simgear/scene/sky/cloud.cxx

   1 // cloud.cxx -- model a single cloud layer
   2 //
   3 // Written by Curtis Olson, started June 2000.
   4 //
   5 // Copyright (C) 2000  Curtis L. Olson  - http://www.flightgear.org/~curt
   6 //
   7 // This library is free software; you can redistribute it and/or
   8 // modify it under the terms of the GNU Library General Public
   9 // License as published by the Free Software Foundation; either
  10 // version 2 of the License, or (at your option) any later version.
  11 //
  12 // This library 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 // $Id$
  22
  23 #ifdef HAVE_CONFIG_H
  24 #  include <simgear_config.h>
  25 #endif
  26
  27 #include <simgear/compiler.h>
  28
  29 #include <sstream>
  30
  31 #include <math.h>
  32
  33 #include <osg/AlphaFunc>
  34 #include <osg/BlendFunc>
  35 #include <osg/Geode>
  36 #include <osg/Geometry>
  37 #include <osg/Material>
  38 #include <osg/ShadeModel>
  39 #include <osg/TexEnv>
  40 #include <osg/TexEnvCombine>
  41 #include <osg/Texture2D>
  42 #include <osg/TextureCubeMap>
  43 #include <osg/TexMat>
  44 #include <osg/Fog>
  45
  46 #include <simgear/math/sg_random.h>
  47 #include <simgear/misc/PathOptions.hxx>
  48 #include <simgear/debug/logstream.hxx>
  49 #include <simgear/scene/model/model.hxx>
  50 #include <simgear/scene/util/RenderConstants.hxx>
  51 #include <simgear/scene/util/StateAttributeFactory.hxx>
  52 #include <simgear/math/polar3d.hxx>
  53
  54 #include "newcloud.hxx"
  55 #include "cloudfield.hxx"
  56 #include "cloud.hxx"
  57
  58 using namespace simgear;
  59 #if defined(__MINGW32__)
  60 #define isnan(x) _isnan(x)
  61 #endif
  62
  63 // #if defined (__FreeBSD__)
  64 // #  if __FreeBSD_version < 500000
  65 //      extern "C" {
  66 //        inline int isnan(double r) { return !(r <= 0 || r >= 0); }
  67 //      }
  68 // #  endif
  69 // #endif
  70
  71 #if defined (__CYGWIN__)
  72 #include <ieeefp.h>
  73 #endif
  74
  75 static osg::ref_ptr<osg::StateSet> layer_states[SGCloudLayer::SG_MAX_CLOUD_COVERAGES];
  76 static osg::ref_ptr<osg::StateSet> layer_states2[SGCloudLayer::SG_MAX_CLOUD_COVERAGES];
  77 static osg::ref_ptr<osg::TextureCubeMap> cubeMap;
  78 static bool state_initialized = false;
  79 static bool bump_mapping = false;
  80
  81 bool SGCloudLayer::enable_bump_mapping = false;
  82
  83 // make an StateSet for a cloud layer given the named texture
  84 static osg::StateSet*
  85 SGMakeState(const SGPath &path, const char* colorTexture,
  86             const char* normalTexture)
  87 {
  88     osg::StateSet *stateSet = new osg::StateSet;
  89
  90     osg::ref_ptr<osgDB::ReaderWriter::Options> options
  91         = makeOptionsFromPath(path);
  92     stateSet->setTextureAttribute(0, SGLoadTexture2D(colorTexture,
  93                                                      options.get()));
  94     stateSet->setTextureMode(0, GL_TEXTURE_2D, osg::StateAttribute::ON);
  95     StateAttributeFactory* attribFactory = StateAttributeFactory::instance();
  96     stateSet->setAttributeAndModes(attribFactory->getSmoothShadeModel());
  97     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
  98     stateSet->setMode(GL_CULL_FACE, osg::StateAttribute::OFF);
  99     stateSet->setAttributeAndModes(attribFactory->getStandardAlphaFunc());
 100     stateSet->setAttributeAndModes(attribFactory->getStandardBlendFunc());
 101
 102 //     osg::Material* material = new osg::Material;
 103 //     material->setColorMode(osg::Material::AMBIENT_AND_DIFFUSE);
 104 //     material->setEmission(osg::Material::FRONT_AND_BACK,
 105 //                           osg::Vec4(0.05, 0.05, 0.05, 0));
 106 //     material->setSpecular(osg::Material::FRONT_AND_BACK,
 107 //                           osg::Vec4(0, 0, 0, 1));
 108 //     stateSet->setAttribute(material);
 109
 110     stateSet->setMode(GL_FOG, osg::StateAttribute::OFF);
 111
 112     // OSGFIXME: invented by me ...
