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 <Main/fg_props.hxx>
  28
  29 #include <simgear/constants.h>
  30 #include <simgear/sound/soundmgr_openal.hxx>
  31 #include <simgear/scene/sky/sky.hxx>
  32 #include <simgear/environment/visual_enviro.hxx>
  33 #include <simgear/scene/sky/cloudfield.hxx>
  34 #include <simgear/scene/sky/newcloud.hxx>
  35 #include <simgear/math/sg_random.h>
  36 #include <simgear/props/props_io.hxx>
  37
  38 #include <Main/globals.hxx>
  39 #include <Airports/simple.hxx>
  40 #include <Main/util.hxx>
  41
  42 #include "fgclouds.hxx"
  43
  44 extern SGSky *thesky;
  45
  46
  47 FGClouds::FGClouds() :
  48     snd_lightning(0),
  49     clouds_3d_enabled(false)
  50 {
  51         update_event = 0;
  52 }
  53
  54 FGClouds::~FGClouds() {
  55 }
  56
  57 int FGClouds::get_update_event(void) const {
  58         return update_event;
  59 }
  60
  61 void FGClouds::set_update_event(int count) {
  62         update_event = count;
  63         buildCloudLayers();
  64 }
  65
  66 void FGClouds::init(void) {
  67         if( snd_lightning == NULL ) {
  68                 snd_lightning = new SGSoundSample(globals->get_fg_root().c_str(), "Sounds/thunder.wav");
  69                 snd_lightning->set_max_dist(7000.0f);
  70                 snd_lightning->set_reference_dist(3000.0f);
  71                 SGSoundMgr *smgr = globals->get_soundmgr();
  72                 SGSampleGroup *sgr = smgr->find("weather", true);
  73                 sgr->add( snd_lightning, "thunder" );
  74                 sgEnviro.set_sampleGroup( sgr );
  75         }
  76 }
  77
  78 void FGClouds::buildCloud(SGPropertyNode *cloud_def_root, SGPropertyNode *box_def_root, const string& name, sgVec3 pos, SGCloudField *layer) {
  79         SGPropertyNode *box_def=NULL;
  80         SGPropertyNode *cld_def=NULL;
  81
  82         SGPath texture_root = globals->get_fg_root();
  83         texture_root.append("Textures");
  84         texture_root.append("Sky");
  85
  86         box_def = box_def_root->getChild(name.c_str());
  87
  88         string base_name = name.substr(0,2);
  89         if( !box_def ) {
  90                 if( name[2] == '-' ) {
  91                         box_def = box_def_root->getChild(base_name.c_str());
  92                 }
  93                 if( !box_def )
  94                         return;
  95         }
  96
  97         for(int i = 0; i < box_def->nChildren() ; i++) {
  98                 SGPropertyNode *abox = box_def->getChild(i);
  99                 if( strcmp(abox->getName(), "box") == 0) {
 100                         double x = abox->getDoubleValue("x") + pos[0];
 101                         double y = abox->getDoubleValue("y") + pos[1];
 102                         double z = abox->getDoubleValue("z") + pos[2];
 103                         SGVec3f newpos = SGVec3f(x, z, y);
 104
 105                         string type = abox->getStringValue("type", "cu-small");
 106
 107                         cld_def = cloud_def_root->getChild(type.c_str());
 108                         if ( !cld_def ) return;
 109
 110                         double min_width = cld_def->getDoubleValue("min-cloud-width-m", 500.0);
 111                         double max_width = cld_def->getDoubleValue("max-cloud-width-m", 1000.0);
 112                         double min_height = cld_def->getDoubleValue("min-cloud-height-m", min_width);
 113                         double max_height = cld_def->getDoubleValue("max-cloud-height-m", max_width);
 114                         double min_sprite_width = cld_def->getDoubleValue("min-sprite-width-m", 200.0);
 115                         double max_sprite_width = cld_def->getDoubleValue("max-sprite-width-m", min_sprite_width);
 116                         double min_sprite_height = cld_def->getDoubleValue("min-sprite-height-m", min_sprite_width);
 117                         double max_sprite_height = cld_def->getDoubleValue("max-sprite-height-m", max_sprite_width);
 118                         int num_sprites = cld_def->getIntValue("num-sprites", 20);
 119                         int num_textures_x = cld_def->getIntValue("num-textures-x", 1);
 120                         int num_textures_y = cld_def->getIntValue("num-textures-y", 1);
 121                         double bottom_shade = cld_def->getDoubleValue("bottom-shade", 1.0);
 122                         string texture = cld_def->getStringValue("texture", "cl_cumulus.rgb");
 123
 124                         SGNewCloud *cld =
 125                                 new SGNewCloud(type,
 126                                         texture_root,
 127                                         texture,
 128                                         min_width,
 129                                         max_width,
 130                                         min_height,
 131                                         max_height,
 132                                         min_sprite_width,
