simgear/environment/visual_enviro.cxx

   1 // Visual environment helper class
   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 #ifdef HAVE_CONFIG_H
  23 #  include <simgear_config.h>
  24 #endif
  25
  26 #include <simgear/constants.h>
  27 #include <simgear/structure/SGReferenced.hxx>
  28 #include <simgear/structure/SGSharedPtr.hxx>
  29 #include <simgear/math/sg_random.h>
  30 #include <simgear/math/sg_geodesy.hxx>
  31 #include <simgear/math/point3d.hxx>
  32 #include <simgear/math/polar3d.hxx>
  33 #include <simgear/sound/sample_group.hxx>
  34 #include <simgear/scene/sky/cloudfield.hxx>
  35 #include <simgear/scene/sky/newcloud.hxx>
  36 #include <simgear/props/props.hxx>
  37 #include "visual_enviro.hxx"
  38
  39 #include <vector>
  40
  41 using std::vector;
  42
  43
  44 typedef struct {
  45         Point3D         pt;
  46         int                     depth;
  47         int                     prev;
  48 } lt_tree_seg;
  49
  50 #define MAX_RAIN_SLICE  200
  51 static float rainpos[MAX_RAIN_SLICE];
  52 #define MAX_LT_TREE_SEG 400
  53
  54 #define DFL_MIN_LIGHT 0.35
  55 sgVec3 SGEnviro::min_light = {DFL_MIN_LIGHT, DFL_MIN_LIGHT, DFL_MIN_LIGHT};
  56 #define DFL_STREAK_BRIGHT_NEARMOST_LAYER 0.9
  57 SGfloat SGEnviro::streak_bright_nearmost_layer = DFL_STREAK_BRIGHT_NEARMOST_LAYER;
  58 #define DFL_STREAK_BRIGHT_FARMOST_LAYER 0.5
  59 SGfloat SGEnviro::streak_bright_farmost_layer = DFL_STREAK_BRIGHT_FARMOST_LAYER;
  60 #define DFL_STREAK_PERIOD_MAX 2.5
  61 SGfloat SGEnviro::streak_period_max = DFL_STREAK_PERIOD_MAX;
  62 #define DFL_STREAK_PERIOD_CHANGE_PER_KT 0.005
  63 SGfloat SGEnviro::streak_period_change_per_kt = DFL_STREAK_PERIOD_CHANGE_PER_KT;
  64 #define DFL_STREAK_PERIOD_MIN 1.0
  65 SGfloat SGEnviro::streak_period_min = DFL_STREAK_PERIOD_MIN;
  66 #define DFL_STREAK_LENGTH_MIN 0.03
  67 SGfloat SGEnviro::streak_length_min = DFL_STREAK_LENGTH_MIN;
  68 #define DFL_STREAK_LENGTH_CHANGE_PER_KT 0.0005
  69 SGfloat SGEnviro::streak_length_change_per_kt = DFL_STREAK_LENGTH_CHANGE_PER_KT;
  70 #define DFL_STREAK_LENGTH_MAX 0.1
  71 SGfloat SGEnviro::streak_length_max = DFL_STREAK_LENGTH_MAX;
  72 #define DFL_STREAK_COUNT_MIN 40
  73 int SGEnviro::streak_count_min = DFL_STREAK_COUNT_MIN;
  74 #define DFL_STREAK_COUNT_MAX 190
  75 #if (DFL_STREAK_COUNT_MAX > MAX_RAIN_SLICE)
  76 #error "Bad default!"