 113 //     stateSet->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
 114 //     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::ON);
 115
 116 //     stateSet->setMode(GL_LIGHT0, osg::StateAttribute::OFF);
 117
 118     // If the normal texture is given prepare a bumpmapping enabled state
 119 //     if (normalTexture) {
 120 //       SGPath normalPath(path);
 121 //       normalPath.append(normalTexture);
 122 //       stateSet->setTextureAttribute(2, SGLoadTexture2D(normalPath));
 123 //       stateSet->setTextureMode(2, GL_TEXTURE_2D, osg::StateAttribute::ON);
 124 //     }
 125
 126     return stateSet;
 127 }
 128
 129 // Constructor
 130 SGCloudLayer::SGCloudLayer( const string &tex_path ) :
 131     cloud_root(new osg::Switch),
 132     layer_root(new osg::Switch),
 133     group_top(new osg::Group),
 134     group_bottom(new osg::Group),
 135     layer_transform(new osg::MatrixTransform),
 136     cloud_alpha(1.0),
 137     texture_path(tex_path),
 138     layer_span(0.0),
 139     layer_asl(0.0),
 140     layer_thickness(0.0),
 141     layer_transition(0.0),
 142     layer_coverage(SG_CLOUD_CLEAR),
 143     scale(4000.0),
 144     speed(0.0),
 145     direction(0.0),
 146     last_lon(0.0),
 147     last_lat(0.0)
 148 {
 149     // XXX
 150     // Render bottoms before the rest of transparent objects (rendered
 151     // in bin 10), tops after. The negative numbers on the bottoms
 152     // RenderBins and the positive numbers on the tops enforce this
 153     // order.
 154   cloud_root->addChild(layer_root.get(), true);
 155   layer_root->addChild(group_bottom.get());
 156   layer_root->addChild(group_top.get());
 157   osg::StateSet *rootSet = layer_root->getOrCreateStateSet();
 158   rootSet->setRenderBinDetails(CLOUDS_BIN, "DepthSortedBin");
 159   rootSet->setTextureAttribute(0, new osg::TexMat);
 160   // Combiner for fog color and cloud alpha
 161   osg::TexEnvCombine* combine0 = new osg::TexEnvCombine;
 162   osg::TexEnvCombine* combine1 = new osg::TexEnvCombine;
 163   combine0->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 164   combine0->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 165   combine0->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 166   combine0->setSource1_RGB(osg::TexEnvCombine::TEXTURE0);
 167   combine0->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 168   combine0->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 169   combine0->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 170   combine0->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 171   combine0->setSource1_Alpha(osg::TexEnvCombine::TEXTURE0);
 172   combine0->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 173
 174   combine1->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 175   combine1->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 176   combine1->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 177   combine1->setSource1_RGB(osg::TexEnvCombine::CONSTANT);
 178   combine1->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 179   combine1->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 180   combine1->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 181   combine1->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 182   combine1->setSource1_Alpha(osg::TexEnvCombine::CONSTANT);
 183   combine1->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 184   combine1->setDataVariance(osg::Object::DYNAMIC);
 185   rootSet->setTextureAttributeAndModes(0, combine0);
 186   rootSet->setTextureAttributeAndModes(1, combine1);
 187   rootSet->setTextureMode(1, GL_TEXTURE_2D, osg::StateAttribute::ON);
 188   rootSet->setTextureAttributeAndModes(1, StateAttributeFactory::instance()
 189                                        ->getWhiteTexture(),
 190                                        osg::StateAttribute::ON);
 191   rootSet->setDataVariance(osg::Object::DYNAMIC);
 192
 193   base = osg::Vec2(sg_random(), sg_random());
 194
 195   group_top->addChild(layer_transform.get());
 196   group_bottom->addChild(layer_transform.get());
 197
 198   layer3D = new SGCloudField();
 199   cloud_root->addChild(layer3D->getNode(), false);
 200
 201   rebuild();
 202 }
 203
 204 // Destructor
 205 SGCloudLayer::~SGCloudLayer()
 206 {
 207   delete layer3D;
 208 }
 209
 210 float
 211 SGCloudLayer::getSpan_m () const
 212 {
 213     return layer_span;
 214 }
 215
 216 void
 217 SGCloudLayer::setSpan_m (float span_m)
 218 {
 219     if (span_m != layer_span) {
 220         layer_span = span_m;
 221         rebuild();
 222     }
 223 }
 224
 225 float
 226 SGCloudLayer::getElevation_m () const
 227 {
 228     return layer_asl;
 229 }
 230
 231 void
 232 SGCloudLayer::setElevation_m (float elevation_m, bool set_span)
 233 {
 234     layer_asl = elevation_m;
 235
 236     if (set_span) {
 237         if (elevation_m > 4000)
 238             setSpan_m(  elevation_m * 10 );
 239         else
 240             setSpan_m( 40000 );
 241     }
 242 }
 243
 244 float
 245 SGCloudLayer::getThickness_m () const
