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 "fgclouds.hxx"
  28
  29 #include <cstring>
  30 #include <cstdio>
  31 #include <Main/fg_props.hxx>
  32
  33 #include <simgear/constants.h>
  34 #include <simgear/sound/soundmgr_openal.hxx>
  35 #include <simgear/scene/sky/sky.hxx>
  36 //#include <simgear/environment/visual_enviro.hxx>
  37 #include <simgear/scene/sky/cloudfield.hxx>
  38 #include <simgear/scene/sky/newcloud.hxx>
  39 #include <simgear/structure/commands.hxx>
  40 #include <simgear/props/props_io.hxx>
  41
  42 #include <Main/globals.hxx>
  43 #include <Main/util.hxx>
  44 #include <Viewer/renderer.hxx>
  45 #include <Airports/airport.hxx>
  46
  47 // RNG seed to ensure cloud synchronization across multi-process
  48 // deployments
  49 static mt seed;
  50
  51 FGClouds::FGClouds() :
  52     clouds_3d_enabled(false),
  53     index(0)
  54 {
  55         update_event = 0;
  56 }
  57
  58 FGClouds::~FGClouds()
  59 {
  60 }
  61
  62 int FGClouds::get_update_event(void) const {
  63         return update_event;
  64 }
  65
  66 void FGClouds::set_update_event(int count) {
  67         update_event = count;
  68         buildCloudLayers();
  69 }
  70
  71 void FGClouds::Init(void)
  72 {
  73         mt_init_time_10(&seed);
  74
  75         globals->get_commands()->addCommand("add-cloud", this, &FGClouds::add3DCloud);
  76         globals->get_commands()->addCommand("del-cloud", this, &FGClouds::delete3DCloud);
  77         globals->get_commands()->addCommand("move-cloud", this, &FGClouds::move3DCloud);
  78 }
  79
  80 // Build an invidual cloud. Returns the extents of the cloud for coverage calculations
  81 double FGClouds::buildCloud(SGPropertyNode *cloud_def_root, SGPropertyNode *box_def_root,
  82                             const std::string& name, double grid_z_rand, SGCloudField *layer)
  83 {
  84         SGPropertyNode *box_def=NULL;
  85         SGPropertyNode *cld_def=NULL;
  86         double extent = 0.0;
  87
  88         SGPath texture_root = globals->get_fg_root();
  89         texture_root.append("Textures");
  90         texture_root.append("Sky");
  91
  92         box_def = box_def_root->getChild(name.c_str());
  93
  94         string base_name = name.substr(0,2);
  95         if( !box_def ) {
  96                 if( name[2] == '-' ) {
  97                         box_def = box_def_root->getChild(base_name.c_str());
  98                 }
  99                 if( !box_def )
 100                         return 0.0;
 101         }
 102
 103         double x = mt_rand(&seed) * SGCloudField::fieldSize - (SGCloudField::fieldSize / 2.0);
 104         double y = mt_rand(&seed) * SGCloudField::fieldSize - (SGCloudField::fieldSize / 2.0);
 105         double z = grid_z_rand * (mt_rand(&seed) - 0.5);
 106
 107         float lon = fgGetNode("/position/longitude-deg", false)->getFloatValue();
 108         float lat = fgGetNode("/position/latitude-deg", false)->getFloatValue();
 109
 110         SGVec3f pos(x,y,z);
 111
 112         for(int i = 0; i < box_def->nChildren() ; i++) {
 113                 SGPropertyNode *abox = box_def->getChild(i);
 114                 if( strcmp(abox->getName(), "box") == 0) {
 115
 116                         string type = abox->getStringValue("type", "cu-small");
 117                         cld_def = cloud_def_root->getChild(type.c_str());
 118                         if ( !cld_def ) return 0.0;
 119
 120                         double w = abox->getDoubleValue("width", 1000.0);
 121                         double h = abox->getDoubleValue("height", 1000.0);
 122                         int hdist = abox->getIntValue("hdist", 1);
 123                         int vdist = abox->getIntValue("vdist", 1);
 124
 125                         double c = abox->getDoubleValue("count", 5);
 126                         int count = (int) (c + (mt_rand(&seed) - 0.5) * c);
 127
 128                         extent = std::max(w*w, extent);
 129
 130                         for (int j = 0; j < count; j++) {
 131
 132                                 // Locate the clouds randomly in the defined space. The hdist and
 133                                 // vdist values control the horizontal and vertical distribution
 134                                 // by simply summing random components.
