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/sound/sample_group.hxx>
  32 #include <simgear/scene/sky/cloudfield.hxx>
  33 #include <simgear/scene/sky/newcloud.hxx>
  34 #include <simgear/props/props.hxx>
  35 #include "visual_enviro.hxx"
  36
  37 #include <vector>
  38
  39 using std::vector;
  40
  41
  42 typedef struct {
  43         SGVec3d         pt;
  44         int                     depth;
  45         int                     prev;
  46 } lt_tree_seg;
  47
  48 #define MAX_RAIN_SLICE  200
  49 static float rainpos[MAX_RAIN_SLICE];
  50 #define MAX_LT_TREE_SEG 400
  51
  52 #define DFL_MIN_LIGHT 0.35
  53 sgVec3 SGEnviro::min_light = {DFL_MIN_LIGHT, DFL_MIN_LIGHT, DFL_MIN_LIGHT};
  54 #define DFL_STREAK_BRIGHT_NEARMOST_LAYER 0.9
  55 SGfloat SGEnviro::streak_bright_nearmost_layer = DFL_STREAK_BRIGHT_NEARMOST_LAYER;
  56 #define DFL_STREAK_BRIGHT_FARMOST_LAYER 0.5
  57 SGfloat SGEnviro::streak_bright_farmost_layer = DFL_STREAK_BRIGHT_FARMOST_LAYER;
  58 #define DFL_STREAK_PERIOD_MAX 2.5
  59 SGfloat SGEnviro::streak_period_max = DFL_STREAK_PERIOD_MAX;
  60 #define DFL_STREAK_PERIOD_CHANGE_PER_KT 0.005
  61 SGfloat SGEnviro::streak_period_change_per_kt = DFL_STREAK_PERIOD_CHANGE_PER_KT;
  62 #define DFL_STREAK_PERIOD_MIN 1.0
  63 SGfloat SGEnviro::streak_period_min = DFL_STREAK_PERIOD_MIN;
  64 #define DFL_STREAK_LENGTH_MIN 0.03
  65 SGfloat SGEnviro::streak_length_min = DFL_STREAK_LENGTH_MIN;
  66 #define DFL_STREAK_LENGTH_CHANGE_PER_KT 0.0005
  67 SGfloat SGEnviro::streak_length_change_per_kt = DFL_STREAK_LENGTH_CHANGE_PER_KT;
  68 #define DFL_STREAK_LENGTH_MAX 0.1
  69 SGfloat SGEnviro::streak_length_max = DFL_STREAK_LENGTH_MAX;
  70 #define DFL_STREAK_COUNT_MIN 40
  71 int SGEnviro::streak_count_min = DFL_STREAK_COUNT_MIN;
  72 #define DFL_STREAK_COUNT_MAX 190
  73 #if (DFL_STREAK_COUNT_MAX > MAX_RAIN_SLICE)
  74 #error "Bad default!"
