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     globals->get_commands()->removeCommand("add-cloud");
  61         globals->get_commands()->removeCommand("del-cloud");
  62         globals->get_commands()->removeCommand("move-cloud");
  63
  64 }
  65
  66 int FGClouds::get_update_event(void) const {
  67         return update_event;
  68 }
  69
  70 void FGClouds::set_update_event(int count) {
  71         update_event = count;
  72         buildCloudLayers();
  73 }
  74
  75 void FGClouds::Init(void)
  76 {
  77         mt_init_time_10(&seed);
  78
  79         globals->get_commands()->addCommand("add-cloud", this, &FGClouds::add3DCloud);
  80         globals->get_commands()->addCommand("del-cloud", this, &FGClouds::delete3DCloud);
  81         globals->get_commands()->addCommand("move-cloud", this, &FGClouds::move3DCloud);
  82 }
  83
  84 // Build an invidual cloud. Returns the extents of the cloud for coverage calculations
  85 double FGClouds::buildCloud(SGPropertyNode *cloud_def_root, SGPropertyNode *box_def_root,
  86                             const std::string& name, double grid_z_rand, SGCloudField *layer)
  87 {
  88         SGPropertyNode *box_def=NULL;
  89         SGPropertyNode *cld_def=NULL;
  90         double extent = 0.0;
  91
  92         SGPath texture_root = globals->get_fg_root();
  93         texture_root.append("Textures");
  94         texture_root.append("Sky");
  95
  96         box_def = box_def_root->getChild(name.c_str());
  97
  98         string base_name = name.substr(0,2);
  99         if( !box_def ) {
 100                 if( name[2] == '-' ) {
 101                         box_def = box_def_root->getChild(base_name.c_str());
 102                 }
 103                 if( !box_def )
 104                         return 0.0;
 105         }
 106
 107         double x = mt_rand(&seed) * SGCloudField::fieldSize - (SGCloudField::fieldSize / 2.0);
 108         double y = mt_rand(&seed) * SGCloudField::fieldSize - (SGCloudField::fieldSize / 2.0);
 109         double z = grid_z_rand * (mt_rand(&seed) - 0.5);
 110
 111         float lon = fgGetNode("/position/longitude-deg", false)->getFloatValue();
 112         float lat = fgGetNode("/position/latitude-deg", false)->getFloatValue();
 113
 114         SGVec3f pos(x,y,z);
 115
 116         for(int i = 0; i < box_def->nChildren() ; i++) {
 117                 SGPropertyNode *abox = box_def->getChild(i);
 118                 if( strcmp(abox->getName(), "box") == 0) {
 119
 120                         string type = abox->getStringValue("type", "cu-small");
 121                         cld_def = cloud_def_root->getChild(type.c_str());
 122                         if ( !cld_def ) return 0.0;
 123
 124                         double w = abox->getDoubleValue("width", 1000.0);
 125                         double h = abox->getDoubleValue("height", 1000.0);
 126                         int hdist = abox->getIntValue("hdist", 1);
 127                         int vdist = abox->getIntValue("vdist", 1);
 128
 129                         double c = abox->getDoubleValue("count", 5);
 130                         int count = (int) (c + (mt_rand(&seed) - 0.5) * c);
 131
 132                         extent = std::max(w*w, extent);
 133
 134                         for (int j = 0; j < count; j++) {
 135
 136                                 // Locate the clouds randomly in the defined space. The hdist and
 137                                 // vdist values control the horizontal and vertical distribution
 138                                 // by simply summing random components.