 246 {
 247     return layer_thickness;
 248 }
 249
 250 void
 251 SGCloudLayer::setThickness_m (float thickness_m)
 252 {
 253     layer_thickness = thickness_m;
 254 }
 255
 256 float
 257 SGCloudLayer::getTransition_m () const
 258 {
 259     return layer_transition;
 260 }
 261
 262 void
 263 SGCloudLayer::setTransition_m (float transition_m)
 264 {
 265     layer_transition = transition_m;
 266 }
 267
 268 SGCloudLayer::Coverage
 269 SGCloudLayer::getCoverage () const
 270 {
 271     return layer_coverage;
 272 }
 273
 274 void
 275 SGCloudLayer::setCoverage (Coverage coverage)
 276 {
 277     if (coverage != layer_coverage) {
 278         layer_coverage = coverage;
 279         rebuild();
 280
 281         double coverage_norm = 0.0;
 282         if( coverage ==  SG_CLOUD_FEW)
 283             coverage_norm = 2.0/8.0;    // <1-2
 284         else if( coverage == SG_CLOUD_SCATTERED )
 285             coverage_norm = 4.0/8.0;    // 3-4
 286         else if( coverage == SG_CLOUD_BROKEN )
 287             coverage_norm = 6.0/8.0;    // 5-7
 288         else if( coverage == SG_CLOUD_OVERCAST )
 289             coverage_norm = 8.0/8.0;    // 8
 290
 291         layer3D->setCoverage(coverage_norm);
 292         layer3D->applyCoverage();
 293     }
 294 }
 295
 296 void
 297 SGCloudLayer::setTextureOffset(const osg::Vec2& offset)
 298 {
 299     osg::StateAttribute* attr = layer_root->getStateSet()
 300         ->getTextureAttribute(0, osg::StateAttribute::TEXMAT);
 301     osg::TexMat* texMat = dynamic_cast<osg::TexMat*>(attr);
 302     if (!texMat)
 303         return;
 304     texMat->setMatrix(osg::Matrix::translate(offset[0], offset[1], 0.0));
 305 }
 306
 307 // build the cloud object
 308 void
 309 SGCloudLayer::rebuild()
 310 {
 311     // Initialize states and sizes if necessary.
 312     if ( !state_initialized ) {
 313         state_initialized = true;
 314
 315         SG_LOG(SG_ASTRO, SG_INFO, "initializing cloud layers");
 316
 317         osg::Texture::Extensions* extensions;
 318         extensions = osg::Texture::getExtensions(0, true);
 319         // OSGFIXME
 320         bump_mapping = extensions->isMultiTexturingSupported() &&
 321           (2 <= extensions->numTextureUnits()) &&
 322           SGIsOpenGLExtensionSupported("GL_ARB_texture_env_combine") &&
 323           SGIsOpenGLExtensionSupported("GL_ARB_texture_env_dot3");
 324
 325         osg::TextureCubeMap::Extensions* extensions2;
 326         extensions2 = osg::TextureCubeMap::getExtensions(0, true);
 327         bump_mapping = bump_mapping && extensions2->isCubeMapSupported();
 328
 329         // This bump mapping code was inspired by the tutorial available at
 330         // http://www.paulsprojects.net/tutorials/simplebump/simplebump.html
 331         // and a NVidia white paper
 332         //  http://developer.nvidia.com/object/bumpmappingwithregistercombiners.html
 333         // The normal map textures were generated by the normal map Gimp plugin :
 334         //  http://nifelheim.dyndns.org/~cocidius/normalmap/
 335         //
 336         cubeMap = new osg::TextureCubeMap;
 337         cubeMap->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
 338         cubeMap->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
 339         cubeMap->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP_TO_EDGE);
 340         cubeMap->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP_TO_EDGE);
 341         cubeMap->setWrap(osg::Texture::WRAP_R, osg::Texture::CLAMP_TO_EDGE);
 342
 343         const int size = 32;
 344         const float half_size = 16.0f;
 345         const float offset = 0.5f;
 346         osg::Vec3 zero_normal(0.5, 0.5, 0.5);
 347
 348         osg::Image* image = new osg::Image;
 349         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 350         unsigned char *ptr = image->data(0, 0);
 351         for (int j = 0; j < size; j++ ) {
 352           for (int i = 0; i < size; i++ ) {
 353             osg::Vec3 tmp(half_size, -( j + offset - half_size ),
 354                           -( i + offset - half_size ) );
 355             tmp.normalize();
 356             tmp = tmp*0.5 - zero_normal;
 357
 358             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 359             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 360             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 361           }
 362         }
 363         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_X, image);
 364
 365         image = new osg::Image;
 366         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 367         ptr = image->data(0, 0);
 368         for (int j = 0; j < size; j++ ) {
 369           for (int i = 0; i < size; i++ ) {
 370             osg::Vec3 tmp(-half_size, -( j + offset - half_size ),
 371                           ( i + offset - half_size ) );
 372             tmp.normalize();
 373             tmp = tmp*0.5 - zero_normal;
 374