  77 #endif
  78 int SGEnviro::streak_count_max = DFL_STREAK_COUNT_MAX;
  79 #define DFL_CONE_BASE_RADIUS 15.0
  80 SGfloat SGEnviro::cone_base_radius = DFL_CONE_BASE_RADIUS;
  81 #define DFL_CONE_HEIGHT 30.0
  82 SGfloat SGEnviro::cone_height = DFL_CONE_HEIGHT;
  83
  84
  85 void SGEnviro::config(const SGPropertyNode* n)
  86 {
  87         if (!n)
  88                 return;
  89
  90         const float ml = n->getFloatValue("min-light", DFL_MIN_LIGHT);
  91         sgSetVec3(min_light, ml, ml, ml);
  92
  93         streak_bright_nearmost_layer = n->getFloatValue(
  94                         "streak-brightness-nearmost-layer",
  95                         DFL_STREAK_BRIGHT_NEARMOST_LAYER);
  96         streak_bright_farmost_layer = n->getFloatValue(
  97                         "streak-brightness-farmost-layer",
  98                         DFL_STREAK_BRIGHT_FARMOST_LAYER);
  99
 100         streak_period_max = n->getFloatValue(
 101                         "streak-period-max",
 102                         DFL_STREAK_PERIOD_MAX);
 103         streak_period_min = n->getFloatValue(
 104                         "streak-period-min",
 105                         DFL_STREAK_PERIOD_MIN);
 106         streak_period_change_per_kt = n->getFloatValue(
 107                         "streak-period-change-per-kt",
 108                         DFL_STREAK_PERIOD_CHANGE_PER_KT);
 109
 110         streak_length_max = n->getFloatValue(
 111                         "streak-length-max",
 112                         DFL_STREAK_LENGTH_MAX);
 113         streak_length_min = n->getFloatValue(
 114                         "streak-length-min",
 115                         DFL_STREAK_LENGTH_MIN);
 116         streak_length_change_per_kt = n->getFloatValue(
 117                         "streak-length-change-per-kt",
 118                         DFL_STREAK_LENGTH_CHANGE_PER_KT);
 119
 120         streak_count_min = n->getIntValue(
 121                         "streak-count-min", DFL_STREAK_COUNT_MIN);
 122         streak_count_max = n->getIntValue(
 123                         "streak-count-max", DFL_STREAK_COUNT_MAX);
 124         if (streak_count_max > MAX_RAIN_SLICE)
 125                 streak_count_max = MAX_RAIN_SLICE;
 126
 127         cone_base_radius = n->getFloatValue(
 128                         "cone-base-radius", DFL_CONE_BASE_RADIUS);
 129         cone_height = n->getFloatValue("cone_height", DFL_CONE_HEIGHT);
 130 }
 131
 132
 133 /**
 134  * A class to render lightnings.
 135  */
 136 class SGLightning {
 137 public:
 138     /**
 139      * Build a new lightning.
 140      * The lightning has a limited life time. It will also play a thunder sounder once.
 141      * @param lon lon longitude in degree
 142      * @param lat lat latitude in degree
 143      * @param alt asl of top of lightning
 144      */
 145         SGLightning(double lon, double lat, double alt);
 146         ~SGLightning();
 147         void lt_Render(void);
 148         void lt_build(void);
 149         void lt_build_tree_branch(int tree_nr, Point3D &start, float energy, int nbseg, float segsize);
 150
 151         // contains all the segments of the lightning
 152         lt_tree_seg lt_tree[MAX_LT_TREE_SEG];
 153         // segment count
 154         int             nb_tree;
 155         // position of lightning
 156         double  lon, lat, alt;
 157         int             sequence_count;
 158         // time to live
 159         double  age;
 160 };
 161
 162 typedef vector<SGLightning *> list_of_lightning;
 163 static list_of_lightning lightnings;
 164
 165 SGEnviro sgEnviro;
 166
 167 SGEnviro::SGEnviro() :
 168         view_in_cloud(false),
 169         precipitation_enable_state(true),
 170         precipitation_density(100.0),
 171         precipitation_max_alt(0.0),
 172         turbulence_enable_state(false),
 173         last_cloud_turbulence(0.0),
 174         cloud_turbulence(0.0),
 175         lightning_enable_state(false),
 176         elapsed_time(0.0),
 177         dt(0.0),
 178         sampleGroup(NULL),
 179         snd_active(false),
 180         snd_dist(0.0),
 181         min_time_before_lt(0.0),
 182         fov_width(55.0),
 183         fov_height(55.0)
 184
 185 {
 186         for(int i = 0; i < MAX_RAIN_SLICE ; i++)