 135                                 double x = 0.0;
 136                                 double y = 0.0;
 137                                 double z = 0.0;
 138
 139                                 for (int k = 0; k < hdist; k++)
 140                                 {
 141                                         x += (mt_rand(&seed) / hdist);
 142                                         y += (mt_rand(&seed) / hdist);
 143                                 }
 144
 145                                 for (int k = 0; k < vdist; k++)
 146                                 {
 147                                         z += (mt_rand(&seed) / vdist);
 148                                 }
 149
 150                                 x = w * (x - 0.5) + pos[0]; // N/S
 151                                 y = w * (y - 0.5) + pos[1]; // E/W
 152                                 z = h * z + pos[2]; // Up/Down. pos[2] is the cloudbase
 153
 154                                 //SGVec3f newpos = SGVec3f(x, y, z);
 155                                 SGNewCloud cld(texture_root, cld_def, &seed);
 156
 157                                 //layer->addCloud(newpos, cld.genCloud());
 158                                 layer->addCloud(lon, lat, z, x, y, index++, cld.genCloud());
 159                         }
 160                 }
 161         }
 162
 163         // Return the maximum extent of the cloud
 164         return extent;
 165 }
 166
 167 void FGClouds::buildLayer(int iLayer, const string& name, double coverage) {
 168         struct {
 169                 string name;
 170                 double count;
 171         } tCloudVariety[20];
 172         int CloudVarietyCount = 0;
 173         double totalCount = 0.0;
 174
 175     SGSky* thesky = globals->get_renderer()->getSky();
 176
 177         SGPropertyNode *cloud_def_root = fgGetNode("/environment/cloudlayers/clouds", false);
 178         SGPropertyNode *box_def_root   = fgGetNode("/environment/cloudlayers/boxes", false);
 179         SGPropertyNode *layer_def_root = fgGetNode("/environment/cloudlayers/layers", false);
 180         SGCloudField *layer = thesky->get_cloud_layer(iLayer)->get_layer3D();
 181         layer->clear();
 182
 183         // If we don't have the required properties, then render the cloud in 2D
 184         if ((! clouds_3d_enabled) || coverage == 0.0 ||
 185                 layer_def_root == NULL || cloud_def_root == NULL || box_def_root == NULL) {
 186                         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(false);
 187                         return;
 188         }
 189
 190         // If we can't find a definition for this cloud type, then render the cloud in 2D
 191         SGPropertyNode *layer_def=NULL;
 192         layer_def = layer_def_root->getChild(name.c_str());
 193         if( !layer_def ) {
 194                 if( name[2] == '-' ) {
 195                         string base_name = name.substr(0,2);
 196                         layer_def = layer_def_root->getChild(base_name.c_str());
 197                 }
 198                 if( !layer_def ) {
 199                         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(false);
 200                         return;
 201                 }
 202         }
 203
 204         // At this point, we know we've got some 3D clouds to generate.
 205         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(true);
 206
 207         double grid_z_rand = layer_def->getDoubleValue("grid-z-rand");
 208
 209         for(int i = 0; i < layer_def->nChildren() ; i++) {
 210                 SGPropertyNode *acloud = layer_def->getChild(i);
 211                 if( strcmp(acloud->getName(), "cloud") == 0) {
 212                         string cloud_name = acloud->getStringValue("name");
 213                         tCloudVariety[CloudVarietyCount].name = cloud_name;
 214                         double count = acloud->getDoubleValue("count", 1.0);
 215                         tCloudVariety[CloudVarietyCount].count = count;
 216                         int variety = 0;
 217                         char variety_name[50];
 218                         do {
 219                                 variety++;
 220                                 snprintf(variety_name, sizeof(variety_name) - 1, "%s-%d", cloud_name.c_str(), variety);
 221                         } while( box_def_root->getChild(variety_name, 0, false) );
 222
 223                         totalCount += count;
 224                         if( CloudVarietyCount < 20 )
 225                                 CloudVarietyCount++;
 226                 }
 227         }
 228         totalCount = 1.0 / totalCount;
 229
 230         // Determine how much cloud coverage we need in m^2.