  75 #endif
  76 int SGEnviro::streak_count_max = DFL_STREAK_COUNT_MAX;
  77 #define DFL_CONE_BASE_RADIUS 15.0
  78 SGfloat SGEnviro::cone_base_radius = DFL_CONE_BASE_RADIUS;
  79 #define DFL_CONE_HEIGHT 30.0
  80 SGfloat SGEnviro::cone_height = DFL_CONE_HEIGHT;
  81
  82
  83 void SGEnviro::config(const SGPropertyNode* n)
  84 {
  85         if (!n)
  86                 return;
  87
  88         const float ml = n->getFloatValue("min-light", DFL_MIN_LIGHT);
  89         sgSetVec3(min_light, ml, ml, ml);
  90
  91         streak_bright_nearmost_layer = n->getFloatValue(
  92                         "streak-brightness-nearmost-layer",
  93                         DFL_STREAK_BRIGHT_NEARMOST_LAYER);
  94         streak_bright_farmost_layer = n->getFloatValue(
  95                         "streak-brightness-farmost-layer",
  96                         DFL_STREAK_BRIGHT_FARMOST_LAYER);
  97
  98         streak_period_max = n->getFloatValue(
  99                         "streak-period-max",
 100                         DFL_STREAK_PERIOD_MAX);
 101         streak_period_min = n->getFloatValue(
 102                         "streak-period-min",
 103                         DFL_STREAK_PERIOD_MIN);
 104         streak_period_change_per_kt = n->getFloatValue(
 105                         "streak-period-change-per-kt",
 106                         DFL_STREAK_PERIOD_CHANGE_PER_KT);
 107
 108         streak_length_max = n->getFloatValue(
 109                         "streak-length-max",
 110                         DFL_STREAK_LENGTH_MAX);
 111         streak_length_min = n->getFloatValue(
 112                         "streak-length-min",
 113                         DFL_STREAK_LENGTH_MIN);
 114         streak_length_change_per_kt = n->getFloatValue(
 115                         "streak-length-change-per-kt",
 116                         DFL_STREAK_LENGTH_CHANGE_PER_KT);
 117
 118         streak_count_min = n->getIntValue(
 119                         "streak-count-min", DFL_STREAK_COUNT_MIN);
 120         streak_count_max = n->getIntValue(
 121                         "streak-count-max", DFL_STREAK_COUNT_MAX);
 122         if (streak_count_max > MAX_RAIN_SLICE)
 123                 streak_count_max = MAX_RAIN_SLICE;
 124
 125         cone_base_radius = n->getFloatValue(
 126                         "cone-base-radius", DFL_CONE_BASE_RADIUS);
 127         cone_height = n->getFloatValue("cone_height", DFL_CONE_HEIGHT);
 128 }
 129
 130
 131 /**
 132  * A class to render lightnings.
 133  */
 134 class SGLightning {
 135 public:
 136     /**
 137      * Build a new lightning.
 138      * The lightning has a limited life time. It will also play a thunder sounder once.
 139      * @param lon lon longitude in degree
 140      * @param lat lat latitude in degree
 141      * @param alt asl of top of lightning
 142      */
 143         SGLightning(double lon, double lat, double alt);
 144         ~SGLightning();
 145         void lt_Render(void);
 146         void lt_build(void);
 147         void lt_build_tree_branch(int tree_nr, SGVec3d &start, float energy, int nbseg, float segsize);
 148
 149         // contains all the segments of the lightning
 150         lt_tree_seg lt_tree[MAX_LT_TREE_SEG];
 151         // segment count
 152         int             nb_tree;
 153         // position of lightning
 154         double  lon, lat, alt;
 155         int             sequence_count;
 156         // time to live
 157         double  age;
 158 };
 159
 160 typedef vector<SGLightning *> list_of_lightning;
 161 static list_of_lightning lightnings;
 162
 163 SGEnviro sgEnviro;
 164
 165 SGEnviro::SGEnviro() :
 166         view_in_cloud(false),
 167         precipitation_enable_state(true),
 168         precipitation_density(100.0),
 169         precipitation_max_alt(0.0),
 170         turbulence_enable_state(false),
 171         last_cloud_turbulence(0.0),
 172         cloud_turbulence(0.0),
 173         lightning_enable_state(false),
 174         elapsed_time(0.0),
 175         dt(0.0),
 176         sampleGroup(NULL),
 177         snd_active(false),
 178         snd_dist(0.0),
 179         min_time_before_lt(0.0),
 180         fov_width(55.0),
 181         fov_height(55.0)
 182
 183 {
 184         for(int i = 0; i < MAX_RAIN_SLICE ; i++)