 375             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 376             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 377             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 378           }
 379         }
 380         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_X, image);
 381
 382         image = new osg::Image;
 383         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 384         ptr = image->data(0, 0);
 385         for (int j = 0; j < size; j++ ) {
 386           for (int i = 0; i < size; i++ ) {
 387             osg::Vec3 tmp(( i + offset - half_size ), half_size,
 388                           ( j + offset - half_size ) );
 389             tmp.normalize();
 390             tmp = tmp*0.5 - zero_normal;
 391
 392             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 393             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 394             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 395           }
 396         }
 397         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_Y, image);
 398
 399         image = new osg::Image;
 400         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 401         ptr = image->data(0, 0);
 402         for (int j = 0; j < size; j++ ) {
 403           for (int i = 0; i < size; i++ ) {
 404             osg::Vec3 tmp(( i + offset - half_size ), -half_size,
 405                           -( j + offset - half_size ) );
 406             tmp.normalize();
 407             tmp = tmp*0.5 - zero_normal;
 408
 409             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 410             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 411             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 412           }
 413         }
 414         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Y, image);
 415
 416         image = new osg::Image;
 417         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 418         ptr = image->data(0, 0);
 419         for (int j = 0; j < size; j++ ) {
 420           for (int i = 0; i < size; i++ ) {
 421             osg::Vec3 tmp(( i + offset - half_size ),
 422                           -( j + offset - half_size ), half_size );
 423             tmp.normalize();
 424             tmp = tmp*0.5 - zero_normal;
 425
 426             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 427             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 428             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 429           }
 430         }
 431         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_Z, image);
 432
 433         image = new osg::Image;
 434         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 435         ptr = image->data(0, 0);
 436         for (int j = 0; j < size; j++ ) {
 437           for (int i = 0; i < size; i++ ) {
 438             osg::Vec3 tmp(-( i + offset - half_size ),
 439                           -( j + offset - half_size ), -half_size );
 440             tmp.normalize();
 441             tmp = tmp*0.5 - zero_normal;
 442             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 443             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 444             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 445           }
 446         }
 447         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Z, image);
 448
 449         osg::StateSet* state;
 450         state = SGMakeState(texture_path, "overcast.png", "overcast_n.png");
 451         layer_states[SG_CLOUD_OVERCAST] = state;
 452         state = SGMakeState(texture_path, "overcast_top.png", "overcast_top_n.png");
 453         layer_states2[SG_CLOUD_OVERCAST] = state;
 454
 455         state = SGMakeState(texture_path, "broken.png", "broken_n.png");
 456         layer_states[SG_CLOUD_BROKEN] = state;
 457         layer_states2[SG_CLOUD_BROKEN] = state;
 458
 459         state = SGMakeState(texture_path, "scattered.png", "scattered_n.png");
 460         layer_states[SG_CLOUD_SCATTERED] = state;
 461         layer_states2[SG_CLOUD_SCATTERED] = state;
 462
 463         state = SGMakeState(texture_path, "few.png", "few_n.png");
 464         layer_states[SG_CLOUD_FEW] = state;
 465         layer_states2[SG_CLOUD_FEW] = state;
 466
 467         state = SGMakeState(texture_path, "cirrus.png", "cirrus_n.png");
 468         layer_states[SG_CLOUD_CIRRUS] = state;
 469         layer_states2[SG_CLOUD_CIRRUS] = state;
 470
 471         layer_states[SG_CLOUD_CLEAR] = 0;
 472         layer_states2[SG_CLOUD_CLEAR] = 0;
 473     }
 474
 475     scale = 4000.0;
 476     last_lon = last_lat = -999.0f;
 477
 478     setTextureOffset(base);
 479     // build the cloud layer
 480     const float layer_scale = layer_span / scale;
 481     const float mpi = SG_PI/4;
 482
 483     // caclculate the difference between a flat-earth model and
 484     // a round earth model given the span and altutude ASL of
 485     // the cloud layer. This is the difference in altitude between
 486     // the top of the inverted bowl and the edge of the bowl.