 231         double cov = coverage * SGCloudField::fieldSize * SGCloudField::fieldSize;
 232
 233         while (cov > 0.0f) {
 234                 double choice = mt_rand(&seed);
 235
 236                 for(int i = 0; i < CloudVarietyCount ; i ++) {
 237                         choice -= tCloudVariety[i].count * totalCount;
 238                         if( choice <= 0.0 ) {
 239                                 cov -= buildCloud(cloud_def_root,
 240                                                 box_def_root,
 241                                                 tCloudVariety[i].name,
 242                                                 grid_z_rand,
 243                                                 layer);
 244                                 break;
 245                         }
 246                 }
 247         }
 248
 249         // Now we've built any clouds, enable them and set the density (coverage)
 250         //layer->setCoverage(coverage);
 251         //layer->applyCoverage();
 252         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(clouds_3d_enabled);
 253 }
 254
 255 void FGClouds::buildCloudLayers(void) {
 256         SGPropertyNode *metar_root = fgGetNode("/environment", true);
 257
 258         //double wind_speed_kt   = metar_root->getDoubleValue("wind-speed-kt");
 259         double temperature_degc  = metar_root->getDoubleValue("temperature-sea-level-degc");
 260         double dewpoint_degc     = metar_root->getDoubleValue("dewpoint-sea-level-degc");
 261         double pressure_mb       = metar_root->getDoubleValue("pressure-sea-level-inhg") * SG_INHG_TO_PA / 100.0;
 262         double rel_humidity      = metar_root->getDoubleValue("relative-humidity");
 263
 264         // formule d'Epsy, base d'un cumulus
 265         double cumulus_base = 122.0 * (temperature_degc - dewpoint_degc);
 266         double stratus_base = 100.0 * (100.0 - rel_humidity) * SG_FEET_TO_METER;
 267
 268     SGSky* thesky = globals->get_renderer()->getSky();
 269         for(int iLayer = 0 ; iLayer < thesky->get_cloud_layer_count(); iLayer++) {
 270                 SGPropertyNode *cloud_root = fgGetNode("/environment/clouds/layer", iLayer, true);
 271
 272                 double alt_ft = cloud_root->getDoubleValue("elevation-ft");
 273                 double alt_m = alt_ft * SG_FEET_TO_METER;
 274                 string coverage = cloud_root->getStringValue("coverage");
 275
 276                 double coverage_norm = 0.0;
 277                 if( coverage == "few" )
 278                         coverage_norm = 2.0/8.0;        // <1-2
 279                 else if( coverage == "scattered" )
 280                         coverage_norm = 4.0/8.0;        // 3-4
 281                 else if( coverage == "broken" )
 282                         coverage_norm = 6.0/8.0;        // 5-7
 283                 else if( coverage == "overcast" )
 284                         coverage_norm = 8.0/8.0;        // 8
 285
 286                 string layer_type = "nn";
 287
 288                 if( coverage == "cirrus" ) {
 289                         layer_type = "ci";
 290                 } else if( alt_ft > 16500 ) {
 291 //                      layer_type = "ci|cs|cc";
 292                         layer_type = "ci";
 293                 } else if( alt_ft > 6500 ) {
 294 //                      layer_type = "as|ac|ns";
 295                         layer_type = "ac";
 296                         if( pressure_mb < 1005.0 && coverage_norm >= 0.5 )
 297                                 layer_type = "ns";
 298                 } else {
 299 //                      layer_type = "st|cu|cb|sc";
 300                         if( cumulus_base * 0.80 < alt_m && cumulus_base * 1.20 > alt_m ) {
 301                                 // +/- 20% from cumulus probable base
 302                                 layer_type = "cu";
 303                         } else if( stratus_base * 0.80 < alt_m && stratus_base * 1.40 > alt_m ) {
 304                                 // +/- 20% from stratus probable base
 305                                 layer_type = "st";
 306                         } else {
 307                                 // above formulae is far from perfect
 308                                 if ( alt_ft < 2000 )
 309                                         layer_type = "st";
 310                                 else if( alt_ft < 4500 )
 311                                         layer_type = "cu";
 312                                 else
 313                                         layer_type = "sc";
 314                         }
 315                 }
 316
 317                 cloud_root->setStringValue("layer-type",layer_type);
 318                 buildLayer(iLayer, layer_type, coverage_norm);
 319         }
 320 }
 321
 322 void FGClouds::set_3dClouds(bool enable)
 323 {
 324         if (enable != clouds_3d_enabled) {
 325                 clouds_3d_enabled = enable;
 326                 buildCloudLayers();
 327         }
 328 }
 329
 330 bool FGClouds::get_3dClouds() const
 331 {
 332         return clouds_3d_enabled;
 333 }
 334
 335 /**
 336  * Adds a 3D cloud to a cloud layer.