 185                 rainpos[i] = sg_random();
 186         radarEcho.reserve(100);
 187 }
 188
 189 SGEnviro::~SGEnviro(void) {
 190         if (sampleGroup) delete sampleGroup;
 191
 192   // OSGFIXME
 193   return;
 194         list_of_lightning::iterator iLightning;
 195         for( iLightning = lightnings.begin() ; iLightning != lightnings.end() ; iLightning++ ) {
 196                 delete (*iLightning);
 197         }
 198         lightnings.clear();
 199 }
 200
 201 void SGEnviro::startOfFrame( sgVec3 p, sgVec3 up, double lon, double lat, double alt, double delta_time) {
 202   // OSGFIXME
 203   return;
 204         view_in_cloud = false;
 205         // ask the impostor cache to do some cleanup
 206         last_cloud_turbulence = cloud_turbulence;
 207         cloud_turbulence = 0.0;
 208         elapsed_time += delta_time;
 209         min_time_before_lt -= delta_time;
 210         dt = delta_time;
 211
 212         sgMat4 T1, LON, LAT;
 213     sgVec3 axis;
 214
 215     sgMakeTransMat4( T1, p );
 216
 217     sgSetVec3( axis, 0.0, 0.0, 1.0 );
 218     sgMakeRotMat4( LON, lon, axis );
 219
 220     sgSetVec3( axis, 0.0, 1.0, 0.0 );
 221     sgMakeRotMat4( LAT, 90.0 - lat, axis );
 222
 223     sgMat4 TRANSFORM;
 224
 225     sgCopyMat4( TRANSFORM, T1 );
 226     sgPreMultMat4( TRANSFORM, LON );
 227     sgPreMultMat4( TRANSFORM, LAT );
 228
 229     sgCoord pos;
 230     sgSetCoord( &pos, TRANSFORM );
 231
 232         sgMakeCoordMat4( transform, &pos );
 233     last_lon = lon;
 234     last_lat = lat;
 235         last_alt = alt;
 236
 237         radarEcho.clear();
 238         precipitation_max_alt = 400.0;
 239 }
 240
 241 void SGEnviro::endOfFrame(void) {
 242 }
 243
 244 double SGEnviro::get_cloud_turbulence(void) const {
 245         return last_cloud_turbulence;
 246 }
 247
 248 // this can be queried to add some turbulence for example
 249 bool SGEnviro::is_view_in_cloud(void) const {
 250         return view_in_cloud;
 251 }
 252 void SGEnviro::set_view_in_cloud(bool incloud) {
 253         view_in_cloud = incloud;
 254 }
 255
 256 bool SGEnviro::get_turbulence_enable_state(void) const {
 257         return turbulence_enable_state;
 258 }
 259
 260 void SGEnviro::set_turbulence_enable_state(bool enable) {
 261         turbulence_enable_state = enable;
 262 }
 263 // rain/snow
 264 float SGEnviro::get_precipitation_density(void) const {
 265         return precipitation_density;
 266 }
 267 bool SGEnviro::get_precipitation_enable_state(void) const {
 268         return precipitation_enable_state;
 269 }
 270
 271 void SGEnviro::set_precipitation_density(float density) {
 272         precipitation_density = density;
 273 }
 274 void SGEnviro::set_precipitation_enable_state(bool enable) {
 275         precipitation_enable_state = enable;
 276 }
 277
 278 // others
 279 bool SGEnviro::get_lightning_enable_state(void) const {
 280         return lightning_enable_state;
 281 }
 282
 283 void SGEnviro::set_lightning_enable_state(bool enable) {
 284         lightning_enable_state = enable;
 285         if( ! enable ) {
 286                 // TODO:cleanup
 287         }
 288 }
 289
 290 void SGEnviro::setLight(sgVec4 adj_fog_color) {
 291   // OSGFIXME
 292   return;
 293         sgCopyVec4( fog_color, adj_fog_color );
 294         if( false ) {
 295         //    ssgGetLight( 0 ) -> setColour( GL_DIFFUSE, l->scene_diffuse() );
 296         }
 297 }
 298 #if 0
 299 void SGEnviro::callback_cloud(float heading, float alt, float radius, int family, float dist, int cloudId) {
 300         // send data to wx radar
 301         // compute turbulence
 302         // draw precipitation
 303         // draw lightning
 304         // compute illumination
 305
 306         // http://www.pilotfriend.com/flight_training/weather/THUNDERSTORM%20HAZARDS1.htm
 307         double turbulence = 0.0;
 308         if( dist < radius * radius * 2.25f ) {
 309                 switch(family) {
 310                         case SGNewCloud::CLFamilly_st:
 311                                 turbulence = 0.2;
 312                                 break;
 313                         case SGNewCloud::CLFamilly_ci:
 314                         case SGNewCloud::CLFamilly_cs:
 315                         case SGNewCloud::CLFamilly_cc:
 316                         case SGNewCloud::CLFamilly_ac:
 317                         case SGNewCloud::CLFamilly_as:
 318                                 turbulence = 0.1;
 319                                 break;
 320                         case SGNewCloud::CLFamilly_sc:
 321                                 turbulence = 0.3;
 322                                 break;
 323                         case SGNewCloud::CLFamilly_ns:
 324                                 turbulence = 0.4;
 325                                 break;
 326                         case SGNewCloud::CLFamilly_cu:
 327                                 turbulence = 0.5;
 328                                 break;
 329                         case SGNewCloud::CLFamilly_cb:
 330                                 turbulence = 0.6;
 331                                 break;
 332                 }
 333                 // full turbulence inside cloud, half in the vicinity
 334                 if( dist > radius * radius )
 335                         turbulence *= 0.5;
 336                 if( turbulence > cloud_turbulence )
 337                         cloud_turbulence = turbulence;
 338                 // we can do 'local' precipitations too
 339         }
 340
 341         // convert to LWC for radar (experimental)
 342         // http://www-das.uwyo.edu/~geerts/cwx/notes/chap08/moist_cloud.html
 343         double LWC = 0.0;
 344         switch(family) {
 345                 case SGNewCloud::CLFamilly_st:
 346                         LWC = 0.29;
 347                         break;
 348                 case SGNewCloud::CLFamilly_cu:
 349                         LWC = 0.27;
 350                         break;
 351                 case SGNewCloud::CLFamilly_cb:
 352                         LWC = 2.0;
 353                         break;
 354                 case SGNewCloud::CLFamilly_sc:
 355                         LWC = 0.44;
 356                         break;
 357                 case SGNewCloud::CLFamilly_ci:
 358                         LWC = 0.03;
 359                         break;
 360                 // no data
 361                 case SGNewCloud::CLFamilly_cs:
 362                 case SGNewCloud::CLFamilly_cc:
 363                 case SGNewCloud::CLFamilly_ac:
 364                 case SGNewCloud::CLFamilly_as:
 365                         LWC = 0.03;
 366                         break;
 367                 case SGNewCloud::CLFamilly_ns:
 368                         LWC = 0.29*2.0;
 369                         break;
 370         }
 371
 372         // add to the list for the wxRadar instrument
 373         if( LWC > 0.0 )
 374                 radarEcho.push_back( SGWxRadarEcho ( heading, alt, radius, dist, LWC, false, cloudId ) );
 375
 376         // NB:data valid only from cockpit view
 377
 378         // spawn a new lightning
 379         if(lightning_enable_state && min_time_before_lt <= 0.0 && (family == SGNewCloud::CLFamilly_cb) &&
 380                 dist < 15000.0 * 15000.0 && sg_random() > 0.9f) {
 381                 double lat, lon;
 382                 SGVec3d orig, dest;
 383                 orig.setlat(last_lat * SG_DEGREES_TO_RADIANS );
 384                 orig.setlon(last_lon * SG_DEGREES_TO_RADIANS );
 385                 orig.setelev(0.0);
 386                 dist = sgSqrt(dist);
 387                 dest = calc_gc_lon_lat(orig, heading, dist);
 388                 lon = dest.lon() * SG_RADIANS_TO_DEGREES;
 389                 lat = dest.lat() * SG_RADIANS_TO_DEGREES;
 390                 addLightning( lon, lat, alt );
 391
 392                 // reset timer
 393                 min_time_before_lt = 5.0 + sg_random() * 30;
 394                 // DEBUG only
 395 //              min_time_before_lt = 5.0;
 396         }
 397         if( (alt - radius * 0.1) > precipitation_max_alt )
 398                 switch(family) {
 399                         case SGNewCloud::CLFamilly_st:
 400                         case SGNewCloud::CLFamilly_cu:
 401                         case SGNewCloud::CLFamilly_cb:
 402                         case SGNewCloud::CLFamilly_ns:
 403                         case SGNewCloud::CLFamilly_sc:
 404                                 precipitation_max_alt = alt - radius * 0.1;
 405                                 break;
 406                 }
 407 }
 408
 409 #endif
 410
 411 list_of_SGWxRadarEcho *SGEnviro::get_radar_echo(void) {
 412         return &radarEcho;
 413 }
 414
 415 // precipitation rendering code
 416 void SGEnviro::DrawCone2(float baseRadius, float height, int slices, bool down, double rain_norm, double speed) {
 417   // OSGFIXME
 418   return;
 419         sgVec3 light;
 420         sgAddVec3( light, fog_color, min_light );
 421         float da = SG_PI * 2.0f / (float) slices;
 422         // low number = faster
 423         float speedf = streak_period_max - speed * streak_period_change_per_kt;
 424         if( speedf < streak_period_min )
 425                 speedf = streak_period_min;
 426         float lenf = streak_length_min + speed * streak_length_change_per_kt;
 427         if( lenf > streak_length_max )
 428                 lenf = streak_length_max;
 429     float t = fmod((float) elapsed_time, speedf) / speedf;
 430 //      t = 0.1f;
 431         if( !down )
 432                 t = 1.0f - t;
 433         float angle = 0.0f;
 434         //glColor4f(1.0f, 0.7f, 0.7f, 0.9f); // XXX unneeded? overriden below
 435         glBegin(GL_LINES);
 436         if (slices >  MAX_RAIN_SLICE)
 437                 slices = MAX_RAIN_SLICE; // should never happen
 438         for( int i = 0 ; i < slices ; i++ ) {
 439                 float x = cos(angle) * baseRadius;
 440                 float y = sin(angle) * baseRadius;
 441                 angle += da;
 442                 sgVec3 dir = {x, -height, y};
 443
 444                 // rain drops at 2 different speed to simulate depth
 445                 float t1 = (i & 1 ? t : t + t) + rainpos[i];
 446                 if(t1 > 1.0f)   t1 -= 1.0f;
 447                 if(t1 > 1.0f)   t1 -= 1.0f;
 448
 449                 // distant raindrops are more transparent
 450                 float c = t1 * (i & 1 ?
 451                                 streak_bright_farmost_layer
 452                                 : streak_bright_nearmost_layer);
 453                 glColor4f(c * light[0], c * light[1], c * light[2], c);
 454                 sgVec3 p1, p2;
 455                 sgScaleVec3(p1, dir, t1);
 456                 // distant raindrops are shorter
 457                 float t2 = t1 + (i & 1 ? lenf : lenf+lenf);
 458                 sgScaleVec3(p2, dir, t2);
 459
 460                 glVertex3f(p1[0], p1[1] + height, p1[2]);
 461                 glVertex3f(p2[0], p2[1] + height, p2[2]);
 462         }
 463         glEnd();
 464 }
 465
 466 void SGEnviro::drawRain(double pitch, double roll, double heading, double hspeed, double rain_norm) {
 467   // OSGFIXME
 468   return;
 469
 470 #if 0
 471         static int debug_period = 0;
 472         if (debug_period++ == 50) {
 473                 debug_period = 0;
 474                 cout << "drawRain("
 475                         << pitch << ", "
 476                         << roll  << ", "
 477                         << heading << ", "
 478                         << hspeed << ", "
 479                         << rain_norm << ");"
 480                         //" angle = " << angle
 481                         //<< " raindrop(KTS) = " << raindrop_speed_kts
 482                         << endl;
 483         }
 484 #endif
 485
 486
 487         glBindTexture(GL_TEXTURE_2D, 0);
 488
 489         glDisable(GL_DEPTH_TEST);
 490         glShadeModel(GL_SMOOTH);
 491         glEnable(GL_BLEND);
 492         glBlendFunc( GL_ONE, GL_ONE_MINUS_SRC_ALPHA );
 493         glDisable( GL_FOG );
 494         glDisable(GL_LIGHTING);
 495
 496         int slice_count = static_cast<int>(
 497                         (streak_count_min + rain_norm*(streak_count_max-streak_count_min))
 498                                 * precipitation_density / 100.0);
 499
 500         // www.wonderquest.com/falling-raindrops.htm says that
 501         // Raindrop terminal velocity is 5 to 20mph
 502         // Rather than model it accurately (temp, pressure, diameter), and make it
 503         // smaller than terminal when closer to the precipitation cloud base,
 504         // we interpolate in the 5-20mph range according to rain_norm.