 487     // const float alt_diff = layer_asl * 0.8;
 488     const float layer_to_core = (SG_EARTH_RAD * 1000 + layer_asl);
 489     const float layer_angle = 0.5*layer_span / layer_to_core; // The angle is half the span
 490     const float border_to_core = layer_to_core * cos(layer_angle);
 491     const float alt_diff = layer_to_core - border_to_core;
 492
 493     for (int i = 0; i < 4; i++) {
 494       if ( layer[i] != NULL ) {
 495         layer_transform->removeChild(layer[i].get()); // automatic delete
 496       }
 497
 498       vl[i] = new osg::Vec3Array;
 499       cl[i] = new osg::Vec4Array;
 500       tl[i] = new osg::Vec2Array;
 501
 502
 503       osg::Vec3 vertex(layer_span*(i-2)/2, -layer_span,
 504                        alt_diff * (sin(i*mpi) - 2));
 505       osg::Vec2 tc(layer_scale * i/4, 0.0f);
 506       osg::Vec4 color(1.0f, 1.0f, 1.0f, (i == 0) ? 0.0f : 0.15f);
 507
 508       cl[i]->push_back(color);
 509       vl[i]->push_back(vertex);
 510       tl[i]->push_back(tc);
 511
 512       for (int j = 0; j < 4; j++) {
 513         vertex = osg::Vec3(layer_span*(i-1)/2, layer_span*(j-2)/2,
 514                            alt_diff * (sin((i+1)*mpi) + sin(j*mpi) - 2));
 515         tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale * j/4);
 516         color = osg::Vec4(1.0f, 1.0f, 1.0f,
 517                           ( (j == 0) || (i == 3)) ?
 518                           ( (j == 0) && (i == 3)) ? 0.0f : 0.15f : 1.0f );
 519
 520         cl[i]->push_back(color);
 521         vl[i]->push_back(vertex);
 522         tl[i]->push_back(tc);
 523
 524         vertex = osg::Vec3(layer_span*(i-2)/2, layer_span*(j-1)/2,
 525                            alt_diff * (sin(i*mpi) + sin((j+1)*mpi) - 2) );
 526         tc = osg::Vec2(layer_scale * i/4, layer_scale * (j+1)/4 );
 527         color = osg::Vec4(1.0f, 1.0f, 1.0f,
 528                           ((j == 3) || (i == 0)) ?