 139                                 double x = 0.0;
 140                                 double y = 0.0;
 141                                 double z = 0.0;
 142
 143                                 for (int k = 0; k < hdist; k++)
 144                                 {
 145                                         x += (mt_rand(&seed) / hdist);
 146                                         y += (mt_rand(&seed) / hdist);
 147                                 }
 148
 149                                 for (int k = 0; k < vdist; k++)
 150                                 {
 151                                         z += (mt_rand(&seed) / vdist);
 152                                 }
 153
 154                                 x = w * (x - 0.5) + pos[0]; // N/S
 155                                 y = w * (y - 0.5) + pos[1]; // E/W
 156                                 z = h * z + pos[2]; // Up/Down. pos[2] is the cloudbase
 157
 158                                 //SGVec3f newpos = SGVec3f(x, y, z);
 159                                 SGNewCloud cld(texture_root, cld_def, &seed);
 160
 161                                 //layer->addCloud(newpos, cld.genCloud());
 162                                 layer->addCloud(lon, lat, z, x, y, index++, cld.genCloud());
 163                         }
 164                 }
 165         }
 166
 167         // Return the maximum extent of the cloud
 168         return extent;
 169 }
 170
 171 void FGClouds::buildLayer(int iLayer, const string& name, double coverage) {
 172         struct {
 173                 string name;
 174                 double count;
 175         } tCloudVariety[20];
 176         int CloudVarietyCount = 0;
 177         double totalCount = 0.0;
 178
 179     SGSky* thesky = globals->get_renderer()->getSky();
 180
 181         SGPropertyNode *cloud_def_root = fgGetNode("/environment/cloudlayers/clouds", false);
 182         SGPropertyNode *box_def_root   = fgGetNode("/environment/cloudlayers/boxes", false);
 183         SGPropertyNode *layer_def_root = fgGetNode("/environment/cloudlayers/layers", false);
 184         SGCloudField *layer = thesky->get_cloud_layer(iLayer)->get_layer3D();
 185         layer->clear();
 186
 187         // If we don't have the required properties, then render the cloud in 2D
 188         if ((! clouds_3d_enabled) || coverage == 0.0 ||
 189                 layer_def_root == NULL || cloud_def_root == NULL || box_def_root == NULL) {
 190                         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(false);
 191                         return;
 192         }
 193
 194         // If we can't find a definition for this cloud type, then render the cloud in 2D
 195         SGPropertyNode *layer_def=NULL;
 196         layer_def = layer_def_root->getChild(name.c_str());
 197         if( !layer_def ) {
 198                 if( name[2] == '-' ) {
 199                         string base_name = name.substr(0,2);
 200                         layer_def = layer_def_root->getChild(base_name.c_str());
 201                 }
 202                 if( !layer_def ) {
 203                         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(false);
 204                         return;
 205                 }
 206         }
 207
 208         // At this point, we know we've got some 3D clouds to generate.
 209         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(true);
 210
 211         double grid_z_rand = layer_def->getDoubleValue("grid-z-rand");
 212
 213         for(int i = 0; i < layer_def->nChildren() ; i++) {
 214                 SGPropertyNode *acloud = layer_def->getChild(i);
 215                 if( strcmp(acloud->getName(), "cloud") == 0) {
 216                         string cloud_name = acloud->getStringValue("name");
 217                         tCloudVariety[CloudVarietyCount].name = cloud_name;
 218                         double count = acloud->getDoubleValue("count", 1.0);
 219                         tCloudVariety[CloudVarietyCount].count = count;
 220                         int variety = 0;
 221                         char variety_name[50];
 222                         do {
 223                                 variety++;
 224                                 snprintf(variety_name, sizeof(variety_name) - 1, "%s-%d", cloud_name.c_str(), variety);
 225                         } while( box_def_root->getChild(variety_name, 0, false) );
 226
 227                         totalCount += count;
 228                         if( CloudVarietyCount < 20 )
 229                                 CloudVarietyCount++;
 230                 }
 231         }
 232         totalCount = 1.0 / totalCount;
 233
 234         // Determine how much cloud coverage we need in m^2.