 505         double raindrop_speed_kts
 506                 = (5.0 + rain_norm*15.0) * SG_MPH_TO_MPS * SG_MPS_TO_KT;
 507
 508         float angle = atanf(hspeed / raindrop_speed_kts) * SG_RADIANS_TO_DEGREES;
 509         glPushMatrix();
 510                 // the cone rotate with hspeed
 511                 angle = -pitch - angle;
 512                 glRotatef(roll, 0.0, 0.0, 1.0);
 513                 glRotatef(heading, 0.0, 1.0, 0.0);
 514                 glRotatef(angle, 1.0, 0.0, 0.0);
 515
 516                 // up cone
 517                 DrawCone2(cone_base_radius, cone_height,
 518                                 slice_count, true, rain_norm, hspeed);
 519                 // down cone (usually not visible)
 520                 if(angle > 0.0 || heading != 0.0)
 521                         DrawCone2(cone_base_radius, -cone_height,
 522                                         slice_count, false, rain_norm, hspeed);
 523
 524         glPopMatrix();
 525
 526         glEnable(GL_LIGHTING);
 527         glBlendFunc ( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ) ;
 528         glEnable( GL_FOG );
 529         glEnable(GL_DEPTH_TEST);
 530
 531 }
 532
 533 void SGEnviro::set_sampleGroup(SGSampleGroup *sgr) {
 534         sampleGroup = sgr;
 535 }
 536
 537 void SGEnviro::drawPrecipitation(double rain_norm, double snow_norm, double hail_norm, double pitch, double roll, double heading, double hspeed) {
 538   // OSGFIXME
 539   return;
 540         if( precipitation_enable_state && rain_norm > 0.0)
 541           if( precipitation_max_alt >= last_alt )
 542                 drawRain(pitch, roll, heading, hspeed, rain_norm);
 543 }
 544
 545
 546 SGLightning::SGLightning(double _lon, double _lat, double _alt) :
 547         nb_tree(0),
 548         lon(_lon),
 549         lat(_lat),
 550         alt(_alt),
 551         age(1.0 + sg_random() * 4.0)
 552 {
 553 //      sequence_count = 1 + sg_random() * 5.0;
 554         lt_build();
 555 }
 556
 557 SGLightning::~SGLightning() {
 558 }
 559
 560 // lightning rendering code
 561 void SGLightning::lt_build_tree_branch(int tree_nr, SGVec3d &start, float energy, int nbseg, float segsize) {
 562   // OSGFIXME
 563   return;
 564 }
 565
 566 void SGLightning::lt_build(void) {
 567   // OSGFIXME
 568   return;
 569
 570 }
 571
 572
 573 void SGLightning::lt_Render(void) {
 574   // OSGFIXME
 575   return;
 576 }
 577
 578 void SGEnviro::addLightning(double lon, double lat, double alt) {
 579   // OSGFIXME
 580   return;
 581         if( lightnings.size() > 10)
 582                 return;
 583         SGLightning *lt= new SGLightning(lon, lat, alt);
 584         lightnings.push_back(lt);
 585 }
 586
 587 void SGEnviro::drawLightning(void) {
 588   // OSGFIXME
 589   return;
 590 }
 591
 592
 593 void SGEnviro::setFOV( float w, float h ) {
 594         fov_width = w;
 595         fov_height = h;
 596 }
 597
 598 void SGEnviro::getFOV( float &w, float &h ) {
 599         w = fov_width;
 600         h = fov_height;
 601 }