 187                 rainpos[i] = sg_random();
 188         radarEcho.reserve(100);
 189 }
 190
 191 SGEnviro::~SGEnviro(void) {
 192         if (sampleGroup) delete sampleGroup;
 193
 194   // OSGFIXME
 195   return;
 196         list_of_lightning::iterator iLightning;
 197         for( iLightning = lightnings.begin() ; iLightning != lightnings.end() ; iLightning++ ) {
 198                 delete (*iLightning);
 199         }
 200         lightnings.clear();
 201 }
 202
 203 void SGEnviro::startOfFrame( sgVec3 p, sgVec3 up, double lon, double lat, double alt, double delta_time) {
 204   // OSGFIXME
 205   return;
 206         view_in_cloud = false;
 207         // ask the impostor cache to do some cleanup
 208         last_cloud_turbulence = cloud_turbulence;
 209         cloud_turbulence = 0.0;
 210         elapsed_time += delta_time;
 211         min_time_before_lt -= delta_time;
 212         dt = delta_time;
 213
 214         sgMat4 T1, LON, LAT;
 215     sgVec3 axis;
 216
 217     sgMakeTransMat4( T1, p );
 218
 219     sgSetVec3( axis, 0.0, 0.0, 1.0 );
 220     sgMakeRotMat4( LON, lon, axis );
 221
 222     sgSetVec3( axis, 0.0, 1.0, 0.0 );
 223     sgMakeRotMat4( LAT, 90.0 - lat, axis );
 224
 225     sgMat4 TRANSFORM;
 226
 227     sgCopyMat4( TRANSFORM, T1 );
 228     sgPreMultMat4( TRANSFORM, LON );
 229     sgPreMultMat4( TRANSFORM, LAT );
 230
 231     sgCoord pos;
 232     sgSetCoord( &pos, TRANSFORM );
 233
 234         sgMakeCoordMat4( transform, &pos );
 235     last_lon = lon;
 236     last_lat = lat;
 237         last_alt = alt;
 238
 239         radarEcho.clear();
 240         precipitation_max_alt = 400.0;
 241 }
 242
 243 void SGEnviro::endOfFrame(void) {
 244 }
 245
 246 double SGEnviro::get_cloud_turbulence(void) const {
 247         return last_cloud_turbulence;
 248 }
 249
 250 // this can be queried to add some turbulence for example
 251 bool SGEnviro::is_view_in_cloud(void) const {
 252         return view_in_cloud;
 253 }
 254 void SGEnviro::set_view_in_cloud(bool incloud) {
 255         view_in_cloud = incloud;
 256 }
 257
 258 bool SGEnviro::get_turbulence_enable_state(void) const {
 259         return turbulence_enable_state;
 260 }
 261
 262 void SGEnviro::set_turbulence_enable_state(bool enable) {
 263         turbulence_enable_state = enable;
 264 }
 265 // rain/snow
 266 float SGEnviro::get_precipitation_density(void) const {
 267         return precipitation_density;
 268 }
 269 bool SGEnviro::get_precipitation_enable_state(void) const {
 270         return precipitation_enable_state;
 271 }
 272
 273 void SGEnviro::set_precipitation_density(float density) {
 274         precipitation_density = density;
 275 }
 276 void SGEnviro::set_precipitation_enable_state(bool enable) {
 277         precipitation_enable_state = enable;
 278 }
 279
 280 // others
 281 bool SGEnviro::get_lightning_enable_state(void) const {
 282         return lightning_enable_state;
 283 }
 284
 285 void SGEnviro::set_lightning_enable_state(bool enable) {
 286         lightning_enable_state = enable;
 287         if( ! enable ) {
 288                 // TODO:cleanup
 289         }
 290 }
 291
 292 void SGEnviro::setLight(sgVec4 adj_fog_color) {
 293   // OSGFIXME
 294   return;
 295         sgCopyVec4( fog_color, adj_fog_color );
 296         if( false ) {
 297         //    ssgGetLight( 0 ) -> setColour( GL_DIFFUSE, l->scene_diffuse() );
 298         }
 299 }
 300 #if 0
 301 void SGEnviro::callback_cloud(float heading, float alt, float radius, int family, float dist, int cloudId) {
 302         // send data to wx radar
 303         // compute turbulence
 304         // draw precipitation
 305         // draw lightning
 306         // compute illumination
 307
 308         // http://www.pilotfriend.com/flight_training/weather/THUNDERSTORM%20HAZARDS1.htm
 309         double turbulence = 0.0;
 310         if( dist < radius * radius * 2.25f ) {
 311                 switch(family) {
 312                         case SGNewCloud::CLFamilly_st:
 313                                 turbulence = 0.2;
 314                                 break;
 315                         case SGNewCloud::CLFamilly_ci:
 316                         case SGNewCloud::CLFamilly_cs:
 317                         case SGNewCloud::CLFamilly_cc:
 318                         case SGNewCloud::CLFamilly_ac:
 319                         case SGNewCloud::CLFamilly_as:
 320                                 turbulence = 0.1;
 321                                 break;
 322                         case SGNewCloud::CLFamilly_sc:
 323                                 turbulence = 0.3;
 324                                 break;
 325                         case SGNewCloud::CLFamilly_ns:
 326                                 turbulence = 0.4;
 327                                 break;
 328                         case SGNewCloud::CLFamilly_cu:
 329                                 turbulence = 0.5;
 330                                 break;
 331                         case SGNewCloud::CLFamilly_cb:
 332                                 turbulence = 0.6;
 333                                 break;
 334                 }
 335                 // full turbulence inside cloud, half in the vicinity
 336                 if( dist > radius * radius )
 337                         turbulence *= 0.5;
 338                 if( turbulence > cloud_turbulence )
 339                         cloud_turbulence = turbulence;
 340                 // we can do 'local' precipitations too
 341         }
 342
 343         // convert to LWC for radar (experimental)
 344         // http://www-das.uwyo.edu/~geerts/cwx/notes/chap08/moist_cloud.html
 345         double LWC = 0.0;
 346         switch(family) {
 347                 case SGNewCloud::CLFamilly_st:
 348                         LWC = 0.29;
 349                         break;
 350                 case SGNewCloud::CLFamilly_cu:
 351                         LWC = 0.27;
 352                         break;
 353                 case SGNewCloud::CLFamilly_cb:
 354                         LWC = 2.0;
 355                         break;
 356                 case SGNewCloud::CLFamilly_sc:
 357                         LWC = 0.44;
 358                         break;
 359                 case SGNewCloud::CLFamilly_ci:
 360                         LWC = 0.03;
 361                         break;
 362                 // no data
 363                 case SGNewCloud::CLFamilly_cs:
 364                 case SGNewCloud::CLFamilly_cc:
 365                 case SGNewCloud::CLFamilly_ac:
 366                 case SGNewCloud::CLFamilly_as:
 367                         LWC = 0.03;
 368                         break;
 369                 case SGNewCloud::CLFamilly_ns:
 370                         LWC = 0.29*2.0;
 371                         break;
 372         }
 373
 374         // add to the list for the wxRadar instrument
 375         if( LWC > 0.0 )
 376                 radarEcho.push_back( SGWxRadarEcho ( heading, alt, radius, dist, LWC, false, cloudId ) );
 377
 378         // NB:data valid only from cockpit view
 379
 380         // spawn a new lightning
 381         if(lightning_enable_state && min_time_before_lt <= 0.0 && (family == SGNewCloud::CLFamilly_cb) &&
 382                 dist < 15000.0 * 15000.0 && sg_random() > 0.9f) {
 383                 double lat, lon;
 384                 Point3D orig, dest;
 385                 orig.setlat(last_lat * SG_DEGREES_TO_RADIANS );
 386                 orig.setlon(last_lon * SG_DEGREES_TO_RADIANS );
 387                 orig.setelev(0.0);
 388                 dist = sgSqrt(dist);
 389                 dest = calc_gc_lon_lat(orig, heading, dist);
 390                 lon = dest.lon() * SG_RADIANS_TO_DEGREES;
 391                 lat = dest.lat() * SG_RADIANS_TO_DEGREES;
 392                 addLightning( lon, lat, alt );
 393
 394                 // reset timer
 395                 min_time_before_lt = 5.0 + sg_random() * 30;
 396                 // DEBUG only
 397 //              min_time_before_lt = 5.0;
 398         }
 399         if( (alt - radius * 0.1) > precipitation_max_alt )
 400                 switch(family) {
 401                         case SGNewCloud::CLFamilly_st:
 402                         case SGNewCloud::CLFamilly_cu:
 403                         case SGNewCloud::CLFamilly_cb:
 404                         case SGNewCloud::CLFamilly_ns:
 405                         case SGNewCloud::CLFamilly_sc:
 406                                 precipitation_max_alt = alt - radius * 0.1;
 407                                 break;
 408                 }
 409 }
 410
 411 #endif
 412
 413 list_of_SGWxRadarEcho *SGEnviro::get_radar_echo(void) {
 414         return &radarEcho;
 415 }
 416
 417 // precipitation rendering code
 418 void SGEnviro::DrawCone2(float baseRadius, float height, int slices, bool down, double rain_norm, double speed) {
 419   // OSGFIXME
 420   return;
 421         sgVec3 light;
 422         sgAddVec3( light, fog_color, min_light );
 423         float da = SG_PI * 2.0f / (float) slices;
 424         // low number = faster
 425         float speedf = streak_period_max - speed * streak_period_change_per_kt;
 426         if( speedf < streak_period_min )
 427                 speedf = streak_period_min;
 428         float lenf = streak_length_min + speed * streak_length_change_per_kt;
 429         if( lenf > streak_length_max )
 430                 lenf = streak_length_max;
 431     float t = fmod((float) elapsed_time, speedf) / speedf;
 432 //      t = 0.1f;
 433         if( !down )
 434                 t = 1.0f - t;
 435         float angle = 0.0f;
 436         //glColor4f(1.0f, 0.7f, 0.7f, 0.9f); // XXX unneeded? overriden below
 437         glBegin(GL_LINES);
 438         if (slices >  MAX_RAIN_SLICE)
 439                 slices = MAX_RAIN_SLICE; // should never happen
 440         for( int i = 0 ; i < slices ; i++ ) {
 441                 float x = cos(angle) * baseRadius;
 442                 float y = sin(angle) * baseRadius;
 443                 angle += da;
 444                 sgVec3 dir = {x, -height, y};
 445
 446                 // rain drops at 2 different speed to simulate depth
 447                 float t1 = (i & 1 ? t : t + t) + rainpos[i];
 448                 if(t1 > 1.0f)   t1 -= 1.0f;
 449                 if(t1 > 1.0f)   t1 -= 1.0f;
 450
 451                 // distant raindrops are more transparent
 452                 float c = t1 * (i & 1 ?
 453                                 streak_bright_farmost_layer
 454                                 : streak_bright_nearmost_layer);
 455                 glColor4f(c * light[0], c * light[1], c * light[2], c);
 456                 sgVec3 p1, p2;
 457                 sgScaleVec3(p1, dir, t1);
 458                 // distant raindrops are shorter
 459                 float t2 = t1 + (i & 1 ? lenf : lenf+lenf);
 460                 sgScaleVec3(p2, dir, t2);
 461
 462                 glVertex3f(p1[0], p1[1] + height, p1[2]);
 463                 glVertex3f(p2[0], p2[1] + height, p2[2]);
 464         }
 465         glEnd();
 466 }
 467
 468 void SGEnviro::drawRain(double pitch, double roll, double heading, double hspeed, double rain_norm) {
 469   // OSGFIXME
 470   return;
 471
 472 #if 0
 473         static int debug_period = 0;
 474         if (debug_period++ == 50) {
 475                 debug_period = 0;
 476                 cout << "drawRain("
 477                         << pitch << ", "
 478                         << roll  << ", "
 479                         << heading << ", "
 480                         << hspeed << ", "
 481                         << rain_norm << ");"
 482                         //" angle = " << angle
 483                         //<< " raindrop(KTS) = " << raindrop_speed_kts
 484                         << endl;
 485         }
 486 #endif
 487
 488
 489         glBindTexture(GL_TEXTURE_2D, 0);
 490
 491         glDisable(GL_DEPTH_TEST);
 492         glShadeModel(GL_SMOOTH);
 493         glEnable(GL_BLEND);
 494         glBlendFunc( GL_ONE, GL_ONE_MINUS_SRC_ALPHA );
 495         glDisable( GL_FOG );
 496         glDisable(GL_LIGHTING);
 497
 498         int slice_count = static_cast<int>(
 499                         (streak_count_min + rain_norm*(streak_count_max-streak_count_min))
 500                                 * precipitation_density / 100.0);
 501
 502         // www.wonderquest.com/falling-raindrops.htm says that
 503         // Raindrop terminal velocity is 5 to 20mph
 504         // Rather than model it accurately (temp, pressure, diameter), and make it
 505         // smaller than terminal when closer to the precipitation cloud base,
 506         // we interpolate in the 5-20mph range according to rain_norm.
