we can't find a definition for this cloud type, then render the cloud in 2D
 205         SGPropertyNode *layer_def=NULL;
 206         layer_def = layer_def_root->getChild(name.c_str());
 207         if( !layer_def ) {
 208                 if( name[2] == '-' ) {
 209                         string base_name = name.substr(0,2);
 210                         layer_def = layer_def_root->getChild(base_name.c_str());
 211                 }
 212                 if( !layer_def ) {
 213                         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(false);
 214                         return;
 215                 }
 216         }
 217
 218         // At this point, we know we've got some 3D clouds to generate.
 219         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(true);
 220
 221         double grid_z_rand = layer_def->getDoubleValue("grid-z-rand");
 222
 223         for(int i = 0; i < layer_def->nChildren() ; i++) {
 224                 SGPropertyNode *acloud = layer_def->getChild(i);
 225                 if( strcmp(acloud->getName(), "cloud") == 0) {
 226                         string cloud_name = acloud->getStringValue("name");
 227                         tCloudVariety[CloudVarietyCount].name = cloud_name;
 228                         double count = acloud->getDoubleValue("count", 1.0);
 229                         tCloudVariety[CloudVarietyCount].count = count;
 230                         int variety = 0;
 231                         cloud_name = cloud_name + "-%d";
 232                         char variety_name[50];
 233                         do {
 234                                 variety++;
 235                                 snprintf(variety_name, sizeof(variety_name) - 1, cloud_name.c_str(), variety);
 236                         } while( box_def_root->getChild(variety_name, 0, false) );
 237
 238                         totalCount += count;
 239                         if( CloudVarietyCount < 20 )
 240                                 CloudVarietyCount++;
 241                 }
 242         }
 243         totalCount = 1.0 / totalCount;
 244
 245         // Determine how much cloud coverage we need in m^2.
 246         double cov = coverage * SGCloudField::fieldSize * SGCloudField::fieldSize;
 247
 248         while (cov > 0.0f) {
 249                 double choice = mt_rand(&seed);
 250
 251                 for(int i = 0; i < CloudVarietyCount ; i ++) {
 252                         choice -= tCloudVariety[i].count * totalCount;
 253                         if( choice <= 0.0 ) {
 254                                 cov -= buildCloud(cloud_def_root,
 255                                                 box_def_root,
 256                                                 tCloudVariety[i].name,
 257                                                 grid_z_rand,
 258                                                 layer);
 259                                 break;
 260                         }
 261                 }
 262         }
 263
 264         // Now we've built any clouds, enable them and set the density (coverage)
 265         //layer->setCoverage(coverage);
 266         //layer->applyCoverage();
 267         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(clouds_3d_enabled);
 268 }
 269
 270 void FGClouds::buildCloudLayers(void) {
 271         SGPropertyNode *metar_root = fgGetNode("/environment", true);
 272
 273         //double wind_speed_kt   = metar_root->getDoubleValue("wind-speed-kt");
 274         double temperature_degc  = metar_root->getDoubleValue("temperature-sea-level-degc");
 275         double dewpoint_degc     = metar_root->getDoubleValue("dewpoint-sea-level-degc");
 276         double pressure_mb       = metar_root->getDoubleValue("pressure-sea-level-inhg") * SG_INHG_TO_PA / 100.0;
 277         double rel_humidity      = metar_root->getDoubleValue("relative-humidity");
 278
 279         // formule d'Epsy, base d'un cumulus
 280         double cumulus_base = 122.0 * (temperature_degc - dewpoint_degc);
 281         double stratus_base = 100.0 * (100.0 - rel_humidity) * SG_FEET_TO_METER;
 282
 283     SGSky* thesky = globals->get_renderer()->getSky();
 284         for(int iLayer = 0 ; iLayer < thesky->get_cloud_layer_count(); iLayer++) {
 285                 SGPropertyNode *cloud_root = fgGetNode("/environment/clouds/layer", iLayer, true);
 286
 287                 double alt_ft = cloud_root->getDoubleValue("elevation-ft");
 288                 double alt_m = alt_ft * SG_FEET_TO_METER;
 289                 string coverage = cloud_root->getStringValue("coverage");
 290
 291                 double coverage_norm = 0.0;
 292                 if( coverage == "few" )
 293                         coverage_norm = 2.0/8.0;        // <1-2
 294                 else if( coverage == "scattered" )
 295                         coverage_norm = 4.0/8.0;        // 3-4
 296                 else if( coverage == "broken" )
 297                         coverage_norm = 6.0/8.0;        // 5-7
 298                 else if( coverage == "overcast" )
 299                         coverage_norm = 8.0/8.0;        // 8
 300