 133                                         max_sprite_width,
 134                                         min_sprite_height,
 135                                         max_sprite_height,
 136                                         bottom_shade,
 137                                         num_sprites,
 138                                         num_textures_x,
 139                                         num_textures_y);
 140                         layer->addCloud(newpos, cld);
 141                 }
 142         }
 143 }
 144
 145 void FGClouds::buildLayer(int iLayer, const string& name, double alt, double coverage) {
 146         struct {
 147                 string name;
 148                 double count;
 149         } tCloudVariety[20];
 150         int CloudVarietyCount = 0;
 151         double totalCount = 0.0;
 152
 153         SGPropertyNode *cloud_def_root = fgGetNode("/environment/cloudlayers/clouds", false);
 154         SGPropertyNode *box_def_root   = fgGetNode("/environment/cloudlayers/boxes", false);
 155         SGPropertyNode *layer_def_root = fgGetNode("/environment/cloudlayers/layers", false);
 156         SGCloudField *layer = thesky->get_cloud_layer(iLayer)->get_layer3D();
 157         layer->clear();
 158
 159         // If we don't have the required properties, then render the cloud in 2D
 160         if ((! clouds_3d_enabled) || coverage == 0.0 ||
 161                 layer_def_root == NULL || cloud_def_root == NULL || box_def_root == NULL) {
 162                         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(false);
 163                         return;
 164         }
 165
 166         // If we can't find a definition for this cloud type, then render the cloud in 2D
 167         SGPropertyNode *layer_def=NULL;
 168         layer_def = layer_def_root->getChild(name.c_str());
 169         if( !layer_def ) {
 170                 if( name[2] == '-' ) {
 171                         string base_name = name.substr(0,2);
 172                         layer_def = layer_def_root->getChild(base_name.c_str());
 173                 }
 174                 if( !layer_def ) {
 175                         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(false);
 176                         return;
 177                 }
 178         }
 179
 180         // At this point, we know we've got some 3D clouds to generate.
 181         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(true);
 182
 183         double grid_x_size = layer_def->getDoubleValue("grid-x-size", 1000.0);
 184         double grid_y_size = layer_def->getDoubleValue("grid-y-size", 1000.0);
 185         double grid_x_rand = layer_def->getDoubleValue("grid-x-rand", grid_x_size);
 186         double grid_y_rand = layer_def->getDoubleValue("grid-y-rand", grid_y_size);
 187         double grid_z_rand = layer_def->getDoubleValue("grid-z-rand");
 188
 189         for(int i = 0; i < layer_def->nChildren() ; i++) {
 190                 SGPropertyNode *acloud = layer_def->getChild(i);
 191                 if( strcmp(acloud->getName(), "cloud") == 0) {
 192                         string cloud_name = acloud->getStringValue("name");
 193                         tCloudVariety[CloudVarietyCount].name = cloud_name;
 194                         double count = acloud->getDoubleValue("count", 1.0);
 195                         tCloudVariety[CloudVarietyCount].count = count;
 196                         int variety = 0;
 197                         cloud_name = cloud_name + "-%d";
 198                         char variety_name[50];
 199                         do {
 200                                 variety++;
 201                                 snprintf(variety_name, sizeof(variety_name) - 1, cloud_name.c_str(), variety);
 202                         } while( box_def_root->getChild(variety_name, 0, false) );
 203
 204                         totalCount += count;
 205                         if( CloudVarietyCount < 20 )
 206                                 CloudVarietyCount++;
 207                 }
 208         }
 209         totalCount = 1.0 / totalCount;
 210
 211         for(double px = 0.0; px < SGCloudField::fieldSize; px += grid_x_size) {
 212                 for(double py = 0.0; py < SGCloudField::fieldSize; py += grid_y_size) {
 213                         double x = px + grid_x_rand * (sg_random() - 0.5) - (SGCloudField::fieldSize / 2.0);
 214                         double y = py + grid_y_rand * (sg_random() - 0.5) - (SGCloudField::fieldSize / 2.0);
 215                         double z = grid_z_rand * (sg_random() - 0.5);
 216
 217                         if (sg_random() < coverage) {
 218                                 double choice = sg_random();
 219
 220                                 for(int i = 0; i < CloudVarietyCount ; i ++) {
 221                                         choice -= tCloudVariety[i].count * totalCount;