 507         double raindrop_speed_kts
 508                 = (5.0 + rain_norm*15.0) * SG_MPH_TO_MPS * SG_MPS_TO_KT;
 509
 510         float angle = atanf(hspeed / raindrop_speed_kts) * SG_RADIANS_TO_DEGREES;
 511         glPushMatrix();
 512                 // the cone rotate with hspeed
 513                 angle = -pitch - angle;
 514                 glRotatef(roll, 0.0, 0.0, 1.0);
 515                 glRotatef(heading, 0.0, 1.0, 0.0);
 516                 glRotatef(angle, 1.0, 0.0, 0.0);
 517
 518                 // up cone
 519                 DrawCone2(cone_base_radius, cone_height,
 520                                 slice_count, true, rain_norm, hspeed);
 521                 // down cone (usually not visible)
 522                 if(angle > 0.0 || heading != 0.0)
 523                         DrawCone2(cone_base_radius, -cone_height,
 524                                         slice_count, false, rain_norm, hspeed);
 525
 526         glPopMatrix();
 527
 528         glEnable(GL_LIGHTING);
 529         glBlendFunc ( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ) ;
 530         glEnable( GL_FOG );
 531         glEnable(GL_DEPTH_TEST);
 532
 533 }
 534
 535 void SGEnviro::set_sampleGroup(SGSampleGroup *sgr) {
 536         sampleGroup = sgr;
 537 }
 538
 539 void SGEnviro::drawPrecipitation(double rain_norm, double snow_norm, double hail_norm, double pitch, double roll, double heading, double hspeed) {
 540   // OSGFIXME
 541   return;
 542         if( precipitation_enable_state && rain_norm > 0.0)
 543           if( precipitation_max_alt >= last_alt )
 544                 drawRain(pitch, roll, heading, hspeed, rain_norm);
 545 }
 546
 547
 548 SGLightning::SGLightning(double _lon, double _lat, double _alt) :
 549         nb_tree(0),
 550         lon(_lon),
 551         lat(_lat),
 552         alt(_alt),
 553         age(1.0 + sg_random() * 4.0)
 554 {
 555 //      sequence_count = 1 + sg_random() * 5.0;
 556         lt_build();
 557 }
 558
 559 SGLightning::~SGLightning() {
 560 }
 561
 562 // lightning rendering code
 563 void SGLightning::lt_build_tree_branch(int tree_nr, Point3D &start, float energy, int nbseg, float segsize) {
 564   // OSGFIXME
 565   return;
 566
 567         sgVec3 dir, newdir;
 568         int nseg = 0;
 569         Point3D pt = start;
 570         if( nbseg == 50 )
 571                 sgSetVec3( dir, 0.0, -1.0, 0.0 );
 572         else {
 573                 sgSetVec3( dir, sg_random() - 0.5f, sg_random() - 0.5f, sg_random() - 0.5f);
 574                 sgNormaliseVec3(dir);
 575         }
 576         if( nb_tree >= MAX_LT_TREE_SEG )
 577                 return;
 578
 579         lt_tree[nb_tree].depth = tree_nr;
 580         nseg = 0;
 581         lt_tree[nb_tree].pt = pt;
 582         lt_tree[nb_tree].prev = -1;
 583         nb_tree ++;
 584
 585         // TODO:check agl
 586         while(nseg < nbseg && pt.y() > 0.0) {
 587         int prev = nb_tree - 1;
 588         nseg++;
 589                 // add a branch
 590         if( energy * sg_random() > 0.8f )
 591                         lt_build_tree_branch(tree_nr + 1, pt, energy * 0.9f, nbseg == 50 ? 10 : static_cast<int>(nbseg * 0.4f), segsize * 0.7f);
 592
 593                 if( nb_tree >= MAX_LT_TREE_SEG )
 594                         return;
 595                 sgSetVec3(newdir, (sg_random() - 0.5f), (sg_random() - 0.5f) - (nbseg == 50 ? 0.5f : 0.0), (sg_random() - 0.5f));
 596                 sgNormaliseVec3(newdir);
 597                 sgAddVec3( dir, newdir);
 598                 sgNormaliseVec3(dir);
 599                 sgVec3 scaleDir;
 600                 sgScaleVec3( scaleDir, dir, segsize * energy * 0.5f );
 601                 pt[PX] += scaleDir[0];
 602                 pt[PY] += scaleDir[1];
 603                 pt[PZ] += scaleDir[2];
 604
 605                 lt_tree[nb_tree].depth = tree_nr;
 606                 lt_tree[nb_tree].pt = pt;
 607                 lt_tree[nb_tree].prev = prev;