 337  *
 338  * Property arguments
 339  * layer - the layer index to add this cloud to. (Defaults to 0)
 340  * index - the index for this cloud (to be used later)
 341  * lon/lat/alt - the position for the cloud
 342  * (Various) - cloud definition properties. See README.3DClouds
 343  *
 344  */
 345  bool FGClouds::add3DCloud(const SGPropertyNode *arg)
 346  {
 347    int l = arg->getIntValue("layer", 0);
 348    int index = arg->getIntValue("index", 0);
 349
 350    SGPath texture_root = globals->get_fg_root();
 351          texture_root.append("Textures");
 352          texture_root.append("Sky");
 353
 354          float lon = arg->getFloatValue("lon-deg", 0.0f);
 355          float lat = arg->getFloatValue("lat-deg", 0.0f);
 356          float alt = arg->getFloatValue("alt-ft",  0.0f);
 357          float x   = arg->getFloatValue("x-offset-m",  0.0f);
 358          float y   = arg->getFloatValue("y-offset-m",  0.0f);
 359
 360    SGSky* thesky = globals->get_renderer()->getSky();
 361    SGCloudField *layer = thesky->get_cloud_layer(l)->get_layer3D();
 362    SGNewCloud cld(texture_root, arg, &seed);
 363    bool success = layer->addCloud(lon, lat, alt, x, y, index, cld.genCloud());
 364
 365    // Adding a 3D cloud immediately makes this layer 3D.
 366    thesky->get_cloud_layer(l)->set_enable3dClouds(true);
 367
 368    return success;
 369  }
 370
 371  /**
 372   * Removes a 3D cloud from a cloud layer
 373   *
 374   * Property arguments
 375   *
 376   * layer - the layer index to remove this cloud from. (defaults to 0)
 377   * index - the cloud index
 378   *
 379   */
 380  bool FGClouds::delete3DCloud(const SGPropertyNode *arg)
 381  {
 382    int l = arg->getIntValue("layer", 0);
 383    int i = arg->getIntValue("index", 0);
 384
 385    SGSky* thesky = globals->get_renderer()->getSky();
 386    SGCloudField *layer = thesky->get_cloud_layer(l)->get_layer3D();
 387          return layer->deleteCloud(i);
 388  }
 389
 390 /**
 391  * Move a cloud within a 3D layer
 392  *
 393  * Property arguments
 394  * layer - the layer index to add this cloud to. (Defaults to 0)
 395  * index - the cloud index to move.
 396  * lon/lat/alt - the position for the cloud
 397  *
 398  */
 399 bool FGClouds::move3DCloud(const SGPropertyNode *arg)
 400  {
 401    int l = arg->getIntValue("layer", 0);
 402    int i = arg->getIntValue("index", 0);
 403       SGSky* thesky = globals->get_renderer()->getSky();
 404
 405          float lon = arg->getFloatValue("lon-deg", 0.0f);
 406          float lat = arg->getFloatValue("lat-deg", 0.0f);
 407          float alt = arg->getFloatValue("alt-ft",  0.0f);
 408          float x   = arg->getFloatValue("x-offset-m",  0.0f);
 409          float y   = arg->getFloatValue("y-offset-m",  0.0f);
 410
 411    SGCloudField *layer = thesky->get_cloud_layer(l)->get_layer3D();
 412          return layer->repositionCloud(i, lon, lat, alt, x, y);
 413  }