 529                           ((j == 3) && (i == 0)) ? 0.0f : 0.15f : 1.0f );
 530         cl[i]->push_back(color);
 531         vl[i]->push_back(vertex);
 532         tl[i]->push_back(tc);
 533       }
 534
 535       vertex = osg::Vec3(layer_span*(i-1)/2, layer_span,
 536                          alt_diff * (sin((i+1)*mpi) - 2));
 537
 538       tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale);
 539
 540       color = osg::Vec4(1.0f, 1.0f, 1.0f, (i == 3) ? 0.0f : 0.15f );
 541
 542       cl[i]->push_back( color );
 543       vl[i]->push_back( vertex );
 544       tl[i]->push_back( tc );
 545
 546       osg::Geometry* geometry = new osg::Geometry;
 547       geometry->setUseDisplayList(false);
 548       geometry->setVertexArray(vl[i].get());
 549       geometry->setNormalBinding(osg::Geometry::BIND_OFF);
 550       geometry->setColorArray(cl[i].get());
 551       geometry->setColorBinding(osg::Geometry::BIND_PER_VERTEX);
 552       geometry->setTexCoordArray(0, tl[i].get());
 553       geometry->addPrimitiveSet(new osg::DrawArrays(GL_TRIANGLE_STRIP, 0, vl[i]->size()));
 554       layer[i] = new osg::Geode;
 555
 556       std::stringstream sstr;
 557       sstr << "Cloud Layer (" << i << ")";
 558       geometry->setName(sstr.str());
 559       layer[i]->setName(sstr.str());
 560       layer[i]->addDrawable(geometry);
 561       layer_transform->addChild(layer[i].get());
 562     }
 563
 564     //OSGFIXME: true
 565     if ( layer_states[layer_coverage].valid() ) {
 566       osg::CopyOp copyOp;    // shallow copy
 567       // render bin will be set in reposition
 568       osg::StateSet* stateSet = static_cast<osg::StateSet*>(layer_states2[layer_coverage]->clone(copyOp));
 569       stateSet->setDataVariance(osg::Object::DYNAMIC);
 570       group_top->setStateSet(stateSet);
 571       stateSet = static_cast<osg::StateSet*>(layer_states2[layer_coverage]->clone(copyOp));
 572       stateSet->setDataVariance(osg::Object::DYNAMIC);
 573       group_bottom->setStateSet(stateSet);
 574     }
 575 }
 576
 577 // repaint the cloud layer colors
 578 bool SGCloudLayer::repaint( const SGVec3f& fog_color ) {
 579     osg::Vec4f combineColor(fog_color.osg(), cloud_alpha);
 580     osg::TexEnvCombine* combiner
 581         = dynamic_cast<osg::TexEnvCombine*>(layer_root->getStateSet()
 582                                             ->getTextureAttribute(1, osg::StateAttribute::TEXENV));
 583     combiner->setConstantColor(combineColor);
 584
 585     // Set the fog color for the 3D clouds too.
 586     //cloud3dfog->setColor(combineColor);
 587     return true;
 588 }
 589
 590 // reposition the cloud layer at the specified origin and orientation
 591 // lon specifies a rotation about the Z axis
 592 // lat specifies a rotation about the new Y axis
 593 // spin specifies a rotation about the new Z axis (and orients the
 594 // sunrise/set effects
 595 bool SGCloudLayer::reposition( const SGVec3f& p, const SGVec3f& up, double lon, double lat,
 596                                double alt, double dt )
 597 {
 598     // combine p and asl (meters) to get translation offset
 599     osg::Vec3 asl_offset(up.osg());
 600     asl_offset.normalize();
 601     if ( alt <= layer_asl ) {
 602         asl_offset *= layer_asl;
 603     } else {
 604         asl_offset *= layer_asl + layer_thickness;
 605     }
 606
 607     // cout << "asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 608     //      << "," << asl_offset[2] << endl;
 609     asl_offset += p.osg();
 610     // cout << "  asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 611     //      << "," << asl_offset[2] << endl;
 612
 613     osg::Matrix T, LON, LAT;
 614     // Translate to zero elevation
 615     // Point3D zero_elev = current_view.get_cur_zero_elev();
 616     T.makeTranslate( asl_offset );
 617
 618     // printf("  Translated to %.2f %.2f %.2f\n",
 619     //        zero_elev.x, zero_elev.y, zero_elev.z );
 620
 621     // Rotate to proper orientation
 622     // printf("  lon = %.2f  lat = %.2f\n",
 623     //        lon * SGD_RADIANS_TO_DEGREES,
 624     //        lat * SGD_RADIANS_TO_DEGREES);
 625     LON.makeRotate(lon, osg::Vec3(0, 0, 1));
 626
 627     // xglRotatef( 90.0 - f->get_Latitude() * SGD_RADIANS_TO_DEGREES,
 628     //             0.0, 1.0, 0.0 );
 629     LAT.makeRotate(90.0 * SGD_DEGREES_TO_RADIANS - lat, osg::Vec3(0, 1, 0));
 630
 631     layer_transform->setMatrix( LAT*LON*T );
 632
 633     // The layers need to be drawn in order because they are
 634     // translucent, but OSG transparency sorting doesn't work because
 635     // the cloud polys are huge. However, the ordering is simple: the
 636     // bottom polys should be drawn from high altitude to low, and the
 637     // top polygons from low to high. The altitude can be used
 638     // directly to order the polygons!