 608                 nb_tree ++;
 609         }
 610 }
 611
 612 void SGLightning::lt_build(void) {
 613   // OSGFIXME
 614   return;
 615     Point3D top;
 616     nb_tree = 0;
 617     top[PX] = 0 ;
 618     top[PY] = alt;
 619     top[PZ] = 0;
 620     lt_build_tree_branch(0, top, 1.0, 50, top[PY] / 8.0);
 621         if( ! sgEnviro.sampleGroup )
 622                 return;
 623         Point3D start( sgEnviro.last_lon*SG_DEGREES_TO_RADIANS, sgEnviro.last_lat*SG_DEGREES_TO_RADIANS, 0.0 );
 624         Point3D dest( lon*SG_DEGREES_TO_RADIANS, lat*SG_DEGREES_TO_RADIANS, 0.0 );
 625         double course = 0.0, dist = 0.0;
 626         calc_gc_course_dist( dest, start, &course, &dist );
 627         if( dist < 10000.0 && ! sgEnviro.snd_playing && (dist < sgEnviro.snd_dist || ! sgEnviro.snd_active) ) {
 628                 sgEnviro.snd_timer = 0.0;
 629                 sgEnviro.snd_wait  = dist / 340;
 630                 sgEnviro.snd_dist  = dist;
 631                 sgEnviro.snd_pos_lat = lat;
 632                 sgEnviro.snd_pos_lon = lon;
 633                 sgEnviro.snd_active = true;
 634                 sgEnviro.snd_playing = false;
 635         }
 636 }
 637
 638
 639 void SGLightning::lt_Render(void) {
 640   // OSGFIXME
 641   return;
 642         float flash = 0.5;
 643         if( fmod(sgEnviro.elapsed_time*100.0, 100.0) > 50.0 )
 644                 flash = sg_random() * 0.75f + 0.25f;
 645     float h = lt_tree[0].pt[PY];
 646         sgVec4 col={0.62f, 0.83f, 1.0f, 1.0f};
 647         sgVec4 c;
 648
 649 #define DRAW_SEG() \
 650                         {glColorMaterial(GL_FRONT, GL_EMISSION);  \
 651                         glDisable(GL_LINE_SMOOTH); glBegin(GL_LINES); \
 652                                 glColor4fv(c); \
 653                 glVertex3f(lt_tree[n].pt[PX], lt_tree[n].pt[PZ], lt_tree[n].pt[PY]); \
 654                 glVertex3f(lt_tree[lt_tree[n].prev].pt[PX], lt_tree[lt_tree[n].prev].pt[PZ], lt_tree[lt_tree[n].prev].pt[PY]); \
 655                         glEnd(); glEnable(GL_LINE_SMOOTH);}
 656
 657         glDepthMask( GL_FALSE );
 658         glEnable(GL_BLEND);
 659         glBlendFunc( GL_DST_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
 660         glBindTexture(GL_TEXTURE_2D, 0);
 661
 662         glDisable(GL_LIGHTING);
 663         glDisable( GL_FOG );
 664         glPushMatrix();
 665         sgMat4 modelview, tmp;
 666     // OSGFIXME
 667 //     ssgGetModelviewMatrix( modelview );
 668         sgCopyMat4( tmp, sgEnviro.transform );
 669     sgPostMultMat4( tmp, modelview );
 670     // OSGFIXME
 671 //     ssgLoadModelviewMatrix( tmp );
 672
 673     Point3D start( sgEnviro.last_lon*SG_DEGREES_TO_RADIANS, sgEnviro.last_lat*SG_DEGREES_TO_RADIANS, 0.0 );
 674     Point3D dest( lon*SG_DEGREES_TO_RADIANS, lat*SG_DEGREES_TO_RADIANS, 0.0 );
 675     double course = 0.0, dist = 0.0;
 676     calc_gc_course_dist( dest, start, &course, &dist );
 677     double ax = 0.0, ay = 0.0;
 678     ax = cos(course) * dist;
 679     ay = sin(course) * dist;
 680
 681         glTranslatef( ax, ay, -sgEnviro.last_alt );
 682
 683         sgEnviro.radarEcho.push_back( SGWxRadarEcho ( course, 0.0, 0.0, dist, age, true, 0 ) );
 684
 685         for( int n = 0 ; n < nb_tree ; n++ ) {
 686         if( lt_tree[n].prev < 0 )
 687                         continue;
 688
 689         float t1 = sgLerp(0.5, 1.0, lt_tree[n].pt[PY] / h);
 690                 t1 *= flash;
 691                 if( lt_tree[n].depth >= 2 ) {
 692             glLineWidth(3);
 693                         sgScaleVec4(c, col, t1 * 0.6f);
 694                         DRAW_SEG();
 695                 } else {
 696                         if( lt_tree[n].depth == 0 ) {
 697                 glLineWidth(12);
 698                                 sgScaleVec4(c, col, t1 * 0.5f);
 699                                 DRAW_SEG();
 700
 701                 glLineWidth(6);
 702                                 sgScaleVec4(c, col, t1);