 235         double cov = coverage * SGCloudField::fieldSize * SGCloudField::fieldSize;
 236
 237         while (cov > 0.0f) {
 238                 double choice = mt_rand(&seed);
 239
 240                 for(int i = 0; i < CloudVarietyCount ; i ++) {
 241                         choice -= tCloudVariety[i].count * totalCount;
 242                         if( choice <= 0.0 ) {
 243                                 cov -= buildCloud(cloud_def_root,
 244                                                 box_def_root,
 245                                                 tCloudVariety[i].name,
 246                                                 grid_z_rand,
 247                                                 layer);
 248                                 break;
 249                         }
 250                 }
 251         }
 252
 253         // Now we've built any clouds, enable them and set the density (coverage)
 254         //layer->setCoverage(coverage);
 255         //layer->applyCoverage();
 256         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(clouds_3d_enabled);
 257 }
 258
 259 void FGClouds::buildCloudLayers(void) {
 260         SGPropertyNode *metar_root = fgGetNode("/environment", true);
 261
 262         //double wind_speed_kt   = metar_root->getDoubleValue("wind-speed-kt");
 263         double temperature_degc  = metar_root->getDoubleValue("temperature-sea-level-degc");
 264         double dewpoint_degc     = metar_root->getDoubleValue("dewpoint-sea-level-degc");
 265         double pressure_mb       = metar_root->getDoubleValue("pressure-sea-level-inhg") * SG_INHG_TO_PA / 100.0;
 266         double rel_humidity      = metar_root->getDoubleValue("relative-humidity");
 267
 268         // formule d'Epsy, base d'un cumulus
 269         double cumulus_base = 122.0 * (temperature_degc - dewpoint_degc);
 270         double stratus_base = 100.0 * (100.0 - rel_humidity) * SG_FEET_TO_METER;
 271
 272     SGSky* thesky = globals->get_renderer()->getSky();
 273         for(int iLayer = 0 ; iLayer < thesky->get_cloud_layer_count(); iLayer++) {
 274                 SGPropertyNode *cloud_root = fgGetNode("/environment/clouds/layer", iLayer, true);
 275
 276                 double alt_ft = cloud_root->getDoubleValue("elevation-ft");
 277                 double alt_m = alt_ft * SG_FEET_TO_METER;
 278                 string coverage = cloud_root->getStringValue("coverage");
 279
 280                 double coverage_norm = 0.0;
 281                 if( coverage == "few" )
 282                         coverage_norm = 2.0/8.0;        // <1-2
 283                 else if( coverage == "scattered" )
 284                         coverage_norm = 4.0/8.0;        // 3-4
 285                 else if( coverage == "broken" )
 286                         coverage_norm = 6.0/8.0;        // 5-7
 287                 else if( coverage == "overcast" )
 288                         coverage_norm = 8.0/8.0;        // 8
 289
 290                 string layer_type = "nn";
 291
 292                 if( coverage == "cirrus" ) {
 293                         layer_type = "ci";
 294                 } else if( alt_ft > 16500 ) {
 295 //                      layer_type = "ci|cs|cc";
 296                         layer_type = "ci";
 297                 } else if( alt_ft > 6500 ) {
 298 //                      layer_type = "as|ac|ns";
 299                         layer_type = "ac";
 300                         if( pressure_mb < 1005.0 && coverage_norm >= 0.5 )
 301                                 layer_type = "ns";
 302                 } else {
 303 //                      layer_type = "st|cu|cb|sc";
 304                         if( cumulus_base * 0.80 < alt_m && cumulus_base * 1.20 > alt_m ) {
 305                                 // +/- 20% from cumulus probable base
 306                                 layer_type = "cu";
 307                         } else if( stratus_base * 0.80 < alt_m && stratus_base * 1.40 > alt_m ) {
 308                                 // +/- 20% from stratus probable base
 309                                 layer_type = "st";
 310                         } else {
 311                                 // above formulae is far from perfect
 312                                 if ( alt_ft < 2000 )
 313                                         layer_type = "st";
 314                                 else if( alt_ft < 4500 )
 315                                         layer_type = "cu";
 316                                 else
 317                                         layer_type = "sc";
 318                         }
 319                 }
 320
 321                 cloud_root->setStringValue("layer-type",layer_type);
 322                 buildLayer(iLayer, layer_type, coverage_norm);
 323         }
 324 }
 325
 326 void FGClouds::set_3dClouds(bool enable)
 327 {
 328         if (enable != clouds_3d_enabled) {
 329                 clouds_3d_enabled = enable;
 330                 buildCloudLayers();
 331         }
 332 }
 333
 334 bool FGClouds::get_3dClouds() const
 335 {
 336         return clouds_3d_enabled;
 337 }
 338
 339 /**
 340  * Adds a 3D cloud to a cloud layer.