 639     group_bottom->getStateSet()->setRenderBinDetails(-(int)layer_asl,
 640                                                      "RenderBin");
 641     group_top->getStateSet()->setRenderBinDetails((int)layer_asl,
 642                                                   "RenderBin");
 643     if ( alt <= layer_asl ) {
 644       layer_root->setSingleChildOn(0);
 645     } else if ( alt >= layer_asl + layer_thickness ) {
 646       layer_root->setSingleChildOn(1);
 647     } else {
 648       layer_root->setAllChildrenOff();
 649     }
 650
 651
 652     // now calculate update texture coordinates
 653     if ( last_lon < -900 ) {
 654         last_lon = lon;
 655         last_lat = lat;
 656     }
 657
 658     double sp_dist = speed*dt;
 659
 660     if ( lon != last_lon || lat != last_lat || sp_dist != 0 ) {
 661         Point3D start( last_lon, last_lat, 0.0 );
 662         Point3D dest( lon, lat, 0.0 );
 663         double course = 0.0, dist = 0.0;
 664
 665         calc_gc_course_dist( dest, start, &course, &dist );
 666         // cout << "course = " << course << ", dist = " << dist << endl;
 667
 668         // if start and dest are too close together,
 669         // calc_gc_course_dist() can return a course of "nan".  If
 670         // this happens, lets just use the last known good course.
 671         // This is a hack, and it would probably be better to make
 672         // calc_gc_course_dist() more robust.
 673         if ( isnan(course) ) {
 674             course = last_course;
 675         } else {
 676             last_course = course;
 677         }
 678
 679         // calculate cloud movement due to external forces
 680         double ax = 0.0, ay = 0.0, bx = 0.0, by = 0.0;
 681
 682         if (dist > 0.0) {
 683             ax = cos(course) * dist;
 684             ay = sin(course) * dist;
 685         }
 686
 687         if (sp_dist > 0) {
 688             bx = cos((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 689             by = sin((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 690         }
 691
 692
 693         double xoff = (ax + bx) / (2 * scale);
 694         double yoff = (ay + by) / (2 * scale);
 695
 696         const float layer_scale = layer_span / scale;
 697
 698         // cout << "xoff = " << xoff << ", yoff = " << yoff << endl;
 699         base[0] += xoff;
 700
 701         // the while loops can lead to *long* pauses if base[0] comes
 702         // with a bogus value.
 703         // while ( base[0] > 1.0 ) { base[0] -= 1.0; }
 704         // while ( base[0] < 0.0 ) { base[0] += 1.0; }
 705         if ( base[0] > -10.0 && base[0] < 10.0 ) {
 706             base[0] -= (int)base[0];
 707         } else {
 708             SG_LOG(SG_ASTRO, SG_DEBUG,
 709                 "Error: base = " << base[0] << "," << base[1] <<
 710                 " course = " << course << " dist = " << dist );
 711             base[0] = 0.0;
 712         }
 713
 714         base[1] += yoff;
 715         // the while loops can lead to *long* pauses if base[0] comes
 716         // with a bogus value.
 717         // while ( base[1] > 1.0 ) { base[1] -= 1.0; }
 718         // while ( base[1] < 0.0 ) { base[1] += 1.0; }
 719         if ( base[1] > -10.0 && base[1] < 10.0 ) {
 720             base[1] -= (int)base[1];
 721         } else {
 722             SG_LOG(SG_ASTRO, SG_DEBUG,
 723                     "Error: base = " << base[0] << "," << base[1] <<
 724                     " course = " << course << " dist = " << dist );
 725             base[1] = 0.0;
 726         }
 727
 728         // cout << "base = " << base[0] << "," << base[1] << endl;
 729
 730         setTextureOffset(base);
 731         last_lon = lon;
 732         last_lat = lat;
 733     }
 734
 735     layer3D->reposition( p, up, lon, lat, dt, layer_asl);
 736     return true;
 737 }
 738
 739 void SGCloudLayer::set_enable3dClouds(bool enable) {
 740
 741     if (layer3D->defined3D && enable) {
 742         cloud_root->setChildValue(layer3D->getNode(), true);
 743         cloud_root->setChildValue(layer_root.get(),   false);
 744     } else {
 745         cloud_root->setChildValue(layer3D->getNode(), false);
 746         cloud_root->setChildValue(layer_root.get(),   true);
 747     }
 748 }