 703                                 DRAW_SEG();
 704                         } else {
 705                 glLineWidth(6);
 706                                 sgScaleVec4(c, col, t1 * 0.7f);
 707                                 DRAW_SEG();
 708                         }
 709
 710             if( lt_tree[n].depth == 0 )
 711                 glLineWidth(3);
 712                         else
 713                 glLineWidth(2);
 714
 715             sgSetVec4(c, t1, t1, t1, t1);
 716                         DRAW_SEG();
 717                 }
 718
 719         }
 720     glLineWidth(1);
 721         glBlendFunc ( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ) ;
 722         glPopMatrix();
 723         glDepthMask( GL_TRUE );
 724         glEnable( GL_FOG );
 725         glEnable(GL_LIGHTING);
 726 }
 727
 728 void SGEnviro::addLightning(double lon, double lat, double alt) {
 729   // OSGFIXME
 730   return;
 731         if( lightnings.size() > 10)
 732                 return;
 733         SGLightning *lt= new SGLightning(lon, lat, alt);
 734         lightnings.push_back(lt);
 735 }
 736
 737 void SGEnviro::drawLightning(void) {
 738   // OSGFIXME
 739   return;
 740         list_of_lightning::iterator iLightning;
 741         // play 'thunder' for lightning
 742         if( snd_active ) {
 743                 if( !snd_playing ) {
 744                         // wait until sound has reached us
 745                         snd_timer += dt;
 746                         if( snd_timer >= snd_wait ) {
 747                                 snd_playing = true;
 748                                 // compute relative position of lightning
 749                                 Point3D start( sgEnviro.last_lon*SG_DEGREES_TO_RADIANS, sgEnviro.last_lat*SG_DEGREES_TO_RADIANS, 0.0 );
 750                                 Point3D dest( snd_pos_lon*SG_DEGREES_TO_RADIANS, snd_pos_lat*SG_DEGREES_TO_RADIANS, 0.0 );
 751                                 double course = 0.0, dist = 0.0;
 752                                 calc_gc_course_dist( dest, start, &course, &dist );
 753                                 double ax = 0.0, ay = 0.0;
 754                                 ax = cos(course) * dist;
 755                                 ay = sin(course) * dist;
 756                                 SGSharedPtr<SGSoundSample> snd = sampleGroup->find("thunder");
 757                                 if( snd ) {
 758                                         SGVec3d pos = SGVec3d(ax, ay, -sgEnviro.last_alt);
 759                                         snd->set_base_position(pos);
 760                                         snd->play_once();
 761                                 }
 762                         }
 763                 } else {
 764                         if( !sampleGroup->is_playing("thunder") ) {
 765                                 snd_active = false;
 766                                 snd_playing = false;
 767                         }
 768                 }
 769
 770         }
 771         if( ! lightning_enable_state )
 772                 return;
 773
 774         for( iLightning = lightnings.begin() ; iLightning != lightnings.end() ; iLightning++ ) {
 775                 if( dt )
 776                         if( sg_random() > 0.95f )
 777                                 (*iLightning)->lt_build();
 778                 (*iLightning)->lt_Render();
 779                 (*iLightning)->age -= dt;
 780                 if( (*iLightning)->age < 0.0 ) {
 781                         delete (*iLightning);
 782                         lightnings.erase( iLightning );
 783                         break;
 784                 }
 785         }
 786
 787 }
 788
 789
 790 void SGEnviro::setFOV( float w, float h ) {
 791         fov_width = w;
 792         fov_height = h;
 793 }
 794
 795 void SGEnviro::getFOV( float &w, float &h ) {
 796         w = fov_width;
 797         h = fov_height;
 798 }