 341  *
 342  * Property arguments
 343  * layer - the layer index to add this cloud to. (Defaults to 0)
 344  * index - the index for this cloud (to be used later)
 345  * lon/lat/alt - the position for the cloud
 346  * (Various) - cloud definition properties. See README.3DClouds
 347  *
 348  */
 349  bool FGClouds::add3DCloud(const SGPropertyNode *arg)
 350  {
 351    int l = arg->getIntValue("layer", 0);
 352    int index = arg->getIntValue("index", 0);
 353
 354    SGPath texture_root = globals->get_fg_root();
 355          texture_root.append("Textures");
 356          texture_root.append("Sky");
 357
 358          float lon = arg->getFloatValue("lon-deg", 0.0f);
 359          float lat = arg->getFloatValue("lat-deg", 0.0f);
 360          float alt = arg->getFloatValue("alt-ft",  0.0f);
 361          float x   = arg->getFloatValue("x-offset-m",  0.0f);
 362          float y   = arg->getFloatValue("y-offset-m",  0.0f);
 363
 364    SGSky* thesky = globals->get_renderer()->getSky();
 365    SGCloudField *layer = thesky->get_cloud_layer(l)->get_layer3D();
 366    SGNewCloud cld(texture_root, arg, &seed);
 367    bool success = layer->addCloud(lon, lat, alt, x, y, index, cld.genCloud());
 368
 369    // Adding a 3D cloud immediately makes this layer 3D.
 370    thesky->get_cloud_layer(l)->set_enable3dClouds(true);
 371
 372    return success;
 373  }
 374
 375  /**
 376   * Removes a 3D cloud from a cloud layer
 377   *
 378   * Property arguments
 379   *
 380   * layer - the layer index to remove this cloud from. (defaults to 0)
 381   * index - the cloud index
 382   *
 383   */
 384  bool FGClouds::delete3DCloud(const SGPropertyNode *arg)
 385  {
 386    int l = arg->getIntValue("layer", 0);
 387    int i = arg->getIntValue("index", 0);
 388
 389    SGSky* thesky = globals->get_renderer()->getSky();
 390    SGCloudField *layer = thesky->get_cloud_layer(l)->get_layer3D();
 391          return layer->deleteCloud(i);
 392  }
 393
 394 /**
 395  * Move a cloud within a 3D layer
 396  *
 397  * Property arguments
 398  * layer - the layer index to add this cloud to. (Defaults to 0)
 399  * index - the cloud index to move.
 400  * lon/lat/alt - the position for the cloud
 401  *
 402  */
 403 bool FGClouds::move3DCloud(const SGPropertyNode *arg)
 404  {
 405    int l = arg->getIntValue("layer", 0);
 406    int i = arg->getIntValue("index", 0);
 407       SGSky* thesky = globals->get_renderer()->getSky();
 408
 409          float lon = arg->getFloatValue("lon-deg", 0.0f);
 410          float lat = arg->getFloatValue("lat-deg", 0.0f);
 411          float alt = arg->getFloatValue("alt-ft",  0.0f);
 412          float x   = arg->getFloatValue("x-offset-m",  0.0f);
 413          float y   = arg->getFloatValue("y-offset-m",  0.0f);
 414
 415    SGCloudField *layer = thesky->get_cloud_layer(l)->get_layer3D();
 416          return layer->repositionCloud(i, lon, lat, alt, x, y);
 417  }