 222                                         if( choice <= 0.0 ) {
 223                                                 sgVec3 pos={x,z,y};
 224
 225                                                 buildCloud(cloud_def_root,
 226                                                         box_def_root,
 227                                                         tCloudVariety[i].name,
 228                                                         pos,
 229                                                         layer);
 230                                                 break;
 231                                         }
 232                                 }
 233                         }
 234                 }
 235         }
 236
 237         // Now we've built any clouds, enable them and set the density (coverage)
 238         //layer->setCoverage(coverage);
 239         //layer->applyCoverage();
 240         thesky->get_cloud_layer(iLayer)->set_enable3dClouds(clouds_3d_enabled);
 241 }
 242
 243 void FGClouds::buildCloudLayers(void) {
 244         SGPropertyNode *metar_root = fgGetNode("/environment", true);
 245
 246         //double wind_speed_kt   = metar_root->getDoubleValue("wind-speed-kt");
 247         double temperature_degc  = metar_root->getDoubleValue("temperature-sea-level-degc");
 248         double dewpoint_degc     = metar_root->getDoubleValue("dewpoint-sea-level-degc");
 249         double pressure_mb              = metar_root->getDoubleValue("pressure-sea-level-inhg") * SG_INHG_TO_PA / 100.0;
 250
 251         double dewp = pow(10.0, 7.5 * dewpoint_degc / (237.7 + dewpoint_degc));
 252         double temp = pow(10.0, 7.5 * temperature_degc / (237.7 + temperature_degc));
 253         double rel_humidity = dewp * 100 / temp;
 254
 255         // formule d'Epsy, base d'un cumulus
 256         double cumulus_base = 122.0 * (temperature_degc - dewpoint_degc);
 257         double stratus_base = 100.0 * (100.0 - rel_humidity) * SG_FEET_TO_METER;
 258
 259         for(int iLayer = 0 ; iLayer < thesky->get_cloud_layer_count(); iLayer++) {
 260                 SGPropertyNode *cloud_root = fgGetNode("/environment/clouds/layer", iLayer, true);
 261
 262                 double alt_ft = cloud_root->getDoubleValue("elevation-ft");
 263                 double alt_m = alt_ft * SG_FEET_TO_METER;
 264                 string coverage = cloud_root->getStringValue("coverage");
 265
 266                 double coverage_norm = 0.0;
 267                 if( coverage == "few" )
 268                         coverage_norm = 2.0/8.0;        // <1-2
 269                 else if( coverage == "scattered" )
 270                         coverage_norm = 4.0/8.0;        // 3-4
 271                 else if( coverage == "broken" )
 272                         coverage_norm = 6.0/8.0;        // 5-7
 273                 else if( coverage == "overcast" )
 274                         coverage_norm = 8.0/8.0;        // 8
 275
 276                 string layer_type = "nn";
 277                 if( coverage == "cirrus" ) {
 278                         layer_type = "ci";
 279                 } else if( alt_ft > 16500 ) {
 280 //                      layer_type = "ci|cs|cc";
 281                         layer_type = "ci";
 282                 } else if( alt_ft > 6500 ) {
 283 //                      layer_type = "as|ac|ns";
 284                         layer_type = "ac";
 285                         if( pressure_mb < 1005.0 && coverage_norm >= 0.5 )
 286                                 layer_type = "ns";
 287                 } else {
 288 //                      layer_type = "st|cu|cb|sc";
 289                         if( cumulus_base * 0.80 < alt_m && cumulus_base * 1.20 > alt_m ) {
 290                                 // +/- 20% from cumulus probable base
 291                                 layer_type = "cu";
 292                         } else if( stratus_base * 0.80 < alt_m && stratus_base * 1.40 > alt_m ) {
 293                                 // +/- 20% from stratus probable base
 294                                 layer_type = "st";
 295                         } else {
 296                                 // above formulae is far from perfect
 297                                 if ( alt_ft < 2000 )
 298                                         layer_type = "st";
 299                                 else if( alt_ft < 4500 )
 300                                         layer_type = "cu";
 301                                 else
 302                                         layer_type = "sc";
 303                         }
 304                 }
 305
 306                 buildLayer(iLayer, layer_type, alt_m, coverage_norm);
 307         }
 308 }
 309
 310 void FGClouds::set_3dClouds(bool enable)
 311 {
 312   if (enable != clouds_3d_enabled) {
 313     clouds_3d_enabled = enable;
 314     buildCloudLayers();
 315   }
 316 }
 317
 318 bool FGClouds::get_3dClouds() const {
 319   return clouds_3d_enabled;
 320 }
 321