 301                 string layer_type = "nn";
 302
 303                 if( coverage == "cirrus" ) {
 304                         layer_type = "ci";
 305                 } else if( alt_ft > 16500 ) {
 306 //                      layer_type = "ci|cs|cc";
 307                         layer_type = "ci";
 308                 } else if( alt_ft > 6500 ) {
 309 //                      layer_type = "as|ac|ns";
 310                         layer_type = "ac";
 311                         if( pressure_mb < 1005.0 && coverage_norm >= 0.5 )
 312                                 layer_type = "ns";
 313                 } else {
 314 //                      layer_type = "st|cu|cb|sc";
 315                         if( cumulus_base * 0.80 < alt_m && cumulus_base * 1.20 > alt_m ) {
 316                                 // +/- 20% from cumulus probable base
 317                                 layer_type = "cu";
 318                         } else if( stratus_base * 0.80 < alt_m && stratus_base * 1.40 > alt_m ) {
 319                                 // +/- 20% from stratus probable base
 320                                 layer_type = "st";
 321                         } else {
 322                                 // above formulae is far from perfect
 323                                 if ( alt_ft < 2000 )
 324                                         layer_type = "st";
 325                                 else if( alt_ft < 4500 )
 326                                         layer_type = "cu";
 327                                 else
 328                                         layer_type = "sc";
 329                         }
 330                 }
 331
 332                 cloud_root->setStringValue("layer-type",layer_type);
 333                 buildLayer(iLayer, layer_type, coverage_norm);
 334         }
 335 }
 336
 337 void FGClouds::set_3dClouds(bool enable)
 338 {
 339         if (enable != clouds_3d_enabled) {
 340                 clouds_3d_enabled = enable;
 341                 buildCloudLayers();
 342         }
 343 }
 344
 345 bool FGClouds::get_3dClouds() const
 346 {
 347         return clouds_3d_enabled;
 348 }
 349
 350 /**
 351  * Adds a 3D cloud to a cloud layer.
 352  *
 353  * Property arguments
 354  * layer - the layer index to add this cloud to. (Defaults to 0)
 355  * index - the index for this cloud (to be used later)
 356  * lon/lat/alt - the position for the cloud
 357  * (Various) - cloud definition properties. See README.3DClouds
 358  *
 359  */
 360  static bool
 361  do_add_3Dcloud (const SGPropertyNode *arg)
 362  {
 363    int l = arg->getIntValue("layer", 0);
 364    int index = arg->getIntValue("index", 0);
 365
 366    SGPath texture_root = globals->get_fg_root();
 367          texture_root.append("Textures");
 368          texture_root.append("Sky");
 369
 370          float lon = arg->getFloatValue("lon-deg", 0.0f);
 371          float lat = arg->getFloatValue("lat-deg", 0.0f);
 372          float alt = arg->getFloatValue("alt-ft",  0.0f);
 373          float x   = arg->getFloatValue("x-offset-m",  0.0f);
 374          float y   = arg->getFloatValue("y-offset-m",  0.0f);
 375
 376    SGSky* thesky = globals->get_renderer()->getSky();
 377    SGCloudField *layer = thesky->get_cloud_layer(l)->get_layer3D();
 378    SGNewCloud cld(texture_root, arg, &seed);
 379    bool success = layer->addCloud(lon, lat, alt, x, y, index, cld.genCloud());
 380
 381    // Adding a 3D cloud immediately makes this layer 3D.
 382    thesky->get_cloud_layer(l)->set_enable3dClouds(true);
 383
 384    return success;
 385  }
 386
 387  /**
 388   * Removes a 3D cloud from a cloud layer
 389   *
 390   * Property arguments
 391   *
 392   * layer - the layer index to remove this cloud from. (defaults to 0)
 393   * index - the cloud index
 394   *
 395   */
 396  static bool
 397  do_delete_3Dcloud (const SGPropertyNode *arg)
 398  {
 399    int l = arg->getIntValue("layer", 0);
 400    int i = arg->getIntValue("index", 0);
 401
 402    SGSky* thesky = globals->get_renderer()->getSky();
 403    SGCloudField *layer = thesky->get_cloud_layer(l)->get_layer3D();
 404          return layer->deleteCloud(i);
 405  }
 406
 407 /**
 408  * Move a cloud within a 3D layer
 409  *
 410  * Property arguments
 411  * layer - the layer index to add this cloud to. (Defaults to 0)
 412  * index - the cloud index to move.
 413  * lon/lat/alt - the position for the cloud
 414  *
 415  */
 416  static bool
 417  do_move_3Dcloud (const SGPropertyNode *arg)
 418  {
 419    int l = arg->getIntValue("layer", 0);
 420    int i = arg->getIntValue("index", 0);
 421       SGSky* thesky = globals->get_renderer()->getSky();
 422
 423          float lon = arg->getFloatValue("lon-deg", 0.0f);
 424          float lat = arg->getFloatValue("lat-deg", 0.0f);
 425          float alt = arg->getFloatValue("alt-ft",  0.0f);
 426          float x   = arg->getFloatValue("x-offset-m",  0.0f);
 427          float y   = arg->getFloatValue("y-offset-m",  0.0f);
 428
 429    SGCloudField *layer = thesky->get_cloud_layer(l)->get_layer3D();
 430          return layer->repositionCloud(i, lon, lat, alt, x, y);
 431  }